UNITED STATES DEPARTMENT OF AGRICULTURE BULLETIN No. 826 Contribution from the Bureau of Entomology L. O. HOWARD, Chief Washington, D. C. PROFESSIONAL PAPER. August 10, 1920 GENERIC CLASSIFICATION OF THE HEMIPTEROUS FAMILY APHIDID AE.' r^S 6 By A. C? BAKER, Entomologist, Deciduous Fruit Insect Investigations. CONTENTS. Superfamily Aphldoidea Page. 2 Subfamily III, Eriosomatinae Page. 62 Phylogeny of the Aphididae 3 Tribe Eriosomatini 65 Key to the subfamilies of the Aphididae. . 10 Tribe Pemphigini 68 Subfamily I, Aphidinae 10 Tribe Melphini 73 Tribe T,achnini 12 Tribe Prootphilini 75 Tribe Thelaxini 20 Tribe Fordini . . 77 Tribe Callipterini 21 Subfamily IV, Hormaphidinae ... 81 Tribe Greenideini. 37 Tribe Hormaphidini 83 Tribe Setaphidini 38 Tribe Oregmini . . . 84 Tribe Aphidini 39 Tribe Cerataphidini . . . 86 Pnhfamily TT Mindarina<> 61 Genera not placed 88 Probably no group of insects has received more attention at the hands of economic entomologists than aphids, or plant-lice. Their interesting and often complicated biologies have attracted the atten- tion of investigators, not only among entomologists, but among workers in the larger fields of zoology and general biology. While a large amount of work on the life histories and biologies of aphids has been done, corresponding progress in their classification has not been made. This is probably due to several causes, su^h as the lack of correlation of biologic and taxonomic facts, and the failure of aphidologists to consider sufficiently the results of the work of others. On account of the great economic importance of aphids and the necessity of their study in the development of control measures, the lack of knowledge concerning their systematic relationships results in much confusion. Some biologic workers, in fact, do not now at- tempt to give the name of the species being studied on account of the difficulty experienced in securing correct determinations. 1 This paper is the first of a series treating the Aphididae. It will be followed by others dealing with the economic importance, biologies, and relationships of species in the different genera. 141613 20 Bull. 826 1 2 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. The present work was undertaken in the hope of remedying such a condition to some extent at least. The genera of the world have been studied. Many workers have lent material and the large col- lections of the National Museum and Bureau of Entomology have been drawn upon. In the National Museum collection a large per- centage of types has been available. To the study of preserved material have been added embryological, anatomical, and biological investigations that a better understanding of the natural relationships might be gained. Besides many aphidologists in this country and abroad, who have given helpful suggestions and many of whom have read and criticized the manuscript, the writer is indebted to Dr. A. L. Quaintance, of the Bureau of Entomology, for the f acilities for conducting many of the biological investigations which to a large extent have laid the foundation for the systematic treatment here given. Superfamily APfflDOIDEA. There appear to be two distinct families in the superfamily Aphi- doidea. These are the Aphididae and the Phylloxeridae. The present paper deals only with the Aphididae. Members of the Phylloxeridae differ markedly from forms belong- ing to the Aphididae. In the first place their biologies are quite different in that parthenogenetic oviparous forms occur during the summer. In the Aphididae only the sexed females which are pro- duced in the fall are normally oviparous. In structure the two families are separated at once by the formation of the stigma of the forewing. The wing itself seems very little different in an Adelges or Phylloxera from that in some of the special- ized genera of the Aphididae. An examination of the freshly emerged wing, however, as has been pointed out by Dr. Patch, shows that the stigma in the Phylloxeridae is formed by the radial sector and the stigmal vein is the media. In the Aphididae, on the other hand, the stigma is formed by radius x and the stigmal vein is the radial sector. The two families may thus be separated as follows: KEY TO THE FAMILIES OF THE APHIDOIDEA. Summer parthenogenetic oviparous forms produced: Stigma formed by the radial sector PHYLT-OXERIDAE. Only sexual oviparous forms produced : Stigma formed by radiusj APHIDIDAE. A word of explanation in regard to the name Phylloxeridae may be necessary. The genus Chennes was erected by Linnaeus in 1758 and in 1862 was replaced by Psylla Geoffrey. For this genus CTiermes ficus L. was set as type by Lamarck in 1801. Ficus, therefore, be- comes ipso facto the type of Chermes, and Chermidae the family name of the "jumping plant-lice." The family name for the aphi- doidean group, therefore, is derived from the genus Phylloxera Boyer (1834). GENERIC CLASSIFICATION OF APHIDIDAE. 3 PHYLOGENY OF THE APHIDIDAE. In many published classifications of the Aphididae those groups which according to the writer's conception are the most specialized have been placed as the most primitive. This is the case with those FIG. l. Phytogeny of the hemipterous fainily Aphididae. insects forming in the present classification the Eriosomatinae and the Hormaphidmae. A study of the anatomy and the biology of aphids makes it evident that there are three main groups of living forms for which subfamily 4 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. names are here used : Aphidinae, Eriosomatinae, and Hormaphidinae. Besides these there is the one species, in some -ways a relic of the past, forming th'e Mindarinae. As will be seen by the diagram (fig. 1), the Aphidinae is considered the most primitive subfamily of the three main groups. This is substantiated by the habits of the insects, by the structure of the wings, beak, etc., and by the sexual forms. Practically all of these insects are foliage or twig feeders. They live, as a rule, in colonies and have not developed any very special methods of We, such as highly complex gall formation. With the exception of the Mindarinae the most primitive wing structure oc- curring in the family is met with here. The media is most commonly twice branched throughout the subfamily and even in the Mindarinae there is more of a reduction than this. The antennae are of six segments, the largest number found in the family, and the sen- soria are simpler in nature than those met with in the other two large subfamilies. The beak in the Lachnini shows also a primitive condition in its segmentation. The sexual forms are most primitive in the Aphidinae. Winged sexes often occur, at least the males are very commonly winged. Both sexes still retain their beaks and feed on their hosts in the same way as do the other forms, and the ovaries of the female develop normally, and she produces several eggs. When the phylogeny of this subfamily is studied, there becomes evident the primitive character retained by the Lachnini. In these forms the beak structure and the nature of the antennae and cornicles point to a primitive condition. The sexes, too, indicate this, though not markedly more than in other tribes. But the fact that these forms are mostly conifer feeders should not be overlooked. It is the opinion of the writer that this is a primitive habit. The Lachnus branch, therefore, may be considered the lowest branch of the Aphidinae. If the wings of fossil aphids be examined it will be seen that by far the greater number of them possess a wing structure quite different from that of our living forms. The radial sector arises back of the stigma, which is usually very long and narrow. This character is retained probably only in the Mindarinae. It is evident, then, that during the development of the present Aphidinae this vein migrated toward the tip of the wing until it came to stand either in the middle of the stigma or near its tip. On one line of this migration is the Lachnina wherein the vein has reached nearly to the tip of the wing and become short and straight. The remain- ing characters apart from the wings have in these forms remained quite primitive. The subtribe Eulachnina is evidently a more specialized group on this same line of development, for it possesses GENERIC CLASSIFICATION OF APHIDIDAE, 5 the same type of wing. Therefore this subtribe is considered quite closely related to the subtribe Lachnina but differing from it in specialization of body form, cornicles, and eyes. The other sub- tribes of the Lachnini have quite a different whig structure. While the radial sector has changed its position considerably from that found in the fossils it has not reached the tip of the stigma and is not straight, but much curved. In this regard, therefore, the Pterochlor- ina is perhaps the most primitive subtribe in the Lachnini, although in many respects it is specialized. On the other hand there are two highly specialized subtribes, the Anoecina and the Tramina. It is usually the custom to place the Anoecina with the Pemphigina. Its relations, however, are here. The adult forms are very similar in- deed to the lachnids. The sexual forms, on the other hand, are small and apterous and suggestive of the sexes of the Eriosomatinae, and there is considerable ground for placing the Anoecina there. These sexual forms, however, seem to differ quite distinctly from those of the Eriosomatinae, which are beakless and the oviparous female of which never develops more than one egg. The develop- ment of the stigma shows quite an extreme modification from the long, narrow, primitive stigma. Near this same line of development is the rather highly specialized subtribe Tramina. The most marked character of this subtribe is the extreme modification of the hind tarsi. In considering only the genus Trama it might be thought that the tribe should belong with the Eriosomatinae. The species troglodytes has often been figured with cornicles in the apterous form. Specimens from Mordwilko and Schouteden determined as this species lack them and the writer therefore considers Trama as the most specialized genus in the sub- tribe. Another genus represented by radicis Kalt. shows cornicles very large and of a typical Lachnus character. Through this genus, therefore, the subtribe can be placed at once with its relatives in the Lachnini. Apart from the peculiar tibial character this genus is very lachnid-like. The next branch from the Aphidinae is the Callipterus branch, which may be considered as arising somewhat later than the Lachnus branch. From this offshoot soon after it arose and before the present genera of the Callipterini appeared the Thelaxini separated. This tribe, the old Vacuini, also has usually been placed with the Eriosomatinae. There are some resemblances, it is true; only one egg, for instance, is usually laid by the sexual female. But this is not always the case, for, according to Buckton, more than one egg is sometimes laid. Such a condition shows that the one egg habit is of much more recent development than in the Eriosomatinae. More- over, the sexual female is very different in structure. She is not the 6 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. degenerate, beakless, norifeeding individual of the Eriosomatinae, but feeds upon the leaf like the viviparous forms. Moreover, in external structure these insects resemble certain ones of the Callipterini, to such an extent, indeed, that Davidson has described one of these forms as a Chaitophorus. Certain of the structures met with in these forms resemble those found in the Hormaphidinae and on these structures the tribe might be placed there. The writer believes, however, that the true affinities of the tribe are shown by comparison with the Phyllaphidina. It will be seen at a glance that there is a very close resemblance in all main characters. But the sexual forms are different, although not so strikingly different as would appear at first. In the Phyllaphidina both winged and wingless ovipara and as a rule winged males occur. But in some species (quercifoliae) intermediate and apterous males also occur. It is not a very long call, therefore, from the apterous males and females of the Phyl- laphidina to the apterous sexes of the Thelaxini. But the habit of egg laying met with in this last tribe shows that it has been on this course of development longer than has the Phyllaphidina. The group is therefore considered as a tribe which has separated some- what earlier and yet has paralleled in some ways certain characters of the Phyllaphidina. Continuing with the Callipterus branch we find two somewhat similar lines of development, the one represented by the Callipterina and the other represented by the Chaitophorina. Both are similar in many regards, but are quite different in the armature, particularly of the antennae. The first subtribe separating from that offshoot represented by the Callipterina is the Phyllaphidina. This seems evident from the fact that the oviparous forms of some species are yet alate, a primi- tive condition found very seldom in the Aphididae. The next off- shoot resulted in the Callipterina where the oviparous forms are apter- ous, the cornicles of moderate development, and the wing veins usually not reduced. From this offshoot the Saltusaphidina evi- dently arose. This little subtribe is closely related to the Callip- terina in many ways, but there are some new developments. In the first place the power of leaping has become developed by the enlarging of the femora. Secondly, both the sexual forms have lost their wings, which the male usually retains in the Callipterina. One of the most important points, however, is the fact that in the Sal- tusaphidina the ocular tubercles which represent the retained larval eyes are absent, whereas they are quite conspicuous in the Callip- terina. On this same Callipterus branch, but somewhat more specialized than the Callipterina, are two subtribes. These have specialized in opposite directions, the one toward the elimination of the cornicles GENERIC CLASSIFICATION OF APHIDIDAE. 7 and the other toward the development of them. The first subtribe, the Monaphidina, lacks cornicles above. The second of these two, the Drepanaphidina, possesses them in varying degrees. In this last subtribe the males are winged, and the females have developed an extremely long, narrow ovipositor. Coming now to that line represented by Chaitophorus, the Chai- tophorina are found to be the most generalized, corresponding quite closely with the Callipterina. In this subtribe males are winged as a rule, but sometimes in the same species they are intermediate or apterous. Arising from the same branch with the Chaitophorina are two subtribes specialized in different directions, like the sub- tribes of Callipterus. Tlie first, Fullawayina, lacks cornicles entirely, whereas the Pterocommina has developed them in varying degrees, as has the Drepanaphidina. This concludes the subtribes of the Callipterus branch. In connection with these insects the tribe Greenideini should be considered. The cornicles of the primitive aphids were evidently small, somewhat rounded or conical, and armed with ban's. In the Greeliideini the insects have very long cylindric or somewhat swollen cornicles which are thickly covered with prominent hairs. No such well-developed cornicles are met with in any of the other tribes of the family, although they are approached in the Macrosiphina. In this latter subtribe species occasionally occur which show a few short hairs on the cornicles. It seems evident then that the Greenideini separated from the Aphidinae before the hairs of the cornicles disappeared. This was evidently more recent than the development of the tribe Lachmni which possesses a much more primitive cornicle. At about the same time that the ancestors of the CaUipterini separated from the Aphidinae, other forms probably separated and more or less paralleled in some ways the ancestors of the Macrosiphina, but unlike them carried the hairs of the cornicles. They thus resulted in forms with very long cornicles similar to those of the Macrosiphma but armed with long hairs. In other characters, too, they of course differ, particularly in regard to the cauda. In considering the further development of the Aphidinae, a more or less distinct development of the cornicles and antennal tubercles is found. There are thus two types which separate themselves, rep- resented by Aphis and ' Macrosiphum respectively. These may be considered as leaving the aphid line at about the same time after the development of prominent cornicles. There are, consequently, two subtribes, the Aphidina and the Macrosiphina. The Cervaphidina represents a group of insects armed with long, somewhat cylindric cornicles, and very prominent spinelike protuberances. The number of antenna! segments is somewhat reduced, as is also the wing s T ena- tion. It seems evident then that this is a subtribe on somewhat the 8 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. same line of development as the Aphidina but developing these spec- ialized spines during the same period in which the wings and antennas have become reduced. Still another subtribe, the Pentalonina, shows a very peculiar wing venation. This is not so much a primitive wing as a more specialized one. It is placed, therefore, as one of the highest subtribes of the Aphidini. There remains yet for discussion the tribe Setaphidini. This, it seems evident, belongs with the Aphidinae. In regard to the an- tennse and the wings it is quite highly specialized but in regard to the cornicles, cauda, and anal plate this statement can not be made. The natural position of this tribe is somewhat doubtful. Its ancestors evidently separated from the aphidian line before the prominent corn- icles of the Aphidina, Macrosiphina, etc., appeared and yet the species are more specialized in many ways than are members of those sub- tribes. It would appear that the lines separated after that of the Greenideini, for the cornicles are not hairy. Yet this separation must have taken place a considerable time before that of the Aphidina and Macrosiphina. The tribe is placed, therefore, as indicated in the diagram (fig. 1). The subfamilies, other than the Aphidinae, include the most spec- ialized members of the family. By far the most primitive of these subfamilies is the Mindarinae. This subfamily, as has been indicated, is a remnant from the past, giving some idea of the ancestors of the Eriosomatinae and the Hormaphidinae. The wing structure is partic- ularly worthy of study. The wing of no other living aphid is like it, but this peculiar structure is abundantly met with in fossil forms. The media, it is true, is more reduced than in certain members of the Aphidinae, but this is of very little importance as compared with the wing's peculiar structure. The form also feeds upon conifers and this is undoubtedly a primitive habit. The cauda and anal plate are unlike those met with either in the Eriosomatinae or the Hormaph- idinae. The sexual forms are interesting. They have become sufficiently specialized toward the Eriosomatinae to have lost the wings, but they retain the beak, at least in most individuals, and feed. The ovaries of the oviparous female also are developed so that a number of eggs are laid. The two remaining subfamilies are the most highly specialized of all aphids. The Eriosomatinae are in many ways more specialized than the Hormaphidinae, but in other ways they are more primitive. The whole Eriosoma line separates at once on the sexual forms. These are small, apterous, and beakless. Throughout their life they take no nourishment, and the ovaries of the oviparous female become atrophied, so that only one develops and of the eggs therein only one GENERIC CLASSIFICATION OF APHIDIDAE. 9 reaches maturity. The most primitive tribe on this line is the Eriosomatini. The forms of this tribe are not as a rule distinct gall formers. They possess rather prominent cornicles and have devel- oped special wax glands. They live as a rule upon deciduous trees, the summer forms of many species alternating upon the roots of plants. More specialized than the Eriosomatini are the Pemphigini, which, however, are very similar to the former in many respects. These are distinct and true gall formers on deciduous trees. For part of the year they are usually altogether closed within the gall. Wax secre- tion is common and the cornicles are present, but reduced to mere rings. The Melaphini are closely related to the Pemphigini and are gall formers like them. These forms, however, have lost entirely the cornicles which are usually still retained in the Pemphigini. \ A somewhat different specialization is met with in the Prociphilini. Here wax secretion has developed at the expense of the cornicles so that these organs are absent, at least in nearly all the forms of the species. Large wax plates have taken their places. The species are not true gall formers, but live upon foliage which they cause to roll or crumple into a pseudogall. Development along this line is also pres- ent in the next tribe, the Fordini. Here the cornicles are also absent, being replaced by large wax glands, but the species are nearly all root feeders and are usually associated with ants, often living with them in their nests. This tribe may be considered the most specialized of all the Eriosomatinae. The same specialization in the sexual forms has not occured in the Hormaphidinae. They are small and apterous, it is true, but they possess beaks, they feed, and the oviparous female lays more than one egg. In one regard, however, these insects are more specialized. Many of them have developed a pecular aleyrodiform stage, which is quite different from anything occuring elsewhere in the family. Along with this development peculiar wax glands have made their appear- ance so that some of these forms look very much like aleyrodids and are indeed often mistaken for them. The most primitive tribe here is the Oregmini, which, although it possesses many of the other characters met with in these forms, lacks the aleyrodiform stage. These insects possess quite distinct cornicles. Closely related to the Oregmini is the Cerataphidini. These insects likewise possess cornicles and in several ways suggest the Oregmini, but they have developed a distinct aleyrodiform stage and in this regard are much more advanced than the members of that tribe. Lastly, and perhaps most specialized of all, are the Hormaphidini. These insects are curious gall formers, not only on their primary host, but often on their secondary one as well. They lack cornicles and 10 BULLETIN 826, IT. S. DEPARTMENT OF AGRICULTURE. have developed aleyrodiform generations and wax secreting structures. In many ways the specialization of these insects is most remarkable. KEY TO THE SUBFAMILIES OF THE APHIDIDAE. 1. Sexual forms small with functioning mouth parts absent. Oviparous female with all the egg tubes present or indicated in the embryo but the adult possessing only one tube and maturing one cell so that one egg only is laid. Cornicles much reduced or absent. Wax glands abundantly developed. Wing veins usually reduced. Antennal sensoria prom- inent ERIOSOMATIXAK. Sexual forms with functioning mouth parts. Nearly all the ovarian tubes developed in the adult oviparous female .-. 2. 2. Radial sector of forewing inserted mesad of the stigma. Sexes small. Ovi- parous female laying several eggs MINDARINAE. Radial sector not so inserted but arising from the stigma 3." 3. Forms usually gall makers. Wing veins much reduced so that the media is usually simple. Wax glands usual. Antennal sensoria annular. Aley- rodiform stages common. Sexes wingless as a rule and small. .HORMAPHIDINAE. Forms not usually gall makers. Wing veins often not reduced. Wax glands not abundant. Antennal sensoria oval or subcircular. Aleyrodi- form stages rare. Cornicles often little reduced . Winged males common. APHIDINAE. Subfamily I, APHIDINAE. The subfamily Aphidinae contains many of the most primitive insects in the family. Indeed, with the exception of the Mindarinae the subfamily may be considered as by far the most primitive. The oviparous female, in all the tribes, develops the ovaries in a normal way and lays several eggs. An exception to this, however, is the Thelaxini, but here two or more eggs are sometimes laid. The males may be either alate, apterous, or intermediate, and in many species which possess the migratory instinct they are often produced on quite a different food plant from the oviparous form. The stem mothers are in practically all cases apterous, but the remaining gener- ations throughout the year may or may not be winged. In many species a larger percentage of winged forms occurs in certain generations and a larger percentage of apterous forms in others. In some species, however, this does not appear to be the case. In certain of the Callipterini practically all of the viviparous forms other than stem mothers are winged. The insects are mainly foliage feeders, but they also attack the stems and roots. They occur both upon woody plants and herbs. Their feeding may have little apparent effect upon the host or it may cause distortions or pseudogalls. Some species are particularly in- jurious to their hosts and when these are economic plants cause much loss. Great variation is met with amongst the members of the subfamily. The antennae are rather long and slender and as a rule are armed with subcircular sensoria. In most of the forms the sixth segment GENEKIC CLASSIFICATION OF APHIDIDAE. 11 possesses an elongate narrow uuguis, which in some of the Callipterini and Aphidini is remarkably developed. In the more primitive groups, however, this is short and thumb-like. The head of the apterous form differs much from that seen in the Eriosomatinae, in that true compound eyes are present and often very prominent, and the small larval eyes are seen as ocular tubercles. It is noteworthy that in the Eriosomatinae the alate forms possess distinct compound eyes but the apterous forms have lost them. The wings are in general quite similar throughout the family in regard to the venation. In color, shape, arid location of the veins there is often considerable difference. Moreover, there are a few genera amongst the different tribes which show abnormal wing form, of which genera Microparsus is a good example. In the typical forms of this subfamily the media of the fore wing is twice branched, but it is very commonly branched only once and it is rarely simple. The cornicles show remarkable variation. In some forms of the Callipterini they are short and slightly swollen at the base, in the Lachnini they are low broad cones, whereas in the Greenideini they are cylindrical and sometimes longer than the body. Between these extremes every gradation occurs. The cornicles may be straight or they may be swollen to a greater or less degree. Practically all forms eject a colored wax from these organs when disturbed. The cauda shows almost as much variation as the cornicles, some- times being short and rounded, in other cases elongate, spatulate, or conical, and in others distinctly knobbed." Variation also is met with in the anal plate, though this usually is rounded, In the Callip- terini, however, it is often bilobed. The tribes of the subfamily may be separated as follows: KEY TO THE TRIBES OF THE APHIDINAE. 