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OF

THE UNIVERSITY
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LOS ANGELES

ECONOMIC SERIES No. 13

BRITISH MUSEUM (NATURAL HISTORY)

MITES INJURIOUS TO
DOMESTIC ANIMALS

(WITH AN APPENDIX ON THE ACAEINE DISEASE
OF HIVE BEES)

BY

STANLEY

ASSISTANT KEEPER, DEPARTMENT OP ZOOLOGY

ILLUSTRATED WITH 85 TEXT-FIGURES

LONDON

PRINTED BY ORDER OF THE TRUSTEES
OF THE BRITISH MUSEUM "

1922

[PRICE THREE SHILLINGS]

BRITISH MUSEUM (NATURAL HISTORY)

ECONOMIC SERIES No. 13.

MITES INJURIOUS TO
DOMESTIC ANIMALS

(WITH AN APPENDIX OX THE ACARINE DISEASE
OF HIVE BEES)

BY

STANLEY HIRST

ASSISTANT KEEPEB, DEPARTMENT OP ZOOLOGY
ILLUSTRATED WITH 85 TEXT-FIGURES

LONDON

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OF THE BRITISH MUSEUM

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1922

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PREFACE.

THANKS are due to the following gentlemen, who have kindly
assisted the author by the loan or gift of specimens of Acari parasitic
on domestic animals, viz., Lieut.-Colonel A. Alcock, C.I.E., F.E.S.,
of the London School of Tropical Medicine ; Professor J. H. Ash-
worth, D.Sc., F.R.S., Department of Zoology, University of Edin-
burgh ; G. A. H. Bedford, Esq., Veterinary Dept., Union of South
Africa ; F. C. Bishopp, Esq., United States Dept. of Agriculture ;
Professor 0. Charnock Bradley, M.D., D.Sc., M.E.V.C.S., Eoyal
(Dick) Veterinary College, Edinburgh ; Rev. G. H. Hewison, M.A. ;
Dr. M. Langeron, Laboratoire de Parasitologie, Faculte de Medecine,
Universite de Paris ; Professor R. G. Linton, M.R.C.V.S., Royal
(Dick) Veterinary College, Edinburgh ; Leslie Linzell, Esq., late of
the Royal Army Veterinary Corps ; Prof. A. Martin, Ecole Nationale
Veterinaire, Toulouse ; C. D. Soar, Esq. ; Prof. E. L. Trouessart,
Museum d'Histoire Naturelle, Paris. Also to Miss E. Knight, of the
Cancer Research Laboratory, Middlesex Hospital.

The majority of the illustrations are reproductions of drawings
made by Mr. P. Highley and Mr. A. J. E. Terzi. These have been
drawn with great skill and care, and the thanks of the Trustees are
due to Mr. Hirst — whose property they are — for allowing them to be
used. Fig. 78 is from a photo by the Rev. G. H. Hewison, M.A.
Fig. 54 is reproduced by permission of Dr. Walter E. Collinge.
Figs. 62-66, 69 (a), 70, and 71 by permission of Dr. G. A. K.
Marshall, C.M.G. Figs. 40 and 79-83, by permission of Messrs.
Taylor and Francis. Figs. 1, 3, and 34 by permission of the
Quekett Microscopical Society.

C. TATE REGAN,

Keeper of Zooloyy.

February, 1922.

CONTENTS.

LIST OF ILLUSTRATIONS . . . . .

INTRODUCTION . ...

SYSTEMATIC INDEX AND LIST OF FAMILIES OF ACARI
MITES INJURIOUS TO DOMESTIC ANIMALS ....
APPENDIX. ON THE ACARINE DISEASE OF HIVE BEES . .

ON MOUNTING MITES FOR EXAMINATION UNDER THE MICRO-
SCOPE .

LITERATURE . .

INDEX

LIST OF ILLUSTRATIONS.

TEXT-FIGURES.

