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 u. s. DEPARTMENTS (^^AGRICULTURE, 
 
 BU'R'EllTof ntflMAL lNDUSTfl.8*|(Cin No. 69. 
 
 D, E. SALMON, D. V. M., Chief of Bureau. 
 
 m^? 
 
 E EXTERNAL PARASITES OFTlOGS, 
 
 BEING AKTICLES ON 
 
 THE HOG LOUSE (Hcematopinus mis) 
 
 MANGE, OR SCABIES, OF HOGS. 
 
 KA1IIVE C!. STEVENSON, B. Sc., A. M., 
 /<wti>yi<-<if Laboratory, litircau of Auinal 
 
 WASHINGTON: 
 
 GOVERNMENT PRINTING OFFICE.
 
 ORGANIZATION OF THE BUREAU OF ANIMAL INDUSTRY. 
 
 Chief: 1>. V.. SALMON, D. V. M. 
 A.^lxf.unt Clilff: A. 1). MKLVIN, D. V. S. 
 (1>'n\f Clerk: E. B. JONES, LL. M., M. D. 
 
 Dni rt/ Division: ED. II. WEBSTER, M.S., chief; CLARENCE B. LANE, B. 8., assistant 
 chief. 
 
 ///X///V//YI// Dirixitin: A. M. FARRINGTON, B. S., D. V. M., chief. 
 
 (jiKiftnitiitf JUria'ton: RICHARD W. HICKMAN, Ph. G., V. M. D., chief. 
 
 Editor: GEORGE FAYETTE THOMPSON, M. S. 
 
 Arlit: W. S. I). RAINES. 
 
 Annnitl Jfiiitlnnichnitti: GEORGE M. ROMMEL, B. S. A. 
 
 Librarian: BEATRICE C. OBERLY. 
 
 LABORATORIES. 
 
 MARION DORSET, M. D., chief. 
 IHrision: JOHN R. MOHLER, A. M., V. M. D., chief. 
 Zoological Division: BRAYTON H. RANSOM, B. Sc., A. M., acting zoologist. 
 
 EXPERIMENT STATION. 
 
 Superintendent: E. C. SCHROEDER, M. D. V. ; expert assistant, W. E. COTTON. 
 
 INSPECTORS IN CHARGE. 
 
 Dr. F. \V. Ainsworth, Union Stock Yards, Pitts- 
 burg. Pa. 
 
 Dr. M. O. Anderson, care Geo. A. Hormel A: Co., 
 Austin. Minn. 
 
 Dr. Don C. Ayer, Post-Office Building, South 
 Omaha, Nebr. 
 
 Dr. G. S. Baker, 6th and Townsend sts.,San Fran- 
 Cal. 
 
 Dr. L. R. Baker, South St. Joseph. Mo. 
 
 Dr. Boyd Baldwin, care Cudahy Bros., Cudahy, 
 
 Wis.' 
 
 Dr. A. E. Behnke, room 432, Federal Building, 
 
 Milwaukee 1 . Wis. 
 
 Dr. John A. Bell, Watertown. N. Y. 
 Dr. S. E. Bennett, room 338, Live Stock Ex- 
 
 inire Building. Kansas City, Kans. 
 Dr. E. L. Bertram, care J. S. Gi'lmore, Davenport, 
 
 Iowa. 
 Dr. Fred Braginton.care Continental Packing Co., 
 
 Bloomington, ill. 
 Dr. .1. .1. Brougham, care Missouri Stock Yards, 
 
 St. I.oiiK Mo. 
 Dr. G. W. Butler, care Drummond Bros., Eau 
 
 Claire. Wis. 
 
 Dr. J. B. Clancy. National Stock Yards. 111. 
 Dr. Lowell Clarke, room 320, Quincy Building, 
 
 Denver. Colo. 
 
 Dr. Charles Cowie. Ogdensburg, N". Y. 
 Dr. David CuiiiiiiinL'.'.)!^ Lapeerave., Port Huron, 
 
 Mich. 
 Dr. Robert Darling, care Chas. S. Hardy, San 
 
 Cal. 
 
 Dr. E. T. Davison, Kushville, Nebr. 
 Dr. .1. F. Deadman, Sunk Ste. Marie. Mich. 
 Mr. Albert Dean, room 32>j, Stock Yard Station, 
 
 Kansas City, Kans. 
 
 Dr. F. L. De Wolf, care Chas. Wolff Packing Co., 
 Topeka, Kans. 
 
 Dr. Geo. Ditewig, care Union Stock Yards, Cin- 
 cinnati, Ohio. 
 
 Dr. E. P. Dowd, care White, Pevey & Dexter Co., 
 Worcester. Mass. 
 
 Dr. O. E. Dyson, 316 Exchange Building, Union 
 Stock Yards, Chicago, 111. 
 
 Dr. Geo. C. Faville, P. O. box 796, Norfolk, Va. 
 
 Dr. J. W. Fink, care Swift & Co., Harrison sta- 
 tion, Newark. N. J. 
 
 Dr. T . A. Gecldes, care U. S. consul, London, Eng- 
 land. 
 
 I>r. H. H. George, r>07 Johnson St., Louisville. Ky. 
 
 Dr. W. H. Gibbs, care Morton-Gregson Co., Ne- 
 braska City, Nebr. 
 
 Dr. L. K. Green, care Hammond, standish <t Co.-, 
 Detroit, Mieh. 
 
 Dr. H. A. Hedrick, '215 St. Paul st., Baltimore. 
 Md. 
 
 Dr. O. B. Hess, care Frye-Bruhn Co., Seattle. Wash. 
 
 Mr. G. S. Hiekox, P. O. box 1145, Salt Lake City. 
 Utah. 
 
 Dr. A. A. Holcombe, Aurora, 111. 
 
 J)r. .lulius Hudson, care Jersey (Uty Stock Yards 
 Co., Jersey City. N. J. 
 
 Dr. K. W. Il'untiiigton, U. S. customs oltice. G. T, 
 K. !!. wharf, Portland, Me. 
 
 Dr. Robert .lay, care Jacob E. Decker A: Son. 
 Mason City, fowa. 
 
 Dr. <;. A. Johnson, Exchange Building, Sioux 
 City. Iowa. 
 
 Dr. James Johnston, care U. S. consul;; 
 Chai>el st., Liverpool. England. 
 
 Dr. E. c. Joss, care, rarstens Packing Co., Tacoma, 
 Wash. 
 
 (Concluded on third page of cover.)
 
 U. S. DEPARTMENT OF AGRICULTURE, 
 
 BUREAU OF ANIMAL INDUSTRY. Bulletin No. 69. 
 
 D. E. SALMON, D. V. M., Chief of Bureau. 
 
 THE EXTERNAL PARASITES OF HOGS. 
 
 BEING ARTICLES ON 
 
 THE HOG LOUSE (Hamatopinus suis) 
 
 MANGE, Oil SCABIES, OF HOGS. 
 
 BY 
 
 KARLK <J. STEVENSON, B. So., A. M., 
 Zoological Laboratory, Bureau of Animal Industry. 
 
 WASHINGTON: 
 
 GOVERNMENT PRINTING OFFICE. 
 
 1905.
 
 LETTER OF TRANSMITTAL 
 
 UNITED STATES DEPARTMENT OF AGRICULTURE, 
 
 BUREAU OF ANIMAL INDUSTRY, 
 Washington, D. C. , January 8, 1905. 
 
 SIR: I have the honor to submit herewith a paper entitled "The 
 External Parasites of Hogs," by Earle C. Stevenson, of the Zoologi- 
 cal Laboratory of this Bureau, and to recommend its publication as a 
 bulletin. 
 
 This paper deals with two enemies of the hog the hog louse, and 
 mange, or scabies, of the hog. The first of these enemies especially, 
 the hog louse, is one with which every hog raiser is familiar, and one 
 that he has been forced to tolerate because he knew of no satisfactory 
 cheap method of getting rid of the lice. This paper is designed, not 
 only to give a technical description of the hog louse and the scab mite, 
 but to give advice as to how to get rid of the lice and the mites and 
 practical suggestions growing out of actual experience. 
 Kespectfully, 
 
 D. E. SALMON, 
 
 Chief of Bureau. 
 Hon. JAMES WILSON, 
 
 Secretary.
 
 CONTENTS. 
 
 Page. 
 
 Introduction 7 
 
 The hog louse (Hxmatopimis Kids (Linnaeus, 1758) Leach, 1817 ) 9 
 
 Brief historical review 9 
 
 Synonymy 10 
 
 Classification 11 
 
 Geographical distribution 12 
 
 Description 12 
 
 Egg of the hog louse 15 
 
 Injurious effects of the hog louse 16 
 
 Treatment for the hog louse 17 
 
 Preventive measures 17 
 
 Treatment of the hogs 18 
 
 Formulas of oil emulsions 20 
 
 Mange, or scabies, of hogs 23 
 
 Cause of mange 23 
 
 Sarcoptic mange 23 
 
 Description 24 
 
 Reproduction 24 
 
 Symptoms 24 
 
 Contagion 24 
 
 The injurious effects of mange 25 
 
 Treatment 25 
 
 Remedies 26 
 
 Ointments 26 
 
 Liquid preparations 26 
 
 Demodecic mange 27 
 
 Application of remedies 29 
 
 Dipping 29 
 
 Spraying 33 
 
 Bibliography 35 
 
 5
 
 ILLUSTRATIONS. 
 
 Page. 
 
