key: cord-0042891-vuwv281r
authors: Richards, O. W.
title: Some British species of Leiophron Nees (Hymenoptera: Braconidae, Euphorinae), with the description of two new species
date: 2009-04-24
journal: Ecol Entomol
DOI: 10.1111/j.1365-2311.1967.tb00508.x
sha: 2f743732797aadbcb30da72d14b1d927d303d5f3
doc_id: 42891
cord_uid: vuwv281r

nan

DURING the last few years, Dr. Waloff and myself have been studying the Euphorine parasites of various Miridae (Heteroptera). The parasites belong to the genus Leiophron Nees (= Euphorus Nees), and their taxonomy is in a confused state. There has been no recent revision, and it is difficult to identify even the British species. When I began to work on the genus I discovered that Dr. M. de V. Graham had seen the types of nearly all the European species and had a manuscript key to them. Although he was too busy to join with me in producing a revision, he has been kind enough to allow me to make full use of his work and to examine some of my specimens so that at least those species on which we have most biological data can be identified or described. The types and paratypes of the two new species have been deposited in the British Museum. The species discussed below are all west European, but specific records are given for those that occur in Britain. Muesebeck (1958) showed that Euphorus Nees, 1834 (type, E. pallicornis Nees, 1834) is a synonym of Leiophron Nees, 1818 (type, L. apicalis Haliday, April, 1833) . L. apicalis is one of the three species originally included when species were first put into Leiophron by Haliday (April, 1833) and was designated as type by Viereck (1914) . Curtis (Nov., 1833) designated L. pallipes Curtis, 1833, as the type,, but this species was not originally included by Haliday, so that the designation is invalid. According to Muesebeck, the species hitherto put in Leiophron (allies of L. ater Nees) should be placed in Centistes Haliday, but this suggestion probably needs further investigation and is not considered here. The subfamily name Euphorinae Forster (1862 : 228) still takes precedence over Liophroninae Forster (1862 : 229). There seem to be some biological grounds for treating the Meteorinae Marshall, 1887, as a distinct subfamily.

The species of Leiophron (= Euphorus) are parasites of Heteroptera (almost exclusively Miridae) and of Psocids. Eggs are laid in the young (rarely older) nymphs, and the full-grown larva emerges from the nearly full-grown nymph or more rarely from the adult. In most British species there is only one generation a year. The British species of Leiophron can be divided into two sections by means of a character first pointed out by C. G. Thomson (1891) . In the species allied to L. apicalis Haliday, Trans. R. ent. SOC. Lond. 119 (5). Pp. 171-186, 2 plates. 1967. with very few even of the finest punctures, no distinct keel below the median ocellus, POL : OOL = 4 : 3 in female but almost 4 : 2 in male. Mesoscutum smooth and shining, not punctured or pubescent except weakly so in anterior quarter, notauli strong and meeting in front of scutellum but not punctured. Pleuron shining, smooth above, fairly strongly punctured below. Propodeum not at all truncate, regularly and moderately strongly rugose all over. Wings essentially similar to those of L . orthotyli sp. n. (fig. l) , first abscissa of marginal vein (cross-vein r ) almost or quite obsolete, marginal cell narrow, about one-third as long on costal margin as pterostigma, first free sector of M (= recurrent vein) fully pigmented, entering the distal part of M a little beyond the first free sector of Rs (= first marginal cross-vein) ; hind wing with cell M + Cul well-defined. Hind femora a little thickened. Abdominal petiole not long, not much expanded at apex where it is one and a half times as broad as at base and about the same amount broader than middle of hind femur, surface. moderately shining, rather regularly striate. Hind tibia1 spurs about as long as apical width of hind tibia and a little longer than third tarsal segment. Length about 2.5 mm.

Curtis described Liophron picipes in 1833; the description is very brief, and the species would not be recognisable from it. No specific locality was given. Haliday (1 835) redescribed Curtis' species in greater detail ; again no specific locality was given, and there is indeed no indication that any additional material had been examined. Marshall (1887 : 58-59) first suggested that picipes of Haliday (put by him in the genus Euphorus) was different from picipes Curtis and stated that the latter is distinguished by its small size, darker legs and impunctate mesoscutum. Unfortunately, he published a new name, Euphorus coactus, for Curtis' rather than Haliday's species; moreover, although this was only a new name, he states that he described it from two females from near Barnstaple.