1. Cornicles situated on broad flat cones 2. Cornicles truncate, or more or less elongate 3. 2. Cornicles and antennae hairy. Antennae with the unguis short and thick .. LACHNINI. Cornicles and antennae not hairy. Antennae with the unguis long and slender SETAPHIDINI. 3. Cornicles clothed with long hairs GREENIDEINI. Cornicles never with long hairs 4. 4. Thorax of alate form with the lobes not prominently developed; oviparous form small, often laying one egg. Large wax plates present THELAXINI. Thorax of alate form with the lobes prominently developed; oviparous female laying several eggs. Large wax plates usually absent 5. 5. Cornicles truncate or elongate; when elongate the cauda knobbed, and the anal plate bilobed, or the antennae' prominently hairy CALLIPTERINI. Cornicles not truncate, usually elongate. Cauda never knobbed. Anten- nae with only a few spinelike hairs APHIDINI. 12 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Tribe LACHNINI. The tribe Lachnini is the most primitive of all living aphids, with the exception of the Mindarinae. The genus Mindarus shows in its wing structure characters more primitive than any of the Lachnini, but in other characters such as those of the beak, cornicles, cauda, sensory structures, etc., the Lachnini are very primitive insects. In examining the fossil wings it is to be noted that the radial sector is situated back of the stigma. In practically all living aphids, with the exception of Mindarus, this vein has migrated toward the tip of the wing. In primitive forms the stigma is long and narrow, whereas in most living forms it has become more or less compact. In the subtribe Lachnina the radial sector has become a very short, straight vein almost at the tip of the wing. This shows that the Lachnina are evidently more advanced than the Pterochlorina in which the radial sector is somewhat curved and situated near the middle of the stigma. The subtribe Eulachnina is considerably specialized, as indicated by the eyes, the shape of the body, and the cornicles. It is, however, as closely related to the Lachnina as are any of the other tribes, as will be seen from the formation of the wing. The Anoecina hi the typical genus shows a wing with a short blocky stigma, a condition quite different from that seen in the Lachnina, and the radial sector is here curved. (In Nippolachnus, however, the stigma is still long and straight.) Moreover, the sexual forms are more specialized, being apterous in both cases. Anoecia, therefore, is somewhat removed from Lachnus!" The genus Trama is considerably specialized, in that it lacks cornicles in the apterous form. It is, however, related to Lachnus through Neotrama with small cornicles, and Protrama with large hairy cornicles. The rostrum in the Lachnini is in many species five-segmented, a primitive character most marked in this group. The freshly emerged wing of a lachnid shows that M 1? M 2 , and M 3+4 are the veins repre- sented when the media is twice branched, and that in some species no vein is formed about M 2 . The cubitus and first and second anal are present in the forewing. As in other Aphididae, however, no vein forms about the second anal. The radial sector is in Lachnus a short, straight trachea and a prominent vein forms about it. The stigma, as in all members of the family, is formed by radiusj. In the hindwing both media and cubitus are present and form distinct veins. The antennae of the Lachnini are six-segmented with a short unguis. They are usually armed with oval or subcircular sensoria and prominent hairs. In fact, the entire body of the insect is hairy. The cornicles are characteristic. They are situated on distinct cones which are constricted before the somewhat flanged opening which is not situated over the center of the cone. The cones are arm- GENERIC CLASSIFICATION OF APHIDIDAE. 13 ed with hairs. Some specialized forms have small cornicles or none at all. Wax-secreting structures, but no distinct gland areas, are present in this tribe and a coating of fine wax is often found over the entire insect, including the appendages. This is true of the oviparous forms, as well as of the viviparous ones. The cauda and anal plate are here rounded, never developed into elongate structures as in some of the other tribes of the subfamily. The sexual forms are nearly as unspecialized as the viviparous ones. Both sexes possess a distinct rostrum and take food. The males in the typical subtribes are winged. The females are apterous, but the ovaries are developed and several eggs are laid by each individual. . KEY TO THE SUBTRIBES OF THE LACHNINI. 1. Radial sector of fore wings curved and of moderate length 2. Radial sector of fore wings short and straight, situated near the tip of the wing 4. 2. Hind tarsi extremely elongate, head divided, wing venation usually faint. TRAMINA. Hind tarsi normal 3. 3. Stigma short and thick, sexes both apterous ANOECINA. Stigma elongate, males often winged PTEROCHLORINA. 4. Form elongate and very narrow; antennae with bristles, cornicles not hairy; eyes without ocular tubercles EULACHNINA. Form not elongate ; cornicles on hairy cones ; eyes with ocular tubercles . . LACHNIN A . Subtribe ANOECINA. The subtribe Anoecina is suggestive of the Tramina, but none of the forms are as specialized as some of the genera of that subtribe. The typical genus is quite distinctive in the short rounded stigma and in the sexual forms. The genus Nippolachnus, however, has a stigma quite Lachnus-like in appearance. Only two genera are known at present. KEY TO THE GENERA OP THE ANOECINA. 1. Head not divided; eyes with prominent ocular tubercles; stigma of wing short and rounded Anoecia. 2. Head divided; eyes without ocular tubercles; stigma long and straight. Nippolachnus. Genus ANOECIA Koch. Plate 1, A-F, I. 1857. A noecia Koch, Die Pflanzenlaiise Aphiden, p. 275. Characters. Head not divided, front somewhat rounded. Eyes prominent but not distinctly set off from the head. Antennae of six segments, armed with subcircular or oval or elongate sensoria and covered with hairs. Fore wings with the media once branched. Stigma short and thick. Hind wings with both media and cubitus present. Cornicles situated on broad hairy cones. Cauda and anal plate somewhat rounded. Spring forms free, living in colonies; summer forms often subterranean. Sexes small and apterous, possessing beaks and feeding. Oviparous female laying one or more than one egg. Type (mono typical), Aphis corni Fab. 14 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Genus NIPPOLACHNUS Matsumura. Plate I, G, H, J, K. 1917. Nlppolachnus Matsumura, Journ. Coll. Agr. Tohoku Univ., v. 7, pt. 6, p. 382. This genus is closely related to Anoecia Koch and yet it retains many Lachnus characters which are not present in Anoecia. It is separated from that genus by several important points. The head is distinctly divided as it is not in Anoecia. The stigma is long and Lachnus-like and the eyes have not the small prominent ocular tubercles of Anoecia, but are rounded on their posterior margins. Characters. Antennae of six segments, armed with prominent protruding sensoria and many hairs; head divided; eyes without prominent ocular tubercles. Wings with the media once branched, the stigma rather long and narrow. Cornicles on large broad cones entirely covered with hairs. Spring forms free, migrating in summer to alternate hosts. Sexes small, males winged. Type (fixed by Matsumura, 1917), Nippolachnus piri Mats. Subtribe EULACHNINA. The sub tribe Eulachnina is related to the Lachnina quite closely, as can be seen by the wing structure where the radial sector is a straight, short vein extending across the tip of the wing. The media also is faintly indicated. In the other branch of the tribe in which the Anoecina and Tramina are found, the radial sector is curved as it is in Aphidina, etc. Members of the Eulachnina may, however, be separated ai> once from the Lachnina on the elongate, narrow shape of the body, the abruptly rounded cauda, the character of the cornicles, and the absence of ocular tubercles upon the eyes. The subtribe is evidently quite specialized as compared to the Lach- nina. Characters. Eyes large and set off from the head; ocular tubercles not evident; antennae slender, armed with bristles or spines, not slender hairs. Cornicles shallow, not on distinct hairy cones. Cauda abruptly rounded. Body very elongate and slender, scarcely 'wider than the head. KEY TO THE GENERA OP THE EULACHNINA. 1. Antennae of five segments, armed with minute bristles Essigella. Antennae of six segments 2. 2. Media once branched, antennas with long stout spines Eulachnus. Media twice branched Todolachnus. Genus ESSIGELLA Del Guercio. Plate I, S-Y. 1909. Essigella Del Guercio, Rivista Patol. Vegetale, n. s., v. 3, p. 329. The genus Essigella is quite similar to Eulachnus with the excep- tion of the antennae. Characters. Head with large outstanding eyes, very much broader than long. Antennae of five segments, imbricated, armed only with a few minute bristles. Fore wings with the media faintly indicated, once branched, hind wings with both media and cubitus present. Cornicles chitinized rings situated close to the body, no hairy cones present. Cauda rounded. Body elongate and narrow. Type (mono typical), Lachnus calif arnieus Essig GENERIC CLASSIFICATION OF APHIDIDAE. 15 Genus EULACHNUS Del Guercio. Plate I, L-R. 71853. Cinaria Curtis, British Entomology, v. 12, section 576. 1909. Eulachnus Del Guercio, Rivista Patol. Vegetale, n. s., v. 3, p. 329. 1915. Protolachnus Theobald, Bull. Ent. Res., v. 6, p. 145. Del Guercio erected the genus Eulachnus without setting a type, but Wilson 1 has indicated agilis Kalt. as the type. Apparently, therefore, the genus must be based upon that species. Theobald's genus was based on his tuberculostemmata, a species in which the char- acters are the same. Cinaria was erected with pini L. as type, but this was questioned. Characters. Head divided, eyes rather large and outstanding; antennae of six seg- ments, armed with long stout bristles. Fore wings with the media faintly indicated and once branched ; hind wings with both media and cubitus present but faint; cornicles minute rings, not situated on hairy cones. Cauda abruptly rounded. Body elongate and narrow. Type (fixed by Wilson, 1911), Lachnus agilis Kalt. Genus TODOLACHNTJS Matsumura. 1917. Todolachnus Matsumura, Jour. Coll. Agr. Tohoku Univ., v. 7, pt. 6, p. 381. The writer has been unable to study the type of this genus, but from the description given it seems to represent a genus belonging here and having a twice-branched media. The description of the cornicles as "wart-like, not broader at base' 7 would indicate its affinities here, also the words "body long, nearly parallel on the lat- eral sides." Type (fixed by Matsumura, 1917), Todolachnus abietis Mats. Subtribe LACHNINA. The members of the subtribe Lachnina may be separated from those of other subtribes with the, exception of the Eulachnina by the character of the venation. The radial sector here has almost reached the tip of the wing and become a short straight vein. The genera may be separated as follows: KEY TO THE GENERA op THE LACHNINA. 1 . Media of fore wings twice branched Dilachnus. Media not twice branched 2. 2. Media once branched 3. Media simple Unilachnus. 3. Labium lance-like Lachnus. Labium obtuse Schizolachnus. Genus LACHNUS Burmeister. 1835. Lachnus Burmeister, Handbuch der Ent., v. 2, pt. 1, p. 91. 1909. Lachniella Del Guercio, Redia, v. 5, p. 286. The genus Lachnus Burmeister was erected with the following included species: lapidarius F&fo.,fagi Linn., quercus Linn., fasdatus Burm., and punctatus Burm. Of these species the following were removed as types of other genera: fagi, 1857, PTiyllaphis, and quercus, 1870, Stomapkis. 1 Wilson, II. F. Xotes on the synonymy of the genera included in the tribe Lachnini. In Ann. Ent. Soc. Amer. v. 4, p. 51-54, 1911. 16 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. The following type fixations have been made for Lachnus: 1840. Aphis roboris Linnaeus, Westwood. 1863. Lachnus pinicola Kaltenbacb, Passerinl. 1908. A phis nudus De Geer, Mordwilko. 1910. Lachnus punctatus Burmeister, Wilson. 1911. Lachnus fasciatus Burmeister, Wilson. Now the first three fixations are invalid, since the species were not included in the original genus. The first valid fixation, there- fore, is that of Wilson, 1910, when he set punctatus as type. This fixation, according to present rules, can not be changed in 1911 because it is an unfortunate fixation, but punctatus must remain the type of the genus Lachnus. The question is now purely zoo- logical. At present punctatus is unknown and, therefore, the genus Lachnus must remain unknown until punctatus is discovered. This is the situation, if the rules are followed, and the well-known genus name will be lost to us. At the suggestion of numerous aphid workers we are holding fasciatus as the type of Lachnus and the Commission will be asked to suspend the rules in this case on account of the long usage of the name Lachnus. In 1909 Del Guercio erected the genus Lachniella without setting a type but in 1911 Wilson interpreted this genus as Lachnus with fasciatus Burm. as type. Following this the writer definitely desig- nated this species as type. Therefore, Lachniella will become a syno- nym of Lachnus. Characters. Eyes large, with distinct ocular tubercles present. Antennae of six segments and with rather prominent hairs. Cornicles on somewhat shallow hairy cones. Fore wings with the radial sector short and straight ; stigma elongate ; media once branched. Labium lance-like. Type (by suspension of rules), fasciatus Burm. Genus DILACHNUS Baker. Plate II, A-C. 1919. Wilsonia Baker, Can. Ent., v. 51, p. 212. 1919. Dilachnus Baker, Can. Ent., v. 51, p. 253. Characters. Eyes with distinct ocular tubercles. Antennae of six segments and armed with slender hairs and circular sensoria. Cornicles on rather broad hairy cones. Fore wings with radial sector straight, media twice branched ; hind wings with both media and cubitus present. Type (fixed by Baker, 1919), Lachniella gradlis Wlsn . Genus SCHIZOLACHNUS Mordwllko. Plate II, D. 1908. Schizolachnus Mordwilko, Ann. Mus. Zool. 1'Acad. Imp. des Sci., St. Petersbourg, v. 13, p. 375. The genus Schizolachnus was erected by Mordwilko with tomen- tosus De Geer (pineti Fab.) as type. Characters. Eyes large and with ocular tubercles present. Antennae of six seg- ments and with rather prominent hairs. Cornicles on somewhat shallow hairy cones. Fore wings with the radial sector straight; stigma elongate; media once branched. Labium obtuse. Type (fixed by Mordwilko, 1908), Aphis tomentosus De Geer. GENERIC CLASSIFICATION OF APHIDIDAE. 17 Genus UNILACHNUS Wilson. Plate II, E-G. 1919. Vnllachnus V^'ilson, Ent. News, v. 30, p. 5. The genus Unilachnus Wilson appears to be a connecting link between this subtribe and the Eulachnina. In some respects the genus is very suggestive of that subtribe. The form is elongate and the cornicles are reduced. They are armed, however, with hairs and are not so reduced as in the Eulachnina. The ocular tubercles here are very rudimentary, almost absent, and in this regard, too, the genus suggests the Eulachnina, but it seems to belong in this subtribe. Characters. Form elongate; cornicles somewhat reduced; ocular tubercles small; media of fore wings simple. Antennae of six segments moderately armed. Type, Lachnus parvus Wilson. Subtribe PTEROCHLORINA. The genera belonging in the subtribe Pterochlorina are in some ways more primitive than those of the Lachnina, but in other respects some of them are more specialized. The radial sector of the fore wings is still curved and in some genera quite elongate. This is much nearer the early type of wing than is the wing of the Lachnina where the radial sector is short and has migrated almost to the tip of the wing. Of course, the distinct curving of this vein found in some of the genera is an advance on the slightly curved elongate vein usually met with in the fossils, but to our mind the location and character of this vein are much more primitive than in the Lachnina. The stigmal area and the sexual forms appear considerably more primitive than in the Anoecina, the specialization of which has been in a different direction from that of the Lachnina. The male of Stomaphis is, however, an exception. Characters. -Head often divided; antennae of six segments, armed with hairs and subcircular sensoria. Fore wings with radial sector somewhat curved and not close to the tip of the wing. Cornicles on broad hairy cones. Males usually winged. KEY TO THE GEN T ERA OF THE PTEROCHLORIXA. 1. Stigma extending along costal margin almost to the tip of the wing..Longistigma. Stigma not so extending 2. 2. Beak extremely long, very much longer than body; antennie covered with very fine, short hairs Stomaphia. Beak normal in length; antennae with rather stout hairs, often quite long Pterochlorus. Genus LONGISTIGMA Wilson. Plate II, II-L. 1909. Longistigma Wilson, Can. En< ., v. 41, p. 3S5. 1909. Davisia Del Gucrcio, Redia, v. 5, p. 185. The genus Longistigma Wilson can be distinguished at once by the shape of the stigma which is drawn out at the tip to an acute point which extends almost to the tip of the wing. The type species is 141613 120 Bull. 826 2 18 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. very large, one of the largest aphids. Del Guercio set no type for his subgenus which was published shortly after Wilson's. Wilson placed this species as a synonym of caryae Harris which he made the type of Longistigma. Characters. Size large. Head somewhat divided. Eyes large, with distinct ocular tubercles. Antennae of six segments, armed with subcircular sensoria and prominent hairs. Fore wings with media twice branched, radial sector not a great way from the tip of wing and stigma extending around almost to tip; hind wings with both media and cubitus present. Cornicles on broad, shallow, hairy cones. Cauda and anal plate somewhat rounded. viparous female apterous. Males winged. Type (monotypical), Aphis caryae Harris. Genus PTEROCHLORUS Rondani. Plate II, S-X. 1848. Ptenchlorus Rondani, "Familia Hemipterorum Aphidinse'J in Nuovi Annali delle Scienze Natural!, p. 35. 1855. Dryobius Koch, Die Pflanzenlause Aphiden, p. 225. 1908. Tuberolachnus Mordwjlko, Ann. Mus. Zool. de 1'Acad. Imp. des Sei. St. Petersbourg, v. 13, p. 374. 1909. Dry aphis Del Guereio, Rcdia, v. 5, p. 262. 1913. Schizodryobius Van der Goot, Tidj. voor Ent., v. 56, p. 130. 1917. Pterochlorid.es Archangelsky, Turkestan Ent. Stn. Kept. Tashkent. 1918. Tuberodryobius Das, Mem. Ind. Mus., v. 6, p. 259. The generic name Cinaria was used for Aphis pini L ?, and Aphis roboris L. with A. pini as type. In the writer's opinion Cinaria can not be used now with roboris as type. Roboris was used as the type of Dryobius,, therefore this name is clear. Dryaphis was used with Pterochlorus as a synonym but the name as a generic name was really first used by Del Guercio in 1909. Tuberolachnus was erected in 1908 with viminalis Boyer as type but the difference in the abdominal tubercle is not, in the writer's opinion, sufficient for a distinction. Van der Goot's genus is plainly a synonym. The other two generic names listed were used with LacTinus persicae Choi, as type. This species has several abdominal dorsal tubercles but for the same reason as Tuberolachnus is held to be a synonym. . Characters.- Head somewhat rounded. Antennae of six segments, armed with subcircular sensoria and prominent hairs. Fore wings with radial sector distinctly curved, inserted some distance from tip; media twice branched. Hind wings with both media and cubit as present. Wings often banded or mottled, cornicles on hairy cones. Cauda and anal plate rounded. Abdomen sometimes with dorsal tubercles. Type (fixed by Rondani, 1848), Aphis roboris Fab. (=roboris L.). Genus STOMAPHIS Walker. Plate II, M-R. 1870. Stomaphis Walker, The Zoologist, v. 28, p. 2000. 1881. Rhynchoclcs Altum, Forst Zool., v. 3, p. 350. Of the five species originally in the genus Lachnus the species guercus Linn, was removed by Walker as the type of his genus Stoma- phis. Little confusion has arisen in regard to this species. Altum's genus was erected for RJiynchocles longirostris. GENERIC CLASSIFICATION OF APHIDIDAE. 19 Characters. Head slightly rouuded; eyes large with distinct ocular tubercles. Antenme of six segments armed with large subcircular sensoria and thickly covered with fine hairs. Cornicles situated on very broad, shallow, hairy cones. Cauda sub- conical, slightly rounded. Anal plate rounded. Fore wings with radial sector rather long and somewhat curved. Media twice branched ; hind wings with both media and cubitus present, quite widely separated. Beak very long, much longer than body. Males wingless and with rudimentary mouth parts. Type (fixed by Walker, 1870), Aphis qitercus Linn. Subtribe TRAMINA. The subtribe Tramina is composed of insects quite specialized in nature, subterranean and often associated with ants. The typical genus Trama is the most specialized of all and is in some char- acters suggestive of the Fordina. Its relations with the other Lachnini, however, are shown clearly by the other genera. The genus Trama, as described by Del Guercio (Redia, v. 5) possesses small cornicles. Specimens of troglodytes, however, received from Schouteden, Mordwilko, and others lack cornicles entirely. Some other forms possess them either as very small cones or as large Lachnus-like structures. These latter are evidently the most primi- tive and to these is given the name Protrama. The insects with small cornicles are grouped under the name Neotrama. The genera may be separated as follows : KEY TO THE GENERA OF THE TRAMINA. 1. Apterous form entirely without cornicles and with rudimentary eyes Trama. Apterous form with cornicles 2. 2. Apterous form with large, broad, Lachnus-like cornicles and large distinct compound eyes Protrama. Apterous form with small cone-like cornicles armed with a few hairs and more or less rudimentary eyes : Neotrama. Genus PROTRAMA, n. gen. Plate III, P-T. Head divided, front straight, eyes prominent and set off from the head. Antenna? of six segments armed with haira and small subcircular protruding sensoria. Cornicles situated on broad, low, hairy cones. Cauda and anal plate rounded. Hind tarsi extremely elongate. Wing venation faint; fore wings with the media twice branched; hind wings with both media and cubitus present. Type. Trama radicis Kalt. Genus TRAMA, Heyden. Plate III, N. 1837. Trama Hcydcn, Mus. Senkb., v. 2, p. 293. Head divided but not prominently so, front straight. Apterous form with the eyes reduced to a few facets. Antennae of six segments; cornicles absent; cauda sub conical, rounded. Anal plate rounded. Entire insect minutely hairy. Type (mono typical), Trama troglodytes Heyden. 20 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Genus NEOTRAMA, n. gen. Plate III, M, O. Head somewhat flat. In the apterous form the eyes reduced ; antennae of six segments and the cornicles on very small cones with a few scattered hairs. Cauda subconical, rounded. Anal plate rounded. Entire body covered with fine hairs. Hind tarsi greatly elongate. Type, Trama troglodytes Del Guercio (=Neotrama delguercioi Baker). Tribe THELAXINI. It has been the custom of most writers to place the Thelaxini (Vacuini) in the Eriosomatinae, often possibly because of the fact that only one egg is laid by the oviparous female. But the female is quite different in structure from the beakless females of the Eriosomatinae and the other forms are very different indeed. With the Hormaphidinae there are more resemblances, the most striking of which is the structure of the thorax. The mesothorax indicates very faintly the lobes so prominent in most forms. The presence of distinct cornicles, however, is very different from the forms in the Hormaphidinae lacking these although possessing a some- what similar thorax. The sensory structures, too, are widely different, being similar to those found in the Phyllaphidina. Indeed, the antennae are very like those of that subtribe. The oviparous forms of the Phyllaphidina, however, lay several eggs and may be either winged or apterous and the males, though sometimes apterous, are usually winged. The venation of the Thelaxini is more reduced than in the Phyllaphidina. Taking all of these facts into consideration it seems evident that the Thelaxini should be placed in the Aphidinae and somewhat related to the Phyllaphidina, a subtribe which belongs in the Callipterini. It is evident, however, that the Thelaxini must stand somewhat apart; it is placed, therefore, as a tribe of the subfamily Aphidinae next to the Callipterini. In this tribe the specialization of the ovipara has advanced beyond that of the Callipterini in that only one egg is laid, but according to Buckton several eggs may be laid and the distinct beak is evidence of relationship. Characters. Cornicles present as chitinized rings on shallow hairy cones. An- tennae somewhat setose, with oval or subcircular sensoria. Cauda somewhat semi- circular or distinctly knobbed. Body usually armed Avith hairs or etout spines. Sexual forms small and apterous, possessing beaks; oviparous female as a rule laying only one egg. Forms living free upon the foliage. The genera may be separated by the following key: KEY TO THE GENERA OF THE THELAXINI. Cauda distinctly knobbed Thelaxes. Cauda not knobbed but somewhat semicircular Glyphina. GENERIC CLASSIFICATION OF APHIDIDAE. 21 Genus GLYPHINA Koch. Plate III, G-L 1857. Glyphina Koch, Die Pflanzenlause Aphiden, p. 259. 1911. Travaresiella Del -Guercio, Redia, v. 7, p. 299. Characters. Corrncles present as somewhat elevated rings. Antenna 5-seg- mented, minutely setose, armed with a few stout hairs and somewhat subcircular sensoria. Fore wings with the media once branched; hind wings with only the media present. Cauda not knobbed, fomewhat rounded, anal plate rounded. Body covered with hairs. Forms living upon the foliage of plants. Type (monotypical), Glyphina betulae Kalt. Genus THELAXES Westw. Plate III, A-F. Vacuna of authors, not Heydcn. 