 FIG. 1. Dorsal view of female louse 9 
 
 2. Dorsal view of male louse 10 
 
 3. Ventral view of last three abdominal segments of male louse 12 
 
 4-8. Cross section of stylet, or so-called sucking-tube, of louse 13 
 
 9-11. Basal parts of stylet 13, 14 
 
 12. Dorsal view of everted proboscis, showing the hooks and also the 
 
 parts of the protruded stylet 14 
 
 13. Claw of hog louse 15 
 
 14. P^gg of hog louse 15 
 
 15. Shell of egg from which the young louse has escaped 15 
 
 16. View of outer surface of egg shell 16 
 
 17. View of inner surface of egg shell 16 
 
 18. Dorsal view of female mite (Sarcoptes scabiei var. suis) causing sar- 
 
 coptic mange 23 
 
 19. Dorsal view of male mite (Sarcoptes scabiei var. suis) of sarcoptic mange. 24 
 
 20. Egg of mite of sarcoptic mange 24 
 
 21. Ventral view of male mite (Demodex folliculorum var. suis) causing 
 
 follicular mange 27 
 
 22. Ventral view of female mite of follicular mange 27 
 
 23. Egg of mite of follicular mange 27 
 
 24-25. Plans for dipping tank 30, 31 
 
 26-28. Simple spraying apparatus 32, 33 
 
 29. Sectional view of oak post to be saturated with kerosene for use as 
 
 a rubbing post for lousy hogs 34 
 
 6
 
 THE EXTERNAL PARASITES OF HOGS. 
 
 By EARLE C. STEVENSON, B. Sc., A. M., 
 Zoological Laboratory, Bureau of Animal Industry. 
 
 INTRODUCTION. 
 
 In most of the published works on hogs and the prevention and 
 treatment of their diseases the subject of external parasites is disposed 
 of within the brief space of one or two pages, and the very short notes 
 given on the prevention and destruction of these pests are no doubt 
 due to the tendency to underestimate the economic importance of these 
 parasites, for the reason that the injurious eft'ects they produce are 
 not always recognized as being of parasitic origin. The poor condi- 
 tion of health and stunted growth of some droves of hogs in a locality 
 where other herds thrive on practically the same food and care is 
 very frequently observed, particularly among young animals. This 
 unhealthy condition may result from various causes. Observation 
 and experiment, however, have demonstrated that not infrequently 
 the trouble is to be traced to the presence of parasites on the skin of 
 the animals. These parasites produce a diseased condition of the skin, 
 annoy and irritate the hogs, and, in spite of excellent care and good 
 food provided for them, interfere with the general health and growth 
 of the animals. The injurious effects have been known to become so 
 severe as to cause death to young pigs. 
 
 The three principal external parasites of the hog are the large louse 
 (Hsematoplnus suis), the small itch mite (Sarcoptes scabiei var. suis}, 
 and the minute mite of follicular mange (Demodex folliculorum var. 
 suis). Other external parasites have been noted by Jarvis (1904), who 
 found in the Umtali District, South Africa, a number of ticks on hogs 
 that were suffering from a disease known as " porcine malaria." This 
 disease is said to be most prevalent during the rainj^ season, when ticks 
 are most abundant. These ticks were determined as Amblyomma 
 varigata (misprint for variegata), A. flava, Ithipicephalm appendicu- 
 laris (misprint for appendiculatus), and Rhipicephalus sp. ? 
 
 Demodex folliculorum is of common occurrence, but seems to be of 
 
 little economic importance to the farmer. It is found buried deep in 
 
 the follicles of the skin and does not yield to ordinary treatment. 
 
 Hsematopinus suis is the largest representative of its family, and it 
 
 19185 No. 6905 2 7
 
 8 BUREAU OF ANIMAL INDUSTRY. 
 
 forms the principal subject of this discussion. Sarcoptes scdbiei var. 
 suis not infrequently becomes more injurious than the hog louse and 
 therefore is of considerable economic importance. 
 
 The scope of this article includes a review of the literature on the 
 subjects of lice and mange of hogs, a record of the new experiments 
 performed, and a more complete account of the large louse (Hsema- 
 topinus suis). (For Bibliography, see p. 35.)
 
 THE HOW LOUSE. 
 
 (Hacmatopinus suis (Linnseus, 1758) Leach, IS 17.) 
 
 BRIEF HISTORICAL REVIEW. 
 
 Mouffettus (1634, p. 265) mentions the hog louse and refers to 
 Albertus (twelfth century) as having named it Pediculus urius, from 
 the Latin word " urendo," meaning " to irritate." This early histori- 
 cal reference places the hog louse 
 among the oldest recognized spe- 
 cies of parasitic insects. Linnaeus 
 (1758) described it under the name 
 Pediculus suis. Panzer (1T98) 
 used the name given by Linnaeus, 
 and states that Fabricius classed 
 this parasite with Pediculus asini 
 of Redi (1671). This reference 
 to Fabricius, cited by Panzer, is 
 not at hand, but in a later publi- 
 cation (1805) Fabricius gives the 
 synonymy corresponding to the 
 statement of Panzer. A compari- 
 son of Redi's figure of Pediculus 
 asini with a specimen of Ild&ma- 
 topinus suis shows a striking 
 resemblance between the two, but 
 Linnaeus based in part his species 
 Pediculus asini, on Redi's figure 
 and Panzer disregarded the clas- 
 sification of Fabricius. Leach 
 (1817) subdivided the genus Pedi- 
 culus into four genera Phthi- 
 rus, Ifsematopinus, Pediculus, and 
 Nirmus classing the hog louse 
 as type of the new genus ILsmatopinus. Nitzsch (1818) revived the 
 specific name vrius, combining it with the generic name Pediculus. 
 Giebel (187-1), in describing the parasite, named it Haematopinus 
 urius. 
 
 9 
 
 FKJ. 1. Dorsal view of female hog louse, x 15. 
 a, antenna;; b, eye; c, spiracles; d, protxwcis or 
 haustellum.
 
 10 
 
 BUREAU OF ANIMAL INDUSTRY. 
 
 SYNONYMY. 
 
 The historical account given above shows the correct name of the 
 hog louse, according to the rule of priority, to be Hs&matopinus suis. 
 It has, however, received various designations as is shown by the fol- 
 lowing synonymy, which includes the different names under which this 
 parasite has been known, together with the authors and their dates: 
 
 FIG. 2. Dorsal view of male hog louse, x 15. 
 
 1758: Pediculus suis LINNAEUS, 1758, p. 611; 1798, v. 3, p. 18. MUELLER, 1764, p. 90; 
 1776, p. 184. CUVIER, 1817, p. 165. PANZER. [1798], pi. 16, FABRICIUS, 
 1805a, p. 342. DE OLFERS, 1816, p. 86. [As synonym of ILvmatopinus suix in 
 LEACH, 1817, p. 66. SAMOUELLE, 1819, p. 143; 1824, p. 143. STEPHENS, 1829, 
 p. 329. DENNY, 1842, p. 34; 1852, p. 4. WALCKENAER, 1844, p. 306. CUVIER, 
 1851, p. 489; [?] (Les Insectes), p. 74. RAILLIET, 1895, p. 831.] [As syno- 
 nym of Pediculus urius in NITZSCH, 1818, p. 305. BURMEISTEK, 1838, p. [13]; 
 1847, p. 577.] [As synonym of Hxmatopinus urius in GIEBEL, 1874, p. 45. 
 PIAGET, 1880, p. 654. TASCHENBERG, 1880, pp. 103, 105, 106. ZURN, 1882, 
 p. 65. PICAGLIA, 1885, p. 146. OSBORN, 1891, p. 19; 1892, p. 205, pi. 1, fig. 5.] 
 
 1817: Hxmatopinus suts (LINNAEUS, 1758) LEACH, 1817, p. 65, 66, pi. 46 [first use of 
 name was in Encycl. Brit., Suppl. 1, p. 24, ? 1810]. SAMOUELLE, 1819, p. 
 143; 1824, p. 143. STEPHENS, 1829, p. 329. DENNY, 1842a, p. 7, 34, pi. 25, 
 fig. 2; 1852, p. 4. GURLT, 1843, p. 12, pi. 1, fig. 11; 1857, p. 281-309; 1878, 
 p. 165. GRUBE, 1854, p. 242. GERVAIS & VAN BENEDEN, 1859a, p. 382, fig. 
 81. GERST.ECKER, 1863, p. 307. VERRILL, 1870, p. 112; [1871], p. 41, fig. 
 39. PACKARD, 1873, p. 102, fig. 120. HURTREL, 1875, p. 286, fig. 962. 
 MURRAY [1877], p. 386. LAW, 1877, p. 284, 285, fig. 1. COBBOLD, 1879, p. 
 414. LANESSAN, 1882, p. 525. WEST, 1882, p. 148, pi. 15, figs. 1-4. LINTNER, 
 1882, p. 48. PERRONCITO, 1882, p. 486, fig. 209; 1886, p. 333; 1901, p. 599. 
 GRIFFITH & II EN FRY, 1883, p. 369, pi. 35, fig. 4. UHLER, 1884, p. 294. 
 RAILLIET, 1886, p. 586; 1895, p. 831, fig. 570. BROCCHI, 1886, p. 837, fig. 
 532. FRIEDBERGER & FROEHNER, 1886, p. 632; 1895, p. 90. POWER & SEDG- 
 WICK, 1886, p. . LUDWIG, 1886, p. 480. COMSTOCK, 1888, p. 132, fig. 118.
 
 EXTERNAL PARASITES OF HOGS. 11 
 
 GILLETTE, 1889, p. 286, fig. 26; 1890, p. 47, figs, a-d. SIEDAMGEOTZKY, 1889, 
 p. 296. BLANCHAKD, 1890, v. 2, p. 436, fig. 675. BRANDT, 1890, p. 96, tig. 
 79. OSBORN, 1891b, p. 191. Bos, 1891, p. 659. BROWN, 1895, p. 60, fig. 
 35. BLANCHON, 1899, p. 249. GALLI-VALERIO, 1901, p. 349. GUENAUX, 
 1904, p. 454, fig. 299. [As synonym of Hsematopinus urius in GIEBEL, 1874, 
 p. 45. PIAGET, 1880, p. 645. ZDRN, 1882, p. 65. PICAGLIA, 1885, p. 147. 
 NEUMANN, 1888, p. 64, figs. 23, 30; 1892, p. 72, 73, figs. 25, 26. GALLI- 
 VALERIO, 1896, p. iii.] [As synonym of Pediculus suis LINN, in WALCKENAER, 
 1844, p. 306.] [As synonym of Hsematopinus irritans in LAW, 1903, p. 13.] 
 