Curtis states that L. picipes (? female) has 16 antennal segments; Haliday states that the female has 18 antennal segments and that the disk of the mesoscutum is obsoletely punctured. According to Marshall (1887) , picipes Haliday has 16-18 antennal segments in the female and 18 in the male (19-21 in Marshall, 1891 : 8) and the mesoscutum is shining and punctate; coactus Marshall (= picipes Curtis) has 16 antennal segments in the female (16 also in Marshall, 1891 : 12) (male unknown) and the mesoscutum is impunctate. Thomson (1891 : 1748) correctly used Curtis' name for a small species with head and mesoscutum scarcely punctured (female antennae with 16 segments) and split the picipes of Marshall into two species, Euphorus facialis and E. microcerus. All three species were recorded from Sweden. Thomson's treatment seems to be taxonomically correct; moreover, the Haliday specimens of picipes from the National Museum of Ireland belong to Curtis' species and have an unpunctured head and mesoscutum. Marshall's specimens of coactus in the British Museum collection (2 females, Barnstaple) also seem to belong to L. picipes, although they are rather small, the legs are not very dark, and in spite of Marshall's statement, the mesoscutum has some obsolescent punctures. Marshall's series in the same collection of what he called picipes is a mixture of L. microcerus (Thomson) (1 male) and L. facialis (Thomson) (5 males). Marshall (1897 : 204) disagrees with Thomson and repeats his earlier statements but does not mention any further specimens. The only specimens of L. picipes that I have seen are four males and three females from Haliday's collection in the National Museum of Ireland and one male and one female from Silwood Park, Berks. The data are as follows: 4 6 (2 on one mount) 3 9 (Haliday coll ., labelled picipes Curtis by Mr. A. W. Stelfox); Berks., Silwood Park, on young broom, 1 .v. 58, 1 6 (0. W. Richards), on old broom, 29.iv. 57, 1 9 (0. W. Richards).

Mr. Stelfox had labelled one female lectotype and one male allotype, but as Haliday was merely redescribing Curtis' species these specimens can hardly be regarded as types. The real type is in Curtis' collection at Melbourne and has been seen by Dr. Graham.

The measurements (in mm.) of these specimens are shown below. 

Black; mandibles yellowish, with red tips, ventral margin of clypeus sometimes reddish, antennae and legs yellow-brown, distal half of antenna and hind femora and coxae more or less darkened. Wings hyaline, venation light yellow-brown, pterostigma brown except for a small pale proximal patch. Eyes a little longer, more swollen and more convergent below in female than male. In female, eyes at narrowest separated by the length of antennal segments 2 + 3 + 4, or hardly more than half their own length. Malar space in female about as long as scape, in male malar space a little longer than scape. Antennae with segment 3 a little longer than segment 1 (about equal in male) but clearly longer than 4 ; number of segments: female (43 specirnens)4 with 15,21 with 16, 17 with 17, 1 with 18, male (10 specimens)-5 with 19, 3 with 20, 1 with 21, 1 with 22; length of penultimate segments about as in L. picipes. Generally very similar to L. picipes but head, including frons, with usually quite numerous but very fine hair-bearing punctures, frons usually with a weak keel in front of the median ocellus. Mesoscutum finely punctured, notaulices with large but not very distinct punctures. Size about the same. 15.v.58, 3 9, 18.v.58, 3 ?,22 .v.58, 2 9, 29.v.58, 1 9; broom plantation, emerging from litter, 9.v.62, 1 9, 11 .v.65, 3 9, 15 .v.62, 1 9; caught in suction trap near the broom (and the oaks), 2.v.65, 1 9, 6.v.65, 1 9, 7.v.65, 4 9 , 8.v.65, 3 6 , 109, 9.v.65, 2 6 , 49, 10 .v.65, 1 6, 19, . The species appears to be a parasite of species of Psallus, but the oak-living bugs are often blown off on to the broom and may stay there for a long time. Probably for this reason most of our specimens were captured on broom (with which our main work was concerned) and not on oak, on which we rarely collected. The species is mostly found in the first half of May, whereas L. orthoryli is found right up to June.

Leiophron facialis (Thomson) Euphorus facialis Thomson, 1891 : 1747. Euphorus picipes: Marshall, 1887 : 58, part, not of Curtis.

Black; mandibles yellowish, clypeus reddish; antennae and legs yellow-brown, distal part of antennae and hind legs except coxa not appreciably darker. Wings hyaline, venation light yellowbrown, pterostigma hardly paler proximally. Eyes in male smaller and less convergent than in female, at narrowest separated by the length of antennal segments 3 + 4 or about three-quarters their own length. In female, eyes at narrowest separated by about the length of antennal segments 2 + 3 or about half their own length. Malar space a little shorter than scape. Antennae rather long, segment 3 a little longer than segment 1 in female, of about same length in male, clearly longer than 4 in female, of same length in male; number of segments: female (11 specimens)-1 with 17, 4 with 18, 6 with 19, male (9 specimens)-3 with 20,2 with 21,4 with 23; penultimate segments fully one and a half times as long as broad in male, quadrate in female. Generally very similar to L. picipes but larger, head including from finely punctured, sometimes with a central keel in front.

Mesoscutum finely punctured, notaulices with distinct punctures. Petiole a little broader posteriorly. Size clearly larger, length about 3.0 mm.