FIG. 1. — Otodectes cynotis, var. felis, ' showing distribution of

tracheal tubes, (a) Portion of tube greatly magnified

to show striation . . . . . . .15

,, 2. — (a) Distal end of leg of Chorioptes or Otodectes . . 16

(b) Distal end of leg of Psoroptes ..... 16

,. 3. — Posterior abdominal lobes of males of Psoroptes . . 17
» 4. — Ventral view of male nymph of Psoroptes communis, var.

ovis. (a) Posterior end of female (pubescent) nymph 18

,, 5. — Dorsal view of male of Psoroptes communis, var. ovis . 19
„ 6. — Ventral view of male of Chorioptes [ = Symbiotes], from foot

of sheep . . . . . . . . 22

„ 7. — Dorsal view of male of Otodectes cynotis, var. canis . . 24

,, 8. — Sarcoptes scabiei, var. equi, 9 . Dorsal view ... 26

„ 9.— „ ,, ,, (5. Ventral view. . . 27

,, 10. — Notoedrus cati, var. cuniculi. Dorsal view of female . 28

,, 11. — ,, ,, ,, . Ventral view of male . 29

,, 12. — Notoedrus muris. Dorsal view of female ... 30

,, 13. — Cnemidocoptes mutans. Dorsal view of female . . 31

„ 14. — ,, ,, Ventral view of male . . 32

„ 15. — Cnemidocoptes laevis, var. gallinae. Dorsal view of female 33

,, 16. — Cytoleichus nudus. Ventral view of female . 34

,, 17. — Laminosioptes cysticola. Ventral view of female . . 35

,, 18. — Hypopial nymph (" Hypodectes ") of Falculifer rostratus . 36

,, 19. — Megninia sp. Ventral view of male .... 37

,, 20. — Megninia columbae. Ventral view of male . 38
,,21. — ,, ,, (a) Tarsus of fourth leg of male.

(b) Tarsus of third leg of male 39

,, 22. — (a) Posterior end of body of male of Megninia velata . 40
(b) ,, ,, ,, ,, cubitalis,

var. ginglymura ....... 40

,, 23. — Pterolichus obtusus. Female from above . . .41

,, 24. — ,, ,, Male from below .... 42

„ 25. — Posterior abdominal lobes of male of (a) Pterolichus

bicaudatus ; (b) of P. sculpturatus .... 43

,, 26. — (a) Posterior end of nymph of Pterolichus bicaudatus . 44

(b) ,, ,, ,, sculpturatus . 44
,, 27. — Pterolichus sp. Female from below, (a) Tarsus of second

leg of same, (b) Denticle on first tarsus . . . 45

,, 28. — Pterolichus sp. Male from above . .-.'.. . 46

,, 29. — ,, ,, Cast skin of nymph . . . . 47

,, 30. — Freyana chanayi, <5 . Dorsal view . . . . 48

List, of Illustrations.

PAGE

FIG 31.- — Dermoglyphus elongatus. (a) Male ; (b) Female . . 49

,, 32. — Epidermoptes bilobatus, 9 . From below ... 50

„ 33.— „ J „ ... 51

,, 34. — Listrophorid mite, showing distribution of tracheal tubes 52

,, 35. — Ohirodiscoides caviae. Ventral view of male . . . 52

,, 36. — Hypopial or travelling nymphs of Tyroglyphidae . . 53
,, 37. — Tyroglyphus longior, var. castellanii, c5 . Dorsal and

ventral aspects . . . . . .' . 53

,, 38. — Glycyphagus domesticus . . . . . . 54

?) 39. — Cheyletid mites, (a) Psorergates musculi. Dorsal view

of male, (b) Myobia sp. Dorsal view of male . . 55

,, 40. — Cheyletiella parasitivorax. Dorsal view of female . . 56
,, 41. — (a) Syringophilus bipectinatus. (b) S. columbae. Dorsal

aspect of females . . . . ' . . . 57

,, 42. — (a) Tarsus of leg of Syringophilus bipectinatus . . 58

(b) ,, „ ,, columbae . , • - 58
., 43. — Tydeus molestus, 9 . From below, (a) Leg. (b) Palp,