1840. Thelaxes Westw., Int. Mod. Class. Ins. Synopsis, v. 2, p. 118. In 1837, Heyden erected his genus Vacuna based on coccinea Hey den. He definitely stated that he thought Phylloxera Boyer was the same genus. Kaltenbach stated that coccinea is a Phylloxera and so considered dryophila as type of Vacuna, as this species was in- cluded in the genus by Heyden. On the authority of Schouteden and other European workers coecinea is now considered a Phylloxera and another type, dryopJiilo,, can not be set for the genus- in order to apply Vacuna to the genus as now understood. Vaouna with coccinea as type will become a synonym of Phylloxera and another name will be necessary to apply to the genus having dryophila as type. The next name used appears to be Thelaxes Westwood. Characters. Cornicles present as chitinized rings on broad lov/ cones. Antennae of the stem mother 5-segmented. Alate form with 3-segmented antennae, sensoria oval or subcircular. Fore wings with the media once branched, hind wings with the cubitus lacking. Cauda distinctly knobbed, anal plate rounded. Sexual forms small and apterous, possessing distinct beaks and feeding; oviparous female producing normally but one egg. Type (fixed by Westwood, 1840), Thelaxes quercicola Westw. (= Aphis dryophila Schr.) Tribe CALLIPTERINI. The tribe Callipterini is composed of forms which live upon the foliage of plants. The species in many of the sub tribes hare developed peculiar habits. Some forms are almost solitary whereas others live in colonies. Some have developed the power of leaping, while others are sedentary. The sexual forms do not vary greatly from the viviparous forms. In nearly all of the subtribes the males arc winged, though in the Saltusaphidina they are apterous. In the other tribes intermediate males may occur in the same species with alato males. The oviparous females are nearly always apterous, although in the Phyllaphidina alate ovipara may occur. Both sexes feed and the ovaries of the oviparous female are developed so that several eggs are, laid. 22 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. The wing veins are not reduoed in most species. In some, however the radial sector of the fore wings is very faint or entirely absent. This condition is met with in several genera of the Callipterina. That it is this vein which is lacking is indicated by the trachea of the freshly emerged wing. Here the media is represented by M 1? M 2 , and M 3+4 . The oubitus and first anal are distinct tracheae, whereas the second anal is faintly indicated. In the hindwing besides the radial sector three oblique tracheae are present ; these are the media, cubitus, and first anal. Only the media and cubitus are represented in the vena- tion. Considerable variation is met with in the cornicles of this tribe but they are never long and prominent as in the Aphidini. The usual form is the truncate one represented in Myzocallis, Chaitophorus, etc. Very often the cornicles are sculptured. In some cases they are reduced to small cup-shaped structures and in others they are represented by mere rings. The antennse, as a rule, are long and slender and armed with few sensoria. These sensoria are usually small, subcircular or oval. In rare cases they are somewhat elongate. The cauda in this tribe is as a rule knobbed and the anal plate bilobed. In some cases, ho\vever, the cauda and anal plate are both rounded. In the Saltusaphidina the anal plate is divided and the cauda remains distinctly knobbed. Wax secretion is present to a limited extent in this tribe. It is most developed in the Phyllaphidina. Here there are large lateral ab- dominal wax plates in all of the forms and the insects present a wool- like appearance on the foliage. In the genus Euceraphis wax secretion is found to a limited extent. In one species, mucidus Fitch, it is, however, abundant and the insects of this species often seem to float in the air, a peculiar appearance cdmmon also in the Erioso- matinae. In the Saltusaphidina also distinct wax plates occur, particularly in the oviparous forms. These are arranged along the abdominal segments. The habit of leaping is common in the Saltusaphidina as the name implies. Here the muscles of the femora are greatly enlarged for this purpose. Many of the other members of the tribe approach this con- dition, especially in the genus Monellia. Others, although they do not distinctly leap, drop so suddenly when disturbed that they almost ap- pear to leap from the foliage. Our common Symydobius on the birch is difficult to collect on account of such a habit and other forms of Callipterina are very similar in action. Certain species in this tribe are closely attended by ants in return for the honeydew excreted. Some species are protected by these Hymenoptera by means of sheds or roofs built over colonies on the leaves or twigs. These sheds are found quite commonly upon the leaves of the oaks protecting the spe- GENERIC CLASSIFICATION OF APHIDIDAE. 23 cies described as Symydobius albasiphus by Davis and here placed as Neosymydobius. The internal structure of insects of this tribe appears not to differ markedly from the structure in other groups. Witlaczil, however, has reported that in certain members of this tribe the intestine forms a closed loop almost similar to that found in the Chermidae. As a rule, in this tribe, the various forms met with in the subfamily occur. In the genus Monellia, however, in some species at least, ap- terous viviparous forms seldom occur, nearly all the viviparous forms being alate. The subtribes may be separated by the following key: KEY TO THE SUBTRIBES OF THE CALLIPTERINI. 1. Eyes with ocular tubercles present, head not elongate 2. Eyes without ocular tubercles present, head often elongate SALTUSAPHIDINA. 2. Antennae armed with rather long, prominent hairs 3. Antennae usually only with minute, sometimes stout bristles 5. 3. Cornicles absent FULLAWAYINA. Cornicles present 4. 4. Cornicles cylindrical or vasiform , PTEROCOMMIXA. Cornicles truncate, enlarged at base CHAITOPHORINA. 5. Cornicles absent above MONAPHIDINA. Cornicles present, position as usual G. 6. Cornicles reduced to mere rings; large lateral abdominal wax plates present PHYLLAPHIDIXA. Cornicles usually not reduced to mere rings; no large abdominal wax plates present 7. 7. Cornicles variable, often long and somewhat swollen; oviparous female with an elongate ovipositor DREPANAPHIDIXA. Cornicles never long; always short and truncate; oviparous fem?le not always with an elongate ovipositor CALLIPTERIXA. Subtribe PHYLLAPHDOINA. The subtribe Phyllaphidina is erected for the species related to the genus Phyllaphis. Many of the characters show these species as quite closely related to the Callipterina, while in other ways they very strongly suggest the Thelaxini, as indicated under the discussion of the tribe. Characters. Cornicles present; antennae of six segments, minutely setose, sensoria elongate or subcircular; cauda knobbed or rounded, anal plate often bilobed, wax glands present. Forms living free or in pseudogalls. Sexual forms often alate, some- times, however, apterous or intermediate, showing that the apterous condition has developed but recently; oviparous female producing several eggs. KEY TO THE GENERA OF THE PUYLLAPHIDINI. 1. Anal plate deeply cleft and U-shaped Shivaphis. Anal plate entire or somewhat bilobed, not deeply cleft 2. 2. Cauda rounded, anal plate entire 3. Cauda knobbed, anal plate somewhat bilobed Phyllaphis. 3. Oviparous females with annular sensoria Neophyllaphis. Oviparous females with small transverse sensoria Taraalia. 24 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Genus NEOPHYLLAPHIS Takahashi. 1920. Neophylla/Jiis Takahashi, Can. Knt., v. 52, p. 20. Cfutracters. Cornicles slightly elevated. Antennae of six segments, with narrow, traasverse sensoria. Fore wings with media twice branched, hind wings with both media and cubitus present. Cauda and anal plate rounded, cauda sometimes slightly constricted. Oviparous females winged and possessing annular sensoria. Forms wax secreting and living free on the plants. Type (monotypical), Neophyllaphis podocarpi Takahashi. Genus PHYLLAPHIS Koch. Tlate IV, FF, GO. 1857. Phyllaphis Koch, Die Pflanzenlause Aphiden, p. 248. The well-known genus Phyllaphis Koch is represented by/agriL., but as indicated under Tamalia has been made to include species of somewhat different structure. Characters. Cornicles present as chitinized rings which are very slightly elevated on low conical bases. Antennae of six segments, long and slender, minutely setose, sen- soria narrowly oval. Fore wings with the media twice branched; hind wings with both media and cubitus faintly indicated. Cauda knobbed, anal plate slightly divided. Forms living upon the foliage, sometimes producing a curling of the leaves. Males usually winged; oviparous form apterous, producing several eggs. Type (monotypical), Aphis fagi L. Genus TAMALIA n. gen. Plate IV, HH, II. The genus Tamalia Baker is erected for Pemphigus coweni Ckll., a species which has since been placed in Phyllaphis. It is, however, quite distinct from the type of the genus and undoubtedly represents a new genus. Mr. Theodore Pergande received this species, coweni, from California and made some notes on the material, thinking, how- ever, that it was a new species. He gave it a provisional name and the new generic name here used. This name, as far as our knowledge goes, never was published. Among the large number of new genera conceived by Pergande this is one of the few valid ones and his man- uscript name, therefore, is used here. Characters. Cornicles present as mere flanges on low, broad, conical bases. Antennae of six segments minutely setose and with narrow sensoria. Fore wings with media once branched, hind wings with both media and cubitus present. Cauda and anal plate both rounded. Abdominal wax plates present. Forms living in pseud ogalls. Sexes sometimes both winged, oviparous form pro- ducing several eggs. Type, Pemphigus cou-eni Ckll. Genus SHIVAPHIS Das. 1918. Shivaphis Das, Mem. Ind. MILS., vol. 6, p. 215. The genus Shivaphis was erected with celti Das as type, and celti is evidently the species rcclescribed as ChromapJiis celticolens by Essig. 1 1 ESSIG, E. O., and KUWANA, S. I. Some Japanese Aphididfe. In Proc. Cal. Acad. Sci., v. 8, no. 3, p. 95, 1918. GENERIC CLASSIFICATION OF APHIDIDAE. 25 The writer has studied a series' of specimens of this species taken in 1907 on Celtis sinensis. There seems little doubt that the genus is related to Phyllaphis. The dorsal wax glands are of much the same structure as those found in fagi L. The deeply cleft anal plate, however, at once separates the two. The cauda which is almost cylindrical in some specimens is quite distinctly knobbed in others. Characters. Cornicles present as mere rings. Head without prominent antennal tubercles. Antennae of six segments, sensoria elliptical. Fore wings with the media twice branched, hind wings with both media and cubitus present. Cauda cylindrical or knobbed. Anal plate deeply divided. Males winged. Oviparous females apter- oue. Rows of wax glands present. Type (monotypical), Shivaphis celli Das. Subtribe CALLIPTERINA. The subtribe Callipterina is a somewhat large and interesting one. Some of the species are very large and more or less solitary, others are small and live in colonies. In some genera apterous viviparous forms, with the exception of the stem mother, seldom occur, while in other genera they are as a rule, present. The males are in most cases alate and the oviparous forms apterous. The species of nearly all the genera live upon the leaves of plants. They do not affect these greatly, as a rule, although when abundant the insects often seriously interfere with the proper development of the trees attacked. Many of the insects are armed upon their bodies with prominent spines or tubercles. Characters. Cornicles present, truncate in form. Antennae with setae or spines, of six segments, and armed with subciroular or in a few cases somewhat elongate sen- soria. Wings often clouded, mottled, or banded. Cauda as a rule knobbed, anal plate usually more or less indented or bilobed. Body often armed with capitate spines or tubercles. KEY TO THE GENERA OF THE CALLIPTERINA. 1. Cauda distinctly knobbed, anal plate usually bilobed or sometimes deeply divided 3. Cauda not distinctly knobbed, anal plate entire or almost so 2. 2. Antennae minutely setose, sensorium at base of unguis oval or somewhat rounded ; oviparous female with secondary sensoria Symydobius. Antennas not minutely setose, sensorium at base of unguis long and narrow, oviparous female without secondary sensoria Euceraphis. 3. Anal plate deeply divided with a U-shaped cleft so that the lobes appear as distinct; cauda knobbed Therioaphis. Anal plate bilobed, not deeply divided ; cauda very markedly knobbed ... 4. 4. Antenna? and often the cornicles with prominent hairs Callipterus. Cornicles and antennae without such hairs 5. 5. Cornicles much reduced; wings sometimes horizontal in repose Monellia. Cornicles truncate, fairly well developed; wings not horizontal in repose 6. 26 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. 6. More or less distinct antennal tubercles present; oviparous female with secondary sensoria Calaphis. No distinct antennal tubercles present ; oviparous female without secondary sensoria 7. 7. Anal plate slightly indented, sometimes almost entire; no apterous vivi- parous forms developed Chromaphis. Anal plate distinctly bilobed; apterous viviparous forms common Myzocallis. Genus CALAPHIS Walsh. Plate IV, S, U. 1863. Calaphis Walsh, Proc. Ent. Soc. Phila., v. 1, p. 301. 1913. Siphonocallis Del Guercio, Redia, v. 9, p. 293. 1913. Callipterindla Van der Goot, Tijdschr. voor Ent., v. 56, p. 118. Walsh erected his genus Calaphis for his betulella, a species which lacks the radial sector in the wing, and on this character he based his genus. Del Guercio based his Siphonocallis on betulaecolens Fitch, distinguishing it from his conception of the genus Callipterus, which conception, however, was not according to type. A study of betida-ecolens shows that in all respects, with the exception of the radial sector, this species is similar to betulella. Many specimens of betula-e- colens lack the radial sector and in most cases it is only faintly indi- cated at best. These two species, therefore, are probably congeneric. The genus Callipterinella was based on betularius Kalt., and this species proves to be very similar to betulaecolens. It is true that the frontal tubercles are not prominent in this species as they are in the type of Calaphis. There seems no doubt, however, that all of these three species are closely related. This relation is shown in part by the sexual forms. The oviparous females all possess sensoria on the antennas and are very similar in other body characters. This pres- ence of sensoria in the oviparous form, while not important in some groups, separates quite distinctly this small group of species from those of the Myzocallis type. It seems evident that the relations of betu- larius are with betulaecolens and betulella. Callipterinella, therefore, is also a synonym. Characters. Cornicles present, distinct, truncate. Antennae of six segments, armed with oval sensoria and placed on more or less distinct tubercles. Fore wings with the media twice branched, the radial sector either absent or faintly indicated, sometimes, however, complete; hind wings with both media and cubitus present. Cauda distinctly knobbed, anal plate bilobedj body with prominent hairs. Forms living more or less solitary upon the foliage, sexes notmarkedly different from the other forms; oviparous female producing several eggs and possessing sensoria upon the antennae. Type (monotypical), Calaphis betulella Walsh. GENERIC CLASSIFICATION OF APHIDIDAE. 27 Genus CALLIPTERUS Koch. Plate IV, I, J. 1855. Callipterus Koch, Die Pflanzenlaiise Aphiden, p. 208. 1870. Callaphis Walker, The Zoologist, v. 5, p. 2000. 1881. Ptychodes Buckton, Mon. British Aphids, v. 3, p. 39. 1904. Panaphis Kirkaldy, The Entomologist, v. 37, p. 279. 1917. Nippocallis Matsumura, Jour. Coll. Agr. Tohoku Univ., v. 7, pt. 6, p. 365. In erecting the genus Callipterus, Koch included a number of species among which was juglandis Kalt, In I860, Passerini set juglandis as the type of Callipterus and erected his Myzocallis for species similar to coryli Goetz. Most writers overlooked Passerini's work and considered the genus Callipterus in the light of Myzocallis. This is the conception com- monly held by many to-day. The application of Callipterus, how- ever, must be restricted to species essentially like juglandis. All the other generic names listed as synonyms were, with one exception, used with this same species juglandis as type and therefore require little comment. The genus Xippocallis was erected with Tcuricola Mats, as type. Specimens of this species studied by the writer are not in good con- dition for the observation of the anal plate. All the characters visible, however, indicate that this species is a Callipterus. Characters. Cornicles present, truncate in form, rather prominent and often armed with long hairs. Antennae of six segments, armed with stout hairs, sensoria usually oval. Fore wings with the media twice branched, hind wings with both cubitus and media present. Veins usually bordered. Radial sector often faintly indicated. Cauda not distinctly knobbed in all cases. Anal plate bilobed; body usually covered with prominent hairs. Forma living free upon the foliage. Sexual forms not differing markedly from the other forms, oviparous female producing several eggs. Type (fixed by Passerini, 1860), Aphis juglandis Frisch. Genus CHROMAPHIS Walker. Plate IV, O, P. 1870. Chromaphis Walker, The Zoologist, v. 5, p. 2001. The genus Chromaphis was erected with juglandicola Kalt. as type. It is related quite closely to Monellia. Characters. Cornicles moderate in size, somewhat flanged. Antennae of seven seg- ments armed with oval sensoria. Fore wings with the media twice branched, hind wings with media and cubitus present, wings not held horizontally in repose. Cauda knobbed, anal plate slightly indented. Sexual forms somewhat similar to the vivip- arous ones. Males usually winged. Oviparous female with the ovaries developed normally, laying numerous eggs. 1 Forms living free upon the foliage usually all summer; viviparous generations winged. Type (inonotypical), Aphis juglandicola Kalt. i Davidson believes as many as 30 may be produced by one female. 28 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Genus THERIOAPHIS Walker. Plate IV, K, I,. 1870. Thcrioaphis Walker, The Zoologist, p. 1999. 1905. Kallistaphis Kirkaldy, Can. Ent., v. 37, p. 417. 1906. EucaTipterus Schouteden, Ann. Ent. Soe. Belg., v. .50, p. 31. 1 1915. Neocallipterus Van der Goot, Beitrage zur Kennt. der IIoll. Blattlause, p. 320. The genus Therioaphis Walker was erected with ononidis Kalt. as type, and ononidis has been shown by Theobald to be the common "yellow clover aphis," trifolii of Monell. This species has a deeply cleft anal plate quite different from that of Myzocallis. Eucallipterus was erected with tiliae L. as type, &, species with quite similar struc- ture. Eucallipterus, therefore, will become a synonym. Betulicola Kalt. has been used as type by Kirkaldy and Van der Goot. Accord- ing to Das, Van der Goot considers this congeneric with trifolii. Therefore Therioaphis is the name that must be used. Characters. Cornicles truncate, rather constricted mesad of apex. Antennae cf six segments without prominent hairs and armed with subcircular sensoria. Fore wings with media twice branched ; hind wings with both media and cubitus present. Wings often variously marked. Prothorax rather elongate; cauda knobbed* Anal plate deeply bifid so that two long, narrow lobes are formed. Body often with prominent hairs. Type (monotypical), Aphis ononidis Kalt. Genus EUCERAPHIS Walker. Plate IV, Q, Pv. 1S70. Euceraphis Walker, The Zoologist, p. 2001. 1908. CaUipteroides Mordvrilko, Ann. Mus. Zool. 1'Acad. Imp. des Fci. St. Petersbourg, v. 13, p. 377. 1913. CaUipteroides Van der Goo:, Tijd. voor. Ent., v. 56, p. 151. When Walker erected his genus Euceraphis with betulae L. as type he had in mind evidently the same species as that described by Koch under the same specific name, and thus separated species of this type. Mordwilko in 1900 erected the genus CaUipteroides with nigritarsus Heyden as type. Specimens of this species received from Mordwilko. show that the species he had was the betulae of Koch or at least a species very close to it. This would then make CaUipte- roides a synonym of Euceraphis. In 1913 Van der Goot used the name CaUipteroides with beiulae Koch as type and his placing, there- fore, should be under Euceraphis. Characters. Cornicles present, truncate. Antennae of six segments, long and slender, armed with rather narrow sensoria usually near the base of segment III, the unguis of segment VI usually not much longer than the base, sensorium at the base of unguis long, oval, and fringed ; more or less distinct frontal tubercles present. Fore wings with the media twice branched, hind wings with both media and cubitus present. Cauda usually knobbed and rather large. Anal plate usually entire. Abdomen of the alate form often with distinct wax-producing glands. Forms very large and usually solitary in habit, sexes similar to the other forms; oviparous female producing several eggs. Type (fixed by Walker, 1870), Aphis betulae (L.) Walker (=Callipterus betulae Koch). i There is considerable evidence for keeping this genus distinct. GENERIC CLASSIFICATION OF APHIDIDAE. 2& Genus MONELLIA Oestlund. Plate IV, M, N. 1887. AfoneUia Oestlund, Osol. and Nat. Hist. Survey Minn., Bui. no. 4, p. 41. The genus Monellia Oestlund was erected for caryeUus Fitch and only one species was included in the genus at the time. Several other species, however, were made synonyms of caryeUus which are quite different from that species and fall into other 'genera. Characters. Cornicles present as mere rings; antennae slender, of six segments; sen- soria oval or subcircular; head broad for its length; prothorax prominently separated from the mesothorax. Fore wings with the media twice branched ; hind wings with both media and cubitus present. Wings often held flat upon the back, cauda knobbed, anal plate bilobed. Forms living solitary upon the leaves, sometimes haying the power of leaping. Apterous forms rare. Sexes feeding; oviparous female laying several eggs. Type (monotypical), Aphis caryella Fitclu Genus MYZOCALLIS Pass. Plate IV, G, H. 1860. Myzocallis Passerinl, Gli Afldi, p. 28. 1860. Pterocallis Passerini, Gli Afidi, p. 28. 1894. Subcallipterus Mordwilko, Varshava Univ. Izviestiia, v. 8, no. 58, p. 53. 1894. Tuberculatus Mordwilko, Varshava Univ. Izviestiia, v. 8, no. 58, p. 60. 1913. Callipterus Van der Goot, Tijd. voor Ent., v. 56, p. 116. 1915. Tuberculoides Van der Goot, Beitrage zur Kennt. der Holl. Blattlause, p. 313. 1917. Acanihocallis Matsumura, Jour. Coll. Apr. Tohoku Univ., v. 7, pt. 6, p. 368. 1917. Takecallis Matsumura, Jour. Coll. Agr. Tohoku Univ., v. 7, pt. 6, p. 373. When Passerini erected the genus Myzocallis in 1860 he placed coryli Goetz as type. Later in the same work he erected his genus Pterocallis with dlni Pass, as type. This species proves to be very similar indeed to coryli, so similar in most of the characters that the writer believes the genus Pterocallis to be a synonym of Myzocallis. The type of the genus, coryli Goetz, was also placed as the type of Callipterus by Van der Goot, in 1913, in spite of the fact that another type for that genus had been set in 1860. Callipterus Van der Goot (1913) is therefore a synonym of Myzocallis. The species alni Pass, is universally considered the same species as alni Fab., and this species was made the type of the genus Subcallipterus by Mordwilko in 1894. Subcallipterus Mordwilko, 1894, is therefore a synonym of Myzocallis for the same reason as is Pterocallis Pass., 1860. The species querceus Kalt. was made the type of the Tuberculatus by Mordwilko in 1894, but this species seems too closely related to coryli. Tuberculatus, therefore, becomes a synonym. The species quercus Kalt. was made the type of Tuberculoides by Van der Goot, 1915, and this is quite typically a Myzocallis. A number of genera have been erected by Matsumura which are so very little different from the type species that they are listed here as synonyms. This author follows the idea of proportions of the antennal segments as generic characters. 30 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Characters. Cornicles truncate without a very distinct neck; antennae of six segments armed with a few minute bristles and oval or subcircular sensoria. Fore wings with the media twice branched ; hind wings with both media and cubitus present. Cauda knobbed; anal plate bilobed, not divided; body usually with stout hairs. Type (fixed by Passerini, 1860), Aphis coryli Goetz. Genus SYMYDOBIUS Mordwilko. Plate IV, DD, EE. 1894. SymydMus Mordwilko, Varshava Universitetskiia Izviestiia, v. 8, no. 58, p. 65. 1917. Yczocallis Matsumura, Jour. Coll. Agr. Tohoku Univ., v. 7, p.t. 6, p. 369. Symdobius of later authors. The genus Symydobius Mord., which was erected for obloTigus Heyden, has often been spelled Symdobius by subsequent writers. This is probably due to the erection of the genus in a Russian publi- cation which is available to few workers, at least in this country. Specimens of this species studied were collected by Mordwilko at Petrograd and Warsaw and by Schouteden at Brussels. The species which passes under the name of oblongus hi America is quite distinct, as has been pointed out by the writer. Characters. Cornicles present, truncate or with an evident neck and on a broad low base. Antennae of six segments armed with numerous delicate hairs, sensoria somewhat oval or subcircular; sensorium at the base of the unguis not long and nar- row, with a fringe but without a prominent one, cauda semicircular, anal plate similar in shape, sometimes slightly indented. Fore wings with the media twice forked; hind wings with both media and cubitus present, somewhat separated at the base. Type (monotypical), Aphis oblonga Heyden. Subtribe SALTUSAPHIDINA. The subtribe Saltusaphidina is separated from the other related ones principally on the nature of the head. The most important character, possibly, is the structure of the eyes, in which the ocular tubercles appear to be wholly lacking. Characters. Forms living usually in damp places upon the foliage of sedges and grasses, narrow elongate bodies, eyes with ocular tubercles lacking, legs often modi- fied for leaping. Oviparous forms apteious, somewhat similar to the viviparous forms, producing several eggs. KEY TO THE GENERA OF THE SALTUSAPHIDINA. Head considerably elongate, cornicles cup shaped, legs modified for leap- ing Saltusaphis. Head not much elongated, cornicles mere rings, legs not modified for leap- ing Thripeaphis. Genus THRIPSAPHIS Gillette. Plate IV, X. 1917. Thripsaphis Gillette, Can. Ent., v. 49, p. 193. The genus Thripsaphis was separated from Saltusaphis for &o$i Gillette, which the present writer had included in that genus, and certain other similar species. GENERIC CLASSIFICATION OF APHIDIDAE. 