 1818: Pediculus urius NITZSCH, 1818, p. 305; 1852, p. 130. BURMEISTER, 1838, p. [13], 
 pi. [1] Phthirius, fig. 4, pi. [2] Pediculus, figs. 9, 10, 13, 14; 1847, p. 577-578, 
 pi. 1. figs. 1-10. SCHIODTE, 1864, p. 50; 1866, p. 215. [As synonym of Hssma- 
 topinus urius in GIEBEL, 1874, p. 45. PIAGET, 1880, p. 654. PICAGLIA, 1885, 
 p. 146.] [As synonym of Hsematopinus siiis in STEPHENS, 1829, p. 329. 
 Denny, 1842, p. 34; 1852, p. 4. RAILLIET, 1895, p. 831.] [As synonym of 
 Pediculus suis in WALCKENAER, 1844, p. 396.] 
 
 1866: Hamatopinus suis L. GOUREAU, 1866, p. 205. [Misprint.] 
 
 1874: Hfematopinus urius (NITZSCH, 1818) GIEBEL, 1874, p. 45, pi. 2, fig. 6. GURLT, 
 1878, p. 165. PIAGET, 1880, p. 654, pi. 53, fig. 4. TASCHENBERG, 1880, p. 
 103, 105, 106. ZURN, 1882, p. 65. NEUMANN, 1888, p. 64, figs. 23, 30; 1892, 
 p. 72, 73, fig. 36 OSBORN, 1891, p. 18, 20, fig. 8; 1892a, p. 338, pi. 1, fig. 5; 
 1892b, p. 204; 1896, p. 178, 179, fig. 102. FRANCIS, 1894, p. 452. LUGGER, 
 1896, p. 129, fig. 70. GALLI-VALERIO, 1896, p. 110. MCCARTHY, 1896, p. 134, 
 fig. 24. SMITH, 1900, p. 80. NILES, 1900, p. 66, 67, fig. 26. LEWIS, 1902, p. 
 14, fig. 6. PETERS, 1902, p. 21, fig. 7. THEOBALD, 1904, p. 22. CRAIG, 1904, 
 p. 947, fig. 2. [As synonym of Hsematopinus suis in RAILLIET, 1886, p. 586. 
 BRANDT, 1890, p. 96, fig. 79. As synonym of Hsematopinus irritans in LAW, 
 1903, p. 13.] 
 
 1886: Hematopinus suis (LINNAEUS, 1758) DELAFOND & BOURGUIGNON, 1862, p. 561. 
 MEGNIN, 1886, p. 77, 78; 1895, p. 77, 78. [Misprint.] 
 
 1890: Haematopius urius (NITZSCH, 1818) HARZ, 1890, p. 486. [Misprint] 
 
 1896: Haemolopinm snis, SCHNEIDEMUHL, 1896, p. 346. [Misprint.] 
 
 1896: Haemotopinos urins, SCHNEIDEMUHL, 1896, p. 346. [Misprint.] 
 
 1896: Pedikulus suis, SCHNEIDEMUHL, 1896 [as synonym of Hsemotopinos urius in 
 SCHNEIDEMUHL, 1896, p. 346.] [Misprint.] 
 
 1900: Hsematopinus urinus (NITZSCH, 1818) NILES, 1900, p. 67. [Misprint.] 
 
 1900: Hsematopium urius, STEVENS, 1900, p. 28. [Misprint.] 
 
 1903: Hsematopinus irritans, LAW, 1903, p. 13. 
 
 1904: Hsematopinus uris, CRAIG & BITTING, 1904, p. 169. [Misprint.] 
 (?): Ricinus (ILcmatopinus) suis, LEACH in CUVIEK [Insectes], pi. 14, fig. 3. 
 
 CLASSIFICATION. 
 
 Ilsematopinu* SUM is one of the wingless Arthropoda formerly 
 classed by Osborn (1896) in the family Pediculidee of the suborder 
 Parasita, under the order ilemiptera of the class Hexapoda, or six- 
 footed insects. On the basis of an embryological study of the Pedi- 
 culidae, Kholodkovsky (1903) arrived at the conclusion that they should 
 be classed under a separate order, for which he proposed the name 
 Pseudorhynchota. 
 
 Enderlein (1904), in his recent revision of the classification of 
 the Pediculidtu, established the new family Ilamiatopinidie, with a
 
 12 BUREAU OF ANIMAL INDUSTRY. 
 
 subfamily Haematopinina?, which includes the genus Haematopinus, 
 with Pediculus suis Linn. (==Haematopimi8 suis Leach), as type. 
 Enderlein classes the family Haematopinidae in the suborder Anoplura 
 Leach (1817) under the order Rhynchota, and. makes Siphunculata 
 Meinert (1891), Pseudorhynchota Kholodkovsky (1903), and Lipog- 
 natha Burner (1904) synonymous with Anoplura. 
 
 GEOGRAPHICAL DISTRIBUTION. 
 
 This parasite lives on both domesticated and wild hogs of any age 
 and condition. The numerous references in literature to the hog louse 
 and reports of its occurrence in different countries show that this 
 parasite exists wherever the hog is found. 
 Denny (1842) writes of its common occurrence 
 in Ireland but comparative rarity in England. 
 It is common on hogs everywhere in the 
 United States. Stockmen handling hogs often 
 become temporary hosts of the louse, but it 
 FIG. 3. ventral view of last has never been known to remain for any length 
 ^^^ eaaS ^ i of time on the human body, and is not known 
 to exist on any animal other than the hog. 
 
 Attempts made at this laboratory to propagate Hsematopinus suis on 
 dogs have met with repeated failure. 
 
 DESCRIPTION. 
 
 The hog louse is the largest representative of its family, and, as the 
 generic name indicates, is a blood-sucking parasite. The female 
 attains a length of 6 mm. (one-fourth inch). The male is smaller than 
 the female and is readily distinguished by the dark streak along the 
 ventral median line of the last three abdominal segments (fig. 3). The 
 division of the body into head, thorax, and abdomen is distinct. ' 
 
 Head: The head is narrow, elongated, and rounded at the anterior 
 end. The conical, unjointed haustellum, or proboscis, is very promi- 
 nent, and about the middle of the lateral margins of the head are situ- 
 ated the slender, filiform, five-jointed antennae, one on each side. 
 Each joint of the antennae has a dark brownish ring about its middle, 
 the distal joint often being entirely fuscous, and bears on its extremity 
 a tuft of hairs, or bristles. The eyes are flat and of a pale bluish color; 
 they are located posterior and dorsal of the base of the antennae and are 
 very conspicuous. 
 
 Mouth parts: The mouth parts are of particular importance in the 
 present connection as it is due to their action that the irritation and 
 inflammation of the skin, occurring in infested hogs is produced. 
 They are also of interest in view of the possibility that certain dis- 
 eases, such as hog cholera, may be transmitted by the hog louse.
 
 EXTERNAL PARASITES OF HOGS. 
 
 13 
 
 Burmeister (1847) states that the protrusible haustellum bears a 
 double crown of hooks, with 10 or 12 hooks in each row, and that 
 the sucking tube, or stylet, is formed of an inner and an outer 
 tube, each made up of symmetrical halves. Erichson (1839), Simon 
 (1851), and Landois (1864) each describes mandibles in Pediculidse. 
 Schiodte (1864) states that the "haustellum" described by Burmeister 
 represents the labium, which may be retracted into the head, and that 
 the supposed mandibles seen by Erichson, Simon, and Landois are 
 parts of the labium. Briihl (1871) states that the stylet is formed of 
 dorsal and ventral halves, which are protruded separately and after- 
 wards brought together to form a tube. Gerstfeldt (1853) states that 
 the st} T let is formed of two chitinous half cylinders united, and includes 
 two setae likewise united. Packard (1888) says the Pediculina have a 
 
 FIG. 4. Cross section of anterior part of 
 
 stylet or so-called sucking tube, a, ven- -. ^ 
 tral part; bb, dorsal part; c, capillary 
 
 tube. PIG. 9. Posterior 
 
 FIGS. 5-6. Cross sections of intermediate part of capillary 
 
 portion of the stylet. tube and ven- 
 
 FIGS. 7-8. Cross sections of posterior or tral part of sty- 
 basal part of stylet. Fig. 8 shows di- let showing the 
 verging roots of the stylet. (Magnified basal branches 
 850 times. ) or roots. 
 
 FIG. 10. Posterior 
 portion of dorsal part 
 of stylet showing the 
 basal branches or 
 roots. 
 
 beak-like sucker which is soft and retractile, with two protrusible 
 chitinous bristles. Kholodkovsky (1903) states that the stylet does not 
 function as a sucking tube, but is merely a piercing organ used to pro- 
 duce a wound and does not convey the blood into the mouth. Ender- 
 lein (1904) states that the stylet is formed of two ventral parts (lobi 
 internus and hypopharynx) united to form a tube and a dorsal part con- 
 sisting of two chitinous bands. 
 
 A cross section of the stylet (figs. 4 to 8) shows that it is formed of 
 three chitinous parts a ventral half cylinder (a), within the concavity 
 of which lies a minute capillary tube (c), 2 /* in diameter, and a dorsal 
 part (JJ), which is formed of two half cylinders lying side by side and 
 fused together. Each half of the dorsal part is bilobed at its distal 
 extremity (fig. 12).
 