much enlarged . ... . . . . .58

,, 44. — Leptus (Trombicula ?) similis ...... 59

,, 45. — Schongastia americana ....... 60

,, 46. — Capitulum of Demodex folliculorum . . . .61

,, 47. — Dorsal spinule on capitulum (palp) of Demodex spp. . 61
, 48. — Demodex canis, 9 . Ventral v.iew ; and capitulum from

above . . ... . . . . .62

., 49 — Demodex equi. Male and female. Also capitulum from

above 62

,, 50. — (a) Demodex canis, var. ovis. 9. From below . . 63
(b) Capitulum of same, from above, (c and d) Demodex

phylloides, 9 . Dorsal and ventral aspects (e) D. cati,

<5 , from above . . . . . . .63

„ 51. — Demodex bovis. Ventral view of female, and dorsal and

lateral views of male ... . . 64

,, 52. — Stages in life cycle of Demodex 65

„ 53.— (a) Penis of Demodex cati. (b) Early larva of D. bovis.

(c, d, and e) Penis of D. bovis 66

.. 54. — Anterior end of Dermanyssus, showing chelicerae in situ . 66
,, 55. — Dermanyssus gallinae, 9. Dorsal view . . . .67

„ 56. — ,, ,,9. Ventral view ... 68

» 57-— »> » 6 „ . . . 69

„ 58. — ,, ,, Second nymph. Ventral view . 70

,, 59. — ,, ,, First nymph. Dorsal view . . 71

„ 60.— „ „ „ Ventral view . . 72

»» 61. — ,, ,, Larva. Dorsal view ... 73

,, 62. — Dermanyssus muris, 9 . Dorsal and ventral aspects . 74

„ 63. — ,, sanguineus, 9 . Dorsal and ventral aspects 75

" 64. — ,, aegyptius, 9 ,, ,, ,, 76

,, 65. — Liponyssus bacoti, 9 . ,, ,, ,, 77
„ 66. — ,, bursa, 9 . Dorsal aspect . . . .78

,. 67. — (a) Sternal plate of Liponyssus bursa, 9 ... 79

(b) ,, ,, „ ,, sylviarum, 9 . 79

,, 68. — (a) Posterior end of dorsal shield of Liponyssus bursa, 9 . 80

(k) „ „ „ „ „ sylviarum, 9 80

List of Illustrations. 9

PAGE

FIG. 69. — (a) Liponyssus bursa, c5 • From below . . .81

(b) ,, sylviarum, $ . From below . . . 81

,, 70. — Liponyssus bursa, dorsal aspect of protonymph . . 82

,, 71. — Laelaps echidninus, 9. From below . . .83

,, 72. — Raillietia auris, 9. Dorsal aspect. .... 84
,, 73. — „ 9 . Ventral aspect .... 85

„ 74. — ,, „ (a) Second leg of male, (b) Chelicera

of male 87

,, 75. — Sternostomum rhynolethrum, 9- Dorsal view . . 89

,, 76. — „ „ 9. Ventral view . . 91

„ 77. — Holothyrus sp. From below . . . . . . 9'2

,, 78. — Tracheal tube of honey bee infested with Acarapis woodi 95
„ 79. — Acarapis woodi, 9 . Dorsal aspect .... 96

„ 80. — „ „ 9 . Ventral aspect .... 97

„ 81.— „ „ <f. Dorsal aspect .... 98

,, 82. — ,, ,, (a) Larva. (b) The same still enclosed

in egg-shell . . . . • . . .' .99

,, 83. — ,, „ (a) Fourth leg of female. (b) Egg

(c) Posterior leg of larva (d) First leg of larva . 100
,, 84. — Larva of Tarsonemua, and end of second leg of same . 100
85. — Tarsonemus apis. Ventral view of female, (a) Last leg of

male of same species , . . . . .101

INTRODUCTION.