31 Characters. Cornicles .present as slightly elevated rings; antennae of six segments armed with subcircular sensoria. Eyes without ocular tubercles. Fore wings with the media twice branched, hind wings with the cubitus sometimes absent, cauda knobbed, anal plate divided, body with spinelike hairs. Forms living free upon grasses and sedges in moist localities. Sexes apterous, oviparous female producing several eggs. Type (fixed by Gillette, 1917), Brachycolus balli Gill. Genus SALTUSAPHIS Theobald. Plate IV, V, W. 1915. Saltusaphis Theobald, Bull. Ent. Research, v. 6, pt. 2, p. 138. Characters. Cornicles present, cup-shaped or truncate; antennae of five segments, minutely setose; sensoria small and subcircular. Head elongate, ocular tubercles absent. Fore wings with the media twice branched; hind wings with the cubitus usually absent; cauda knobbed; anal plate divided, caudal extremity of the abdomen sometimes bilobed; body covered with spines which are often modified into different shapes. Forms living more or less solitary upon the leaves of grasses or sedges in marshy regions. Sexual forms apterous, oviparous female laying several eggs. Type (monotypical), Saltusaphis stir pus Theo. Subtribe DREPANOSIPHINA. The subtribe Drepanosiphina is evidently related to the callip- terine branch of the tribe rather than the chaitophorine one. It has specialized in the opposite direction from the Monaphidina in that the cornicles are more or less prominently developed. It would appear to bear the same relation to this branch of the tribe as does the Pterocommina to the chaitophorine one. There is considerable variation in the development of the cornicles, even within certain of the genera. Some have very large cornicles, others have small ones. They all appear, however, to have the same general structure. Characters. Cornicles present, varying greatly in development from very small to very large. Cauda somewhat knobbed, anal plate slightly indented. Oviparous female with a long drawn out ovipositor. KEY TO THE GENERA OF THE DEEPANOSIPHINA. 1. Cornicles extremely long and somewhat swollen in the middle Drepanosiphum. Cornicles not extremely long and larger atthe base 2. 2. Cornicles very small, truncate Neosymydobius. Cornicles large with a swollen region at the base Drepanaphis. Genus DREPANAPHIS Del Guercio. Plate IV, JJ-LL. 1909. Drepanaphis Del Guercio, Ri vista di Patologia Vegetale, n. s., v. 4, no. 4, p. 49-50. 1909. Phymatosiphum Davis, Annals Ent. Soc. America, v. 2, p. 196. The two generic names given were both used with the same type species, and therefore no discussion in regard to the use of the names is necessary. Characters. Cornicles large but not of the same shape as those of Drepanosiphum, being rather narrow toward the distal extremity and swollen at the base. Antennae of six segments armed with subcircular or oval sensoria and a few scattered hairs. Fore wings with the media twice branched, hind wings with both media and cubitus present. Cauda knobbed, anal plate somewhat indented. Forms living more or less 32 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. solitary upon the foliage of trees. Males winged. Oviparous female with a distinct elongated ovipositor and producing several eggs. Type (monotypical), Drepanosiphum acerifolii Thos. Genus DREPANOSIPHUM Koch. Plate IV, MM. 1855. Drepanosiphum Koch, Die Fflanzenlaiise Aphidcn, p. 201. 1885. Type fixation, Lichtenstein, Monographic des Aphidiens, p. 175. Cornicles very long, quite distinctly swollen in the middle or subcylindric. An- tennae of six segments with short, scattered hairs and oval or subcircular sensoria. Fore wings with the media twice branched. Hind wings with both media and cubitus present. Cauda knobbed, anal plate slightly indented. Forms living upon the foliage of plants, males usually winged. Oviparous female with a distinct elongated ovipositor. Type ffixed by Lichtenstein, 1885), Aphis platanoides Schr. Genus NEOSYMYDOBIUS, n. gen. The genus Neosymydobius is erected for species similar to that described as Symydobius albasipTius Davis. It is evident that this species is not a Symydobius. Members of that genus are very large and differ in several ways. We place the present genus here with considerable doubt. Characters. Cornicles small, truncate, Callipterus-like. Antennae of six segments which are armed with a few rather stout hairs. Fore wings with the media twice branched, hind wings with both media and cubitus present. Cauda knobbed, anal plate slightly indented. Forms living in colonies upon the foliage of trees. Body, particularly of the apterous forms, covered with rather stout spine-like hairs. Ovipar- ous female with a long ovipositor and depositing several eggs. Males usually winged. Type, Symydobius albasiphus Davis. Sub tribe MONAPHIDINA. The sub tribe Monaphidina, erected for the genus Monaphis, is very similar in most respects to the Callipterina, but lacks the cornicle dorsally. It seems evident that it is a specialization from insects of the Callipterus type in much the same way that Fullawaya is related to those of the Chaitophorus type. One genus only is known at present. This differs more from the Callipterina than does Fullawaya from the Chaitophorina. Genus MONAPHIS Walker. 1870. Monaphis Walker, The Zoologist, p. 2001. 1894. Bradyaphis Mordwilko, Varshava Univcrsitetskiia Izviestiia, v. 8, p. 59. Few remarks on the synonymy of the genus Monaphis Walker are necessary as the same species was used as type in both cases men- tioned. The genus is a very remarkable one, being peculiar in many ways. Characters. Cornicles faint; antennje of six segments, without distinct hairs, eensoria small and circular; cauda somewhat rounded but with an acute point or pro- jection; anal plate similar; fore wings with the media twice branched ; hind wings with both media and cubitus present. Type (fixed by Walker, 1870), Aphis antenna in Kalt. GENERIC CLASSIFICATION OF APHIDIDAE. 33 Subtribe CHAITOPHORINA. The sub tribe Chaitophorina is composed of aphids which' are similar in many ways to the Callipterina. They differ in that they are always armed with long hairs which quite prominently cover the antenna as well as the other parts of the body. Some of the species perhaps are given more to living in colonies than are the Callipterina, but this habit varies in that subtribe as well. KEY TO THE GENERA OF THE CHAITOPHORIXA. 1 . Cauda quite distinctly knobbed 2. Cauda not knobbed but rounded 3. 2. Antennae of five segments Sipha. Antennae of six segments Chaitophorus. 3. Body elongate ; small dimorphic forms developed Periphyllus. Body not elongate ; no dimorphic forms developed 4. 4. Antennae of five segments Atheroides. Antennae of six segments 5 5. Anal plate entire or slightly indented Xeothomasia. Anal plate divided into two quite separate parts Patchia. Genus ATHEROIDES Haliday. 1839. Atheroides Haliday, Ann. and Mag. Xat. Hist., v. 2, p. 189. More careful collecting of marsh-inhabiting species may show that this genus is a specialization from the Chaitophorina as is the Saltu- saphidina from the Callipterina, for most specimens falling here seem to lack ocular tubercles. Characters. Antennae of five segments armed with stout spines. Fore wings with media twice branched; hind wings with both media and cubitus present. Cornicles reduced to mere rings. Cauda broadly rounded. Form elongate and flat. Entire insect prominently spined. Species living on sedges and grasses. Type (set by Kirkaldy, 1906), Atheroides stmdatus Ilaliday. Genus CHAITOPHORUS Koch. Plate IV, CC. 1854. Chaitophorus Koch, Die Pflanzenlause Aphiden, p. 1. 1870. Tranaphis Walker, The Zoologist, p. 1999. 1870. A rctaphis Walker, The Zoologist, p. 2000. 1912. Eichochaitophorus Esslg, Pom. Coll. Journ. Ent., v. 4, p. 721. 1912. Micrella Essig, Pom. Coll. Journ. Ent., v. 4, p. 716. 1856. Type fixation, Gerstaecker, Bericht for 1854, p. 162. Ill 1854 Koch erected the genus Chaitophorus with several species. Aphis populi was made the type by Gerstaecker in 1856. The same species was used by Walker as type of his genus Arctaphis and there- fore this name will become a synonym. The types of both of Essig's genera show that these vary little from populi. The genus Tranaphis was erected with salicivorus Walker as type and this species is similar in general characters to -populi. Therefore, Tranaphis will become a synonym. 141013 -20 Bull. 820 3 34 BULLETIN $26, u. S. DEPARTMENT OF AGRICULTURE. In 1860 Passerini used cuceris L. as the type of Chaitophorus and this placing has often been followed, but that of Gerstaecker has priority. Characters. Cornicles present, truncate, rather prominent. Antennae of &ix seg- ments, armed with subcircular sensoria and rather prominent hairs. Fore wings with the media normally twice branched, hind wings with both media and cubitus piesent. Cauda distinctly knobbed. Anal plate entire, sometimes somewhat indented. Sex- ual forms not differing markedly from the vi viparous ones. Males winged, as a rule, but sometimes intermediate or apterous. Oviparous females apterous with the ovaries normally developed and producing several eggs. Both sexes feeding. Forms living usually upon the leaves of trees; no dimorphic forms developed. Type (fixed by Gerstaecker, 1856), Aphis populi L. Genus PAT CHI A, n. gen. Characters. Cornicles truncate; antennae of six segments, hairy and with circular sensoria. Fore wings with the media twice branched, the radial sector absent or faintly indicated; hind wings with both media and cubitus present. Cauda rounded or slightly conical; anal plate divided into two separate parts. Type, Patfhia rirginiana Baker. Patchia virginiana, n. sp. Alate viviparous female. Antennae as follows: III, 0.48 mm., with an even row of about 12 subcircular sensoria; IV, 0.288 mm.; V, 0.24 mm.; VI (0.16-0.192 mm.). Color brown with a large black patch on dorsum of abdomen and with lateral patches of same color. Wings with the radial sector absent and the veins heavily bordered. Apterous form almost solid velvety black. Both forms secreting wax. Found on the bark of chestnut at East Falls Church, Va. The type is in the U. S. National Museum (Cat. No. 23063). Genus PERIPHYLLUS Van der Hoeven. Plate IV, A A, BB. 1852. Phittophorus Thornton, Proc. Ent. Soc. London, n. s., v. 2, p. 78. 1858. Chelymorpha Clark, The Microscope. 1863. Periphyllus Van dor Hoeven, Tijd. voor. Ent., v. 6, p. 7. 1913. Chaitophorinella Van der Goot, Tijd. voor Ent., v. 56, p. 150. 1917. Arakawana Matsumura, Journ. Coll. Agr. Tohoku Univ., v. 7, pt. 6, p. 375. "In 1852 Thornton used the name Phillophorus with his testudinatus as type. This name had, however, been used in 1840. Koch erected the genus Chaitophorus in 1854 and included therein a number of species. In 1856 Gerstaecker set Aphis populi L. as the type of Chaitophorus and therefore prevented the use of the name for spe- cies such as testudinatus unless all of Koch's species are included. In 1858 Clark used the name Chelymorpha with the specific name 'pliyllopliora. The species he discussed is the testudinatus of Thorn- . ton. The generic name Chelymorpha, however, was used as early as 1834 and, therefore, is not available. In 1863 Van der Hoeven employed the generic term Periphyllus with his species testudo as type. This name is a synonym of testudinatus Thornton, and the generic name seems to be the first one available. In 1913 Van der Goot employed the generic name Chaitophorinella with testudinatus as type, and this name, therefore, will become a synonym of Periphyllus. GENERIC CLASSIFICATION OF APHIDIDAE. 35 Characters. Cornicles present, truncate in form, often sculptured. Antennae of six segments (with the exception of the dimorph) armed with oval sensoria and promi- nent hairs. Fore wings with the media twice branched; hind wings with both media and cubitus present. Cauda and anal' plate rounded. Forms living upon the foliage of trees. Sexes not strikingly different from the other forms, possessing beaks and feeding. Males winged, oviparous females with the ovaries normally developed, thus laying several eggs. Small lamellate or hairy dimorphic forms produced in summer. Type (monotypical), Periphyllus testudo Van der Hoeven (=testudinatus Thorn- ton). Genus NEOTHOMASIA, n. n. Plate IV, Y, Z. 1910. Thomasia Wilson, Can. Ent., v. 42, p. 386. Wilson erected the genus Thomasia with populicola Thos. as type, and his description appeared in December, 1910. The same name had, however, been used for a genus of Diptera, the description of which appeared in September, 1910. A new name, Neothomasia, therefore, is necessary for Wilson's genus. Characters. Cornicles present; antennae of six segments armed "with subcircular sensoria and prominent hairs. Fore wings with the media twice branched, hind wings with both media and cubitus present. Cauda and anal plate both rounded. Forms living in colonies upon the leaves or bark of trees; no dimorphic forms pro- duced; sexual forms not markedly different from the viviparous ones. Oviparous females laying several eggs. Type (monotypical), Chaitophorus populicola Thos. Genus SIPHA Pass. 1860. SipTia Passerini, Gil Afldl, p. 29. This genus and Atheroides are distinct from the other genera in the sub tribe by possessing five-segmented antennae instead of six- segmented ones. The genus has not been much confused excepting by Thomas's placing of rubifolii. For a time some workers in this country were led to conceive of the genus as indicated by that spe- cies which in reality belongs in the Aphidini. Characters. Cornicles present, truncate, short, almost mere rings. Antennae of five segments armed with large circular seneoria. Body form flat, entire insect cov- ered with rather long stout hairs. Fore wings with the media twice bran died, hind wings with both media and cubitus present. Cauda knobbed, anal plate rounded. Forms living upon the leaves of grasses usually in moist localities, sometimes even submerged, the water appearing to affect them little. Type (fixed by Passerini. 1SGO), Aphis glyccriae Kalt. Subtribe PTEROCOMMINA. The subtribe Pterocommina is composed, of bark-feeding insects, some of which retain quite primitive characters. It is the writer's opinion, however, that they are, as a group, more specialized than the Chaitophorina, but closely related. This is indicated by the development of the cornicles met with in the species. Like the 36 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Drepanosiphina, this development varies to a great extent in the different species. Only two genera occur in the tribe. They may be separated as follows : KEY TO THE GENERA OF THE PTEROCOMMINA. Cornicles cylindrical Pterocomma. Cornicles somewhat swollen Melanoxantherium. Genus PTEROCOMMA Buckton. Plate IV, P P. 1857. Cladobius Koch, Die Pflanzenlause Aphidcn, p. 251. 1860. ApUoides Passerini, Gli Audi, p. 28. 1879. Pterocomma Buckton, Monog. Br. Aphides, v. 2, p. 142. 1905. Aristaphis Kirkaldy, Can. Ent., v. 37, p. 416. In 1857 Koch erected the genus Cladobius with populeus Kalt. as type. This name, however, had been used previously. So Passerini in 1860 employed the name Aphioides. This name had also been used. Kirkaldy, therefore, gave the new name Aristaphis in 1905. In 1879, however, Buckton described the genus Pterocomma with a very similar species as type. Characters. Cornicles- present, rather short and cylindrical. Antennae of six segments armed with prominent hairs and sub circular sensoria. Fore wings with the media twice branched; hind winga with both media and cubitus present. Cauda and anal plate rounded. Type (monotypical), Pterocomma pilosa Buckt. Genus MELANOXANTHERIUM Schouteden. Plate IV, NN, OO. 1879. Jfelanoxanthus Buckton, Monog. Br. Aphides, v. 2, p. 21. 1901. Melanoxantherium Schouteden, Ann. Ent. Soc. Belg., v. 45, p. 113. In 1879 Buckton described the genus Melanoxanthus with solids L. as type, but, as this name was preoccupied, Schouteden suggested the name Melanoxantherium. Characters. Cornicles present, variable in size, but usually more or less swollen. Antennae of six segments armed thickly with hairs and possessing oval or sub circular sensoria. Fore wings with the media twice branched, hind wings with both media and cubitus present. Cauda and anal plate rounded. Forms living in colonies usually on the bark of trees, males usually winged. Ovi- parous females laying several eggs. Type (monotypical), Aphis salitis L. 1 Subtribe FULLAWAYINA. The sub tribe Fullawayina is related somewhat closely to the Chaitophorina from which it is a specialization, as is evidenced by the reduction and total lack of the cornicles. It is very suggestive of Monaphis, but evidently arose from quite a different line of develop- ment, following Chaitophorus rather than the Callipterus group. Only one genus is represented. 1 The writer is forced to change his view that Pterocomma pilosa is closely related to populifoliae Fitch. This was based on Pergande's published statement of his examination of the type. Later notes on the type indicated that it resembles populea. GENERIC CLASSIFICATION OF APHIDIDAE. 37 Genus FULLAWAYA Essig. 1912. Fullawaya Essig, Pomona C!oll. Journ. Ent., v. 4, p. 716. The genus Fullawaya seems to bear somewhat the same relation to Chaitophorus that Monaphis does to Myzocallis. Were it not for the hairy condition of the antennae and the character of the cauda and anal plate, Fullawaya might he placed as a synonym of Monaphis, hut it is evidently unrelated. Characters. Corniclea absent; antennae of six segments, armed with rather long bristle-like hairs, sensoria small and circular, cauda rounded and armed with long curved hairs. Fore wings with the media twice branched, hind winga with both media and cubitus present. Forms living upon the roots of plants. Type (monotypical), Fullawaya saliciradicis Essig. Tribe GREENIDEINI. The tribe Greenideini was first separated by Wilson under the name Trichosiphina. The insects falling here show a most remarkable development of the cornicles. These are sometimes as long as the entire body in the alate forms. In the apterous individuals they are usually swollen. In both they are very thickly covered with long hairs, a condition not met with in any of the other Aphidinae with long cornicles. It is true that some species of Macrosiphum and occa- sionally species of the other genera show here and there minute hairs on the cornicles, but they do not approach in any way members of this tribe in cornicle armature. The development of the cauda in this group is also remarkable. Characters. Cornicles present and remarkably developed into cylindrical or slightly swollen tubes often as long as the body and thickly covered with long hairs. Antennae of five or six segments armed with oval or subcircular sensoria. Males winged. Forms living free upon the foliage. KEY TO GEXESA OF GREKXIDEIXI. 1 . Antennae of five segments Eutrichosiphum. Antennae of six segments 2. 2. Fore wings with the media twice branched, hind wings with both media and cubitus present Greenidea. Fore winga with media once branched, hind wings with neither media nor cubitus present Greenideoida. Genus GREENIDEA Schouteden. riato V, F-K. 1905. Greenidea Schouteden, Spol. Zcylan, v. 2, p. 181. 1906. Trichosiphum 1'ergandc, Ent. News, v. 17, p. 206. In 1905, Schouteden erected a genus for the SipJionopTiora artocarpi of Westwood and redescribed the species, giving details lacking in Westwood's paper. Pergande erected his genus Trichosiphum, making his anonae the type. The characters Pergande used to sep- arate his genus were in reality those of Greenidea. 38 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Characters. Cornicles extremely long and hairy; antenna? of six segments armed \vith oval or subcircular senspria and distinct hairs. Fore wings with media twice branched; hind wings with both media and cubit us present. Sexes winged. Type (monotypical), Kiphonophora artocarpi Westw. Genus GREENLDEOIDA Van der Goot. Plate V, L-P. 1900. Greenidea Wilson, not Schoutcden, Ann. Ent. Soe. Amer., v. 3, p. 317. 1916. Greenideoida Van der Goot, Zur Kenntniss der Blattliiuse Java's, p. 140. In discussing the genera of the Trichosiphini in 1910, Wilson based his descriptions and key on specimens in the collection of the Bureau of Entomology. Material hi that collection determined as artocarpi by Pergande proves not to be that species for it does not agree with the descriptions given either by Westwood or Schouteden. 'Wilson, therefore, used the two generic terms Trichosiphum and Greenidea. In reality the species listed as artocarpi was undescribed at that time and the species of Trichosiphum presented all of the characters of Greenidea. Since that time Van der Goot has erected the genus Greenideoida for such species as that understood by Wilson to be artocarpi. Characters. Cornicles present, very long, subcylindrical, and armed with long hairs. Antennse of six segments armed with oval or eubcircular sensoria. Fore wings with the media once branched ; hind wings reduced in size and lacking both the media and cubitue. Cauda and anal plate rounded. Type (fixed by Van der Goot, 1916), Gremideaida elongata V. d. , p. SI. 1913. Ovalus Van dor Goot, Tijd. voor Ent.. v. 56, p. SI. 10H. ^^y^odcs Mordwilko, Faune Russ. Aphidoidea, p. 52. 191 1. AulacorHium Mordwilko, Faunc Russ. Aphidoidea, p. 5S. 1910. Neomyzus Van dcr Goot, Zur Kennt. der Blattliiuse Java's, p. 50. 1918. Myzopsis Matsumura, Trans. Sapporo Nat. I list. Poo., v. 7, pt. 1, p. 19. 58 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. The genus Myzus was erected with Aphis cerasi Fab. as type. In the same year Passerini used ApJiis persicae Sulz. as type of Rhopalosiphum Koch. Aphis nympJiaeaelj., however, had been set as the type of that genus in 1856. Persicae seems to be very closely related to cerasi and Rhopalosiphum (Koch) Pass., therefore, is placed as a synonym of Myzus. In 1913 Van der Goot placed certain other species hi Myzus and the type of the genus he made the type of his Myzoides. This will evidently then become a synonym, as it has the same type. In 1916 Van der Goot erected the genus Neomyzus with circum- Jlexum Buckt. as type. While the frontal tubercles of this species do not converge quite to the same extent as those of cerasi, they are quite similar and the cauda is somewhat conical as in that species. Neonrvzus, therefore, is believed to be a synonym. Mordwilko used the name Myzodes with tabaci Mord. as type. This species he does not fully describe, but gives a figure and describes the characters of the genus. From the information given it appears to be a synonym of Myzus. The writer also believes that the genus Ovatus V. d. Goot is a synonym of Myzus. This genus was erected with mespili V. d. Goot as type. The genus Aulacorthum Mord. was erected with pelargonii as type. A study of this species shows the antennal tubercles very similar to those of cerasi. The cornicles, too, are quite similar, although the cauda is a little more Aphis-like. The writer believes this genus is a synonym. Characters. Head with distinct antennal tubercles present which, particularly in the apterous form, project inward and are strongly gibbous. Antennae of six seg- ments, the first segment gibbous like the antennal tubercles. Wing venation normal. Cornicles rather long and subcylindrical. Cauda somewhat short and conical, con- stricted very slightly, if at all. Type (fixed by Passerini, 1860), Aphis cerasi Fab. Genus PHORODON Passerini. Plate VIII, N-Q. 1800. Pharodon Passerini, Gli Afidi, p. 27, Characters. Head in the alate form with distinct antennal tubercles which project somewhat inward, first antennal segment gibbous. In the apterous form the antennal tubercles possess very prominent projections which extend forward in front of the head. First antennal segment with a projecting process. Fore wings with media twice branched; hind wings with both media and cubitus present. Cornicles cylin- drical, in the apterous form somewhat curved; cauda rather acutely conical, not as long as the cornicles. Males as a rule winged and oviparous females apterous. Type (fixed by Passerini, 1860), Aphis humuli Schrk. Genus RHOPALOSEPHONINUS, n. gen. Plate IV, D-F. The genus Rhopalosiphoninus is erected for latysiphon Davidson, a species with very peculiar cornicles. It appears to be somewhat related to Amphorophora. GENERIC CLASSIFICATION OF APHIDIDAE. 59 Characters. Head with prominent antennal tubercles which project inward and are armed with prominent spines. Anteniue of six segments armed with subcircular Bensoria and in the first segment with spines similar to those of the antennal tubercles. Wing venation normal. Cornicles narrow and cylindrical at the base, then abruptly and prominently swollen, returning again abruptly to the normal size near the tip. Cauda rather short and conical. Type, Amphorophora latysiphon Davidson. Subtribe PENTALONINA. The subtribe Pentalonina is one of the Aphidini in which specialization in the whig venation has taken place in a peculiar manner. The radial sector has in one genus extended downward and coalesced with the upper branch of the media. In the genus Idiopterus the two have not become entirely fused, though in some specimens they have almost done so. In Pentalonia, however, the veins have become permanently united, and a very peculiar-looking venation is the result. A closed cell is formed by the radial sector when it meets the upper branch of the media, and when it leaves this again it gives a three-branched appearance to the upper branch of the media. The explanation of this peculiar venation is, however, easily understood by comparison with the venation of Idiopterus. In some of the genera the hind wings are greatly reduced, so that some- times only one vein remains, while in other genera this reduction has not taken place. Most of the wing veins are clouded with brownish borders. The insects feed usually upon ferns or tropical plants. KEY TO THE GENERA OF THE PENTALONINA. 1 . Hind wings much reduced in size, lacking at least the cubitus 2. Hind wings nearly normal in size and with both media and cubitus present. 3. 2. Radial sector of fore wing fused with the upper branch of the media, forming a closed cell Pentalonia. Radial sector of fore wings not so fused, but normal Microparsus. 3. Cornicles cylindrical Idiopterus. Cornicles somewhat swollen near their distal extremities 4. 4. Media of fore wings twice branched Fullawayella. Media of fore wings once branched Keotoxoptera. Genus FULLAWAYELLA Del Guerclo. 1011. Fullau-ayclla Del Oucrcio, Redia, v. 7, p. 462. 