 14 
 
 BUREAU OF ANIMAL INDUSTRY. 
 
 bb 
 
 If a louse is placed on the hand and allowed to thrust its stylet into 
 the skin, a sharp stinging sensation is felt. Soon blood will be seen in 
 a pulsating ventricle in the head of the louse. If the head is now cut 
 off just back of the antennae, and carefully pulled loose from the hand, 
 the proboscis is seen to be everted, with the hooks on its outer surface 
 directed backward, and the stylet, still protruding, is 
 covered with blood stain. This indicates that the stylet 
 is not withdrawn after making a wound, and that blood 
 flows along the parts of the stylet into the mouth cavity, 
 the flow being kept up by the pumping ventricle, which 
 is a modified portion of the esophagus provided with 
 muscle attachments for expanding its walls. The stylet 
 is contained in a movable sheath (fig. 11) in a canal which 
 lies ventral of the esophagus and opens into the mouth 
 cavity. The 12 hooks (fig. 12) on the proboscis are 
 located on its dorsal and lateral surface, none occurring 
 on the ventral side. The hooks are drawn inside the pro- 
 boscis when it is retracted. 
 
 Measurements of the stjdet from 
 its base to its extremity give a 
 length of li to 1 mm. 
 
 Figure 11, taken from Bur- 
 meister (1847), shows the posterior 
 portion of the stylet with the 
 sheath containing it. The parts 
 Hb and c, described by Burmeister 
 as roots of the inner tube, constitute the origin 
 of the two ventral parts of the stylet (fig. 9, , c). 
 The parts aa, described as roots of the outer 
 tube of the st} T let, form part of the origin of 
 the dorsal part of the stylet (fig. 10). The parts 
 cc, described as diverging branches of the sheath 
 containing the stylet, are not only connected 
 with the base of the sheath, but also help to 
 form the origin of the dorsal part of the stylet 
 (fig. 10). Figure 12 is a greatly enlarged dor- 
 sal view of the proboscis protruded, showing 
 the 12 hooks everted, also the parts of the sty- 
 let. When the stylet is normally protruded its 
 parts are closely approximated and can not be 
 distinguished, except in instances where the k 
 dorsal part lib is partially retracted and the ventral parts remain 
 protruded. 
 
 Thorax: The thorax is broader than long; anterior dorsal margin 
 concave; posterior dorsal margin slightty notched at the median line; 
 
 FIG. 11. Basal 
 branches of 
 stylet and the 
 sheath con- 
 taining the 
 stylet. (After 
 Burmeister, 
 1847, fig. 6.) 
 
 FIG. 1.2. Dorsal view of 
 everted proboscis, a, ven- 
 tral part of stylet; bb, dorsal 
 part of stylet; c, capillary 
 tube of stylet; d, hook with 
 single prong; c, hook with 
 double prong. The parts of 
 the stylet are separated to 
 show their relations. (Mag- 
 nified 440 times.)
 
 EXTERNAL PARASITES OF HOGS. 
 
 15 
 
 posterior lateral angles acute. On each side, near the anterior lateral 
 margin is a spiracle opening on the dorsal surface. On the ventral 
 surface between the appendages is a chitinous shield. In each anterior 
 lateral angle of this shield or plate is an opening called the osteole, 
 leading from a canal that extends cephalad. 
 
 Abdomen: The abdomen is divided into nine segments. The second 
 to the seventh segments inclusive are bor- 
 dered on each side with a horny excresence 
 surrounding a light-colored spiracula (tig. 
 1, c). The first and last segments are with- 
 out spiracula, and the last segment has on 
 the dorsal surface two dark-colored, chitin- 
 ous plates joined ante- 
 riorly by a narrow strip 
 of chitin. The color of 
 the abdomen varies from 
 ashy bl ue tonearly white. 
 
 FIG. 13. Claw of Hxmatopinus 
 *uit. a, pad in the end of tibia 
 against which the hair is pressed 
 by the tarsus; b, tarsus; c, tibial 
 tooth. 
 
 Legs: The legs, attached 
 on the ventral side of the 
 thorax, are long and thick, 
 pale yellow in color, with 
 banded joints. The tar- 
 sus (tig. 13, li) is curved 
 and jointed, enabling the 
 claw to clasp the hair, pressing it against 
 the tibial tooth and retractile disk, or pad, 
 in the end of the tibia (tig. 13). The louse 
 travels sideways and, with the aid of its 
 claws for grasping the hairs, can move quite 
 vapidly. 
 
 EGG OF THE HOG LOUSE. 
 
 FIG. 14. Eggs of 
 Hsematopinus suis 
 attached to a hair 
 (magnified eight 
 times), a, natural 
 size of eggs. 
 
 FIG. 15. Shell of egg from which 
 the young louse has escaped, 
 o, operoulum or lid; b, rup- 
 tured embryonic membrane. 
 (Magnified 27 times. ) 
 
 When a hog is badly affected with lice hundreds of eggs will be 
 found on the hair back of the ears, along the front of the shoulders, 
 and on the flanks. The freshly deposited egg is bluish white in color, 
 elongated, oval in shape, 1.5 mm. long, and is enlarged at the end 
 bearing the circular operculum, or lid, which is forced open when the 
 19 185 No. 6905 3
 
 16 
 
 BUREAU OF ANIMAL INDUSTRY. 
 
 face of shell of egg 
 showing the sto- 
 mata. (Magnified.) 
 
 FIG. 17. Inner sur- 
 face of shell of egg 
 showing the inner 
 orifices of the sto- 
 mata. (Magnified.) 
 
 young louse is ready to hatch out. The egg is attached at its smaller 
 end to the base of the hair by a gluey substance that usually com- 
 pletely encircles the hair (fig. 15). The surface of the egg is covered 
 with small hexagonal punctations, which give it a honeycomb appear- 
 ance. The shell of the egg is per- 
 forated by numerous stomata (figs. 
 16, 17). 
 
 Incubation: It is stated in Coburn's 
 (1888) "Swine Husbandry" that the 
 egg will hatch out in about five days 
 FIG. 16. outer sur- after being deposited. Tests con- 
 ducted at Washington, D. C., how- 
 ever, show that the time of incubation 
 will vary with changes in temperature 
 
 and moisture. It was found that eggs freshly deposited and kept in 
 a room of ordinaiy humidity at a temperature of 85 F. during the 
 month of September hatched out in from fifteen to sixteen days, 
 while the eggs placed in a closed dish containing a receptacle filled 
 with water hatched out in twelve days. Lowering the temperature 
 retards development of the eggs. 
 
 INJURIOUS EFFECTS OF THE HOG LOUSE. 
 
 It seems necessary to emphasize this part of the subject since usually 
 little attention is given by farmers to this parasite. Every farmer 
 and stock raiser is familiar with the frequency and wide distribution 
 of the hog louse, but they do not always attribute to it any pathologic 
 or economic importance. When a drove of hogs is not thriving prop- 
 erly the more common custom is to pronounce them out of condition, 
 or simply off feed, and a patent stock food or a patent condition pow- 
 der is administered, with no evident benefit. In such cases, if a careful 
 examination of the animals is made, the cause of the unthrifty condition 
 is often directly traceable to the presence on the skin of large num- 
 bers of lice or other external parasites. 
 
 When lice increase to large numbers, as they are likely to do if not 
 destroyed, the skin of the animals becomes covered with scales and 
 sores, and in extreme cases swelling and inflammation develop as a 
 result of the parasites piercing the skin with their mouth parts hun- 
 dreds of times each day in their effort to secure blood for food. 
 The irritation thus produced is a source of constant anno} r ance and 
 worry to the hogs, evidenced by their restlessness and incessant rub- 
 bing and scratching against any convenient object. The ultimate 
 effect of such affliction is seriously to interfere with the growth and 
 fattening of hogs, especially of young pigs. 
 
 Lice not only produce a direct injury to hogs by impairment of the 
 skin, but also, by reason of the debilitated condition of the animals
 
 EXTERNAL PARASITES OF HOGS. 17 
 
 which ensues, indirectly create a greater susceptibility to various dis- 
 eases. It is stated by Peters (1902), of the Nebraska Experiment Sta- 
 tion, that observations in his work show that during epidemics of hog 
 cholera animals affected with lice are most susceptible to the disease, 
 and that the percentage of fatalities is greater than among herds free 
 from lice. So evident is this that the first treatment he recommends 
 for hog cholera is to destroy the lice on the animals and disinfect the 
 pens. 
 
 The opinion that the hog louse may cany the infection of hog 
 cholera from sick to healthy animals is not without support among 
 some writers on diseases of hogs. Dodge (1869, pp. 125-217) quote* 
 abstracts from correspondents referring to worms and 'lice causing 
 hog cholera. No positive evidence or experiments have been brought 
 forward, however, and the possibility of the hog louse conveying 
 diseases is an open question. 
 
 The destruction of this parasite is a comparatively easy matter, and 
 practical tests have demonstrated the economic importance of freeing 
 hogs from a pest that deters growth, weakens the general physical 
 condition, and renders the animals an easy prey to contagious maladies. 
 
 TREATMENT FOR THE HOG LOUSE. 
 
 PREVENTIVE MEASURES. 
 
 Any treatment to prove effective against lice on hogs must include 
 preventive measures as well as destructive remedies. The sleeping- 
 quarters of lousy hogs become infested with lice, which crawl off the 
 hogs and secrete themselves in the crevices of the building and in the 
 bedding, while the eggs on the hair that the hogs shed and rub off 
 will hatch out young lice. These parasites in the building immediately 
 reinfest animals from which the lice have been removed by treatment. 
 The selling and slaughtering of the majority of hogs at a comparatively 
 early age, and the consequent destruction of the lice on them in the 
 scalding vat, is naturally a great check to the increase in the number 
 of the parasites. As a usual thing, however, an entire herd of hogs 
 is not sold at one time, and the few remaining animals will serve as 
 hosts for the lice in the building until a new drove of hogs is placed 
 in the same pens, when the lice at once begin to multiply rapidly on 
 their new hosts. A thorough treatment, therefore, includes the 
 destruction of the lice in the buildings and pens in addition to treatment 
 of the animals themselves. If the pens where lousy hogs have been 
 kept are left vacant for a period of two weeks all lice will have per- 
 ished, and any new animals introduced will be in no danger of infection. 
 
 For disinfection of buildings Peters (1902) gives preference to a 3 
 per cent solution of any of the coal-tar preparations, to be applied 
 with a broom or spray pump.
 