MITES, or Acari, belong to the class Arachnida, which also includes
the spiders, scorpions, harvestmen, etc. Arachnids differ from
Insects in having eight legs instead of six. The chief feature
distinguishing mites from other Arachnids is that they have only
three pairs of legs when they are hatched from the egg, the fourth
pair being added later. Most Acari are very small and their body
is usually unsegmented. There is great diversity of structure
in the group.

The names of the principal families are given below, those dealt
with in the present pamphlet being printed in heavier type than
the others. Ticks are not included, but it is hoped that another
pamphlet dealing with them may be issued later.

The parasitic mites found on domestic animals differ greatly in
habits. They may burrow or tunnel in the skin (e.g., Sarcoptes)
or live in the sebaceous glands (e.g., Demodex), or cause crusts or
scabs on the surface of the skin (e.g., Psoroptes). The feather
mites, or Analgesidae, as their popular name implies, live in the
plumage of birds, and some even live in the interior of the quills,
as do also some Trombidiidae (Syringophilus, etc.). The Listro-
phoridae and some Trombidiid mites (Mi/obia) cling to the hairs of
mammals. Many of the Gamasidae live in the nests of rodents,
but may also sometimes be found on their bodies.

SYSTEMATIC INDEX.

CLASS ARACHNIDA.
Order Acari.

Sub-order Sarcoptoidea

Family Sarcoptidae
„ CAXESTRTNIIDAE.
Analgesidae .
Listrophoridae
Tyroglyphidae

Sub-order Cryptostigmata Fainily ORIBATIDAE.

Sub -order Vermiforinia
Sub- order Prostigmata

Sub -order Heterostigma
Sub -order Mesostigraata

Sub-order Notostigmata
Sub-order Tetrapoda

Family Demodicidae .

Family Trombidiidae .
„ ERYTHRAEIDAE.
„ HYDRACHNIDAE.
,, HALACARIDAE.

„ ' NlCOLETIELLIDAE.

Family Tarsonemidae .

[Family Gamasidae
,, Holothyridae .
„ IXODIDAE.
„ ARGASIDAE.

Family OPILIOACARIDAE.
Family ERIOPHYIIDAE.

PAGE

15

61
68
70

78
72

94

86
93

MITES INJURIOUS TO DOMESTIC ANIMALS

SUB-ORDER SARCOPTOIDEA.
FAMILY SARCOPTIDAE.

The mites of this family, commonly called itch mites, are very
small, whitish, and in shape oval or round. They are usually
considered to be without tracheal tubes, but in the genus Otodectes
(fig 1), and possibly in other members of the family, these are
present.

Otodectes cynotis, var. felis, showing distribution of tracheal tubes, x 142.

(a) Portion of tube greatly magnified to show striation. (After Hirst,

Journ. Quekett Microscopical Club (2) xiv, Nov. 1921.)

Genus Psoroptes, Gervais, 1841.

The genus Psoroptes differs from the allied genera Chorioptes
(formerly known as Symbiotes) and Otodectes in having the terminal

1 6 Mites Injurious to Domestic Animals.

sucker of the legs' borne on a long three-segmented peduncle
(fig. 2 b).

There are two distinct species of Psoroptes, viz., P. nataletisis
and P. communis.

Psoroptes natalemis, Hirst, 1919.

In the male of this species two of the hairs on each abdominal
lobe are distinctly flattened and blade-like near the distal end
(fig. 3 h), but not nearly to the same extent as the modified hairs
present in the same position in Chorioptes (Symbiotes).

FIG. 2.

(a) Distal end of leg of Chorioptes, showing the ambulacra 1

sucker borne on a short unsegmented peduncle, (b) Distal end

of leg of Psoroptes, showing the sucker borne on a long three -

segmented peduncle. (Original.)

This species was first described from specimens found on cattle
at Richmond, Natal. Megnin's examples from a buffalo from Cochin
China, determined by him as P. longirostris [P. communis], are
really referable to P. natalensis.