Measurements (in mm.), range, means and standard deviations. This is very close to L . microcerus but is a little larger and has paler legs and antennae and more antennal segments. It is also very close to L. orthotyli, described below, but is paler, with the petiole rather broader, the antennal segments a little longer, and the facial pubescence longer and more silvery. Dr. N. Waloff finds that the larva of L. facialis (2 specimens) is 4-5-5-0 mm. long with the maximum width of the head capsule 1.4-1.5 mm. ; in L. orthotyli (8 specimens) the length is 3-0-3-9 mm. and the width of the head capsule 1.2-1.6mm. Otherwise the larvae seem to be almost identical.

Leiophron orthotyli sp. n.

Black; mandibles yellowish with red tips, clypeus sometimes reddish ventrally, antennae and legs yellow-brown, distal half of antennae and hind femora often somewhat darkened, hind coxa more or less blackened. Wings ( fig. 1 ) hyaline, venation yellow-brown, pterostigma brown, small proximal patch paler. Eyes a little longer and more convergent below in female than in male. In female, eyes at narrowest separated by the length of antennal segments 2 + 3 or a little more, or about two-fifths their own length. Malar space about as long as a p e . Antennae in female with segment 3 not quite as long as 1, clearly longer than 4, in male a little longer than 1 and one and a half times as long as 4; number of segments (see also table below): female (63 specimens)-2 with 17,27 with 18, 33 with 19, 1 with 20, male (68 specimens)-1 with 20, 12 with 21,43 with 22, 12 with 23; penultimate segments just longer than quadrate in female, about one and a half times as long as broad in male.

Generally very similar to L. picipes Curtis, but head and mesoscutum with some, usually many, fine hair-bearing punctures, lower from with a more or less distinct central keel. Notaulices distinctly punctured. Petiole about as in L. picipes and L. microcerus but narrower than in L. facialis. Length 2 4 2 . 9 mm. The species has not so far been obtained outside Silwood Park, where it is common, but it doubtless occurs widely as its Mirid hosts are widespread on broom and Asciodema is also widespread on gorse, Ulex europaeus L.

Measurements (in mm.), with means and standard deviations : After much study, I finally convinced myself that this species must be described as new. It is a little larger and has more antennal segments than L. picipes or L. microcerus; it is also more punctured than the former. It is smaller, darker and has a narrower petiole than L. facialis. The species allied to L. pallipes are still in need of study, and Dr. Graham considers that there are several undescribed ones. The females have 20-25, usually 22-24, antennal segments and the males 22-27, usually 24-26; most of these species are also larger and more strongly punctured.

There are three other species which should also be considered here, namely L. obscuripes (Thomson) , L. laeviventris (Ruthe) and L. relictus (Ruthe) ; they are described below, as I have seen the types, but they differ from the last three species in having an unpunctured mesoscutum and from L. picipes in being larger with more antennal segments.

Leiophron obscuripes (Thomson) Euphorus obscuripes Thomson, 1891 .

Black; mesoscutum somewhat pitchy; mouthparts yellow, tips of mandibles pitchy; antennal segments 1-4 light brown, remaining segments darker, legs light brown, mid and hind femora darker.

Wings hyaline, veins pale, costa, pterostigma and Rs darker. Eyes moderately convergent below, at narrowest separated by two-thirds the length of the eye. Malar space about one-fifth as long as eye, about as long as antennal segment 5. Antennae with segment 3 as long as 1 and just shorter than 4, with 19 segments, penultimate ones a little longer than broad; face immediately below antennae finely granulate, with sparse inconspicuous, silvery pubescence; clypeus with margin slightly recurved, not truncate; head transverse when seen from above, slightly narrowed behind, rather convex, POL just shorter than OOL, frons in front of ocelli with distinct but fine punctures, behind ocelli almost unpunctured. Mesoscutum smooth and unpunctured, notauli deep, with large but rather ill-defined punctures, meeting just in front of scutellum; propodeurn rounded, rather coarsely reticulate-rugose, with a smoother area behind the scutellum. Wings with marginal cell moderately large, on costa half as long as pterostigma, first abscissa of marginal vein (= cross-vein r ) obliterated, cross-vein m-cu (recurrent) distinct; hind wing with cell M + Cu well-defined. Petiole regularly striate, of moderate length, widening very gradually, apex less than twice as wide as base (= 0.62 mm.). Hind tibia 2.21 mm. long, its larger spur rather longer than apical width of tibia. Length about 2.5 mm.

For relations to the other species, see key (p. 183). I do not know the female, but according to Graham it has 19 antennal segments. (Ruthe) Microctonus laeviventris Ruthe 