191t>. Micrnmyzus, Van dor Goot, Zur Kenntniss dor Blattlaiisc Java's, p. 53. This genus is very suggestive of Amphorophora in certain ways but no doubt is related here. Van der Goot's genus was erected with nigrum V. d. Goot as type but this species differs very little from Jcirkdldyi. . Characters. Antenna; on prominent, converging, imbricated antennal tubercles, of six segments and armed with subcircular sensoria. Fore wings with the media twice branched and with the radical sector deeply curved toward the upper branch of the 60 BULLETIN" 826, TJ. S. DEPARTMENT OF AGRICULTURE. media; hind wings with both media and cubitus present. Cornicles somewhat swollen near their distal extremities. Cauda elongate and constricted near the base. Type (mono typical), Macrosiphum Tcirkaldyi Fullaway. Genus IDIOPTERUS Davis. Plato VIII, EE-HH. 1900. Idiopterus Davis, Ann. Ent. Soc. Amer., v. 2, p. 193. Idiopterus, a less specialized genus than Pentalonia, is worthy of special note, as it gives a key to the peculiar venation of the latter genus. The coalescing of the radial sector and the media is here plainly visible and in some specimens a triangular closed cell is formed, although in most examples the two veins can be traced distinctly. Characters. Head with prominent antennal tubercles which project slightly in- wards, and are gibbous. Antennae of six segments, armed with subcircular sensoria, the first segment gibbous like the antennal tubercles. Corniclea subcylindric, rather slender, cauda somewhat elongate, conical. Fore wings with the radial sector extend- ing abruptly downward from the stigma and paralleling the upper branch of the media with which in some specimens it appears to be almost united ; hind wings with both media and cubitus present. Type (mono typical), Idiopterus nephrolepidis Davis. Genus MICROPARSUS Patch. Plate VIII, AA-DD. 1909. Microparsus Patch, Ent. News, v. 20, p. 337. Microparsus is at once distinguished from the other genera related to it by the peculiar venation and the reduction of the hind wing. Characters. Head with distinct antennal tubercles present. Antenna; of six seg- ments, armed with subcircular sensoria. Fore wings with the media once branched; hind wings much reduced in size and lacking both the media and cubitus. Cornicle's subcylindric. Cauda rather long and tapering, almost equal in length to the cornicles. Type (monotypical), Microparsus variabilis Patch. Genus NEOTOXOPTERA Theobald.i 1915. Ncotoxopicra Theobald, Bui. Ent. Res., v. 6, p. 131. This genus is closely related to Fullawayella, from which it can be separated by the venation. There has been some doubt whether or not this is a good genus, for the name will not hold if the type is found to correspond with Pergande's violae, which it resembles. In that case Neotoxoptera would become a synonym of Fullawayella, for Pergande's species is undoubtedly a Fullawayella. Characters. Head with prominent antennal tubercles. Antenme of six segments, armed with subcircular sensoria. Fore wings with the media once branched. Corni- cles swollen, elongate, somewhat conical. Type (monotypical), Neotoxoptera violae Theo. i After this paper v.-asin lype the writer (Bui. Ent. Res., v. 10, p. 45) showed that violae Theo. is a synonym of violae 1'erg. GENERIC CLASSIFICATION OF APHIDIDAE. 61 Genus PENTALONIA CoquereL Plato VIII, II-MM. 1859. Pentalonia Coquerel, Ann. Ent. Soc. France, Ser. 3, v. 7, p. 259. The genus Pentalonia Coquerel is a very peculiar one and possesses a venation unlike that of any other in the Aphididae. It is, however, only a little further development of the condition met with in Idiopterus, which is the less specialized of the two genera. Characters. Head with prominent antennal tubercles which are, more especially in the apterous form, projected inward, gibbous and somewhat Myzus-like in appear- ance. Antennae of six segments, armed with subcircular sensoria, the first segment gibbous like the antennal tubercles. Cornicles somewhat constricted near their middle, then again somewhat swollen near their distal extremity. Cauda rather small but elongate, subconical, slightly constricted about the middle. Fore wings with the radial sector extending abruptly downward and meeting the upper branch of the media with which it fuses but is diverted again toward its natural course near the tip of the wing. A closed cell is thus formed by the radial sector and the media but at the margin of the wing there are the same veins as in the Aphidini (Plate VIII, JJ.) Hind wings very much reduced, cubitus absent. Type (monotypical), Pentalonia nigronervosa Cql. Subfamily II, MINDARINAE. It has been the custom to consider the genus Mindarus as closely re- lated to the Pemphigini, but the writer is unable to do this and concludes that it must represent a subfamily in itself. In some ways abietinus is the most primitive living aphid. It is, in fact, the only one which has retained the general wing structure which is predominant in the fossil forms. It is true that the venation is more reduced than in some of the other subfamilies, but the type of wing in regard to the stigma formation is exactly like most fossil wings and unlike the wings of other living forms. Many of the characters suggest the Eriosomatinae and the genus is no doubt very similar to the ancestors of the insects in that subfamily. The antennal structure and general form are like those in the Eriosomatinae. The sexes, too, are apterous, but though they have developed the small apterous condition they are in many ways more primitive than are the sexes of the Eriosomatinae. The male is small and suggests the condition in those forms. The peculiar habit of copulation is similar, in that the male mounts the female and may remain there inactive for a very long period. The writer has observed a male of Eriosoma lanigerum clinging thus to a female for 48 hours. The sexes of Mindarus, however, have not lost the beak and the male feeds on the juices of its host. In this regard they are more primitive than sexes in the Eriosomatinae. The oviparous female, moreover, develops her ovaries and produces as high as 8 or 9 eggs, in striking contrast with the ovipara in the Eriosomatinae. It is a much less specialized condition. In regard to the alate form the shape of the cauda is quite different from that met with in the Eriosomatinae. 62 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. It seems to the writer that the Mindariiiae give a fair idea of the ancestors of the Eriosomatinae 'and may even represent a group dominant in earlier times from which the Eriosomatinae sprang. Only one genus is represented. Genus MINDARUS Koch. Plate IX, A-F. 1857. Koch, Die Pflanzenlause Aphidcn, p. 277. The peculiar genus Mindarus was erected by Koch with abietinus Koch as type. This species is the only one in the genus, although it has been redescribed as Schizoneura pinicola Thos. and Schizoneura oUiqua Choi. Characters. Cornicles present as mere rings. Large wax plates present. Alate forms with six-segmented antennae armed with oval sensoria. Fore wings with the media once branched; radial sector inserted mesad of the long narrow stigma, thus igiving a very long stigmal cell; bind wings with both media and cubitus present. Cauda rather long, not rounded, but somewhat conical or even spatulate. Sexes email and apterous, beaks present and feeding taking place. Oviparous female with the ovaries developed and laying as high as 9 eggs. Forms living free upon the twigs of conifers which become somewhat distorted by the feeding of the insects. Type (monotypical), Mindarus abietinus Koch. Subfamily HI, ERIOSOMATINAE. The subfamily Eriosomatinae is composed of insects which are perhaps as specialized as any of the Aphididae. They show a re- markable development of the habit of gall formation and in this respect parallel the Hormaphidinae. The insects of that subfamily, however, evidently have developed the habit independently. Many previous authors have placed all of these forms in the present sub- family. This, the writer believes, is incorrect, as shown by the biol- ogies of the insects. The sexual forms give a true understanding of the relationships and of the genera which should be included in the Eriosomatinae. All of the forms included by the writer show evi- dence of a common origin in that the sexes have become degenerate. They have become small apterous forms and have lost the mouth parts and the ability to take food. That this was not their original condition is clearly shown by the history of the family and also by the fact that the sexual forms of some species have a beak when born, but lose this at the first molting. Other species even at the time of birth are devoid of all but a rudimentary trophictubercle. The reproductive system of the female has become greatly altered. As previously pointed out by the writer, the early development of the reproductive system of the sexual female corresponds exactly to that in the apterous forms and to that of the oviparous forms of the more primitive groups. Young embryos * * * show that the ovaries are at first similar to those of the parthenogenetic form. There may be distinguished the four chambers on each side containing egg cells and nutritive cells. In later embryos most of the egg tubes arc in GENERIC CLASSIFICATION OF APHIDIDAE. 63 the process of degeneration and only two ovaries, one on each side, develop. Of these one finally degenerates and the egg of the other grows until it fills almost the entire body and the insect appears to be little else than egg. 1 It will be seen at a glance that such a method of egg development is entirely different from that met with in members of the genera which have been heretofore placed in the subfamily. The Hormaphidini and the Thelaxini, as will be seen under the discussion of those tribes, have sexual females which develop normal ovaries and lay several eggs in the same way as do the Aphidini, Lachnini, and other groups. It is true that some have developed gall formation and highly special- ized, wax-secreting organs, but this is more of a parallelism than a close relationship, as is indicated by the sexual forms. The wax- secreting organs of the Eriosomatinae vary considerably in structure. A study of those in the genus Eriosoma has been presented by the writer (1915). The glands here are compound, each cell containing a central wax chamber into which the wax is secreted and from which it is forced out as a fine waxen thread. In other genera the wax glands take on the nature of plates, illustrated in the genus Prociphilus. These glands are essentially the same in general struc- ture as are those in Eriosoma, but the wax cells are placed very close together and are so extremely elongate that their openings to the surface are very small. A large number of these gives the appearance of a more or less uniform plate. The structure, however, in the two genera follows the same lines. The wing venation in this subfamily presents as great a reduction as in any of the subfamilies of the Aphididae and in this respect it is comparable to the Hormaphidinae. In the fore wings the reduction is shown in the media which is never branched more than once. Dr. Patch has pointed out the homologies of the veins and has indicated that in all of these cases the branches represent M 1+2 and M 3+4 . In some cases, however, it would appear as if they were M t and M 4 . In other genera the media is indicated as a single vein. The radial sector is in nearly every case present and the cubitus and first anal are prominent veins. The tracheae are figured for the subfamily under the genus Eriosoma. In the hind wings the radial sector is always present and two oblique veins are nearly always found. These are the media and the cubitus. In several genera, however, the cubitus has disappeared and only the media remains as the one transverse vein in the hind wings. The cornicles in the genera of this subfamily are not prominently developed. Indeed, they are absent altogether in certain of the tribes. In the genus Eriosoma they are chitinized rings slightly elevated on shallow hairy cones. The opening of the cornicles is closed by a muscle and from the cornicle a narrow duct leads to a 1 Baker, A. C. The woolly apple aphi.s. I'. S. Dcpt. Agr., OH. of Sec., Kept. 101, p. 43. 1915. 64 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. large wax reservoir. The structure of the cornicles themselves in this subfamily is essentially the same in all genera where they are present. In a large number of genera, however, the wax reservoir is absent and in some specialized tribes the cornicles are likewise absent. It is interesting to note that in some genera, though absent in the stem mother, they are present in the alate forms. The habit of gall formation is not found equally in all genera and it would seem that those forms which have become associated with ants have not developed this habit to the same extent as have some of the other groups. However, it must be borne in mind that our knowledge concerning the species associated with ants is very incom- plete, and the writer is convinced that many of the Prociphilini will be found during their summer generations in this relation. Many of the forms cause true galls which are the result of outgrowths of the plant and which completely enclose the insects. Sometimes the stem mother lives in a gall by herself while in other cases the following generations live with her. The original spring gall is usually the result of the activities of the young stem mother. Certain species do not produce true galls but form pseudogalls which are due to the rolling or crumpling of the leaves on which the insects feed. Other species, again, especially during their summer generations, feed 011 the twigs or roots of plants and give rise to excrescences by their feeding.. It often happens that species which in their spring forms are gall makers, attack plants in this way in their summer generations. Others live on the roots of grasses during these generations and do not cause the excrescences produced by those species feeding on trees and woody shrubs. The association with ants is highly developed by one tribe of this subfamily, although all of the other tribes are to a degree tended by these insects. The species of the Fordini live exclusively in the nests of ants or are tended by them, and they are cared for very carefully in return for the honeydew excreted. Ants also attend species which have aerial feeding habits and they may be seen carrying the root generations of species of Eriosoma from one place to another and even distributing them about on the trees. Indeed the writer once took advantage of the presence of ants to infest some apple seed- lings. A vial of apterous insects was emptied at the base of each tree and the ants soon could be seen running about carrying the aphids to suitable positions on the trees. Sometimes, however, they carried them away. GENERIC CLASSIFICATION OF APHIDIDAE. 65 KEY TO THE TRIBES OF THE ERIOSOMATINAE. 1. Cornicles present, at least in the alate forms; however, often mere rings 4. Cornicles absent 2. 2. Forms living in true galls or in pseudogalls on plants 3. Forms living in the nests of ants or at least subterranean, feeding on the roots of plants; wax-secreting areas present; antennae of alate forms rather short and thick with somewhat oval sensoria FORDINI. 3. Forms living in true galls and without wax plates prominently developed on the head and thorax of alate form; wax-secreting areas present but not prominently developed. Alate forms leaving the galls in the late summer or fall. Antennae with annular sensoria MELAPHINI. Forms living in pseudogalls, occasionally in true galls. Antennae of alate form rather long and slender, with narrow or somewhat oval or rounded sensoria . Wax plates well developed and present on the head and thorax of the alate forms which leave the galls in the spring PROCIPHILINI. 4. Forms living in galls, pseudogalls, or free upon their host; -wax glands prom- inently developed; antennae of alate forms armed with annular sensoria which almost completely encircle the segments ERIOSOMATINI. Forms living usually in true galls; wax glands present but not strongly de- veloped; antennae of alate forms armed with narrow, transverse sensoria, somewhat oval or irregular ones, or occasionally without sensoria. .PEJIPHIGINI. Tribe ERIOSOMATINI. The tribe Eriosomatini is composed of insects which have more or less developed the habit of gall formation, which are possessed of wax glands, and the antennae of the alate forms of which are armed usually with annular sensoria. Their typical host group is that of the elms. Characters. Forms living in galls, pseudogalls, or free upon the twigs or roots of their host on which they form excrescences. Prominent wax glands present. Cor- nicles distinct; antennaeof alate forms armed with annular sensoria which often almost completely encircle the segments. Sexual forms small, apterous, beakless; oviparous females developing a solitary egg. KEY TO THE GENERA OF THE ERIOSOMATIVI. 1 . Media of the fore wings of alate form once branched 3. Media of the alate form simple 2. 2. Hind wings with both media and cubitus present Gobaishia. Hind wings with only the media present Tctraneura. 1 3. Hind wings with both media and cubitus present Eriosoma. Hind wings with only the media present 4. 1. Stem mother with four-segmented antennae; antennre of alate form rather short and thick Colopha. Stein mother with five-segmented antenna 1 ; antennae of alate form long and slender Georgia. i There is considerable evidence for separating a tribe Tctraneurini to include the genera Colopha, Tetraneura, and Gobaishia. 141G1.S 20 Bull. 82G 5 66 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Genus COLOPHA Monell. Plate IX, G-L. 1877. Cotopha Monell, Can. Ent., v. fi, p. 102. The genus Colopha was erected for ulmicola Fitch. One of the principal characters whereby it may be separated from Tetraneura is the once-branched character of the media. The two genera, how- ever, are very closely related. The species have the same peculiar structure and the same mode of life. Characters. Cornicles slightly elevated rings. Stem mother with four-segmented antennse. Apterous form with five-segmented or sometimes six-segmented antennse. Wax glands present. Alate form with six-segmented antennae which are armed with annular sensoria partly encircling the segments. Fore wings with the media once branched, hind wings with only the media present. Forms making galls upon the leaves of trees in which the stem mother and her offspring live in company; in summer migrating to the roots of plants. Type (monotypical), Byrsocrypta ulmicola Fitch. Genus ERIOSOMA Leach. Plate IX, M-T. 1818. Eriosoma Leach, Trans. Hort. Soc. London, v. 3, p. 60. 1831. Myzoxylus Blot, Mem. Soc. Roy. Agr. et de Com. Caen., v. 3, p. 332. 1837. Schizoneura Hartig, Jahresb. il. d. Fortschr. d. Forstwiss. und forstl. Naturk., v. 1, p. 645. 1848. Mimaphidus Rondani, Nuovi Annali della Seienze Natural!, ser. 2, v. 9, p. 35. In 1818 Leach erected his genus hi a footnote in connection with a paper read by Mosley. The paper was published in 1818. In 1819 Samouelle published his "Useful Compendium" and on page 232 characterized the genus Eriosoma Leach MSS. The printed copy of the Transactions appeared complete in 1820. In 1824 Blot used the word Myzoxyle which he corrected to Myzoxylus in 1831. For these Aphis lanigera Hausm. was used as type. In 1837 Hartig erected Schizoneura and of this genus ulmi was made type by Passerini in 1860. This then will become a synonym. Corni Fab. was for a time considered the type of this genus but this species was not in the original genus. In 1848 Rondani used Mima- phidus with ulmi Fab. as type, which according to Passerini is the same as lanuginosa Hartig. Therefore, this genus will become a synonym. Characters. Cornicles distinct rings on somewhat elevated tubercles. Apterous form with six-segmented antennae. Stem mother with five-segmented antennas. Wax plates present in the apterous and alate vivipara. Alate form with six-seg- mented antennae armed with annular sensoria. Fore wings with the media once branched, hind wings with both media and cubitus present; cauda and anal plate rounded. Forms living in gall-like formations or causing excrescences on their hosts. Sexual forms small, apterous, beakless. Only one egg of those of the oviparous female develops. Type (monotypical), Aphis lanigera Hausmann. GENERIC CLASSIFICATION OF APHIDIDAE. 67 Genus GEORGIA Wilson. Plate IX, U-Z. 1911. Georgia Wilson, Can. Ent., v. 43, p. 64. The genus Georgia appears to be related to Colopha Mon., and yet many of the characters are so like those of Eriosoma that the insect suggests that genus also. Especially to the species E. americanum Riley there is a striking resemblance. Prominent wax glands are lacking but these are sometimes also lacking in the spring forms of Eriosoma. Characters. Cornicles present and situated on shallow hairy cones as are those of Eriosoma. Stem mother with five-segmented antennae ; alate form with six-segmented antennye which are armed with narrow sensoria that do not encircle the segment to any extent. Fore wings with the media once branched, hind wings with only one oblique vein. Cauda rounded. Prominent wax pores such as those present in Eriosoma lacking, but small wax areas present. Forms living in pseudogalls on plants, the alate individuals migrating from the galls in the early spring. Type (monotypical), Georgia ulmi Wlsn. Genus GOBAISHIA Matsumura. Tlate X, A-G; XI, V. 1909. Byrsocrypta Tullgren, Arkiv for Zoologi, Bd. 5, no. 14, p. 182. 1917. Gobaishia Matsumura, Synopsis of the I'emphigidae of Japan, Gifu, Japan, p. 75. Tullgren used the name Byrsocrypta Hal. as the name of a sub- genus with paUida as type, placing it under Tetraneura. He appar- ently overlooked the fact that Westwood had set bursarius as the type of the genus Byrsocrypta as will be found discussed under the genus Pemphigus. Pallida is different from the species of Tetraneura, in that the cubitus is retained in the hind wing. If Colopha is retained on account of the branched nature of the media in the fore wings it will be necessary to place pallida as typical of a genus related to Tetraneura. In 1917 Matsumura erected the genus Gobaishia with Gobaishia japonica Mats, as type. This species was stated to be very similar to Tetraneura alba Ratz. Tetraneura alba Ratz is the same species as Eriosoma paUida Haliday and the characters given for the genus are, therefore, similar to Tullgren's conception of Byrsocrypta. The figures drawn are from specimens of paUida as no japonica was avail- able to the writer for study. Characters. Cornicles present, stem mother with four-segmented antenna?, alate forms with six-segmented antennae which are armed with annular sensoria. Fore wings with the media usually simple; hind wings with both cubitus and media present. Typ e (fixed by Matsumura, 1917), Gobaishia japonica Mats. 68 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Genus TETRANEURA Hartlg. Plate X, H-M. 1841. Tetraneun Hartig, Germar's Zeitschrift fur die Entomologie, v. 3, p. 366. In 1841 Hartig erected the genus Tetraneura under which he gave Tetraneura ulmi Lin. ? questioned thus and described. He also listed T. rugicornis Hartig. One of these species was questioned and the other merely listed. Ulmi L., however, was questioned only in the sense of the determination, and a good description was given so that it is known what insect Hartig had. In 1843 Kaltenbach gave a description of the genus Tetraneura crediting it to Hartig and described thereunder one species, Aphis ulmi De Geer. ApJiis ulmi De Geer (1773) is the same species as Aphis ulmi Geoffrey (1764) but this name can not be used, since Linnaeus used Aphis ulmi for a different insect. This is the same insect de- scribed by Hartig as T. ulmi L. ? and it is evident that it requires a new name, to which ulmifoliae is given. Characters. Cornicles very slightly elevated rings, not at all prominent. Stem mother with four-segmented antennae; apterous form with five-segmented antennae. Wax glands present. Alate form with six-segmented antennae which are armed with narrow annular sensoria almost completely encircling the segment. Fore wings with the media simple; hind wings with only the media present. Forms living in galls and migrating in spring to other plants. Sexes small, apterous and beakless. Oviparous female developing only one egg. Type, Tetraneura ulmifolix Baker (Aphis ulmi L. of ITartig). Tribe PEMPHIGINI. The tribe Pemphigini is composed of forms which are highly spe- cialized and most of which have developed the habit of true gall formation. The secretion of wax also occurs but wax secreting plates are not developed to the extent met with in some of the other tribes of the subfamily. Alternation of hosts is found to occur, migrants leaving the galls in early spring or summer and returning in autumn. In some species, however, the insects do not leave the galls until the mothers of the sexual forms -are produced. Distinct cornicles are present and by this character forms in some of the other tribes which are suggestive of the Pemphigini may be distinguished. The typical host group is Populus and the galls are normally spring galls. Characters. Forms usually inhabiting true galls and often migrating to other plants during the summer. Antennae of six segments in the alate form and in nearly all genera armed with linear, oval, or somewhat irregularly shaped sensoria. Small wax- secreting areas present. Sexual forms small, apterous, and 'beakless, the oviparous female developing only one egg. Six genera may be included in the tribe and these genera may be separated by the following key : GENERIC CLASSIFICATION OF APHIDIDAE. 69 KEY TO THE GENERA OF THE PEMPHIGINI. 1. Unguis of segment VI of alate form distinctly long and Aphis-like. .Mordwilkoja. Unguis short and knob-like 2. 2. Media once branched 3. Media simple 4. 3. Antennae of alate form usually without secondary sensoria. Winga flat in repose Phloeomyzw. Antennae of alate form with secondary sensoria. Wings not flat in repose Pachypappella . 4. Both media and cubitus present in hind wing 5. One oblique vein only in hind wing Dryopeia. 5. Antennae of alate form without secondary sensoria. Wings flat in repose Rhizoctonus. Antennae of alate form with secondary sensoria. Wings not flat in repose. . . G. 6. Antennae of alate form rather short and thick. Stem mother with four-seg- mented antennae Pemphigus. Antennae of alate form rather long and slender. Stem mother with five-seg- mented antennae Cornaphis. Genus CORNAPHIS Gillette. Plate X, N-T. 1913. Cornaphis C.illette, Ann. Ent. Soc. Am., v. 6, p. 491. The genus Cornaphis was erected by Gillette for his species Corna- pJiis populi. In his description it is stated that the genus is closely related to Asiphum. In Cornaphis, however, there are large corni- cles in the alate form, and in other respects it seems that the genus is closely related to Pachypappella. In that genus, however, the media is once forked, whereas in Cornaphis it appears to be simple, at least as a rule. This difference has led the writer to retain a genus with lactea as type rather than to place that species and similar ones in Cornaphis. Characters. Cornicles present; stem mother with five-segmented antenna? and without wax plates. Alate form with six-segmented antennae armed with rather narrow sensoria; permanent sensoria ciliate. Fore wings with the media simple, hind wings with both media and cubitus present; wax plates present in the apterous form; sexes small, apterous and beakless; the oviparous female developing only one egg. Forms living in galls, the stem mother and the following forms living in the same gall. Type (monotypical), Cornaphis populi Gill. Genus DRYOPEIA Kirkaldy. Plate X, U-Y. 1857. Endeis Koch, Die Pflanzcnliiusc Aphidon, p. 312. 