Psoroptes communis, Fiirstenberg, 1861

The author has examined a large series of specimens of Psoroptes
from various domestic animals, and can find very little structural
difference between them. It seems that the mites of this genus

Mites Injurious to Domestic Animals. 17

(with the exception of Psoroptes natalensis) should be regarded
merely as races or slight varieties of a single species.

The hairs on the abdominal lobes of the male are all normal in
appearance in P. communis (fig. 3 a-g, i), none of them being in the
least flattened or blade-like.

Although differing so little in structure, various observers have

FIG. 3.

Posterior abdominal lobes of males of Psoroptes. (a) Psoroptes
communis, var. equi ; (b) var. ovis, (c) var. cuniculi, (d) var. bovis
(from Johannesburg, South Africa) ; (e) var. caprae (St.
Vincent, West Indies) ; (f) var. bovis (from Amarillo, Texas) ;
(g) and (i) var. cervinae (Colorado) ; (h) Psoroptes natalensis,
Hirst. (After Hirst, Journ. Quekett Microscopical Club, (2) xiv,
Nov. 1921.)

pointed out that it is very difficult to transmit mites of the genus
Psoroptes from one host to another of a different species. For
instance, Delafond and Bourguignon failed to transmit Psoroptes
communis, var. ovis, to any other host.

Psoroptes communis occurs' on the following domestic animals :
sheep, goats, cattle, horses and rabbits.

Scab or Psoroptic Mange in Sheep.— The variety found

c

1 8 Mites Injurious to Domestic Animals.

on sheep (Psoroptes communis, var. ovis, figs. 4 and 5) is of
great economic importance, being the cause of the serious
disease called sheep-scab, which damages the wool and also
occasions much loss of stock. Whilst the sarcoptic mange

FIG. 4.

Ventral view of male nymph of Psoroptes communis, var. ovis., x 102.
(a) Posterior end of female (pubescent) nymph, showing the little
pair of knobs that are grasped by the copulatory suckers of the

"nnal.)

adult male. (Original.)

of the sheep is restricted to the head, the psoroptic occurs
on the parts of the body covered with wool. The 'mites
do not burrow in the skin, but pierce it with their elongated
mandibles. Irritation is intense, and the wool becomes detached
in places, also matted and full of greasy scabs or crusts. Sheep

Mites Injurious to Domestic Animals. 19

suffering from scab are restless and rub themselves against posts,
trees, fences, etc. The disease may be spread through healthy
sheep rubbing themselves against places infected in this manner,
or through actual contact with diseased sheep. This malady is

FIG. 5.

Dorsal view of male of Psoroptes communis, var. ovis, x 102.
(Original.)

very contagious. The Psoroptes is sometimes found in the ears of
sheep, without occurring on the body, and this source of infection
should be borne in mind and the ears examined and treated if
necessary.

Well-fed sheep are much more resistant to this disease than

c 2

20 Mites Injurious to Domestic Animals.

those in poor condition, and are more easily cured. As is well-known,
sheep-scab is treated by dipping, and many patent dips are on the
market. The wool should be clipped from the affected parts before
dipping. Most of the dippings fail to destroy the eggs, hence it is
necessary to give a second immersion at an interval of about eight
days in order to destroy any mites that have developed (before they
start laying eggs themselves). According to Stockman and Beare
creosote dip is very effective against the eggs.

Sheep in the first stage of the disease often show no visible
signs, hence the necessity of systematic dipping.

Much advice on the dipping of sheep is given in leaflets Nos. 61
and 145 issued by the Ministry of Agriculture. Sheep-scab is a
notifiable disease, and it is the duty of the owners of infected sheep
to give notice of the fact to the nearest police constable.