Black; some reddish markings on the head; clypeus brown; mandibles yellow; antennae and legs yellowish, hind coxae blackened at base. Wings hyaline, pterostigma light brown. Eyes not very convergent below, at narrowest separated by four-fifths their length or by the length of antennal segments 3 + 4. Malar space about as long as antennal segment 4. Antennae with segment 3 just longer than 1 or 4, shorter than 1 + 2, with 23 or 24 segments, penultimate segments not quite one and a half times as long as broad. Face moderately shining, with close, moderately fine punctures and dense but rather short, silvery hairs, clypeus with margin slightly upcurved, not truncate; head above with not very close, moderately strong punctures, POL : OOL = 3 : 4. Mesoscutum shining, unpunctured or in one specimen with some rather fine punctures on its front half, notauli deep, not ' punctured, meeting just in front of the scutellum; propodeurn not truncate, irregularly reticulaterugose. Wings with marginal cell three times as long on costa as parastigrna, first abscissa of marginal vein (= cross-vein r ) obsolete, cross-vein m-cu (recurrent) distinct; hind wing with cell M + Cu well-defined. Petiole not long, narrow, one and a third times as wide as maximum width of hind femur, widening only in the last quarter, surface shining with irregular rugae, apex smooth. Larger spur of hind tibia as long as apical width of hind tibia or as long as third hind tarsal segment. Length about 2.5 mm. Width of petiole 058, 0.63 mm., length of hind tibia 2.46, 230 mm. This species might be put near L. picipes because of the reduced punctures of the mesoscutum, but it seems to be rather an outlying member of the group of L. pallipes, the species of which otherwise have a well-punctured mesoscutum.

There are two male specimens from the Ruthe collection in the British Museum: one labelled 59-101 Germany/59-101 Ruthe coll./M. laeviventris Rut./M. laeviventris m. and one with similar labels except for the Latin names. The first specimen, which bears what is probably Ruthe's label, is here chosen as the lectotype. (Ruthe) Microcronus relictus Ruthe, 1856 : 305.

Black, head and mesothorax often somewhat pitchy; clypeus reddish, mandibles yellow with reddish tips; antennae and legs yellow-brown, tips of antennae somewhat dark, hind coxa darkened at base. Wings hyaline, venation and pterostigma yellow-brown, pterostigma a little paler at base. Eyes of female considerably larger than in male and more convergent below, separated in female at narrowest place by two-thirds length of eye, by more than length of antennal segments 2 + 3, less than 3 + 4, in male eyes not convergent, separated by their own length or by that of antennal segments 2 + 3 + 4, post-gena a little narrower than eye in female, a little broader in male; malar space as long as antennal segment 5 in female, as long as 3 in male; clypeus with ventral margin feebly reflexed, face closely punctured, especially in female, with not very dense, rather long silvery pubescence; top of head with sparse, very fine, hair-bearing punctures, a weak central line or furrow in front of median ocellus, POL : OOL = 4 : 3 (female), 3 : 4 (male), temples not greatly enlarged. Antennae in female (6 specimens)-2 with 18 segments, 4 with 19, in male (14 unbroken specimens)-1 with 18 segments, 5 with 19, 5 with 20, and 3 with 21 segments; segment 3 as long as segments 1 + 2 (or hardly as long in male), one and a half times as long as 4, penultimate segments just longer than quadrate in female, one and a half times as long as broad in male. Mesoscutum smooth and shining, with almost no punctures and what there are very fine, notauli very strong, with large but usually ill-defined punctures, meeting in front of the scutellum; mesopleuron mostly strongly and quite closely, rugosely punctured but with some smoother areas behind; propodeum not truncate, with strong, moderately close, reticulate rugae. Wings with first sector of marginal vein (cross-vein r ) almost or quite obliterated, marginal cell not very short, on costa two and a half times as long as parastigma and rather less than half as long as pterostigma, first free sector of Rs (first intercubital) and cross-vein m-cu (recurrent) quite distinct. Abdominal petiole rather short and considerably broadened, two and a half times as long as broad at apex, apical breadth about two and a half times greatest width of the somewhat stout hind femur, surface shining, regularly striate. Longer spur of hind tibia longer than apical width of tibia, about as long as third hind tarsal segment. Length about 2.3-243 mm. Ruthe described this species, which he regarded as common, from 20 males and 12 females from Berlin. The series in the British Museum often have additional small labels, which indicate (probably in Ruthe's writing) what he thought was the sex and the number of antennal segments; the labels are, however, not always correct in these respects. No specimen has a label with his handwritten specific name. I now choose the female in best conditioned, labelled "59-101 Germany, 20, M . relictus Rut., Ruthe coll. 59-101" as lectotype.

Measurements, means and standard deviations (in mm.):

No. This species seems to be nearest to L . obscuripes and L . laeviventris, but the principal differences between them are shown in the key.

Species with M + Cu, cell in hind wing present but notauli weak or absent.

Cross-vein m-cu (recurrent) in fore wing usually weak.

Three species, L. deficiens (Ruthe) , L. fulviceps (Thomson) and L . arenicola (Thomson) have been described in this group. I have examined the types of all three, and a fourth new species is described below.

Leiophron heterocordyli sp. n.