 18 BUREAU OF ANIMAL INDUSTRY. 
 
 Niles (1900) recommends a 2 per cent solution of carbolic acid, solu- 
 tions of benzine and kerosene (said not to be so effective as carbolic 
 acid), and air-slaked lime having a little carbolic acid added and dusted 
 over the floors. 
 
 Probably the most convenient method of combating lice and mites 
 in buildings is the common custom of applying whitewash made by 
 slaking lime with water (1 pounds to 1 gallon of water). Popular 
 usage has made this a standard remedy, for it has been found to be 
 effective. Crude carbolic acid added to the whitewash (1 pint of the 
 acid to 4 gallons of whitewash) is said to increase its effectiveness. 
 
 In treating hogs infected with lice special attention should be given 
 to those parts of the body where the lice congregate in greatest num- 
 bers. They are found principally inside, behind, and in front of the 
 ears, on the breasts, and back of the fore legs. Even with the most 
 thorough treatment, however, some of the lice are apt to escape, and 
 these, if not destroyed, soon increase in numbers. The eggs are not 
 all destroyed by any single treatment. These facts make it necessary 
 to repeat an} T treatment used in order entirely to eradicate these pests 
 from a badly infested herd. When strange hogs are added to a herd 
 they should always be examined for parasites in order that any infested 
 ones ma3 T not cause the spread of lice throughout the entire herd. 
 
 TREATMENT OF THE HOGP. 
 
 Many different preparations have been used to destro} T lice on hogs. 
 Probably the oldest method is the use of washes or liquid insecticides. 
 It is frequently stated that a dust bath for hogs is destructive to lice, 
 butT. J. Brewster (189-t), of Kansas, declares that the lousiest hogs he 
 .ever saw were confined in extremely dusty pens; he recommends kero- 
 sene as an effective remedy. 
 
 The agricultural experiment stations have carried on numerous 
 experiments in the treatment of the hog louse, and a brief review of 
 the work is here given. 
 
 Gillette (1889) successfully used kerosene emulsion, which was 
 sprayed over pigs by means of a force pump and spray nozzle. Thirty- 
 seven hogs, weighing from 125 to 250 pounds, were treated with 6 
 gallons of emulsion, the cost of which (exclusive of labor) was but 13 
 cents. The animals were crowded into a close pen and thoroughly 
 sprayed. The cheapness of this remedy allows it to be used freely 
 and often, as is necessary with the usual treatments. 
 
 Lewis (1902) constructed a dipping vat and used proprietary dips. 
 He states that his experiments proved the remedies to be useless in the 
 weak solutions recommended by the manufacturers. Nothing less 
 than a 2 per cent solution could be relied on to kill the lice. 
 
 A. E. Verrill (1870) reports as the best and simplest remedy a solu-
 
 EXTERNAL PARASITES OF HOGS. 19 
 
 tion of sulphuret of potassium in water from 2 to 4 ounces to 1 gallon 
 of water. Apply the solution with a brush or spray. 
 
 Lugger (1896) recommends pyrethrum mixed with kerosene emul- 
 sion. 
 
 Tracy (1899) used successfully kerosene and water in a spraying 
 pump (see p. 21) with an attachment for mixing the oil and water in 
 the proportion of 5 parts of water to 1 of oil. He recommends spray- 
 ing in the evening, in order that the oil ma} 7 evaporate during the 
 night, thus avoiding the danger of blistering the skin by action of the 
 sun's heat on the oily skin. 
 
 The various stock journals of this country contain frequent notes 
 from rural correspondents reporting success in the use of pure kero- 
 sene, applied to the animals by means of a spraying machine or with 
 a brush or broom. 
 
 E. H. Kern (1904), a Kansas farmer, writes that he used pure kero- 
 sene oil applied with a knapsack sprayer (fig. 26). He states that, 
 contrary to the expectations of his neighbors, the hair did not come 
 off, neither did the skin blister, but on the morning following the 
 application "thousands of dead lice were found among the loose 
 scales of dirt and mange on the backs of the hogs." The animals 
 immediately improved in looks and condition. 
 
 Craig & Bitting (1904) recommend pure kerosene oil as the cheapest 
 remedy for lice on hogs. A sufficient amount of water is placed in the 
 dipping vat and the oil then added to a depth of 1 inch. The hogs, 
 when driven through the.liquid, emerge with a thin coating of oil over 
 the entire body. 
 
 It must be stated, however, that the application of pure kerosene to 
 the skin of hogs has been known to produce blisters and cause the hair 
 to fall out. The writer has observed these results follow such heroic 
 treatment. When pure kerosene is applied, the caution to use it in 
 the evening in order to avoid the effect of the sun's heat on the skin 
 freshly wet with kerosene must be strictly observed, and care be taken 
 not to apply the oil too freely. 
 
 The statement has been made (Knob, 1903) that kerosene used on 
 pregnant sows will produce abortion, but the frequent use of kerosene 
 on pregnant sows without evil results ensuing indicates that such 
 accidents are unusual. 
 
 Oliver (1896) recommends 1 part of kerosene mixed with 2 parts of 
 linseed or cotton-seed oil, applied once a week till the lice are all 
 destroyed. 
 
 A decoction of stavesacre seed (Delphinium sta2)hysagria}, using 2 
 ounces of seed to 1 quart of water, is much used in England to kill 
 lice. Vinegar added to the liquid is said to destroy the eggs of lice. 
 
 A decoction of equal parts of hellebore, sabadilla, and stavesacre 
 has been recommended as effective against lice.
 
 20 BUREAU OF ANIMAL INDUSTRY. 
 
 A herd of lousy hogs in the vicinity of Kensington, Md., was 
 treated in separate lots with kerosene emulsion, several proprietary 
 preparations, and an emulsion of Texas oil. These remedies were all 
 tested at this laboratory by plunging lice into the various solutions 
 and laying them aside to dry. Every preparation in dilute solution 
 killed the lice in a few seconds, excepting the Texas oil, which was 
 effective only in concentrated solution and acted more slowly. 
 
 The hogs were sprayed twice, two weeks intervening between the 
 two treatments. Kerosene in a 10 per cent emulsion proved success- 
 ful. Creolin in a 3 per cent solution also destroyed the lice. The 
 Texas oil in a 10 per cent emulsion was found to be absolutely useless. 
 The exact results of the tests with proprietary preparations could not 
 be determined, for the pigs treated with them escaped from their pen 
 after the first treatment and a few lice were found on some of the 
 animals. 
 
 Later experiments with Texas oil in the crude state have demon- 
 strated its value as a dip for hogs affected with lice and the itch mite 
 (Sarcoptes sccibiei). Fifty-two gallons of oil were placed in a tank 
 with 60 gallons of water and the pigs dipped once. A few days after 
 dipping the lice were found to have disappeared, and the scab mites, 
 with which the animals were severely affected, were also destroyed. 
 
 The foregoing account of results of experiments with different reme- 
 dies used against the hog louse shows that the following are successful, 
 cheap, easily prepared, and readily applied: Kerosene emulsion, kero- 
 sene and water, kerosene (pure, but to be used with caution), Beaumont 
 oil, and benzine emulsion (not much used). None of the arsenical or 
 poisonous insecticides is mentioned, for, when nonpoisonous remedies 
 are thoroughly efficient and readily obtained there is no necessity of 
 running the risks attendant on the use of these poisons. 
 
 The lime-and-sulphur dip recommended as a cure for scabies in cattle 
 and hogs was tried as a remedy for lice on hogs but has not as yet 
 been sufficiently tested for a statement of results at this time. 
 
 FORMULAS OF OIL EMULSIONS. 
 
 1. Kerosene emulsion is prepared according to the proportions in 
 the following formulas: 
 
 (a) Hard soap, pound (one-half bar common soap). 
 
 Kerosene, 2 gallons. 
 
 Water, 1 gallon. 
 
 Boil the water and soap until the latter is dissolved, remove from the fire, then 
 add the kerosene and churn or agitate vigorously till an emulsion is formed. This 
 emulsion, if thoroughly mixed, will form a gelatinous mass on cooling; it keeps 
 indefinitely and may be used at any time by diluting with warm water to 20 gallons. 
 If used after cooling, the mixture should be Seated again (great care must be exer- 
 cised in heating a second time because of the inflammable kerosene present, and for
 
 EXTERNAL PARASITES OF HOGS. 21 
 
 safety the mixture should l)e heated out of doors) and then thoroughly mixed a 
 second time. 
 
 (b) Soft soap, 1 quart. 
 Hard soap, J pound. 
 Kerosene, 1 pint. 
 Water, 2 quarts. 
 
 Mix as in preceding formula and dilute with 1 gallon of warm water. Keheat as 
 in formula (a) 
 
 (c) Sour milk, 4 gallons. 
 Kerosene, 2 gallons. 
 
 Mix the milk and kerosene and dilute with warm water to 20 gallons. 
 
 This formula has the advantage over other methods of making ker- 
 osene emulsion, as it avoids the necessity of making a soap mixture, 
 the milk acting as an emulsifier. 
 
 (d) Hard soap, 2 pound. 
 Pyrethrum, 85 pounds. 
 Kerosene, 2 gallons. 
 Water, 1 gallon. 
 
 Boil the water and soap until the latter is dissolved. Extract the pyrethrum with 
 the kerosene by stirring the pyrethrum and kerosene together and allowing the 
 mixture to stand for twenty-four hours, then pour off the liquid. The kerosene 
 extract is then mixed with the soap solution as in formula (). For use dilute 
 with warm water to 20 gallons. Reheat as in formula (a). 
 
 The pyrethrum is said to add to the effectiveness of the emulsion. 
 
 The kerosene emulsions when prepared should not have oil drops 
 rising to the surface. If drops of oil are seen it is proof that the 
 emulsion has not been sufficiently churned or agitated to emulsify the 
 mixture. 
 