A. W. Shilston has written an excellent account of the habits
of Psoroptes communis, var. ovis, based on observations in South
Africa (Third and Fourth Reports of the Division of Veterinary
Research, Dept. of Agriculture, Union of South Africa, Nov. 1915,
pp. 69-98). He points out that the all-important factor in the
eradication of sheep-scab is the destruction of every mite on the
sheep themselves, and that to ensure this more efficient dipping is
necessary than has usually been employed in the past. He says
that the interval between the first two dippings should be ten days,
and that a third dipping is advisable. The expense of this third
dipping is slight compared to that occasioned by a recurrence of
the disease, possibly some months later, owing to the survival of a
few acari on one or two sheep which may have passed too rapidly
through the tank, or were not completely immersed. " In addition,
a third dipping would greatly lessen the risk of reinfection from
kraals or sleeping places. Acari are known to be unable to live
for more than four weeks apart from sheep (in the experiments all
were dead in twenty-one days), and eggs will not hatch after ten
days, so that by the time the third dipping is given — say twenty to
twenty-four days after the first — acari in the kraals would be dead
or too feeble to infect recently dipped sheep. It would, of course,
be unwise to neglect to thoroughly disinfect all places in which
scabby sheep had been confined, but absolute cleansing of the sheep
is the essential point in the eradication of the disease. The necessity
of treating every sheep in the flock, and not only those visibly
affected, is obvious." The above observations, of course, refer to
sheep as kept in South Africa under different climatic conditions
from those of this country. Shilston especially recommends the June

Mites Injurious to Domestic Animals. 21

and sulphur dip, which, if properly used, and at the right strength,
destroys the eggs as well as the mites.

Shilston was unable to infect goats by placing all stages from
scabby sheep into their ears, for the mites did not live more than
two days. Specimens of sheep Psoroptes were placed by him on
goats, and other goats were kept in contact with scabby sheep for
several months, but with negative results. Similarly, all attempts
to produce otacariasis in rabbits, by infecting them with Psoroptes
communis, var. ovis, were unsuccessful.

Psoroptic Mange or Parasitic Otitis of the Goat. —

Psoroptes communis, var. caprae, like the variety found in rabbits,
is confined to the ears of its host. Usually the presence of the mites
does not seem to be harmful, but occasionally it provokes serious
trouble, inducing deafness and lack of appetite, and sometimes
causing the death of the infected goats.

Shilston found that P. communis, var. caprae, was able to live
and reproduce itself on sheep, but the second generation usually
died on reaching the nymphal stage, and in no case was a third
generation observed.

Otacariasis of the Rabbit. — The Psoroptes of the rabbit
(P. communis, var. cuniculi) usually occurs only in the ear, numerous
specimens being found in a yellowish substance which may fill up
almost the entire cavity. _ Cases have been recorded in which the
face, neck and limbs were also attacked, but they seem to be rare.
Sometimes the body is affected with a combination of psoroptic
and sarcoptic mange.

This variety of Psoroptes is quite a common parasite of English
rabbits,- and also occurs on the Continent, in North America, and
in several parts of Africa.

P. communis, var. cuniculi, can apparently be transmitted to the
horse, and, according to Shilston, it is able to live on sheep for
periods up to seventeen days ; during that time it may lay eggs
and give rise to symptoms and lesions similar to those due to the
sheep Psoroptes. The second generation, however, die before repro-
ducing, and therefore continuous acariasis in sheep cannot result
from infection with rabbit Psoroptes.

Psoroptic Mange in Cattle. — In cattle psoroptic mange
commences at the base of the tail, or on the neck or withers,
and gradually extends to neighbouring parts of the body ; it
is rarely present in a generalised form. In summer this kind of

22 Mites Injurious to Domestic Animals.

mange often almost completely disappears, to return again when
the animals are housed during the winter months.

Psoroptic mange in the horse is dealt with on page 34.

FIG. 6.

Ventral view of male of Chorioptes [ = Symbiotes], from foot of
sheep, X 195. (Original.)

Genus Chorioptes, Gervais, 1859.

(Syn. Symbiotes, Gerlach, 1857, name pre-occupied.)