Black; head and dorsal part of thorax more or less reddish-brown, especially in female, base of gaster more or less similarly tinged; legs and antennae yellow-brown, tips of antennae somewhat darker in female. Wings hyaline, veins and pterostigma very pale brown, parastigma and fork of M and Cu somewhat darkened. Eyes of female a little longer and less circular than those of male. Eyes somewhat convergent downwards, separated at bottom by less than their length, by a distance nearly as long as antennal segments 2 + 3 + 4. Malar space about one-third as long as greatest width of eyes, a little longer than antennal segment 3. Antennae in both sexes with segment 3 clearly shorter than segment 1 and slightly shorter than segment 4; number of segments in female (87 specimens)-7 with 15, 74 with 16, 6 with 17, in male (77 specimens)-30 with 17, 47 with 18; male antennae longer, a little thinner (especially penultimate segments) and usually rather paler than those of female, pubescence a little more conspicuous; face with relatively sparse, short, silvery pubescence; clypeus with ventral margin a little recurved but not at all truncate; head with sparse, very fine, piliferous punctures except immediately in front of ocelli, POL : OOL = 3 : 5. Mesoscutum shining, hardly punctured, notauli only just indicated, hardly perceptibly punctured, meeting well in front of scutellum; pleuron shining, punctures not very close; propodeum scarcely truncate, regularly finely rugose all over. Wings ( fig. 2) Of the allies of this species, L. fulviceps and L. arenicola are smaller and have antennal segment 3 as long or slightly longer than 4 and the first section R s S M even weaker and the marginal cell even shorter on the costa. L. dejiciens has the venation even weaker and is very close to L. arenicola. L . heterocordyli is common at Silwood Park both by breeding from Heterocordylus (normally more than 70 per cent. parasitism) and by beating broom, but it has not so far been captured elsewhere, although it is likely to prove widespread like its host.

A comparison was made of the number of antennal segments, posterior width of abdominal petiole and, as a measure of size, length of hind tibia, in a series of bred and captured specimens. The bred specimens are slightly smaller. Leiophron fulviceps (Thomson) Euphorus furviceps Thomson, 1891 : 1751, Q.

Male holotype: "Lomma 16/7" (Lund Museum): Generally like L. heterocordyli but clearly smaller, pronotum orange-yellow contrasting in colour with the mesothorax; antennae with 15 segments, segment 3 a little shorter than 1 and a little longer than 4. Eyes below separated by much less than their length. Mesoscutum shining, notauli weak. Abdominal petiole a little narrower at its posterior margin than in L. heterocordyli. The marginal cell in the fore wing is shorter than in L. heterocordyli, about as in L. defciens but the wings and their venation are less reduced than in that species. The eyes are more convergent below than in L. arenicola and slightly more than in L. deficiens.

Leiophron arenicola (Thomson) Euphorus arenicola Thomson, 1891 : 1751.

Male holotype: No data (Lund Museum) Generally like L. heterocordyli but smaller, with wings somewhat narrowed and shortened, as in L. deficiens. Colour orange to orange-brown with propodeum and posterior part of gaster darkened; antennae with 15 segments, segment 3 much shorter than I and about as long as segment 4. Eyes below separated by a little less than their length (less than in the other three species). Mesoscutum shining, notauli very weak. Abdominal petiole a little narrower at its posterior margin than in L. heterocordyli. Venation apparently quite similar to that of L. deficiens.

There is also a second specimen in the Lund Museum under this specific name. It is a male, labelled "Sm. Bhn." but belongs to some other species (eyes below separated by more than their length; marginal cell much wider) but as it is not a syntype it need not be considered. (Ruthe) Microctonus defciens Ruthe, 1856 : 301. and is here chosen as the lectotype. The species was described from "Kreuzberge, near Berlin, end June to end July, 10 examples caught on low plants".

Yellowish, mesoscutum, propodeum and gaster somewhat darkened, wings hyaline, pterostigma yellowish. Antennae with 15 segments in female, in male with 2-16, 1-17 segments. Very close to L. arenicola but eyes more convergent below, separated by clearly less than their length, by about the length of antenna1 segments 3 + 4, almost as in L. fulviceps. Notauli very feebly indicated by rows of shallow punctures, ending on disk of mesoscutum. Posterior margin of abdominal petiole: male4.33, 0.42, 0.50, female4.29, 0.42, 0.46, 0.50 mm.; length of hind tibia: male-1.21, 1.29, 1.50, female-1.25, 1.29, 1.33, 1.46 mrn.

Species with no M + Cu, cell in hind wing and notauli nearly always weak or obsolete.

In this group, there is one species of moderate size, L. claviventris (Ruthe) , with strong notauli. Two species are of small to moderate size with dark-marked wings and a narrow, elongate, parallel-sided petiole; these are L . apicalis Haliday and L. fascipennis (Ruthe) and at least the first-named is a parasite of Mirids. Finally, there are a number of small species with unmarked wings and a short, often somewhat widened petiole, of which at least two have been bred from Psocoptera. (Ruthe) Mi&octonus claviventris Ruthe, 1856 : 303. ? Microctonus claviventris Wesmael, 1835 : 71. Euphorus claviventris: Marshall, 1891 Ruthe used Wesmael's name, although he was doubtful if his specimens were really the same as Wesmael's. Ruthe's specimens (2 males, not 2 females as Ruthe supposed) are in the British Museum; not having seen Wesmael's type, I am for the time being using Ruthe's name, although a new one will probably be needed eventually.