1889. Eudcis Ashmead, Ent. Amcr., v. 5, p. 189. 1901. Dryopeia Kirkaldy, The Entomologist, v. 37, p. 279. 1917. Watabura Matsumura, Synopsis of the Pemphigidae of Japan, p. 89. In 1857 Koch erected his genus Endeis with two species, ~bdla Koch and rorea Koch. This name was replaced by Dryopeia in 1904 by Kirkaldy, and bella has been definitely placed as the type. 70 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. In some respects the genus is suggestive of Anoecia, although it seems to be undoubtedly a Pemphiginid and will no doubt be so proven by the sexual forms. In 1917 Matsumura erected his genus Watabura with Watabura nisJiiyae Mats, as type. This species was stated to resemble a Pem- phigus, excepting that the antennal segments are somewhat different and only one oblique vein is in the hind wing. (Two obliques are shown in his PI. XII, 9). The antennae are armed with narrow trans- verse sensoria and there seems little doubt that this genus is a syno- nym of Dryopeia. It is noteworthy that the life history of the type species is not known, but it is thought to live on the roots of trees. The type of the genus Dryopeia is a root feeder. Characters. Cornicles present, situated on broad shallow cones, suggestive of those of Anoecia. Stem mother unknown, apterous forms with six-segmented antennae. Alate forms with six-segmented antennae, armed with narrow transverse sensoria. Fore wings with media simple, hind wings with one oblique vein. Summer forms subterranean, living on the roots of plants. Spring forms and sexes unknown. Apter- ous tarsi one-segmented. Type (fixed by Kirkaldy, 1906), Endeis bella Koch. Genus MORDWILKOJA Del Guercfo. Plate XI, A-G. 1909. Afordwilkoja Del Guercio, Rivista Patol. Veget., v. 4, p. 11. This genus was erected in 1909 for the peculiar species Byrsocrypta vagabunda Walsh. This differs in the antennae quite remarkably from all of the other species belonging to this tribe. The difference is in the long unguis of the sixth segment. However, the other char- acters and the four-segmented nature of the antennae of the stem mother seem to place it with little doubt in the Pemphigini. There has been some doubt cast by Oestlund on the determination of Walsh's species and this has led Cockerell to propose the name oesflundi for the species now known so well, but, as Gillette has pointed out, Walsh evidently accepted the insect of Riley and Monell as the same species as his vagabunda. The insects Riley had were undoubtedly the species we know and the writer therefore accepts vagabunda and the generic name Mordwilkoja. The genus was erected with the name vagabunda used as type and not oestlundi. Characters. Cornicles present as somewhat elevated rings. Stem mother with four- segmented antennae, the unguis of segment VI slender and Aphis-like. Permanent sensoria ciliate. Alate form with five-segmented antennae which are armed with narrow transverse sensoria. Fore wings with the media simple, hind wings with both media and cubitus present. Forms living in galls; the stem mother and her offspring living in the same gall, the alate forms leaving the galls in spring or early summer. Sexes unknown, but no doubt small, apterous, and beakless. Type (monotypical), Byrsocrypta vagabunda Walsh. GENERIC CLASSIFICATION OF APHIDIDAE. 71 Genus PACHYPAPPELLA, n. n. Plate XI, H-M. 1909. Pachypappa Tullgren, Arkiv for Zoologi, Bd. 5, no. 14, p. 69. In 1854 the genus Pachypappa was erected by Koch, with marsu- pialis and vesicalis in the genus. A study of marsupialis shows that this species is in reality a Pemphigus as it shows all the characters of this genus. Tullgren, 1909, noted this and therefore interpreted the genus differently. Marsupialis had, however, been set as the type of the genus. Pachypappa Koch, therefore, becomes a syno- nym of Pemphigus, and Pachypappa Tullgren must receive a new name for which Pachypappella is here given. Cfiaracters. Stem mother without cornicles but -with wax plates; antennae five- segmented. Alate form with cornicles; antennae six-segmented and with transverse sensoria. Fore wings with media once branched, hind wings with both media and cubitua present. Type (present designation), Pachypappa lactea Tullgren. Genus PEMPHIGUS Harttg. Plate XI, N-U. 1837. Pemphigus Hartig, Jahresb. u. d. Fortschr. d. Forstwiss. und forstl. Naturk., v. 1, p. 645. 1839. Byrsocrypta Haliday, Ann. Nat. Hist., v. 2, p. 190. 1840. Brysocrypta Westwood, Int. Mod. Class. Ins., Synopsis, v. 2, p. 118. 1847. Aphioides Rondani, Nuovi Annali Sci. Nat. Bologna (2), v. 8, p. 439. 1857. A myda Koch, Die Pflanz. Aphiden, p. 301. 1857. Pachypappa Koch, Die Pflanz. Aphiden, p. 263. 1857. Rhizomaria Hartig, Verhandl. d. Hils-Solling-Forstvereins, Jahrg. 1856, p. 52. 1859. Tychea Koch, Die Pflanzenlatise Aphiden, p. 296. 1885. Kessleria Lichtenstein, Mon. Puceron du PeupL, p. 16. 1904. Hamadryaphis Kirkaldy, The Entomologist, v. 37, p. 279. In 1837 Hartig erected his genus Pemphigus, although it was not until 1841 that his reference to the genus as generally cited appeared. Passerini in 1860 set bursarius as type. In 1839 Haliday used the generic term Byrsocrypta but mentioned no species. In 1840 West- wood referred to this genus as Brysocrypta and gave bursaria L. as type. In 1859 Koch erected the genus Tychea with graminis Koch as type (mono typical). Schouteden (1906) has described the winged form of Tychea graminis Koch and stated that it is a typical Byrsocrypta. The writer has had no opportunity to study specimens but on the strength of this statement of Schouteden places Tychea as a synonym of Pemphigus. It is worthy of note, however, that Schouteden did not mention the cornicles, and this is a point of considerable difference if graminis is a Pemphigus or if it belongs to the Fordini. In 1857 Hartig described the- genus Rhizomaria with piceae Hartig as type. This species, however, appears to be a typical Pemphigus and Rhizomaria will become ~a synonym. In 1857 Koch erected the genus Amycla and of this genus fuscifrons Koch has boon made the type. The writer has been unable to obtain specimens of this species but from the descriptions it seems almost 72 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. certain that this species is a true Pemphigus. This will thus make the genus Amycla a synonym. In 1847 Rondani described the genus Aphioides of which bursaria Fab. was indicated as the type and Aphioides, therefore, is a synonym. In 1854 Koch erected the genus Pachypappa of which marsupialis Koch has been made the type. Marsupialis, however, is a typical Pemphigus. Pachypappa Koch, therefore, must become a synonym. Tullgren (1909) used Pachypappa in a different sense, v but this is discussed under the genus Pachypappella. In 1886 Lichtenstein erected the genus Kessleria for spiroihica and this name was replaced by Hamadryaphis Kirk, in 1904. A study of this species, however, shows that it is a typical Pemphigus. Therefore, these two names will become synonyms. Characters. Cornicles present; wax plates, if present, weakly developed; stem- mother with four-segmented antennae ; alate form with six-segmented antennae which are armed with narrow, oval or somewhat irregular sensoria. Fore wings with the media simple; hind wings with both media and cubitus present Sexes small, apter- ous, and beakless. Oviparous female developing only one egg. Forms living in galls, the stem-mother and her offspring in the same gall, the alate forms typically leaving the galls in the spring. Type (fixed by Passerini, 1860), Aphis bursaria L. Genus PHLOEOMYZUS Horvath. Plate XI, W-BB. 1886. Lowia Lichtenstein, Mon. Puceron Peupl., p. 37. 1896. Phloeomyzus Ilorvath, Wien. Ent. Zeit., v. 15, p. 5. In 1886 Lichtenstein erected the genus Lowia with Schizoneura passerinii Sig. as type but as this name had been used previously it was replaced in 1896 by Phloeomyzus Horvath. It is with some hesitation that the writer places this genus in the Pemphigini, In some respects it suggests the Melaphini, while in many respects it strongly suggests the Thelaxini or even the Phyllaphidina. Indeed, to the Melaphini it shows striking resemblances. Without a study of the sexual forms it will be very difficult to place the genus definitely. All that can be done at the present time is to place it tentatively with the forms with which it appears to be related, and if further study shows this to be incorrect the genus can be placed definitely with its allies. Characters. Cornicles present, very slightly elevated. Apterous form with six- segmented antennse. Alate form with six-segmented antennae which are rather slender and without secondary sensoria. Fore wings with the media once branched, hind wings with both media and cubitus present. Large wax plates present on the abdomen. Wings held flat in repose. Forms living free upon the bark of trees in colonies. Type (monotypical), Schizoneura passerinii Sig. Study based on specimens received from Mordwilko from Warsaw, Poland, and notes by Pergande on type specimens loaned by Horvath. GENERIC CLASSIFICATION OF APHIDIDAE. 73 Genus RHIZOCTONUS Mokrzecky. 1895. Rhizoctonus Mokrzecky, Horae. Soc. Ent. Ross., v. 30, p. 438. The genus Rhizoctonus was erected for ampelinus Mok., a species occurring on the vine. Through the kindness of H. F. Wilson the writer has been able to examine a slide containing alate forms. These, however, are in a very poor condition and it is impossible to determine whether or not cornicles are present. The antennae too are much distorted. This slide seems to indicate, however, that ampelinus is somewhat related to passeriniiSig., an hypothesis which is strengthened by the fact that both species hold the wings flat in repose. The genus, therefore, is placed here with some hesitation. Characters. Antennae of six segments, without secondary sensoria and rather thick. Fore wings with the media simple. Hind wings with both media and cubitus present. Wings held flat in repose. Cauda and anal plate rounded. Type ("monotypical), Rhizoctonus ampelinus Mok. Tribe MELAPHINI. The tribe Melaphini is suggestive both of the Pemphigini and of the Eriosomatini. It is, however, quite distinct from both. The habits more nearly resemble those of the Pemphigini. The tribe is placed here but a study of the sexes may show that it really belongs to the Hormaphidinae. The typical host group is Rhus, and the galls are typically fall galls. Characters. Gall-inhabiting forms. Cornicles absent; antennae of the alate form of five or six segments armed with somewhat oval or linear transverse sensoria. Sexual forms not known. The genera may be separated as follows: KEY TO THE GENERA OF THE MELAPHINI. 1 . Both media and cubitus present in the hind wings 2. Only the media present in the hind wings Aploneura. 2. Stigma of four wings pointed on distal portion and extending some distance Melaphis. Stigma stopping abruptly on distal extremity 3. ?>. Antennae of five segments Nurudea. Antenme of six segments Pemphigella. Genus APLONEURA. Plato XII, A-E. 1S03. A plonciiri Paswrini, Aphididac Italicao, p. 78. Ii9. Tttrcncma Dcrbes, Ann. des Sc. Nat. Zool. (.">), v. 11, p. 106. 181S. Baizongia Rondani, Nuovi Annali dcllo Sdenze Natural!, v. 9, p. 35. The genus is distinguished quite easily from related one's by the venation of the hind wings, the relation of the cubitus and anal of the fore wings, and by the structure of the antennae The positive determi- nation of the insect of Fabricius may cause Aploneura to fall for Rondani's name. 74 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Characters. Cornicles absent. Stem-mother with five-segmented antennae; alate form with the media simple, thecubitusand anal joined near their bases. Hind wings with only the media present, antennae of six segments, armed with large subcircular or elongate sensoria. Forms living in true galls. Type (monotypical), Tetraneura lentici Pass. Genus MEL APHIS Walsh. Plate XII, F-K. 1866. Melaphis Walsh, Proc. Ent. Soc. Phlla., v. 6, p. 281. 1883. Schlechtendalia Liehtenstein, Stett. Ent. Zeit., v. 44, p. 240. 1905. Abamalekia Del Guercio, Rodia, v. 3, p. 364. Walsh erected his genus for rhois Fitch, a species forming galls on sumach and in his discussion mentioned the Chinese gall, wonder- ing if it could be congeneric. The writer has recently published an account of the Chinese gall 1 and therein placed Schlechtendalia Licht. as a synonym of Melaphis. Del Guercio's genus was erected with his lazarewi as type and placed as a thelaxine. Although the writer has never obtained specimens of this species he is of the opinion that it can not possibly be one of these insects and that it evidently belongs in the Melaphini where the shape of the stigma would imme- diately place it as a Melaphis. Characters. Cornicles absent. Apterous form with five-segmented antennae. Alate form with either five or six segmented antennee which are armed with some- what linear or oval sensoria. Fore wings with the media simple, although sometimes slightly forked, distal extremity of the stigma rather long drawn out; hind wings with both media and cubitus present; abdomen with distinct wax plates. Forms living in galls from which the alate forms escape in late summer or fall. Type (monotypical), Byrsoerypta rhois Fitch. Genus NURUDEA Matsumura. Plate XII, L-Q. 1917. Wurudea Matsumura, Synopsis of the Pemphigidae of Japan, p. 65. 1917. Nurudeopsis Matsumura, Synopsis of the Pemphigidae of Japan, p. 67. 1917. Fushia Matsumura, Synopsis of the Pemphigidae of Japan, p. 70. Matsumura erected his genus Nurudea for his Nurudea Hbqfushi, a species somewhat similar to a species of Melaphis. This species differs quite markedly, however, in the form of the stigma. At the same time he erected the genus Nurudeopsis with N. sliiraii as type. This species differs little from ibofusTii excepting in the proportions of the segments, and in the fact that the cubitus and first anal are some- what closer togetner at the base. The writer is of the opinion that these characters are not sufficient on which to form another genus. In the same work also he erected the genus Fushia with Fushia rosea Mats, as type. This species differs somewhat from the type of Nuru- dea but the writer believes that there are not differences sufficient to cause this to be considered as a separate genus. The antennae i Baker, A. C. On the Chinese gall (Aphididae Horn.). In Ent. News, v. 28. p. 385-393, 1917. GEISTERIC CLASSIFICATION OF APHIDIDAE. 75 are more slender and of somewhat different proportions and the cubitus and anal of the fore wings are united somewhat at base. In other genera, however, this difference between species is to be found, and it seems wisest not to adopt it in this group as of generic im- portance. Characters. Cornicles absent. Antennae of five segments armed with linear or somewhat oval sensoiia. Fore wings with the media simple, the stigma normal; hind wings with both media and cubitus present. Sexes unknown. Forms making galls upon the leaves of plants. Type (fixed by Matsumura, 1917), Nurudea ibofushi Mats. Genus PEMPHIGELLA Tullgren. 1909. Pemphigclla Tullgren, Arkiv for Zool., v. 5, p. 171. 191S. Dasia Van der Goot, Mem. Ind. Mus., v. 6, p. 152. Characters. Cornicles absent. Antennae of six segments armed with oval scnsoria. Hind wings with both media and cubitus present. Sexes unknown. Species form- ing galls on plants. Type (monotypical), Tetrancura cornicularia Pass. Tribe PROCIPHILINI. The tribe Prociphilim contains forms which specialized in some direc- tions more than did the Eriosomatini. In other ways, however, they appear to be more primitive than certain genera of that tribe. The cornicles have here disappeared altogether and largo wax areas have replaced them. In their habits of gall formation, however, the Eriosomatini are more advanced than are members of the present tribe. Characters. Forms living in crumpled or twisted leaves or in a somewhat complete gall caused by the rolling up of the leaves of the host. Wax plates present; cornicles absent; antennae of stem mother of five segments; those of the alate form six segmented and armed with narrow, transverse, or somewhat broadly oval scnsoria. KEY TO THE GENERA OP THE PROCIPHILINI. ] . Media once forked, stem mother usually without wax plates Asiphum. Media simple, stem mother with several rows of wax plates 2. L'. Wax plates large, those on the thorax well developed, stem mother and offspring living together 3. Wax plates not well developed, stem mother usually in a gall by herself . .Thecabius. ?,. Hensoria narrow, linear, ciliate Prociphilus. Hensoria somewhat oval, nonciliate Neoprociphilus. Genus ASIPHUM Koch. Plate XII, K-X. 1857. Asiphum Koch, Die Pflanzenlause Aphidon, p. 246. 1859. Type fixation, Gerstaecker, Bcricht for 1857, p. 249. 1903. Type fixation, Kirkaldy, Can. Ent ., v. 37, p. 418. The genus Asiphum was erected by Koch with two species, populi Fab. and ligustrinellura Koch. lie listed De Geer's work in the literature under populi Fab. The populi of Fabricius proves to be the tremulae of De Gecr. Only the species ligustrinettwn was placed 76 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. in the genus by Liechtenstein (1885) and this species has been indicated as type of the genus by Kirkaldy (1905). Tremulae De Geer is a well- known species but the writer has been unable to obtain ligustrineUum and, in fact, has been unable to learn anything definite in regard to the species. The following conception of the genus, therefore, is based upon tremulae De Geer in view of the fact that ligustrineUum appears to be unknown, and since Aphis populi Fab. was indicated by Gerstaecker in 1859. Characters. Cornicles absent; wax plates present in the alate forms; stem mother with five-segmented antennae. AJate form with six-segmented antennae which are armed with rather narrow transverse sensoria. Fore wings with the media once forked, hind wings with both media and cubitus present. Forms living in the somewhat crumpled leaves of their host. Type (fixed by Gerstaecker, 1859), Aphis populi Fab~ Genus NEOPROCIPHILUS Patch. Plate Xin, A-F. 1912. NeoprocipWus Patch, Bui. Me. Agr. Expt. Sta., no. 202, p. 174. The genus Neoprociphilus Patch is very close indeed to Prociphilus r the characters which separate it being the somewhat more oval or rounded sensoria and the fact that the sensoria are not ciliate. How- ever, in some of the species of ProcipJiilus, particularly in the fall forms, somewhat oval sensoria are met with. It is retained doubt- fully. Characters. Stem mother with five-segmented antennae. Cornicles absent, large wax plates similar to those of Prociphilus present. Alate form with six-segmented antennte which are armed with oval or subcircular nonciliate sensoria. Fore wings with the media simple, hind wings with both media and cubitus present. Sexes small, apterous, and beakless. Oviparous female developing only one egg. Forms living free upon their host, the stem mother and following generations in company. Type (monotypical), Pemphigus uttenuatus O. S. Genus PROCIPHILUS Koch. Plate XIII, G-X. 1857. Prociplrilus Koch, Die Pflanzcnlause, p. 279. 1857. Stagonia Koch, Die Pflanzenlause, p. 284. 1875. Holzneria Liechtenstein, Bui. Soc. Ent. Fr. (5) v. 5, p. LXXVI. 1917. Nishiyana Hatsumura, Synopsis of the Pi-mphigidac of Japan, p. 90. In 1857 Koch erected his genus Prociphilus with three species: lumeliae Schrank, erraticus Koch, and gnaphalii Kalt. Later in the work (p. 284) he used xylostei De Geer as the type of the genus Stagonia. This species, xylostei, is in all respects similar to bumeliae and therefore Stagonia becomes a synonym of Prociphilus. In 1875 Lichtenstein erected the genus Holzneria with poschingeri Holzner as type. Poschingeri has been considered by many authors as the alternate form, of bumcliae. In such case Holzneria must necessarily GENERIC CLASSIFICATION OF APHIDIDAE. 77 be a synonym of Prociphilus. Should poschingeri, however, be proven to be a distinct species it is so similar in all regards that Holzneria must remain a synonym. In 1917 Matsumura erected the genus Nishiyana with N. aomori- ensis Mats, as type, placing it close to Prociphilus. From this genus he separated it because of the absence of wax plates in the thorax and the somewhat shorter antennae. It must be borne in mind, however, that the specimens he had were fall migrants. Fall mi- grants of several species of Prociphilus show very reduced wax plates, and in some these are absent altogether, although distinct in the spring migrants. It is believed that this genus is in reality Proci- philus. Characters. Cornicles aosent, wax plates present, very large and well developed. Stem mother with five-segmented antennas. Alate form with six-segmented antennae armed with narrow transverse sensoria; secondary sensoria fringed. Fore wings with the media simple, hind wings with both media and cubitus present. Sexes small, apterous, and beakless. Oviparous females developing only one egg. Forms living in pseudogalls, the stem mother and her offspring together. Type (fixed by Gerstaecker, 1859), Aphis bumeliae Schr. Genus THECABIUS Koch. Plato XIII, O-U. 1857. Thecabius Koch, Die rflanzcnliiuse, p. 294. 1886. Bucktonia. Lichtenstein, Mortogr. d. puccrons, p. 16. The genus Thecabius was erected by Koch in 1857 for his species populneus. This species proves to be a synonym of Pemphigus affinis Kalt. In 1886 . Lichtenstein erected the genus Bucktonia with o$wis Kalt. as type. Bucktonia, therefore, becomes a synonym. Characters. Cornicles absent; wax plates present but not prominently developed as in Prociphilus. Stem mother with five-segmented antenna? and rather narrow sensoria, secondary sensoria not fringed; fore wings with media simple, hind wings with both media and cubitus present. Sexual forms small, apterous, and beakless, oviparous female developing only one egg. Forms living in galls, the stem mother usually living in a gall by herself. Type (mpnotypical), Thecabius populneus 'Koch (=Pemphigus affinis Kalt.) This genus is closely, related to Prociphilus and it is with some hesitation that the writer places it as distinct. Certain species, such as patchii Gillette, which are undoubtedly congeneric with qffinis, do not show the typical life habit of the stem mother living in a gall alone. However, the character of the sensoria and the undeveloped nature of the wax glands may serve to distinguish the genus. Tribe FORDINI. Members of the Fordini are specialized subterranean forms mostly living in the nests of ants. The aphids excrete honeydew, in return for which they are tended carefully by these insects. The apterous 78 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. forms generally are of a yellowish or brownish-yellow color, some- times a milk white. Wax-secreting plates are present but they are not developed to the same extent as are those of the Prociphilini. The cornicles are lost entirely and the region where these usually occur is occupied by wax plates. In some species the wax areas are reduced. Some species are armed with fine hairs, whereas others are almost entirely smooth. The eyes in the apterous forms are composed of three facets. The alate forms have rather short, thick antennae with somewhat oval sensoria. Three genera compose the tribe and these may be separated as follows: KEY TO THE GENERA OF THE FORDINI. 1. Antennse of the alate form composed of five segments Forda. Antennae of the alate form composed of six segments 2. 2. Sensoria of the antennae of the alate form small and scattered over moat of the segment, a central triangular wax plate on the thorax; apterous form with six-segmented antennas .Paracletua. Sensoria of the antennae of the alate form larger and more evenly placed; the sensoria sometimes extending evenly across the segment. Apterous form with five-segmented antennae, sometimes with six segments present Geoica. Genus FORDA Heyden Plate XIII, V-AA. 1837. Forda Heyden, Mus. Sinkbg., v. 2, p. 291. 1841. Rhizoterus Hartig. Zeit. Ent., v. 3, p. 363. 1849. Smynthurodes Westwood, Gardener's Chron., p. 420. 1896. Pentaphis Horvath, Wien. Ent. Zeit., v. 15, p. 2. 1909. Pentaphis Del Guercio, Rivist. Patol. Vegetale, n. s., v. 3, p. 332. 1914. Rectiwsus Theobald, The Entomologist, v. 47, p. 28. In 1837 Heyden erected his genus Forda, the type of which is formicaria Heyden. In 1896 Horvath erected his genus Pentaphis with marginata Koch as a type, while Del Guercio in 1909 used trivialis Pass, as the type of a genus of the same name. Specimens of marginata Koch from Horvath prove that this species in every respect is similar to the type of the genus. Pentaphis, therefore, will become a synonym of Forda. Likewise specimens of trivialis show that this species belongs in the same genus. In 1841 Hartig erected the genus Rhizoterus, the type of which is vacca. According to Lichtenstein this species is a synonym of formicaria Heyden, and Rhizoterus also, then, becomes a synonym. In 1914 Theobald erected his genus Rectmasus with his buxtoni as type. He based his genus on the proportions of the antennal segments, their length, and the length of the beak. The writei is opposed to basing genera on the proportions of the antennal segments, far in species in which these are of different proportions a very close relationship is evident. This is also true of the beak. Many Ameri- can species .taken in ants' nests and as yet undescribed have beaks ranging from small to longer than the body, but they are all evidently GENERIC CLASSIFICATION OF APHIDIDAE. 79 closely related. The other characters mentioned by Theobald are seen to be present in the type species. The tubercles he figures and describas are the same and the spines on the first and second antennal segments are evidently the thickened, pointed, chitinized articula- tions of the segments common in insects of this type. We believe, 1 therefore, that Rectinasus should be carried as a synonym of Forda. Westwood's genus was erected on his betae which appears to belong here as recently indicated by the writer. Characters. Cornicles wanting; apterous forms with five-segmented antennae and eyes of three facets. Alate form with five-segmented antennae and medium-sized oval, or more or less irregularly shaped sensoria. Fore wings with media simple; hind wings with both media and cubitus present, arising slightly apart. Subterranean forms living usually in the nests of ants and tended by them. Type (monotypical), Forda formicaria Heyden. Gnua GEOICA Hart. Plate XIV, A-K. 1894. Qeoica Hart, 18th Kept. State Ent. 111., p. 101. I860. Tychea Passerini, Gli Afldi, p. 30. 1906. Tychcoides Schouteden, Mem. Soc. Ent. Belg., v. 12, p. 194. 1906. Kaltenbachiclla Schouteden, Mem. Soc. Ent. Belg., v. 12, p. 194. 1909. Trifidaphis Del Guercio, Rivista Patol. Vegetale, n. s., v. 3, p. 332. 