 Goff (1891) describes and figures a spray ing pump for mixing kerosene 
 and water, which mixture is said to be more penetrative than an emulsion. 
 This pump is fitted with a foot-valve admitting oil and water through 
 separate orifices and a graduated screw regulating the proportionate 
 amount of each fluid admitted. The packing and pistons should be 
 made of leather and the valve seats of brass, on account of the destruc- 
 tive action of the liquid on fittings made of other materials. 
 
 2. Benzine emulsion: 
 
 Soft soap, 4 parts. 
 Water, 10 to 15 parts. 
 Benzine, 1 part. 
 
 Boil the water and soap until the latter is dissolved, remove from the lire, then 
 add the benzine and agitate till an emulsion is formed.
 
 MANGE, OR SCABIES, OF HOGS. 
 
 CAUSE OF MANGE. 
 
 Mange in hogs, which is a disease of the skin caused 'by parasitic 
 mites, is of two kinds. The demodecic form is produced by a mite 
 named Demodex folliculorwn var. suis (=J)> phylloides Csokor) (tigs. 
 21, 22). The sarcoptic form, which is better known and considered to 
 be more common than demode- 
 cic mange, is caused by a mite 
 known as Sarcoptes scabiei var. 
 suis (figs. 18, 19). These two 
 parasites of mange in hogs are 
 designated as "variety suis" in 
 order to distinguish them from 
 parasites of the same species 
 which cause mange in the dog, 
 the cat, the sheep, and some 
 other animals. Many writers 
 consider them distinct species, 
 and a third mite, Sarcoptes par- 
 vulus Can., has been described 
 from the hog. 
 
 SARCOPTIC MANGE. 
 
 FIG. 18. Dorsul view oi female mite (Xarcoptes scabiei 
 var. suis) causing sarcoptic mange. (AfterGerlat-h 
 1857.) x 150. 
 
 Neumann (1888) states that 
 Viborg described this disease in 
 the year 1805, but that Spinola 
 first found the sarcopt causing 
 it on wild hogs in the year 1846. 
 Gerlach (1857) mentions its frequent occurrence on wild hogs near 
 Berlin and on hogs in Holland. Miiller (1864) and Kocourek (1865) 
 both found the sarcopt on hogs in China. This parasite has been 
 observed in England, France, Ireland, Denmark, Canada, Japan, and 
 frequently in the United States. 
 
 The disease is 'described by the majority of writers on hog diseases, 
 and numerous references to it are found in the veterinary journals and 
 in periodicals devoted to the hog industry. 
 
 23
 
 24 
 
 BUREAU OF ANIMAL INDUSTRY. 
 
 DESCRIPTION. 
 
 This parasite is the largest variet}^ of its species and can readily be 
 .seen with the aid of a pocket lens. It is small, white, globular in 
 shape, with the body transversety striated. In front is a prominent 
 mobile rostrum. On the dorsal surface of the body are numerous 
 three-cornered scales, also 6 thoracic and 14 abdominal spines. 
 
 The first and second pair of legs in the 
 female bear a pedicellate sucker. The 
 third and fourth pair end in a iQng spine. 
 The first, second, and fourth pair of legs 
 in the male bear a pedicellate sucker, while 
 the third pair end in a long spine. 
 
 The female is nearly one-half millimeter 
 long and about one-third millimeter broad. 
 The male is a little smaller than the female. 
 The egg is 0.17 mm. long and 0.12 mm. 
 broad. 
 
 FIG. 19. Dorsal view of male mite 
 (Sarcoptes scabiei var. suis) of sar- 
 coptic mange. (After Gerlaeh, 
 1857.) X150. . 
 
 REPRODUCTION. 
 
 The eggs (fig. 20) are deposited by the 
 female and hatch, according to different 
 authorities, in three to eight days, under favorable conditions. 
 
 It has been estimated by Gerlaeh that a male and a female sarcopt will, 
 after a period of three months, have a progeny of 1.500, 000 descendants. 
 
 SYMPTOMS. 
 
 the 
 
 The skin is first inflamed and irritated about the eyes and ear 
 pruritis graduall}' spreads over the withers, flanks, and in- 
 ner surface of the thighs, later invading the entire surface 
 of the body. The skin becomes wrinkled, is covered with 
 crusts that take on a bluish gray luster, and the bristles 
 either fall out or become matted with the crusts that are con- 
 tinually forming and dropping off. Beneath the crusts the 
 skin is raw and cracked, the excoriation final^ becoming so 
 severe that bleeding occurs when the crusts are pulled off. 
 
 Conclusive diagnosis of sarcoptic or demodecic mange is obtained by 
 finding the parasites. It is necessary to pull off the crusts and scrape 
 the skin to the quick, and then examine the scrapings with a hand lens. 
 
 FIG. 20. Egg 
 of Sarcopt es 
 scabiei var. 
 suis. (After 
 Gerlaeh, 
 1857.) XI50. 
 
 CONTAGION. 
 
 The disease is distributed only through contagion, either by diseased 
 animals or by means of the buildings and pens where diseased hogs 
 have been kept. It gradually spreads throughout a herd. An infested 
 sow will transfer the disease in a severe form to her young before they 
 are three weeks old.
 
 EXTERNAL PARASITES OF HOGS. 25 
 
 Spinola (1863) states that scabies of the pig is not transferable to 
 other animals. It has, however, been transmitted to the dog, and is 
 said to be transmissible to the horse. Numerous instances are recorded 
 of man contracting the disease through contact with mangy hogs. 
 
 THE INJURIOUS EFFECTS OF MANGE. 
 
 Because of its destructiveness to the skin and the restlessness pro- 
 duced in the animals infested, sarcoptic mange is a most serious disease 
 that increases in severity, and not only prevents proper growth and 
 fattening of hogs, but will finalty cause death to young pigs. It is, 
 too, a more common disease than is generally believed. 
 
 TREATMENT. 
 
 The instructions usually given for treating scabies, or mange, of 
 hogs direct that the animals must be thoroughly cleaned by scrubbing 
 them with soap and water or some strong alkali solution before a 
 remedy is applied. Such care and detail are possible where onh r a few 
 hogs are to be treated, but when herds numbering from 50 to 500 are 
 to be treated such time-consuming and expensive operations are out 
 of the question. Dipping the animals is the only practical method of 
 applying remedies to large herds. Mange is at best a hard disease to 
 combat, especially in hogs, because of their unclean habits and usually 
 rilthy quarters. When mange is discovered, the hogs should be shut 
 away from mud wallows a day or so before treatment in order that 
 the dirt and crusts may become rubbed off the skin. 
 
 It is not a difficult thing to control a hog in a properly constructed 
 dipping vat, and an animal may be kept in the dip as long as desir- 
 able while the liquid is being rubbed into the skin with a brush or 
 broom. Care must be taken to wet the inside of the ears thor- 
 oughly by rubbing them with the hands. If the hogs are simply driven 
 through the dip without any scrubbing it will require a long time to 
 eradicate the disease. After the hogs have been dipped they should 
 be kept away from mud wallows and dust}' pens for a day, in order 
 that the dip may not be absorbed by dust and mud coming in contact 
 with the wet skin. A time should be chosen for dipping when there 
 has been no recent rain to make it possible for hogs to become cov- 
 ered with mud crusts. Never dip in cold weather. If only a few hogs 
 in a herd show symptoms of scabies it is not sufficient to dip only 
 those few that are badly infested, for other animals in the herd are 
 sure to harbor some of the parasites, which will continue to spread 
 the infection. A single dipping is not sufficient for a cure, for some 
 of the parasites will escape destruction by the first dipping and more 
 young mites will hatch from recently deposited eggs. A second dip- 
 ping, therefore, should follow six days after the first treatment. The 
 incubation period of the eggs under favorable conditions is stated to
 
 26 BUREAU OF ANIMAL INDUSTRY. 
 
 be from three to five days. Perseverance is the only way to effect a 
 permanent cure. The improved condition of scabby hogs, even on 
 the day following a successful treatment, will be evident from their 
 unusual quietness and better humor. 
 
 In addition to treating hogs for mange it is necessary either to 
 remove the animals to new quarters for a period of four weeks, after 
 which time the danger of reinfection in the old quarters is past, or to 
 clean and wash the pens and buildings. (See p. 17 for washes for 
 buildings.) 
 
 REMEDIES. 
 
 There are numerous mixtures and compounds that kill the scab 
 mites, but the item of expense and the facility of preparation and 
 application restrict a choice of remedies. Liquid remedies are the 
 only practical ones to be used on a large scale; if ointments are used 
 it is necessary to scrub the animals thoroughly before applying them. 
 
 Ointments. 
 
 (1 ) Helmerich's pomade (=sublimed sulphur 2 parts, potassium carbonate 1 part, 
 lard 8 parts). 
 
 (2) Creosote 1 part, lard 25 parts. 
 
 (3) Sulphur 10 parts, lard 30 parts. 
 
 (4) Turpentine 8 parts, flowers of sulphur 1 part. 
 
 Liquid preparations. 
 
 (1) Lime-and-sulphur dip (=unslaked lime 10 pounds, flowers of sulphur 24 
 pounds, water 100 gallons). 
 
 Slake the lime with sufficient water to make a thin paste and stir in the sulphur. 
 Boil this mixture with 25 or 30 gallons of water for two hours. Pour the liquid into 
 a vessel and allow the sediment to settle. The liquid is then drawn off into the vat 
 (carefully avoid disturbing the sediment) and warm water added to make 100 gallons. 
 The proportions in this mixture must be exact. This preparation is used while warm. 
 
 Mr. J. J. Rosa, of Milford, Del., in a letter dated December 3, 1904, 
 states that he used the above dip on 40 head of hogs affected with mange 
 and reports a perfect cure after a second treatment. 
 
 (2) Potassium pentasulphide, 1 kilogram (2.2 pounds) dissolved in 30 liters (31.5 
 quarts ) of water. 
 
 Scholl (1904) in a recent treatment of 160 hogs badh* infested with 
 mange washed them with soap and water, then applied the above solu- 
 tion. From the first day of treatment, it is reported, the irritation 
 diminished; the skin lesions healed, and the animals rapidly put on 
 flesh. A second treatment was given in two weeks as a precautionary 
 measure. 
 