Dark reddish-brown or in British specimens black or almost black; clypeus yellow or reddishyellow, mandibles yellow with reddish tips; legs and antennae yellow-brown, apex of antennae and base of hind coxae darker. Wings hyaline, venation pale, parastigma and pterostigma darker, proximal part of latter pale, especially along costa. Head subcubical, especially in male in which it is distinctly widened behind the eyes and more produced backwards; in male eye longer than broad, length about equal to that of antennal segments 3 + 4, width to about that of segments 2 + 3, eye much smaller than postgena; female eyes a little larger than in male and about the same width as the postgena; male eyes not convergent below, separated by their own length, female eyes moderately convergent below, at narrowest separated by two-thirds their length or the length of antennal segments 2 + 3; malar space very long in male, as long as antennal segment 3, shorter in female, about two-thirds as long as antennal segment 3; clypeus in male with part of the ventral margin produced into a trapeziform plate of which the edge is feebly emarginate, the details varying in different specimens, the gap between the bottom of the clypeus and the mandibles unusually wide; in female the clypeus is normal, with the ventral margin a little upturned and no wide gap between it and the mandibles; mandibles in male wide at base and suddenly narrowing to an acute point, in female as usual sickleshaped, gradually narrowing; face shining, with sparse fine punctures and silvery hair, longer and less close in male. Antennae in both sexes with 16 segments, segment 3 very long, distinctly longer than 1 or 4, penultimate segments nearly one and a half times as long as broad. Top of head practically unpunctured, with sparse relatively long hairs, POL : OOL= 1 : 1 (female), 5 : 4 (male). Mesoscutum practically unpunctured, with sparse pubescence, with strongly but weakly punctured notauli (punctures large but ill-defined) meeting near centre of scutum; mesopleuron smooth and shining with a punctured furrow in front and below; propodeum not truncate, some strong rugae dorsally, sculpture weaker posteriorly, especially in female. Wings with first sector of marginal vein (cross-vein r ) completely obliterated, marginal cell short, about twice as long on costa as parastigma, about one-third as long as pterostigma, first free sector of Rs (first intercubital) and cross-vein m-cu (recurrent) both rather pale; hind wing with no M + Cui cell though there is a small stub of a vein corresponding to where it would end. Abdominal petiole rather long and narrow, hardly wider posteriorly than maximum width of hind femur, spiracles rather projecting, surface regularly striate in female, more or less irregularly in male. Longer spur of hind tibia longer than apical width of tibia, about as long as second hind tarsal segment. Length, female 2.5 mm., male rather larger. Posterior margin of petiole: male4.46, 0.38, 0.38, female-0.42; length of hind tibia: male-2.08, 2.00, 2.08, female-1.83 mm. fig. 1 (probably) . Euphorus apicalis: Marshall, 1891 : 16. Microctonus farcipennis Ruthe, 1856 : 302, some specimens but not the type.

Lighter or darker testaceous with a patch round ocelli, propodeum and often mesopleuron and sternum, usually petiole and gaster after the proximal half of its second segment, blackish; the exact amount of light and dark pigment varies considerably; legs and antennae light yellow-brown, apex of antennae somewhat darker, especially in female. Eyes bright green, at least in life. Wings with more or less distinct clouds on disk before and after the pterostigma, venation very pale, parastigma and pterostigma darker, proximal third of latter pale. Eyes of female a little larger and more convergent below than those of male, eyes in female at narrowest separated by half their length or by the length of antennal segment 3, in male separated by four-fifths their length or by the length of antennal segments 2 + 3, postgena about three-quarters as wide as eye; malar space about as long as antennal segment 1 or rather longer in male; clypeus with ventral margin feebly reflexed; face shining with short inconspicuous pubescence; top of head unpunctured, bare, POL : OOL = 1 : 1 (female), 3 : 4 (male). Antennae in female (35 specimens)-34 with 16, 1 with 15 segments, in male (23 specimens)-l5 with 17 segments, 8 with 18 segments, segment 3 about as long as 1 + 2 and nearly one and a half times as long as 4, penultimate segments a little longer than broad, pubescence very similar in the sexes. Mesoscutum smooth, shining, unpunctured, notauli not or hardly perceptibly indicated; mesopleuron smooth and shining with traces of punctured furrows in front and below; propodeum hardly truncate, shining, with irregular, not very close rugae. Wings ( fig. 4) with first sector of marginal vein (cross-vein r) almost or quite obliterated, marginal cell very short, no longer on the costa than the parastigma, less than one-quarter as long as pterostigma, first free sector of Rs (first intercubital) very weak, cross-vein m-cu (recurrent) obsolete, bristles in cell Sc + Rs (= basal) short and rather sparse, wing beyond the pterostigma slightly darkened. Abdominal petiole long, fully four times as long as broad, narrow (not broader than greatest width of hind femur), parallel-sided, spiracles distinctly projecting, surface dull, irregularly rugose. Longer spur of hind tibia about as long as apical width of tibia or as long as tarsal segment 3. Length 1.7-2.2 mm.