1912. Tullgrenia V. d. Goot, Tijdschr. voor Ent., v. 15, p. 96. 1913. Trinacriclla Del Guercio, Redia, v. 9, p. 169. 1916. Serrataphis V. d. Goot, Zur Kenntniss der Blattlause Java's, p. 263. In 1860 Passerini used the generic name Tychea of Koch and placed as the typical species pJiaseoli Pass. In 1863 he used the name again, listing several species but not the species included by Koch. Therefore his interpretation of the genus can not be correct. In 1894 Hart erected his genus Geoica with squamosa as type. In 1906 Schouteden noticed Passerini 's mistake and suggested the name Tycheoides but made cragrostidis Pass, the type. In the same year he erected Kaltenbachiella with mentliae Schout. as type. In the year 1909 Del Guercio erected Trifidaphis with radicicola Essig as type. In 1912 Van der Goot noted Passerini's mistake and proposed the name Tullgrenia for the Tychea of Passerini. In 1916 Van der Goot erected the genus Serrataphis with lucifuga Zehntner as type. In studying cotypes and other specimens of squamosa certain generic characters are evident. The species is subterranean. It has five-segmented antennoe in the apterous form and six-segmented ones in the alate. It is true, however, that the apterous form sometimes has only four segments in the antennas and the alate five. Indeed, in some alate forms there is a five-segmented antenna on one side and a six-segmented one on the other. One of these five- segmented antennae was figured by Hart. One wing vein only was figured in the hind wing by Hart, but a very close examination shows that both the media and cubitus, though faint, are present. These are very difficult to trace in balsam mounts. In giving his name 80 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Tycheoides Schouteden makes plain that he is naming the Tychea of Passerini and yet he sets a different type. He further states: <'Le genre Tychea est vraisemblablement destine" a desparaitre, ses especes appartenant en re'alite' a Tetraneura ou Byrsocrypta." He evidently is speaking here of the Tychea of Koch, since specimens of Tychea, Pass, do not possess the cornicles of either of the two genera mentioned. In describing Kaltenbachiella Schouteden gives as a character the four-segmented antennae, etc., of the apterous form. The alate form he did not know, but from his description of the pupa it evi- dently would possess six-segmented antennae. There seems little doubt that this is another such case as squamosa where the apterous form has often four-segmented antennas, although five is the normal number, the alate form normally having six. Hart's description has led Schouteden astray and he places Geoica close to Forda, separating it therefrom by the venation of the hind wing. Consider- ing all of these facts there seems little doubt that Kaltenbachiella should be placed as a synonym of Geoica. Specimens of pTiaseoli show very similar characters in every respect. It is true that the antennas are somewhat longer and the hairs simple, but in every respect of importance the insects agree. The apterous form has five-segmented antennae and the alate form has six-segmented ones with the sensoria very similar in nature. The cauda also is very similar. It is evident then that Tychea Pass, and Tullgrenia V. d. Goot become synonyms of Geoica Hart. Specimens of lucifuga Zehntner show a remarkable resemblance to squamosa with the exception, of course, of the squamae. The apterous form has five-segmented and the alate form six-segmented antennae. In general form and structure of the caudal extremity the insects are the same arid, therefore, Serrataphis V. d. Goot will become a syno- nym of Geoica. There remains, then, to discuss the genus Trifidaphis Del Guercio. The co types of the type. species show a close resem- blance to the general type of squamosa. The apterous forms have five-segmented antennae and in the alate form, as in squamosa, some forms have five segments and some forms have six. The general resemblance in other respects seems to prove that Trifidaphis is a synonym of Geoica. It should be pointed out that the sexes described by Hart are in all probability not sexual forms, but immature specimens. In 1913 Del Guercio erected the genus Trinacriella for his new species magnified. He gave a brief description stating that the apterous forms had five-segmented antennae and the alate forms six. No specimens of this species are available to the writer, but there seems little doubt that Trinacriella will become a synonym of Geoica. GENERIC CLASSIFICATION OF APHIDIDAE. 81 Characters. Cornicles Aranting; apterous form usually with five-segmented antennae and eyes of three facets. With the intermediate forms more facets may occur. Alate form with usually six-segmented antennae and rather large oval sensoria with distinct rims. Fore wings with media simple. Hind wings with both media and cubitus present, though these may be faint and almost obscured in balsam. Cauda large and somewhat rectangular or rounded. Subterranean forms living on the roots of plants. Sexes small, apterous, and beakless. Type (monotypical), Geoica squamosa Hart. Genus PARACLETUS Heyden. Plate XIV, L-S. 1S37. Paradetus Heyden, Mus. Sinkbg., v. 2, p. 295. The genus Paracletus is closely related to Forda Heyden from which it may be distinguished by the number of antennal segments in both alate and apterous forms. As with other genera of this tribe the eyes of the apterous form consist of three facets. Intermediate forms often occur, however, in which the intermediate nature is indicated only by the eyes which have the beginnings of compound eyes, such as are found in the alate form. There never are, however, complete compound eyes. The genus was erected by Heyden in 1837. The species live in close association with ants. Characters. Cornicles absent. Apterous form with six-segmented antennae and eyes of three facets; alate form with six-segmented antennae which possess many rather small, oval sensoria. Fore wings with media simple, hind wings with both media and cubitus present, arising some distance apart. Thorax with a central wax plate. Forms living in the nest of ants and cared for by them. Sexes small, apterous, and beakless. In some cases only one claw is met with on the foot, while in other cases the normal number of two is present. This appears to be no definite character, as sometimes a claw is dropped from one foot and sometimes from another. Type (monotypical), Paracletus cimiciformis Heyden. Subfamily IV, HORMAPHIDINAE. The genera placed in this subfamily have usually been placed with the Eriosomatinae, or Pemphiginae, as it has been sometimes called. Mordwilko, however, placed these forms as his third tribe under the subfamily Aphidinae next to his tribe Callipterea. Something can be said in favor of both of these placings. In the first instance, the species in general form, antennal structure, and habit of gall formation are no doubt suggestive of the Eriosomatinae. On the other hand, their structure in regard to cauda and anal plate is very like the Callipterina and the sexual forms appear to have a development of their own, although they are nearer in many ways to the Aphidinae than to the Eriosomatinae. It is the author's belief that these forms should constitute a sepa- rate subfamily. It has developed the habit of gall formation and the sensory characters which usually accompany it, while at the same time it has retained in the sexual female the normal develop- 141613 20 Bull. 826 6 82 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. ment of the ovaries found in the more primitive groups, and has retained in both sexual forms the beak and the ability to feed. This at once suggests a different line of development from that taken by the Eriosomatinae, although in some of its habits the Hormaphidinae agrees with that subfamily. In other lines, however, marked differences are met with here and one of the most striking of these is development of aleyrodiform generations, which remain stationary upon the host. Such a development is never met with in the Eriosomatinae, although the sexual forms are much more specialized. Since many of the genera of the Hormaphidinae are gall formers, sensoria very similar to those met with in the Eriosomatinae are met with here also. Indeed the same annular sensoria found in the Eriosomatini are even more pronounced in the Hormaphidinae and the sensoria on the wing bases are prominent and often, numerous. The cornicles in the present subfamily are sometimes absent or, as is usually the case, reduced to mere rings. In some genera, how- ever, they may be elevated slightly on broad shallow cones, somewhat suggestive of those of Anoecia. No prominent cornicles, however', occur. In the wing venation there is often a considerable reduction and this shows also the specialized nature of the insects. The venation is comparable to that met with in the Eriosomatinae. In the fore wings the media is either simple or once branched, the radial sector, cubitus, and anal are present, but the cubitus and anal are often fused near their bases. In the hind wings both the media and cubitus are sometimes present, but often only the media remains. Great specialization in wax-producing organs occurs. In many of the forms these agree with the ones found in the Pemphigini. In certain aleyrodiform generations and in some sexual forms agglomerate glands or rather groups of small glands are seen. These may be arranged in different ways and often are placed about the margin of the insect so that it possesses a distinct lateral fringe, ; very like that of an aleyrodid. In fact some of these insects on this account are very often mistaken for aleyrodids. The sexual forms are often quite small and possess large wax- producing areas. Others may lack these. All, however, develop to normal adults. The habit of gall formation is very marked here. Indeed, some species form, galls on two different species of plants, migrating L between the two. Characters. Aerial forms living in galls or sometimes free upon the host. The ! mesothorax in many forms altered so that its divisions are more or less unobservable, the entire mesothorax often showing as only one plate. Scalelike or aleyrodiform GENERIC CLASSIFICATION OF APHIDIDAE. 83 generations often developed. Cornicles often reduced to mere ringlike openings or entirely absent. Sexual forms small and apterous but with fully developed beaks. Oviparous female laying several eggs. KEY TO THE TRIBES OF THE HORMAPHIDINAE, 1. Aleyrodiform generations developed 2. Aleyrodiform generations not developed OREGMINI. 2. Cornicles absent; insects usually gall formers HORMAPHIDINI. Cornicles usually present; insects usually not gall formers CERATAPHIDINI. Tribe HORMAPHIDINI. Members of this tribe are distinguished easily from those of other tribes in that the cornicles are absent and aleyrodiform generations are developed. These remain more or less quiescent upon the foliage. Some different forms of the species are often gall pro- ducers. All secrete wax from special pores. Considerable variation is met with in the development of the aleyrodiform generations. Sensoria of the alate forms are usually narrow and annular. Only two genera are so far recorded. KEY TO THE GENERA OF THE HORMAPHIDINI. Antennae of the alate forms composed of three segments, hind wings with only the media present '. Hormaphis. Antennae of the alate forms composed of five segments, hind wings with both media and cubitus present Hamamelistes. Genus HAMAMELISTES Shimer. Plate XIV, T-X. 1867. Hamamelistes Shimer, Trans. Am. Ent. Soc., v. 1, p. 284. 1896. Tetraphis Horvath, Wicn. Ent. Zeit., v. 15, p. 6. Shimer included two species in this genus, spinosus Shimer and cornu Shimer. The latter species, as suspected by him, is a syno- nym of hamamelidis Fitch. This species has been made the type of Hormaphis. Characters. Cornicles absent. Stem mother with four-segmented antennae. Aley- rodiform generations developed. Alate form with five-segmented antennae which are armed with numerous annular sensoria. Wings held flat in repose; fore wings with the media simple; hind wings with both media and cubitus usually present; cauda knobbed, anal plate bilobed; wax -secreting areas abundantly present in the apterous forms. Sexes small and apterous but with beaks developed, oviparous female laying several eggs. Forms living in galls upon the leaves or scale-like on the leaves or twigs. Type (one unquestioned species), Hamamelistes spinosus Shimer. 84 BULLETIN 826, U. 3. DEPARTMENT OF AGRICULTURE. Genus HORMAPHIS Ostcn-Sacken. Plate XIV, Y-FF. 1861. Hormaphis Osten-Sacken, Stcttiner Ent. Zeit., p. 422. The genus Hormaphis was erected by Osten Sacken for a species he described as hamamelidis. This species it later proved was the same described by Fitch as Byrsocrypta hamamelidis. The genus later was made to include spinosus Shimer, but the distinction between this genus and the one described by Shimer has been pointed out by Pergande. 1 Characters. Cornicles absent; aleyrodiform generations developed; wax glands very numerous; stem mother with three-segmented antennae; alate forms with three- segmented antennae which are armed with distinct annular sensoria. Wings held flat in repose; fore wings with the media simple; hind wings with the cubitus absent. Sexiial forms small and apterous, possessing beaks, oviparous female laying several eggs. Type (monotypical), Hormaphis hamamelidis O. S. (Byrsocrypta hamamelidis Fitch). Tribe OREGMINI. Characters. Forms living in galls or otherwise upon the leaves of plants, possess- ing cornicles and wax secreting glands. Antennae of the winged forms usually armed with annular sensoria; cauda rounded or somewhat knobbed, anal plate somewhat bilobed. No aleyrodiform generations developed. The sexual forms appear to be unknown. KEY TO THE GENERA OF THE OREGMINI. 1. Vertex with two horn-like projections 2. Vertex without such horn-like projections 3. 2. Antennae five-segmented Oregma. Antennae four-segmented Ceratoglyphina. 3. Antennae of apterous form with five segments 4. Antennae of apterous form with four segments Glyphinaphis. 4. Media of fore wings once branched Astegopteryx. Media of fore wings simple Mansakia. Genus ASTEGOPTERYX Karsch. Plate XV, Q-X. 1890. Asteyoptcryx Karsch, Bcr. deutsch Botan. Ges., v. 8, p. 52. 1906. Nipponaphis Pcrgande, Ent. News, v. 17, p. 205. 1916. ScldzoneurapJiis Van der Goot, Zur Kenntniss dcr Rlattlause Java's, p. 245. The genus Astegopteryx was erected with styracophila Karsch as type. Another species, nekoashi, was described by Sasaki before the International Congress at Brussels in 1911 and a third species, styraci, was described by Matsumura in 1917. It is possible, there- fore, to gain a fair conception of the characters. In 1906 Pergande erected his genus Nipponaphis with distychii Perg. as type. This species was stated to be from Distychium racemosum in Japan, on 1 Pergandc, T. The life history of two species of plant lice inhabiting both the witch-hazel and birch. U. S. Dept. Agr. Bur. Ent. Tech. Ser. no. 9. 1901. GENERIC CLASSIFICATION OF" APHIDIDAE. 85 which it forms galls. In 1916 Van der Goot erected nis Schizoneura- phis with gaTlorum V. d. Goot as type. This species was said to form galls on Distylium steUare. The genus Astegopteryx can be separated as far as the recognized forms ure concerned by the proportion of the antennal segments and some variation in the shape of the stigma. These differences are not, however, of large importance and Nipponaphis should be a synonym of Astegopteryx. In the same way, the type of Van der Goot's genus is not sufficiently different to warrant the erection of a new genus and Schizoneuraphis also should be considered a synonym. Characters. Cornicles broad rings; apterous form with five-segmented antennae; alate form with five-segmented antennae which are armed with annular sensoria. fore wings with the media once branched; hind wings with both media and cubitua present. Stigmal vein arising rather far back on the stigma. Cauda rounded, anal plate somewhat bilobed; forms living in galls. Sexual forms unknown. Type (mono typical), Astegopteryx styracophila Karsch. Genus CERATOGLYPHINA Van der Geot. Tlate XV, M-P. 1916. Ceratoglyphina Van der Goot, Zur Kenntniss der Blattlause Java's, p. 237. Characters. Cornicles present as mere pores. Vertex with two hornlike projec- tions. Antennae of four segments; cauda and anal plate both rounded. Winged orms unknown . Type (fixed by V. d. Goot, 1916), Ceratoglyphina bambusaeV. d. Goot Genus GLYPHINAPHIS Van der Goot. Plate XV, H-K. 1916. Glyphinaphis Van der Goot, Zur Kenntniss der Blattlause Java's, p. 232. Characters. Cornicles present as mere pores; antennae of four segments which are armed with linear sensoria. Fore wings with the media once branched; hind wings with both media and cubitus present; cauda knobbed; anal plate rounded; body covered with stout hairs. Type (fixed by V. d. Goot, 1916), Glyphinaphis bambusae V. d. Goot. Genus MANSAKIA Matsumura. Plate XV, L. 1017. ^fantiakia Mutsumura, Synopsis of the Pemphigidae of Japan, p. 59. The author of the genus Mansakia stated that it is closely allied to Hormaphis, but it would appear to the writer to be related to the genera in the Oregmini as understood in the present classification. The presence of the cornicles would indicate that the genus is not related as closely to Hormaphis as to Astegopteryx, but its host and the nature of the gall would place it close to Hamamelistes. Since all of the forms are not known it is impossible to state positively its position. 86 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Characters. Cornicles present as mere rings. Antennae of five segments armed with annular sensoria. Fore wings with the media simple, hind wings with two oblique veins. Cauda rounded, anal plate somewhat bilobed. Sexes not known. Forms causing galls upon plants, the galls usually armed with numerous long pro- jections. Type (fixed by Matsumura, 1917), Mansalda miyabei Mats. Genus OREGMA Buckton. Plate XV, A-G. 1893. Oregma Buckton, Ind. Mas. Notes, v. 3, p. 87. 1897. Ceratovacuna Zehntner, Mededl. Proefs. Java, n. s., no. 37, p. 29. In 1893 Buckton established his genus Oregma with 'bambusae Buckton as type, while in 1897 Zehntner established his Ceratovacuna with lanigera Zehntner as type. Specimens of both of these species sent by Zehntner and specimens of bambusae from Green taken in Ceylon show that these genera must be considered the same. Characters. Both alate and apterous forms with two hornlike projections on the vertex, wax gland areas present; antennae five-segmented, those of the alate form with narrow annular sensoria; cauda rounded or somewhat knobbed; fore' wings with media twice forked, hind wings with both media and cubitus present; cornicles broad, slightly elevated rings. Type (monotypical), Oregma bambusae Buckt. Tribe CERATAPHIDINI. This tribe is closely related to the Hormaphidini but differs in that very distinct cornicles are here present. The apterous forms are scalelike and quiescent and feed upon the surfaces of the leaves. The alate forms possess annular sensoria. Wax secretion is abundant. The genera may be separated as follows: KEY TO THE GENEEA OF THE CEKATAPHJDINI. Antennae of the aleyrodiform generations of five segments Aleurodaphis. Antennae of the aleyrodiform generations of four segments Cerataphis. Antennae of aleyrodiform generations of three segments Thoracaphis. Genus ALETTRODAPHIS Van der Goot. Plate XVI, A-E. 1916. Aleurodaphis Van der Goot, Zur Kenntniss der Blattlause Java's, p. 239. This genus was erected for one species occurring in Java. Characters. Form flat, aleyrodiform, three distinct -divisions evident; cornicles present as mere rings. Margin with wax secreting glands; dorsum also with many small glands. Cauda rather elongate and knobbed, anal plate bilobed. Antennae five-segmented; eyes of the apterous forms with three facets. Type (fixed by Van der Goot, 1916), Aleurodaphis blumeae V. d. Goot. GENERIC CLASSIFICATION OF APHIDIDAE. 87 Genus CERATAPHIS Lichtenstein. Plate XVI, F-M. 1862. Boisduvalia Signoret, Ann. Ent. Soc. France (4), v. 8, p. 400. 1882. CeratapJiis Lichtenstein, Bui. Ent. Soc. France (6), v. 2, p. xvi. Signoret erected his genus Boisduvalia in connection with his aleyrodid monograph. He placed Coccus lataniae Bois. as type. Later, however, he considered this a coccid genus. The name was used in the Diptera in 1830, and is therefore not available. The name Cerataphis used by Lichtenstein in 1882 appears as the next name applied to the genus. Characters. Cornicles present as mere rings. Apterous form with four-segmented antennae and aleyrodiform, with two divisions to the body; wax glands prominent; vertex with two hornlike projections; alate form with five-segmented antennae, the segments armed with narrow annular sensoria. Fore wings with the media once branched, hind wings with both media and cubitus present. Cauda knobbed; anal plate bilobed. Type (monotypical), Coccus lataniae Bois. Genus THORACAPHIS Van der Goot Plate XVI, N-W. 1916. Tharacaphis Van der Goot, Zur Kenntniss der Blattlause Java's, p. 242. Only the apterous form of one species of this genus has been described. Other species, however, are available for study, through the generosity of Professor Van der Goot. Characters. Cornicles present and quite distinct, occasionally absent, however, in the apterous form. Apterous form with three-segmented antennae, flat and with a posterior lobe. Alate form with five-segmented antennae armed with annular sen- soria. Fore wings with the media once branched; hind wings with both media and cubitus present. Cauda somewhat knobbed, anal plate bilobed. Type (monotypical), Thoracaphis arboris V. d. Goot. 88 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. GENERA NOT PLACED. A number of genera have been described which the writer has been unable to place. These genera are discussed in the following notes. Genus RHIZOBIUS Burmeister. 1S35. Rhizobius Burmeister, Handbuch der Entomologic, p. 78. 1819. Rhizophlhiridum Van der Hoeven, Handb. Dierkunde v. 1, p. 508. 1830. Rhyzoicus Passerini, Gli Afldi, p. 30. 1863. Rizolrius Passerini, Aphididae Italicae, p. 79. 1919. Rhizoicus Del Guercio, Redia, v. 12, p. 251. The genus Rhizobius has generally been considered as a good aphid genus and writers have referred to species in this genus as having but one claw to the tarsus. However, as indicated under Paracletus the writer believes this is a variable character and we have no definite knowledge in regard to piloseUae Burm. Buckton's species of course was not in the original genus and therefore can not be used as type nor was it in Passerini's conception of Rhyzoicus. After placing Rhyzoicus Pass, with jujubae Buckton as type, Del Guercio erects the genus Neorhizobius, distinguished by having two claws, and in which he places graminis Thos., poae Del Guercio, stramineus Del Guercio, and ulmipTiilus Del Guercio. In 1860 Passerini set soncTii Pass, as the type of Rhizobius Burm., and in a footnote suggested the name Rhyzoicus as a new name for Rhizobius, since this name had previously been used in the Coleoptera. Such procedure, however, is not allowable since sonchi Pass, was not in the original genus. Of the two species in the original genus pilosettae Burm. has been accepted as type. Del Guercio in 1917 used the generic name Rhizoicus Pass., spelling it with an "i" instead of a "y", and jujubae Buckton as the type. In the writer's opinion the genus Rhizobius must remain unknown until the type species pilosellae becomes known and carefully studied. The name Rhizophthiridum was given to this genus to replace Rhizobius Burm. Genus NEORHIZOBIUS Del Guercio. 1917. Neorhizobius Del Guercio, Redia, v. 12, p. 251. As indicated under the discussion of Rhizobius, four species are placed in this genus by Del Guercio. Three species are described as new and only in the apterous forms. Two of these forms have five-segmented antennae and one of them four-segmented ones, and when the alate forms are found they will in all probability be shown to represent species either of Forda or Geoica. The basing of genera upon the relative lengths of the antennal segments would create a very large number of genera and separate related forms. The genus Neorhizobius, therefore, the GENERIC CLASSIFICATION OF APHIDIDAE. 89 writer considers composed of apterous forms, which really belong in older and well-recognized genera, but which can not be definitely placed until the alate forms have been secured and studied. Genus SCHOUTEDENIA Riibsaamen. 1905. Schautedcnia Riibsaamen, Marcellia, v. 4, p. 19. This genus, which was described for ralumensis Rub., is here listed as unknown. The gall formed by the species is described but the writer, never having been able to obtain either gall or insect, would be able only to guess at its position from the description. Genus CLAVIGERUS Szfepligeti. Clavigerus Szdpligeti, Kovar&szati Lapok, v. 1, p. 4. This genus was described in the only volume issued of the Journal cited. The writer has been unable to secure a copy or any details of the description given. ADDENDA. The following generic names have been employed by Mordwilko (Fauna Russ. vol. 1, Aphidodea) without, apparently, the mention of any species in connection therewith. They have not been con- sidered in the foregoing paper: Anameson, Aorison, Chaetosiphon, Corylobium, Elatobium, Euaulax, Eurythaphis, Halmodaphis, Impatientinum, Jaxart aphis, Nasonovia, Orobion, Paczoskia, Sitobium, Staticobium, Tlja, Turanaphis, Uroleucon (subgenus), Uromelan. The subgenera Dactynotus Raf., Cladoxus Raf., and Adactynus Raf., have not been considered. INDEX TO GENERA. Abamalekia Del Guercio Abura Matsumura Acanthaphis Matsumura... Acanthocallis Matsumura. . . Acaudus Van der Goot Acyrthosiphon Mordwilko . Akkaia Takahashi Aleurodaphis Van der Goot. Amphorophora Buckton Amycla Koch Anoecia Koch Anomalaphis Baker Anuraphis Del Guercio Page. 74 43 54 29 41 56 53 86 54 71 13 52 42 Aphioides Passerini 36 Aphis Linnaeus 43 Apholdes llondani 71 Aploneura Passerini 73 Arakawana Matsumura 34 Arctaphis AValker ." 