In the mites of the genus Chorioptes the suckers of the legs are

borne on quite short unsegmented peduncles (fig. 2 a) ; the abdomen

of the male terminates in paired lobes bearing hairs, two of which

Mites Injurious to Domestic Animals. 23

on each lobe, placed close together, are very wide and flattened
(spatulate) (fig. 6).

The forms of Chorioptes are principally found on domestic
animals, viz., on horses, cattle, sheep, and goats. The author found
specimens of Ckorioptes on the feet of a Huanaco which died in
the Zoological Gardens, London, July, 1918. The forms of
Chorioptes are so similar that they probably belong to a single
species, of which they may be considered to be physiological
varieties (like the forms of Sar copies and Psoroptes communis), which,
although structurally alike, show a marked preference for their own
animal host.

Chorioptic, or symbiotic mange as it is more commonly called,
is usually restricted to the feet or to the base of the tail and anal
fossa in cattle. In some cases it spreads on to the neck and back,
or on to the belly, perineum, etc. This mange is] usually of a
mild type, however, remaining localised and spreading but slowly.
Symbiotic mange in the horse is dealt with on page 34.

Genus Otodectes, Canestrini, 1894.

Very like Chorioptes, the suckers of the feet being borne on short
unsegmented peduncles as in that genus ; but the posterior lobes of
the body of the male are much less salient, and the hairs on them
are not spatulate.

The mites of the genus Otodectes live in the ears of dogs, cats,
and ferrets. They are usually considered to be varieties of
a] single species (Otodectes cynotis, Hering), but apparently do not
differ from one another structurally. Otodectes cynotis, var felis,
Huber, 1861, is a very common parasite of London cats, and the
otitis caused by it is usually known as canker. A little olive oil
mixed with flowers of sulphur or a tenth part of naphthol should
be poured into the ears every few days until a cure is effected.

Dogs used in hunting are especially liable to this kind of otitis
(0. cynotis var. canis (fig. 7)), which sometimes is the cause of fits
very similar to those due to epilepsy. The shape of the ear may
be altered by constant shaking, the lower lobe becoming much
thickened.

A warm solution of potassium sulphide (10 grams in a litre of
water) should be poured twice daily into the ears of dogs suffering
from parasitic otitis, and a cure will be effected in a few days.
Before treatment the ears should be thoroughly cleansed, all visible
waxy secretions being removed. Infected dogs should be isolated
and the kennels disinfected.

24 Mites Injurious to Domestic Animals.

Genus Sarcoptes, Latreille, 1806.

Dorsal surface furnished with characteristic sharply pointed
(dentate) scales and also with symmetrically arranged rod-like
setae posteriorly.

Mites of the genus Sarcoptes are parasitic on a fairly large number

FIG. 7.
Dorsal view of male of Otodecte* cynotis, var. cam*, x 125. (Original.)

of hosts, probably including all the domestic animals (mammals),
but specimens found on different hosts are remarkably similar in
structure. The author has examined examples of Sarcoptes from
man, horses, cattle, sheep, goats, pigs, lions, wolves, dogs, foxes,

Mites Injurious to Domestic Animals. 25

coatimundi, hartebeest, kudu, guinea-pig, and rabbit without being
able to find a constant morphological character by which they
could be satisfactorily distinguished from one another.

The skin complaints induced by the various forms of Sarcoptes
occurring on domestic animals are briefly described below.

For the sake of convenience the three principal kinds of mange
in the horse due to Sarcoptid mites are placed together, see page 34.

Sarcoptic Mange Of the Dog.— Sarcoptic mange is apparently
less common in dogs than the mange due to Demodex, but is more
frequently met with in some countries than others. It is very
much easier to cure than demodectic mange. Apparently the
mange caused by Sarcoptes can make its appearance on any part
of the body, but most frequently commences on the head. It
spreads rapidly, and in a few weeks large areas of the skin may
be invaded by the parasite. The symptoms are very like those of
demodectic mange. There are reddish spots rather like flea bites,
and the scratching of the animal causes reddish places and papules
to appear. The infected part often becomes dry and covered with
yellowish crusts. The hair falls out and the skin becomes thickened,
wrinkled and creased. Pruritus is intense. Sarcoptic mange is
easily confused with the mange caused by Notoedrus cati and by
Demodex, and also with sWeral other skin complaints such as
eczema, etc. The presence of the parasite is the chief distinctive
feature.