Measurements (bred specimens often rather smaller than captured ones but are included below), The adult stage may be found in the field over an unusually long period (Maylate July) and this is doubtless related to a similar range in the time of occurrence of its hosts. There is no evidence, however, that the adults bred from late collected larvae emerged particularly late the following year, so that there does not seem to be a tendency to form host "strains".

The type of Euphorus ornatus Marshall, 1887, seems to be lost but both Dr. Graham and I think that it was probably a slightly abnormal specimen of L. apicalis. It was described from Wilts., Nunton (1 6). Ruthe, 1856 , was synonymised with L. apicalis by Marshall (1887 : 62), but the two specimens in the British Museum belong to different species and Ruthe's name is kept for the one which is distinct from L. apicalis.

Microctonus fascipennis Ruthe, 1856 : 302 (part) .

Yellowish-orange, dorsum of thorax, especially round scutellum, and gaster especially at tip, darker. Eyes bright green, even as a rule in dead specimens. Wings light fuscous with base and a complete narrow band across proximal half of pterostigma hyaline, venation pale, pterostigma with proximal half whitish, distal half light brown. Eyes of female considerably larger than those 0. W. Richards on some British species ojleiophron Nees of male, in female at narrowest separated by one-third length of eye or length of antennal segment 3, in male by three-fifths length of eye or length of antennal segment 2 + 3; postgena very wide, nearly as wide as eye; malar space in female as long as antennal segment 7, in male as long as antennal segment 5 ; clypeus with ventral margin a little recurved and truncate; top of head with a few very sparse punctures and weak transverse striation. POL : OOL about 2 : 3 or 3 : 5. Antennae with 15 segments in female (5 specimens) and 18 segments in male (6 specimens), segment 3 as long as segments 1 + 2 or one and a third times as long as segment 4, segments unusually long even in female, in which penultimate segments are at least one and a half times as long as broad. Mesoscutum with fine microsculpture, not really shining though unpunctured, notauli indicated by lines of feeble transverse striae, meeting in front of scutellum; mesopleuron shining, mostly smooth, with some anterodorsal and posteroventral rugosities; propodeum rather flattened but not at all truncate, with irregular rugae and smoother areas between dorsal and lateral surfaces. Wings with first sector of marginal vein (cross-vein r ) obsolete, marginal cell narrow, on costa about as long as parastigma, about one-quarter as long as pterostigma, first free sector of Rs (first intercubital) weak, cross-vein m-cu (recurrent) obsolete, cell Sc + Rs (basal) without any bristles. Abdominal petiole long (five times as long as broad), narrow (narrower than greatest width of hind femur), parallel-sided, spiracles rather prominent, surface irregularly rugose rather dull. Longer spur of hind tibia longer than apical width of tibia, shorter than second but longer than third hind tarsal segment. Length about 3.0 mm. I have not met the species myself, but I understand that Dr. Graham has caught some specimens.

The species parasitising Psocoptera The last group consists of a number of small species, several of which have been bred from Psocids. There are at least three British species, but the group is in need of further study, and there are probably several undescribed ones. I am unwilling to describe any of these species at present, but it is desirable to give some of the records and also to establish some synonymy and to fix lectotypes of Ruthe's species. All the species have 16 antennal segments or rarely 17 in the male. The sexes are unusually difficult to separate.

Leiophron similis Curtis, 1833 : 476. Microctorius oblifus Ruthe, 1856 : 303. In the British Museum collection are four females from the Marshall collection, Herts., St. Albans; Monmouth, Govilon; Leicester. There are also five females, one male and one specimen of doubtful sex from the Ruthe collection. One of the females labelled "59-101 Germany/M. oblitus Rut./Ruthe coll. 59-101/" is here designated as the lectotype. Ruthe described the species from Germany without giving any locality. The British Museum also has ten specimens from Sweden, SkAne. At Silwood Park, Berks., we have bred two males and one female from litter under broom bushes, emerging between mid-June and early July.

The species is the only one of the group in which the notauli are quite clearly marked. It does not seem to have been bred from any host, although Dr. E. Broadhead has bred a number of specimens of a closely allied but probably different species from Mesopsocus unipunctatus (Miiller) in Yorkshire, emerging in August. As pointed out to me by Mr. R. D. Eady, this species seems to have the head more swollen behind the eyes than has L. similis.

Leiophron fulvipes Curtis, 1833: 476 (wing, see fig. 5 ).