33 Arimakla Matsumura 43 Arlstaphis Kirkaldy 36 Asiphum Koch 75 Asiphonaphis Wilson & Davis 44 Aspidaphis Gillette 44 Astegopteryx Karsch 84 Atarsos G illette 44 Atheroides Ilaliday 33 Aulacorthum Mordwilko 57 Baizongia Rondanl 73 Boisduvalla Signoret 87 Brachycaudus Van der Goot 42 Brachycolus Buckton 45 Brachysiphum Van der Goot 45 Brachyunguis Das 49 Bradyaphis Mordwilko 32 Brevicoryne Van der Goot 45 Brysocrypta Westwood 71 Bucktonia Lichtenstein 77 Byrsocrypta Haliday 71 Byrsocrypta Tullgren 67 Calaphis Walsh 26 Callaphis Walker 27 Callipterinella Van der Goot 26 Callipteroidcs Mordwilko 28 Callipteroides Van der Goot 28 Callipterus Koch 27 Callipterus Van der G oot 29 Capitophorus Van der Goot 55 Carolinaia Wilson 45 Cavariella Del Guercio 46 Cerataphis I/ichtenstein 87 Ceratoglyphina Van der Goot 85 Ceratovacuna Zehntner 86 Cerosipha Del Guercio 4ii Cervaphis Van der Goot 53 Ceylonia Buekton 51 Chaitophorinella Van dt> r Goot 34 Page. Chaitophorus Koch 33 Chelymorpha Clark 34 Chromaphis Walker 27 Cinaria Curtis 15 Cladobius Koch 36 Clavigerus Sze'pligeti 89 Colopha Monell 60 Coloradoa Wilson 49 Cornaphis Gillette 69 Corynosiphon Mordwilko 46 Cryptosiphum Buckton 46 Dasia Van der Goot 75 Davisla Del Guercio 17 Dentatus Van der Goot 42 Dielcysmura Mordwilko 56 Dilachnus Baker 16 Drepanaphis Del Guercio 31 Drepaniella Del Guercio 57 Drepanosiphum Koch 32 Dryaphis Del Guercio 18 Dryobius Koch 18 Dryopeia Kirkaldy 09 Eichochaitophorus Essig 33 Endeis Koch C9 Eriosoma Leach 6G Essigella Del Guercio 14 Eucallipterus Schouteden 28 Euceraphis Walker 28 Eudeis Ashmead 69 Eulachnus Del G uercio 15 Eunectarosiphon Del Guercio 54 Eutrichoslphum Essig & Kuwana 38 Forda Heyden 78 Francoa Del Guercio 55 Fullawaya Essig 37 Fullawayella Del Guercio 59 Fushia Matsumura 74 Geoica Hart 79 Georgia Wilson 6" Glyphina Koch 21 Glyphinaphis Van der Goot 85 Gobaishia Matsumura 67 Greenidea Schouteden 37 Greenidea Wilson 38 Greenideoida Van der Goot 38 Hamadryaphis Kirkaldy 71 Hamamelistes Shinier 83 Hannabura Matsumura 41 Hayhurstia Del Guercio 47 Heteroneura Davis 47 Holzneria Lichtenstein 76 Hormaphis Osten Sacken 84 Hyadaphis Kirkaldy 47 Hyalopteroides Theobald 56 Hyalopterus Koch 47 Hysteroueura Davis 47 91 92 BULLETIN 826, U. S. DEPARTMENT OF AGRICULTURE. Page. Idiopterus Davis 60 lllinoia Wilson 56 Kallistaphis Kirkaldy 28 Kaltenbachiella Schouteden 79 Kessleria Lichtenstein 71 Lachniclla Del Guercio 15 Lachnus Burmeister 15 Liosomaphis Walker 48 Longicaudus Van dor Goot 49 Longistigma Wilson 17 Longiunguis Van der Goot 43 Lowia Lichtenstein 72 Loxerates Rafmesquc 43 Macchiatiella Del Guercio 41 Macrosiphon Del Guercio 57 Macrosiphoniella Del Guercio 50 Macrosiphum Del Guercio 54 Macrosiphura Oestlund 54 Macrosiphum Fasserini 57 Macrosiphum Van der Goot 56 Mansakia Matsumura 85 Mastopoda Oestlund 48 Megoura Buckton 57 Melanaphis Van der Goot 43 Melaphis Walsh 74 Melanoxantherium Schouteden 36 Melanoxanthus Buckton 36 Metaphis Matsumura 46 Metopeurum Mordwilko 56 Micrella Essig - - - - 33 Micromyzus Van der Goot 59 Microparsus Patch 00 Microsiphon Del Guercio 43 Microsiphum Cholodkovsky 49 Mimaphidus Rondani 06 Mindarus Koch 62 Monaphis Walker 32 Monellia Oestlund 29 Monvilkoja Del Guercio 70 Myzaphis Van der Goot 43 Myzocallis Passerini 29 Myzodes Mordwilko 57 Myzoides Van der Goot 57 Myzopsis Matsumura 57 Myzoxylus Blot 66 Myzus Passerini 57 Nectarophora Oestlund 57 Nectarosiphon Schouteden 54 Neocallipterus Van dor Goot 28 Neomyzus Van der Goot 57 Neophyllaphis Takahashi 24 Neoprociphilus Patch 76 Neorhizobius Del Guercio 88 Neosymydobius Baker 32 Neothomasia Baker 35 Neotoxoptera Theobald 60 Neotrama Baker 20 Nippocallis Matsumura 27 Nippolachnus Matsumura 14 Nipponaphis Pergande 84 Nipposiphum Matsumura 46 Nishiyana Matsumura 76 Nurudea Matsumura 74 Nurudeopsis Matsumura 74 Oedisiphum Van der Goot 45 Oregma Buckton Page. Ovatus Van der Goot 57 Pachypappa Koch 71 Pachypappa Tullgren 71 Pachypappella Baker 71 Panaphis Kirkaldy 27 Paracletus Heyden 81 Patchia Baker 34 Pcmphigella Tullgren 75 Pemphigus Hartig 71 Pentalonia Coquerel 61 Pentaphis De! Guercio 78 Pentaphis Horvath 78 Pcrgandeidia Schouteden. 49 Periphyllus Van der Hoeven 34 Phillophorus Thornton 34 Phloeomyzus Horvath 72 Phorodon Passerini 58 Phyllaphis Koch 24 Phymatosiphum Davis 31 Prociphilus Koch 76 Protolachnus Theobald 15 Protrama Baker 19 Pterocallis Passerini 29 Pterochlorides Archangelsky 18 Pterochlorus Rondani 18 Pterocpmma Buckton 36 Ptychodes Buckton 27 Rectinasus Theobald = 78 Rhizoberlesia Del Guercio 49 Rhizobius Burmeister 88 Rhizoctonus Mokrzecky 73 Rhizoicus Del Guercio 88 Rhizoicus Passerini 88 Rhizomaria Hartig 71 Rhizophthiridum Van der Hooven 88 Rhizoterus Hartig 78 Rhopalosiphum Koch 49 Rhopalosiphum Passerini 57 Rhopalosiphum Van der Goot 54 Rhopalosiphon Scudder 49 Rhopalosiphoninus Baker 58 Rhynchocles Altum 18 Rizobius Passerini 88 Saltusaphis Theobald 31 Sanbornia Baker 50 Sappaphis Matsumura 42 Schizodryobius Van der Goot IS Schizolachnus Mordwilko 16 Schizoneura Hartig 66 Schizoneuraphis Van der Goot 84 Schlechtendalia Lichtenstein 74 Schoutedenia Riibsaamen 89 Semiaphis Van der Goot Serrataphis Van der Goot 79 Setaphis Van der Goot 39 Shivaphis Das Sipha Passerini Siphocoryne Passerini 47,49 Siphonaphis Van der Goot 49 Siphoualrophia Swain Siphonocallis Del Guercio 26 Siphonophora Koch Smynthurodes Westv/oo 1 Stagonia Koch ' a Stenaphis Del Guercio 43 Stephensonia Das 49 GENERIC CLASSIFICATION OF APHIDIDAE. 93 Stomaphis Walker Page. 18 Trifidaphis Del Guercio Page. 79 Subcallipterus Mordwilko 29 Trinacriella Del Guercio 79 Symydobius Mordwilko 30 Tuberculatus Mordwilko 29 Takecallis Matsumura 29 Tuberculoides Van der Goot 29 Tamalia Baker 24 Tuberodryobius Das 18 Tetraneura Hartig es Tuberolachnus Mordwilko 18 Tetraphis Horvath 83 Tullgrenia Van der Goot. . 79 Tetrenema Derbe ? 73 Tychea Koch.. 71 Thecabius Koch 77 Tychea Passermi 79 Thelaxes Westwood 21 Tycheoides Schouteden 79 Therioaphis Walter 28 Unilachnus Wilson . . 17 Thomasia Wilson 35 Uraphis Del Guercio 43 Thoracaphis Van der Goot 87 Vannna TTeydfin 21 Thripsaphis G illette 30 Vesiculaphis Del Guercio 51 Todolachnus Matsumura 15 Watabura Matsumura. . . 69 Toxoptera Koch 51 Wilsonia Baker 16 Trama Heyden 19 51 Tranaphis Walker 33 Yezfihnra \fatsiiTpiira " 42 Travaresiella Del Guercio 21 Yezocallis Matsumura 30 Trichosiphum Pergande. . . 37 Yezosiphum Matsumura. . . 49 PLATE I. A. Anoeda querd, apterous form. B. Anoeda querd, wings. C. Anoeda querd, antenna of alate form. D. Anoeda corni, fore wing. E. Anoeda corni, antenna of alate form. F. Anoeda corni, cornicle of alate form. G. Nippolachnus pyri, fore wing. H. Nippolachnus pyri, head of alate form. I. Anoeda corni, head of alate form. J. Nippolachnus pyri, cornicle of alate form. K. Nippolachnus pyri, antenna of alate form. L. Eulachnus agilis, body of alate form. M. Eulachnus agilis, fore wing. N. Eulachnus agilis, antenna of alate form. 0. Eulachnus agilis, cornicle of alate form. P. Eulachnus rileyi, head of alate form. Q. Eulachnus rileyi, cornicle of alate form. R. Eulachnus rileyi, segment III, antenna of alate form. S. Essigella californica, body of alate form. T. Essigella californica, fore wing. IT. Essigella californica, antenna of alate form. V. Essigella californica, cornicle of alate form. W. Essigella californica, head of alate form. X. Essigella californica, cauda of alate form. Y. Essigella californica, antenna of apterous form 94 Bui. 826, U. S. Dept. of Agriculture. PLATE I. 04 Bui. 826, U. S. Dept. of Agriculture. PLATE 1 1 . PLATE II. A. Dilachnus ponderosae, fore wing. B . Dilachnus ponderosae, cornicle of apterous form. C. Dilachnus ponderosae, head of alate form. D. Schizolachnus tomentosus, fore wing. E. Unilachnus parvus, fore wing. F. Unilachnus parvus, cornicle of alate form. G. Unilachnus parvus, head of alate form. H. Longistigma caryae, wings. I. Longistigma caryae, apterous form. J. Longistigma caryae, cornicle. K. Longistigma caryae, cornicle. L. Longistigma caryae, antenna of alate form. M. Stomaphis quercus, alate form. N. Stomaphis quercus, head of alate form. O. Stomaphis quercus, cornicle of alate form. P. Stomaphis quercus, antenna of alate form. Q. Stomaphis quercus, cauda and anal plate. R. Stomaphis quercus, pits on rostrum. S. Pterochlorus roboris, wing. T. Pterochlorus roboris, head of alato form. U. Pterochlorus roboris, cornicle of alate form. V. Pterochlorus riminalis, wings. W. -Pterochlorus viminalis, abdomen of alate form. X. Pterochlorus viminalis, head of alate form. 95 PLATE III. A. Thelaxes dryophila, apterous form. B. Thelaxes dryophila, wings. C. Thelaxes dryophila, cornicle of alate form. D. Thelaxes dryophila, cauda of alate form. E. Thelaxes dryophila, cauda of apterous form. F. Thelaxes dryophila, antenna of alate form. G. Glyphina betulae, apterous form. H. Glyphina betulae, wings. I. Glyphina betulae, antenna of alate form. J. Glyphina betulae, cornicle of alate form. K. Glyphina betulae, cauda and anal plate of alate form. L. Glyphina betulae, cauda and anal plate of apterous form. M. Neotrama delguercioi, apterous form. N. Trama troglodytes, apterous form. O. Neotrama delguercioi, cornicle. P. Protrama radicis, apterous form. Q. Protrama radicis, fore wing. R. Protrama radicis, cornicle of alate form. S. Protrama radicis, antenna of alate form. T. Protrama radicis, tarsus of alate form. 96 Bui. 826, U. S. Dept. of Agriculture. PLATE III. Bui. 826, U. S. Dept. of Agriculture. PLATE I V. PLATE IV. A. Amphorophora rubi, head of apterous form. B. Amphorophora rubi, cornicle. 0. Amphorophora rubi, cauda. D. Rhopalosiphoninus latysiphon, head of alate form. E. Rhopalosiphoninus latysiphon, cornicle of alate form. F. Rhopalosiphoninus latysiphon, cauda of alate form. G. Myzocallis coryli, cornicle. II. Myzocallis coryli, cauda and anal plate. I. Callipterus juglandis, cornicle. J. Callipterus juglandis, cauda and anal plate. K. Tlttrioaphis tiliae, cornicle. L. Therioaphis tiliae, cauda and anal plate. M. Monellia caryella, cauda and anal plate. N. Monellia caryella, cornicle. 0. Chromaphis juglandicola, cornicle. P. Chromaphis juglandicola, cauda and anal plate. Q. Euceraphis betulae, cauda and anal plate. R. Euceraphis betulae, cornicle. S. Calaphis betulella, cauda and anal plate. T. Calaphis betulella, cornicle. U. Calaphis betulella, fore wing. V. Saltusaphis scirpus, head of apterous form. W. Saltusaphis scirpus, cauda and anal plate. X. Thripsaphis balli, head of apterous form. Y. Neothomasia populicola, cornicle. Z. Neothomasia populicola, cauda and anal plate. AA. Periphyllus negundinis, cauda and anal plate. BB. Periphyllus negundinis, cornicle. CC. Chaitophorus populi, cauda and anal plate. DD. Symydobius oblongus, cornicle. EE. Symydobius oblongus, cauda and anal plat/ . FF. Phyllaphis fagi, cauda and anal plate. GG. Phyllaphis fagi, cornicle. till. Tamalea coweni, cornicle. II. Tamalea coweni, cauda and anal plate. JJ. Drepanaphis acerifolii, oviparous abdomen. KK. Drepanaphis acerifolii, cauda and anal plate of alate form. LL. Drepanaphis acerifolii, cornicle. MM. Drepanosiphum platanoides, cornicle. NN. Melanoxantherium populifoliae, cornicle. 00. Melanoxantherium populifoliae, cauda and anal plate. PP. Pterocomma populeus, cornicle. 141613 20 Bull. 826 7 97 PLATE V. A. Eutrichosiphum pasaniae, antenna of alate form. 13. Eutrichosiphum pasaniae, wings. C. Eutrichosiphum pasaniae, cornicle of apteroua form. D. Eutrochosiphum pasaniae, cornicle of alate form. E. Eutrichosiphum pasaniae, antenna of apterous form. F. Greenidea anonae, apterous form. G. Greenidea artocarpi, wings. H. Greenidea artocarpi, cauda of apterous form. I. Greenidea artocarpi, cornicle of apterous form. J. Greenidea anonae, abdomen of alate form. K. Greenidea anonae, head of alate form. L. Greenideoida elongata, wings. M. Greenideoida sp. , head of alate form. N. Greenideoida sp., cornicle of alate form. O. Greenideoida sp., third antennal segment of alate form?} P. Greenideoida hannae, cornicle of apterous form. Q. Setaphis luteus, caudal portion of apteroua form. R. Setaphis luteus, wings. S. Setaphis luteus, head of alate form. T. Setaphis luteus, cornicle of alate form. IT. Setaphis luteus, spine of alate form. V. Setaphis luteus, cornicle of apterous form. W. Setaphis luteus, antenna of alate form. X. Setaphis luteus, antenna of apterous form. 98 Bui. 826, U. S. Dept. of Agriculture. PLATE V. rv UJ O Bui. 826. U. S. Dept. of Agriculture. PLATE VI. ^- //^TTT'i^'L v '"i 1 " ^^^^^ 4l^w^ 8T &~tfk,.|^* ^*. ( - V. : -' .' "--X .%- ./.;-*. PLATE VI. A. Acandus lychnidis, cornicle of alate form. B. Acaudus lychnidis, cauda of alate form. C. Anuraphis amygdali, cornicle of alate form. D. Anuraphis amygdali, cauda of alate form. E. Anuraphis amygdali, head of alate form. F. Anuraphis carotae, cornicle and cauda of alate form. G. Aphis sambuci, head of alate form. H. Aphis sambuci, cornicle of alate form. I. Aphis sambuci, cauda of alate form. J. Brevicoryne brassicae, cauda of alate form. K. Brevicoryne brassicae, cornicle of alate form. L. Aspidaphis polygonii, cornicle of alate form. M. Aspidaphis polygonii, cornicle more enlarged. N. Aspidaphis polygonii, cauda of apterous form. 0. Aspidaphis polygonii, head of apterous form. P. Atarsos grindeliae, cornicle of alate form. Q. Atarsos grindeliae, head of alate form. R. Atarsos grindeliae, cauda of alate form. S. Atarsos grindeliae, tibia of alate form. T. Brachycolus stellariae, cornicle of alate form. U. Brachycolus stellariae, cauda of alate form. V. Carolinaia cyperi, cornicle of alate form. W. Carolinaia cyperi, cauda of alate form. X. Cavariella pastinacae, cornicle of alate form. Y. Cavariella pastinacae, cauda of alate form. Z. Cavariella pastinacae, tubercle of alate form. AA. Hyadaphis xylostei, cauda of apterous form. BB. Hyadaphis xylostei, cornicle of apterous form. CC. Toxoptera aurantiae, head of alate form. DD. Toxoptera aurantiae, cornicle of alate form. EE. Toxoptera aurantiae, cauda of alate form. FF. Rhopalosiphum rufomaculata, cornicle of alate form. GG. Rhopalosiphum rufomaculata, head of alate form. HH. Rhopalosiphum rufomaculata, cauda of alate form. II. Rhopalosiphum nymphaeae, cornicle of alate form. JJ. Rhopalosiphum nymphaeae, cauda of alate form. KK. Pergandeidia ononidis, cauda and cornicle of alate form. LL. Pergandeidia trirhodus, cauda of apterous form. MM. Pergandeidia trirhodus, cornicle of apterous form. NN. Liosomaphis berberidis, cornicle and cauda of apterous form. 00. Liosomaphis berberidis, cauda of alate form. PP. Cryptosiphum artemesuie, cornicle of apterous form. QQ. Cryptosiphum artemesiae, cauda of apterous form. RR. Hyalopterus arundinis, cornicle of alate form. SS. Hyalopterus arundinis, cauda of alate form. TT. Hyalopterus deformans, cauda of apterous form. UU. Hyalopterus deformans, cornicle of apterous form. W. Hyalopterus deformans, cauda of alate form. WW. Hyalopterus deformans, cornicle of alate form. 99 PLATE VII. A. Siphonatrophia cupressi, apterous form. B. Siphonatrophia cupressi, wings. C. Siphonatrophia cupressi, antenna of alate form. D. Siphonatrophia cupressi, cauda of alate form. E. Siphonatrophia cupressi, antenna of apterous form. F. Sanbornia juniperi, apterous form. G. Sanbornia juniperi, \vings. H. Sanbornia juniperi, antenna of alate form. I. Sanbornia juniperi, head of apterous form from beneath. J. Sanbornia juniperi, cauda of alate form. K. Sanbornia juniperi, cornicle. L. Sanbornia juniperi, tarsus. M. Vesiculaphis caricis, apterous form. N. Vesiculaphis caricis, cornicle of alate form. 0. Vesiculaphis caricis, fore wing. P. Vesiculaphis caricis, antenna of alate form. Q. Vesiculaphis caricis, cauda of alate form. R. Acanthaphis rubi, apterous form. S. Acanthaphis rubi, head of apterous form. T. Acanthaphis rubi, cornicle of apterous form. U. Acanthaphis rubi, antenna of apterous form. 100 Bui. 826, U. S. Dept. of Agriculture. PLATE VI I. Bui. 826, U. S. Dept. of Agriculture. PLATE VIM. PLATE VIII. A. Capitophorus shepardiae, cornicle of alate form. B. Capitophorus shepardiae, head of alate form. 0. Capitophorus shepardiae, cauda of alate form. D. Anomalaphis comperi, apterous form. E. Anomalaphis comperi, antenna of apterous form. F. Anomalaphis comperi, wings. G. Cervaphis schoutedeniae, extremity of abdomen. H. Illinoia liriodendri, head of alate form. I. Illinoia liriodendri, cornicle of alate form. J. Illinoia liriodendri, cauda of alate form. K. Myzus cerasi, head of apterous form. L. Myzus cerasi, cauda of apterous form. M. Myzus cerasi, cornicle of alate form. N. Phorodon humuli, head of apterous form. 0. Phorodon humuli, cauda of apterous form. P. Phorodon humuli, cornicle of apterous form. Q. Phorodon humuli, head of alate form. R. Macrosiphonella sanborni, head of alate form. S. Macrosiphonella sanborni, cornicle of alate form. T. Macrosiphonella sanborni, cauda of alate form. IT. Macrosiphum rosae, head of alate form. V. Macrosiphum rosae, cauda of alate form. W. Macrosiphum rosae, cornicle of alate form. X. Myzus persicae, head of apterous form. Y. Myzus persicae, cornicle of alate form. Z. Myzus persicae, cauda of alate form. AA. Microparsus variabilis, cauda of alate form. BB. Microparsus variabilis, wings. CO. Microparsus variabilis, cornicle of alate form. DD. Microparsus variabilis, head of alate form. EE. Idiopterus nephrolepidis , cornicle of alate form. FF. Idiopterus nephrolepidis, fore wing. GG. Idiopterus nephrolepidis, head of alate form. HH. Idiopterus nephrolepidis, cauda of alate form. II. Pentalonia nigronervosa, head of apterous form. JJ. Pentalonia nigronervosa, wings. KK. Pentalonia nigronervosa, cauda of alate form. LL. Pentalonia nigronervosa, head of alate form. MM. Pentalonia nigronervosa, cornicle of alate form. 101 PLATB IX. A. Mindarus abietinus, winga. B. Mindarus abietinus, fore wing showing tracheae. C. Mindarus abietinus, cauda of alate form. D. Mindarus abietinus, antenna of alate form. E. Mindarus abietinus, abdomen of pupa. F. Mindarus abietinus, cornicle of alate form. G. Colopha ulmicola, antenna of alate form. H. Colopha ulmicola, antenna of stem mother. I. Colopha ulmicola, wings. J. Colopha ulmicola, apterous form. K. Colopha ulmicola, antenna of apterous form. L. Colopha ulmicola, antenna of apterous form. M. Eriosoma lanigerum, apterous form. N. Eriosoma lanigerum, wax plate. 0. Eriosoma lanigerum, wax reservoir. P. Eriosoma lanigerum, fore wing. Q. Eriosoma lanigerum, wing pad showing trachea. R. Eriosoma lanigerum, cornicle. S. Eriosoma lanigerum, antenna of alate form. T. Eriosoma lanigerum, oviparous female, showing egg. U. Georgia ulmi, antenna of alate form. V. Georgia ulmi, wings. W. Georgia ulmi, distal segment of antenna of alate form. X. Georgia ulmi, cornicle of alate form. Y. Georgia ulmi, cauda and anal plate of alate form. Z. Georgia ulmi, head of alate form. 102 Bui. 826, U. S. Dept. of Agriculture. PLATE IX. Bui. 826, U. S. Dept. of Agriculture. PLATE X. o PLATE X. A. Gobaishia pallida, antenna of alate form. B. Gobaishia pallida, antenna of stem mother. C. Gobaishia pallida, wings. B. Gobaishia pallida, abdomen of alate form showing cornicle. E. Gobaishia pallida, fore wing. F. Gobaishia pallida, abdomen of pupa. G. Gobaishia pallida, distal segment of antenna of alate form from above. H. Tetraneura ulmifoliae, antenna of alate form. I. Tetraneura ulmifoliae, antenna of stem mother. J. Tetraneura ulmifoliae, antenna of apterous form. K. Tetraneura ulmifoliae, wings. L. Tetraneura ulmifoliae, wings showing tracheae. M. Tetraneura ulmifoliae, cauda and anal plate. N. Cornaphis populi, stem mother. 0. Cornaphis populi, antenna of stem mother. P. Cornaj>his populi, wings. Q. Cornaphis populi, cornicle of alate form. R. Cornaphis populi, antenna of alate form. S. Cornaphis populi, fore wing. T. Cornaphis populi, head showing horn. U. Dryopeia bella, apterous form. V. Dryopeia bella, wings. W. Dryopeia bella, antenna of apterous form. X. Dryopeia bella, antenna of alate form. Y. Dryopeia bella, cornicle of apterous form. 108 PLATE XI. A. Mordwilkoja vagabunda, stem mother. B. Mordwilkoja vagabunda, antenna of stem mother. C. Mordwilkoja vagabunda, antenna of alate form. D. Mordwilkoja vagabunda, wings. E. Mordwilkoja vagabunda, thorax of alate form. F. 'Mordwilkoja vagabunda, cauda of alate form. G. Mordwilkoja vagabunda, cornicle of alate form. H. Asiphum sp. stem mother. I. Asiphum sp. antenna of stem mother. J. Pachypappella vesicalis, wings. K. Pachypappella vesicalis, cornicles and cauda of alate form. L. Pachypappella vesicalis, antenna of alate form. M. Pachypappella vesicalis, wax plate. N. Pemphigus bursarius, antenna of stem mother. O. Pemphigus bursarius, wings. P. Pemphigus bursarius, antenna of alate form. Q. Pemphigus bursarius, antenna of alate form. ~R.~Pemphigus bursarius, antenna of stem mother. S. Pemphigus bursarius, wax plate. T. Pemphigus bursarius, cornicle of alate form. U. Pemphigus populicaulis, antenna of stem mother. V. Gobaishia ulmifuscus, antenna of stem mother. W. Phloeomyzus passerini, apterous form. X. Phloeomyzus passerini, antenna of apterous form. Y. Phloeomyzus passerini, wings. Z. Phloeomyzus passerini, antenna of apterous form. AA. Phloeomyzus passerini, antenna of alate form. BB. Phloeomyzus passerini, wax plate. 104 Bui. 826, U. S. Dept. of Agriculture. PLATE XI. Bui. 826, U. S. Dept. of Agriculture. PLATE XI I. o CO PLATE XII. A. Aploneura lentici, apterous form. ~B.~Aploneura lentici, antenna of apterous form. C. Aploneura lentici, antenna of alate form. D. Aploneura lentici, wings. E. Aploneura lentici, abdominal wax plate. F. Melaphis rhois, antenna of apterous form. G. Melaphis rhois, antenna of alate form. H. -Melaphis rhois, wings. I. Melaphis rhois, abdomen of alate form. J. -Melaphis rhois, antenna of alate form. K. Melaphis chinensis, fore wing. L. Nurudea ibofushi, wings. M. Nurudea ibofushi, antenna of alate form. N. -Nurudea shiraii, wings. O. Nurudea shiraii, antenna of alate form. P. Nurudea rosea, fore wing. Q. Nurudea rosea, antenna of alate form. R. Asiphum tremulae, stem mother. S. Asiphum tremulae, antenna of stem mother. T. Asiphum tremulae, antenna of alate form. U. Asiphum tremulae, wings. V. Asiphum tremulae, abdomen of alate form. W. Asiphum tremulae, wax plates. X. Asiphum tremulae, antenna of apterous form. 105 PLATE XIII. A. Neoprociphilus attenuatus, forewing. B. Neoprociphilus attenuatus, antenna of alate form. C. Neoprociphilus attenuatus, segment V of antenna of alate form. D. Neoprociphilus attenuatus, antenna of apterous form. E. Neoprociphilus attenuatus, antenna of male. F. Neoprociphilus attenuatus, antenna of oviparous female. G. Prociphilus bumeliae, antenna of alate female. H. Prociphilus bumeliae, antenna of stem mother. I. Prociphilus bumeliae, wings. J. Prociphilus bumeliae, abdomen of alate form. K. Prociphilus bumeliae, thoracic wax plates. L. Prociphilus bumeliae, head wax plates. M. Prociphilus xylostei, thoracic wax plates. N. Prociphilus bumeliae (poscheringi) , thoracic wax plates. 0. Thecabius affinis, antenna of stem mother. P. Thecabius affinis, antenna of alate form. Q. Thecabius affinis, wings. R. Thecabius affinis, thorax of alate form. S. Thecabius affinis, head wax plates of stem mother. T. Thecabius affinis, abdominal wax plate. U. Thecabius affinis, abdominal wax plates of stem mother. V. Forda sp., apterous form. W. Forda olivacea, antenna of alate form. X. Forda trivialis, antenna of alate form. Y. Forda marginata, antenna of alate form. Z. Forda olivacea, fore wing. AA. Forda for micaria, antenna of apterous form. 106 Bui. 826, U. S. Dept. of Agriculture. PLATE XII I. o Bui. 826. U. S. Dept. of Agriculture. PLATE XIV. PLATE XIV. A. Geoica squamosa, apterous form. B. Geoica squamosa, antenna of alate form. C. Geoica squamosa, eye of apterous form. D. Geoica squamosa, wings. E. Geoica squamosa, caudal extremity of apterous form. F. Geoica squamosa, squama. G. Geoica squamosa, four-segmented antenna of apterons form. II. Geoica phaseoli, antenna of alate form. I. Geoica phaseoli, antenna of apterous form. J. Geoica radicicola, antenna of alate form. K. Geoica lucifuga, antenna of alate form. 1^. Paracletus cimiciformis, apterous form. M. Paracletus cimiciformis, eye of apterous form. N. Paracletus cimiciformis, intermediate eye. O. Paracletus cimiciformis, median thoracic wax plate of alate form. P. Paracletus cimiciformis, foot of alate form with one claw. Q. Paracletus cimiciformis, ? enna of apterous form. R. Paracletus cimiciformis, .Brewing. S. Paracletus cimiciformis, antenna of alate form. T. Uamamelistes spinosus, hibernating apterons form. U. ITamamelistes spinosus, wings. V. Uamamelistes spinosus, cauda and anal plate of alate form. W. Uamamelistes spinosus, antenna of alate form. X. Hamamelistes spinosus, portion of same, more enlarged. Y. ITormaphis Jiamamelidis, wings. Z. Hormaphis Jiamamelidis, antenna of alate form. AA. Tlormaphis Jiamamelidis, antenna of stem mother. BB. TTormaphis Jiamamelidis, apterous form. CC.TTormaphis Jiamamelidis, antenna of apterous form. DD. Tlormaphis hamamelidis, cauda and anal plate of apterous form. EE. ITormaphis hamamelidis, dorsal wax pores. FF. TTormaphis hamamelidis, cauda and anal plate of alate form. 107 PLATE XV. A. Oregma lanigera, apterous form. B. Oregma lanigera, antenna of alate form. C. Oregma lanigera, cauda and anal plate of alate form. D. Oregma lanigera, wings. E Oregma lanigera, end of abdomen of apterous form. F. Oregma lanigera, antenna of apterous form. G. Oregma bambusae, head of apterous form. H. Glyphinaphis bambusae, apterous form. I. Glyphinaphis bambusae, antenna of apterous form. j. Glyphinaphis bambusae, cornicle of apterous form. K. Glyphinaphis bambusae, cauda and anal plate. L. Mansakia miyabei, wings. M. Ceratoglyphina bambusae, apterous form. X. Ceratoglyphina bambusae, cauda and anal plate. 0. Ceratoglyphina bambusae, cornicle of apterous form. P. Ceratoglyphina bambusae, antenna of apterous form. Q. Astegopteryx distychii, antenna of alate form. R. Astegopteryx distychii, fore wing. S. Astegopteryx distychii, anal plate of alate form. T. Astegopteryx distychii, cauda of alate form. U. Astegopteryx distychii, end of abdomen. V. Astegopteryx styracophila, fore wing. W. Astegopteryx gallarum, fore wing. "S.. Astegopteryx gallarum, tip of antenna of alate form. 108 Bui. 826. U. S. Dept. of Agriculture. PLATE XV. o OQ = Bui. 826, U. S. Dept. of Agriculture. PLATE XVI. PLATE XVI. A. Aleurodaphis blumeac, apterous form. B. Aleurodaphis blumeae, antenna of apterous form. C. Aleurodaphis blumeae, dorsal wax pores. D. Aleurodaphis blumeae, margin. E. Aleurodaphis blumeae, cauda and anal plate. F. Cerataphis lataniae, apterous form. G. Cerataphis lataniae, wings. H. Cerataphis lataniae, cauda and anal plate of apterous form. I. Cerataphis lataniae, antenna of apterous form. J. Cerataphis lataniae, antenna of alate form. K. Cerataphis lataniae, anal plate of alate form. L. Cerataphis lataniae, cauda of alate form. M. Cerataphis lataniae, head of apterous form, central view. N. Thoracaphis arboris, apterous form. O. Thoracaphis arboris, antenna of apterous form. P. Thoracaphis arboris, cauda and anal plate of apterous form. Q. Thoracaphis ficus, antenna of apterous form. R. Thoracaphis ficus, extremity of abdomen, apterous form. S. Thoracaphis castaneae, wings. T. -Thoracaphis castaneae, distal segment of antenna of alate form. U. Thoracaphis castaneae, cauda and anal plate of alate form. V. Thoracaphis castaneae, cornicle of alate form. W. Thoracaphis castaneae, antenna of alate form. 109 ADDITIONAL COPIES OF THIS rUBUCATIOX MAY BE PROCURED FROM THE SUPERINTENDENT OF DOCUMENTS GOVERNMENT POINTING OFFICE WASHINGTON, D. C. \T 30 CKNT3 PER COPY 0-7668 5-45 3 197000871 7180 rary Use Only University of California SOUTHERN REGIONAL LIBRARY FACILITY 405 Hilgard Avenue, Los Angeles, CA 90024-1388 Return this material to the library from which it was borrowed. MAY 1 9 1993 mSSBSSSISSS* y" FAOUIY A 001348477 Universii Southi Libn