 (3) One part of creosote mixed with 30 parts of oil [linseed] is a remedy said to 
 be much used in Germany. 
 
 (4) Beaumont, or Texas, oil. (See p. 20 for method of application.)
 
 EXTERNAL PARASITES OF HOGS. 
 
 27 
 
 Some hogs, belonging to Mr. Vern Godden,of Greenwood, Nebr.,were 
 recently observed by the writer to be in poor condition and covered 
 with grayish scales. Examination gave a diagnosis of sarcoptic infec- 
 tion in a severe form. The animals, without any previous washing or 
 preparation, were dipped in the Beaumont oil. They 
 were driven into the dip and scrubbed with an old 
 broom. Special care was taken to rub the inside of 
 the ears with the hands, since the skin on those parts 
 was raw and cracked, and harbored scores of the 
 parasites. The day following this treatment the 
 animals were more quiet, and ate their food better; 
 this improvement was particularly 
 noticeable in the young pigs. 
 
 On October 6, 1904, one month 
 after treatment, Mr. Godden wrote: 
 "As to the condition of the hogs, 
 they are much better since the 
 treatment; some seem to be en- 
 tirely cured of that scaly look. I 
 would recommend the Texas oil as 
 a good thing for scabby hogs." 
 Failure to dip a second time ac- 
 cording to instructions, accounts for the lack of 
 complete success in this experiment. 
 
 DEMODECIC MANGE. 
 
 FIG. 21. Ventral view 
 of male Dcmodex 
 folliculorum var. 
 subs. (After Csokor, 
 1879). x 240. 
 
 FIG. 22. Ventral view 
 of female Demodex 
 folliculorum var. suis: 
 (After Csokor, 1879.). 
 < Magnified 240 times. ) 
 
 Csokor (1879) first found the Demodex in pigs, and, 
 on account of its resemblance in shape 
 to a laurel leaf, named it Demode,'' 
 phylloides (figs. 21, 22). The para- 
 site, however, is sometimes grouped 
 with the other varieties of the genus Deuwdex found 
 on other animals into a single species follicidorwn, and 
 designated as Demodex folliculorum var. suis. D. 
 folliculorum is said to be of rare occurrence, but this 
 .statement is doubtless incorrect and results from a fail- 
 ure to recognize the parasite. Government inspectors 
 have frequently withheld hogs from the market be- 
 cause of a peculiar appearance of the skin which was 
 shown to be caused by Demodex. Leather manufac- 
 turers state that a large percentage of beef hides re- 
 ceived are partially ruined by the pitted condition of the 
 skin, a condition which is produced by this parasite found on the cattle. 
 It is generally held that D. foUicnlorum does not produce any patho- 
 logic symptoms nor perceptibly interfere with the growth of the 
 
 FIG. 23. Egg of 
 Dcmodrjr folli- 
 ddorum var. 
 *'*. (After 
 Csokor, 1879.) 
 x 240.
 
 28 BUREAU OF ANIMAL INDUSTRY. 
 
 animals, hence it seems to be of direct economic importance to leather 
 manufacturers only. 
 
 The female (tig. 22) is 0.25 mm. long, elongate, with eight pairs of 
 three- jointed legs, each provided with two claws. In front is a short 
 median rostrum. The abdomen is tapering, transversely striate above 
 and below, and rounded at the extremity. The vulva is situated in the 
 anterior portion of the ventral surface of the abdomen, in front of the 
 anus. The egg (fig. 23) is fusiform and hatches a larval hexapod, 
 which moults three times before arriving at maturity. 
 
 The male (fig. 21) is distinguished from the female by the presence 
 of a genital armature in front of the anus, and it is a little smaller 
 in size. 
 
 Demodex folliculorum bores into the hair follicles and sebaceous 
 glands, causing pustules that enlarge, rupture, and leave sores and 
 ulcers on the skin. This disease spreads from the snout, over the neck, 
 the under part of the chest and abdomen, and over the flanks and inner 
 part of the legs. Its deep location in the skin protects the parasite 
 from ordinary treatment.
 
 APPLICATION OF REMEDIES. 
 
 In applying liquid insecticides to hogs, spraying and dipping are the 
 two methods generally used. Where there are only a few animals, 
 the remedy can be easily applied with a brush or broom, but in a large 
 herd a more rapid method of application is desirable. 
 
 DIPPING. 
 
 Dipping the hogs is obviously the most thorough method, but more 
 expensive on account of the labor and material necessary to construct 
 a dipping vat, unless a large number are to be treated. Peters (1902) 
 describes and gives the following instructions for constructing a dip- 
 ping vat costing about $25: 
 
 12 feet 4-by-6-inch white pine or tank lumber. 
 40 feet 4-by-4-inch. 
 16 feet 2-by-6-inch. 
 
 16 feet 2-by-4-inch. 
 24 feet 4-by-4-inch. 
 24 feet 3-by-4-inch. 
 
 For the approaches and dripping platform: 
 
 10 feet 2-by- 12-inch tank lumber. 
 100 feet 4-by-4-inch yellow pine. 
 60 feet 2-by-6-inch. 
 114 feet 2-by-4-inch. 
 162 feet fencing. 
 
 17 pounds 20-penny nails. 
 7 pounds 10- penny nails. 
 10 square feet of zinc. 
 
 4 "T" hinges, 8 inches. 
 
 The accompanying illustration (fig. 24) gives plans for constructing 
 the vat. The zinc is used to cover the incline leading to the vat, in 
 order that the smooth surface afforded will prevent the animals from 
 halting after once starting for the plunge. The zinc covering is, of 
 course, not a necessity, but it is very convenient. The vat is placed in 
 an excavation in the ground, and should project about 6 inches above 
 the surface of the ground, in order to prevent dirt and trash from 
 falling into the dip. 
 
 Most farmers and stock raisers usually have a quantity of waste or 
 unused lumber lying about that may be utilized in constructing a dip- 
 ping plant, thus diminishing the actual cost of construction. A canvas 
 curtain hung at the entrance to the slide will facilitate driving the hogs. 
 
 29
 
 30 
 
 BUREAU OF ANIMAL INDUSTRY.
 
 EXTERNAL PARASITES OF HOGS. 
 
 31 
 
 The dripping platform is constructed of tongued-and-grooved lumber, 
 .slants toward the vat, and is bordered with narrow strips along the 
 sides, in order to direct the liquid back into the vat. The platform is 
 cleated as shown in the cut. The dipping vat should be placed in 
 close proximity to the pens, and where a stationary chute is not built, 
 movable panels of fence will make transferring the hogs an easy 
 matter. 
 
 Lewis (1902), of the Oklahoma Experiment Station, constructed a 
 galvanized-iron 22-gage vat, in which one-half inch gas pipe was used 
 as a framework. The entire cost of such a vat, with inclined entrance 
 and exit, is between $25 and $30. 
 
 FIG. 25. Plans for dipping tank. 
 
 There are several makes of dipping tanks offered on the market, any 
 one of which will give satisfactory results. Galvanized and cast iron 
 tanks of various sixes cost from $10 to $20. 
 
 A simply constructed portable dipping vat (fig. 25), used by the 
 writer for some experiments in treating lousy and scabby hogs, is very 
 serviceable for dipping moderate-sized herds of hogs and is also inex- 
 pensive. No dripping platform was used, consequently considerable 
 liquid was wasted. Where there are more than 40 or 50 hogs to be 
 dipped it is necessary to provide a dipping platform or else replenish 
 the liquid.
 
 32 
 
 BUREAU OF ANIMAL INDUSTRY. 
 
 The following materials are required to construct this vat: 
 
 Two 1 by 12 inch by 14 foot hard pine. 
 One 2 by 12 inch by 24 foot hard pine. 
 Three 2 by 4 inch by 12 foot hard pine. 
 One 1 by 6 inch by 15 foot hard pine. 
 One 2 by 6 inch by 12 foot hard pine. 
 Two pounds 20-penny nails. 
 Two pounds 10-penny nails. 
 
 The 2-iuch planks are used for the bottom and ends of the tank, the 
 1-inch boards for the sides, and the 2-by-4 sticks for braces. When 
 matched lumber is not available, the boards are joined at the edges 
 as perfectly as possible, the cracks smeared with pitch, and calked. 
 The boards for the sides of the tank are cut 6 feet 6f inches long, 
 clamped together (after the edges have been smeared with pitch and 
 dowel pins adjusted), and the proper braces (2 feet 7f inches long) 
 nailed on each end one-half inch from the end, with the braces pro- 
 jecting below the lower edge of the side, 
 as shown in the cut. The middle brace is 
 now nailed on in the position relative to 
 the notch in the bottom made to receive 
 it. The end boards are similarly joined 
 and held together by temporary braces 
 tacked on the outer side. 
 
 The two boards for the bottom are 
 joined, and the braces, cut just long 
 enough to extend between the inner mar- 
 gins of the notches made to receive the 
 side braces, are nailed in place. The 
 sides are then set in the grooves in the 
 bottom (using pitch in the joint), forced 
 firmly into position, and the side braces 
 
 nailed to the bottom and to the ends of the braces on the bottom. 
 The ends are next firmly fitted in the grooves in the bottom, nailed 
 from the under side with 20-penny nails, and then nailed to the sides 
 and side braces. The braces across the top are then nailed on. 
 
 Three pieces of 2 by 6 plank 2f feet long, held together by cleats 
 nailed across them, serve as a ladder for the pigs to crawl out on. The 
 upper end is movable so that it ma,y be raised from position in order 
 to keep the pigs in the dip as long as desired. The lower end of the 
 ladder is supported 6 inches above the floor of the tank and is anchored 
 down with a cord tied to a staple driven into the bottom of the tank. 
 The upper end rests on the brace across the top and is held from slip- 
 ping down by means of a cleat nailed on the under side. The inside 
 measurements of the vat when completed are 6 feet 6 inches long, 
 1 foot 8 inches wide, 2 feet 5 inches deep, and holds 6f gallons of fluid 
 to an inch of depth. Twenty inches of fluid is sufficient to cover a 
 
 FIG. 26. Simple spraying apparatus.
 