In the British Museum collection are four females from the Marshall collection, S. Wilts., Nunton, and a series of 70 specimens from Sweden, SkAne. There are also three males and two females from Leeds, bred by Dr. E. Broadhead from Elipsocus westwoodi McLachlan, emerging in June, and from E. hyalinus (Stephens), emerging in August. At Silwood Park, Berks., we have bred a 'considerable number from litter under broom, emerging mid-May to end-June, and one male from the nymph of Amphigerontia bvasciata (Latreille in Coquillet), collected 26. vi .64, emerged 21. v. 65. A considerable number of the Psocids were parasitised, but only one adult parasite was bred. Psocids did not become really common on the broom at Silwood until 1964, when the broom was seven years old. In the British Museum collection is one male from the Marshall collection, Herts., St. Albans and 25 specimens from Sweden, SkAne. From the Ruthe collection are four females, three males and one doubtful male of Microctonus parvulus Ruthe. A female labelled "159-101 GermanylM. parvulus Rut./Ruthe coll. 59-101/M. parvulus m./" (the last label being in Ruthe's handwriting) is here selected as the lectotype. Ruthe records species from Berlin, end May to early July. We have bred one male at Silwood from litter under broom, emerging in early June.

Species marked with an asterisk are described as new above 1 Hind wing with cell M + Cu, present and fully defined, cross-vein cu-a -Hind wing with cell M + Cu, not defined, at most traces of cross-vein cu-a pigmented. Notauli rarely more than weakly indicated, oqen absent .

2 Mesoscutum with notauli quite strong, meeting one another just in front of the scutellum and often strongly punctured. Fore wings with com--Mesoscutum with notauli very weak, often hardly traceable, meeting nearer the disk of the scutum, never strongly punctured. Fore wing with cross-vein m-cu (recurrent vein) weak or hardly pigmented . . 

Richards on some British species of Leiophron Nees -Mesoscutum and head distinctly punctured, notauli strongly punctured

Synopsis der Familien u

An essay on the classification of the parasitic Hymenoptera of Britain, which corresponds with the Ichneumones minuti of Linnaeus

Monograph of British Braconidae

New neotropical wasps of the family Braconidae (Hymenoptera) in the US. National Museum

Appendix ad Gravenhorst

Prodromus einer Monographie der Gattung "Microctonus Wesm

Bidrag till Braconidernes kannedom

Type species of the genera of ichneumon flies

Monographie des Braconides de Belgique

22-27, usually 24-26 segments . . . . . Group of L. pallipes Curtis -Mesoscutum distinctly punctured, even posteriorly . . . . . . . 8 5 Small species, hind tibia about 2.0 mm. long; antennae and legs more or less darkened; head effectively unpunctured, even in front of ocelli; antennae in female with 16-17 segments, in male with 19-20, segment 3 a little shorter than 1 . . . . . . . . . . L. picipes Curtis -Head distinctly though very finely punctured; antennae in female (this sex not known in two species) with 18-19 segments, in male with 19-24 segments, segment 3 as long or longer than 1 . . . . . . . 6 Species of same size or a little smaller than L. picipes but head and mesoscutum more or less pitchy and legs and antennae yellow-brown. Antennae in female with 18-19, in male with 18-21 segments, segment 3 clearly longer than 1 or 4. POL : OOL in female 4 : 3, in male 3 : 4. Abdominal petiole rather short and broad, two and a half times as wide as hind femur . . . . . . . . . . . (Ruthe) Species clearly larger than L. picipes, hind tibia 2.2-2.5 mm. long; head and mesoscutum black; antennal segment 3 not or hardly longer than 1 or 4; abdominal petiole narrower, hardly one and a half times as wide Antennae and legs rather dark; antennae with 19 segments, segment 3 as long as 1, just shorter than 4; eyes below separated by two-thirds their length; POL just shorter than OOL . . . . L. obscuripes (Thomson) Antennae and legs yellow-brown ; antennae with 23-24 segments, segment 3 just longer than 1 or 4; eyes below separated by four-fifths their length; POL : OOL = 3 : 4 8 Antennae in female with 15-17, rarely with 18 segments, in male with 19-20, rarely with 21 segments, penultimate segments in female quadrate, segment 3 a little longer than 1 in female, of same length in male. Size small, hind tibia 1.50-1-90 mm. long, width of petiole 0.45-0.60 mm.; hind femora and apex of antennae more or less dark 4 Mesoscutum not or hardly punctured . . . . . . . . . . (Ruthe) L. microcerus (Thomson) -Antennae in 9 with 18-19, rarely with 17 or 20 segments, in male with 20-23 segments, penultimate segments usually a little longer. Size a 9 Legs and antennae yellow-brown; eyes at narrowest separated by hardly more than half their length; size larger, hind tibia 1.60-2-25 mm., . L. heterocordyli* Notauli rather stronger; wings not narrowed or shortened; antennal segment 3 a little shorter than 1, a little longer than 4; eyes in female separated below by clearly less than their length .

L. fulviceps (Thomson) Notauli weaker; wings distinctly narrowed and shortened, venation very weak; antennal segment 3 much shorter than 1, about as long as 4 .

Eyes below separated by a little less than their length; colour rather darker; venation rather stronger . . . . . L. arenicola (Thomson) Eyes below separated by clearly less than their length, though by a little more than in L. fulviceps; colour rather paler; venation weaker L. &&ens (Ruthe)