 EXTERNAL PARASITES OF HOGS. 
 
 33 
 
 300-pound hog. When using this vat it is of course necessary to 
 increase the height of the sides by a temporary construction and to 
 construct a chute leading to the vat. The vat should be sunk into the 
 ground a depth of 2 feet, thus saving the trouble of having to force 
 the pigs up an inclined plane. It is most convenient to set the vat in 
 front of a door to a hog house, sink it into the ground till the top is 
 level with or a little below the floor of the house, and then build a 
 barricade from the door along the sides of the vat. 
 
 SPRAYING. 
 
 When the necessary apparatus is provided, dipping the hogs is the 
 most convenient and rapid method of applying insecticides. Experi- 
 
 FIG. 27. Simple spraying apparatus. 
 
 ments, however, have proved that spraying liquids over animals is 
 equally effective if thoroughly performed. A force pump is fitted 
 with a hose of sufficient length to permit freedom of motion to the 
 operator. A spray nozzle is attached to the end of the hose, or, as has 
 
 Fro. 28. Simple spraying apparatus. 
 
 been done in the absence of a suitable nozzle, the end of the hose is 
 simply compressed between the thumb and forefinger, making a fan- 
 like spray that can be readily directed in any quarter. Any outfit for 
 spraying trees is likely to contain nozzles that can be adapted to spray- 
 ing liquids over animals. For those who do not possess a spraying
 
 34 
 
 BUREAU OF ANIMAL INDUSTRY. 
 
 apparatus, and do not care to purchase the more expensive outfits, one 
 of the cheaper pumps put out by firms handling such goods will serve 
 the purpose very well. 
 
 The illustrations of spraying outfits given (figs. 26-28) represent the 
 character of some of the less expensive ones offered for sale. There 
 should be considerable force to the jet of fluid, and the spray must 
 not be too finely divided, otherwise the liquid will not penetrate 
 between the hair and thoroughly wet the skin, 
 as it must do to be effective. 
 
 A method of applying kerosene to hogs that 
 is as simple as it is ingenious was employed by 
 Moore (1891) and Riedel (1891). A 6 by 6 inch 
 oak post is set firmly in the ground (fig. 29). A 
 2-inch hole is bored 12 inches into the top of the 
 post. A IJ-inch hole is bored from each side of 
 the post to open into the bottom of the larger 
 hole. Soft-pine plugs are driven into the small 
 holes and burlap or old cloth is wrapped around 
 the post, covering the pine plugs, and bound 
 down with wire. The hole in the top of the post 
 is then filled with kerosene. In a short time the 
 rags become saturated with the kerosene perco- 
 lating through the pine plugs. Two quarts of 
 oil daily are required the first three or four days 
 and afterwards 1 quart a week. Riedel remarks that "every hog 
 wanted to be first at the post," and that the lice in the herd soon 
 disappeared. A platform should be built around the post in order 
 that the hogs will not dig a mud wallow about its base. 
 
 Byrn (1890) devised a "wholesale method of ridding a herd of lice" 
 by digging a basin, or wallow, in the yard, pouring in water and 
 throwing in a small quantity of kerosene. He states that the pigs 
 frequented this place and the lice soon disappeared. 
 
 FIG. 29. Sectional view of 
 post with holes bored from 
 top and sides.
 
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 HARZ, O. 
 
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 EXTERNAL PARASITES OF HOGS. 39 
 
 HURTREL D'ARBOVAL, [ LOUIS-HENRI- JOSEPH] . 
 
 1875b. Dictionnaire de rnedecine et de chirurgie et d'hygiene veterinaire. Edi- 
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 KHOLODKOVSKY, N. 
 
 1903. Zur Morphologic der Pediculiden <Zool. An/., Leipz., v. 27 (4), 8. Dec., 
 
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 KOCOUREK, J. 
 
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 LATREILLE, PIERRE ANDUE. 
 
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 LEACH, WILLIAM ELFORIJ. 
 
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 40 BUREAU OF ANIMAL INDUSTRY. 
 
 LINNJCUS, CAROLINUS Continued. 
 
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 LUDWIG, HERBERT. 
 
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 MACDOUGAL, R. STUART. 
 
 1899. Insect pests of domesticated animals ^Tr. Highland & Agric. Soc. Scot- 
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 MCCARTHY, GERALD. 
 
 1896. Parasites of domestic animals <Bull. 127, N. Carolina Agric. Exper. Sta- 
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 MEGNIN, PIERRE. 
 
 1880. Les parasites et les maladies parasitaires chez 1'homme, les animaux 
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 1895. Les parasites articul<?s chez 1'homme et les animaux utiles (maladies qu'ils 
 
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 MUELLER, OTTO FRIEDRICH. 
 
 1764. Fauna insectorum Fridrichsdalina sive methodica descriptio insectorum 
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 1864. Kriitze bei Maskenschweinen <Oesterr. vrtljschr. f. wissensch. Veteri- 
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 MURRAY, ANDREW. 
 
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 NEUMANN, Louis GEORG. 
 
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 EXTERNAL PARASITES OF HOGS. 41 
 
 NILES, E. C. 
 
 1900. Animal parasites <Bull. 108, Virginia Agric. Exper. Station, Blacksburg, 
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 1818. Die Familien und Gattungen der Thierinsekten (Insecta epizoica) als 
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 1891. The Pediculi and Mallophaga affecting man and the lower animals 
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 PACKARD, ALPHEUS SPRING. 
 
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 1882. I parassita dell' uomo degli anirnali utili della piii comuni malattie da essi 
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 42 BUREAU OF ANIMAL INDUSTRY. 
 
 PKRRONCITO, EDUAEDO Continued. 
 
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 SAMOUELLE, GEORGE. 
 
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 EXTERNAL PAEASITES OF HOGS. 43 
 
 SCHNEIDEMUHL, GEORG. 
 
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 1803. Fauna Boica. Durchgedachte Geschichte der in Baiern einheimischen 
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 SPENCER, SANDERS. 
 
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 STEPHENS, JAMES FRANCIS. 
 
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 TASCHENBERG, E. L. 
 
 1880. Die Schnabelkerfe, fliigellosen Parasiten und als Anhang einiges Ungezie- 
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 1870. The external parasites of domestic animals: their effects and remedies 
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 44 BUREAU OF ANIMAL INDUSTRY. 
 
 VOGEL. 
 
 1888. Kreolin <Encycl. d. ges. Thier u. Thierzucht (Koch), Wicn u. Leipz., 
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 WEST, TUFFEN. 
 
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 1882. Die Schmarotzer auf und in dem Korper unserer Haussiiugetiere sowie 
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 o
 
 001 104045 8 
 
 (Continued from second page of 
 
 Dr. J. S. Kelly, care Blomor & Michael Co., 
 Quincy, 111. 
 
 Dr. F. D. Ketchum, South St. I'aul, Minn. 
 
 Dr. A. Long, care Sperry & Barnes, New Haven, 
 Conn. 
 
 Dr. C. Lovehorry, room 402 Custom-House (new), 
 Portland, Oreg. 
 
 Dr. H. D. Mayne. Malone. N. V. 
 
 Dr. Louis Metsker, room 22, N. T. Anuijo Build- 
 ing, Albuquerque. N. Mex. 
 
 Dr. J. Miller, care John Morrcll it Co., Ottmmva. 
 Iowa. 
 
 Dr. C. L. Morin, St. Albans, Vt. 
 
 Dr. A. B. Morse, care The Agar Packing Co., Des 
 Mi lines, Iowa. 
 
 Dr. W. ,T. Murphy, care Springfield Provision Co., 
 Brightwood, Mass. 
 
 Dr. W. N. Neil, care John Cudahy Co., Wichita, 
 Kuns. 
 
 Dr. H. D. Paxson, care Swift <!fc Co., Fort Worth, 
 Tex. 
 
 Dr. A. J. Payne, care Western Packing Co., Den- 
 ver, Colo. 
 
 Dr. F. M. Perry, Fort Fairtield. Me. 
 
 Dr. 6. W. Pope, Animal Quarantine Station, 
 Athenia, N. J. 
 
 Dr. H. T. Potter. Calais, Me. 
 
 Dr. J. O. F. Price, care Brittain & Co., Marshall- 
 town, Iowa. 
 
 Dr. R. A. Ramsay, Fargo, N. Dak. 
 
 l>r. A. (',. G. Richardson, 707 Empire Bi 
 Knoxville, Tenn. 
 
 Dr. A. E. Rishel, care Cudahy Packing Co., Los 
 Angeles, Cal. 
 
 Dr. W. H. Rose. 18 Broadway, New York, N. Y. 
 
 Dr. F. L. Russell, Orono, Me. 
 
 Dr. J. F. Ryder, 141 Milk St., Boston, Mass. 
 
 Dr. E. P. Schaffter, care Cleveland Provision Co., 
 Cleveland, Ohio. 
 
 Dr. C. A. Schaufler, 134 South Second st., Phila- 
 delphia. Pa. 
 
 Dr. Tho*. W. Scott, care The Rath Packin 
 Waterloo, Iowa. 
 
 Dr.T. A. Shipley.care T. M. Sinclair & Co. (Ltd.), 
 Cedar Rapids, Iowa. 
 
 Dr. N. C. Sorensen, care Kingan & Co., Indian- 
 apolis, Ind. 
 
 Mr. Wm. H. Wade, Animal Quarantine Station, 
 Halethorp, Md. 
 
 Dr. H. N. Waller, 10'J West Forty-second st.. New 
 York, N. Y. 
 
 Dr. G. W. Ward, Newport, Vt. 
 
 Dr. B. P. Wende, Live Stock Exchange Building, 
 East Buffalo, N. Y. 
 
 Dr. W. H. Wray,34 Streatham Hill, London, S. W., 
 England.