A number of cases of human beings becoming infected with the
Sarcoptes of the dog (Sarcoptes scabiei, var. cam's) have been recorded.

Sarcoptic Mange in Cattle.— The sarcoptic mange of cattle
has been very prevalent in some areas in the United States, and is
usually treated by four dippings in lime sulphur, the interval between
the dippings being from six to ten days. This kind of mange in cattle
has also been a great nuisance in Alberta and Saskatchewan, where
it has been combated by dipping, movement of cattle in the infected
areas being prohibited, except when they are destined for immediate
slaughter. In Britain, sarcoptic mange in cattle seems quite common
in Scotland, and also occurs at Liverpool, and doubtless in other
areas. Milkers often contract sarcoptic mange from cows, the
arms, chest, and neck being affected. The complaint is known as
'' dairyman's itch."

Sarcoptic Mange in Pigs. — In pigs sarcoptic mange usually
starts on the head, especially round the eyes and ears, but the back,

26 Mites Injurious to Domestic Animals.

sides, and inner surface of the thighs may also be invaded ; some-
times the infection is general, the whole body being affected.
Pruritus is intense even in the early stages. The hair falls out, and
the skin becomes coated with dried crusts formed by the morbid
secretions. Sometimes the papillae of the skin become increased

FIG. 8.
Sarcoptes scabiei, var. equi, 9. — Dorsal view, x 209. (Original.)

in size, forming wart-like eminences. In advanced cases the skin
is very much thickened, wrinkled, and covered in places with thick
crusts in which the specimens of Sarcoptes may be present in large
numbers. This kind of mange is said to be more common in
pigs in the United States than the mange due to Demodex.

Mites Injurious to Domestic Animals. 27

If only a few animals have to be treated, crude petroleum applied
with a brush, mop, or cloth is a valuable remedy. Wallows medi-
cated with crude petroleum, and dipping either in water and crude

Sarcoptes scabiei, var. equi, & . — Ventral view, x 312. (Original.)

petroleum or lime sulphur are much preferable, especially when
large numbers of pigs have to be treated. When the lime sulphur
dip is used, four or five dippings with an interval of five or six days
between them are necessary. For further details concerning mange

28 Mites Injurious to Domestic Animals.

in pigs and its treatment, see Farmers' Bulletin, no. 1085, U.S.
Dept. of Agriculture, by Marion Imes.

Sarcoptes scabiei, var. suis, is transmissible to man.

FIG. 10.

Notoedrus cati, var. cuniculi (p. 50). — Dorsal view of female, x 360.
(Original.)

Sarcoptic Mange in Sheep.— In sheep sarcoptic mange is
usually confined to the head. It is only in advanced cases that the
limbs and more rarely the body become affected. The disease does

Mites Injurious to Domestic Animals. 29

not spread to the woolly parts of the body. It occurs, however, in a
generalised form in the Algerian and Tunisian breeds of sheep, also
sometimes in Southdowns, Neapolitan sheep, etc. The Sarcoptes
of the sheep (Sarcoptes scabiei, var. ovis, Megnin) has been trans-
mitted to goats.

FIG

Notoedrus cati, var. cuniculi (p. 50). — Ventral view of male, x 370.
(Original.)

Sarcoptic Mange of the Goat.— The kind of sarcoptic mange
found on goats is said to commence on the head and ears, afterwards
reaching the body and limbs. Dry crusts are formed on the surface
of the skin which, in advanced cases, becomes thickened, folded,
and sometimes cracked, whilst the hair falls out. Pruritus is intense.

30 Mites Injurious to Domestic Animals.

The health of the goats suffering from this kind of scabies is some-
times greatly affected ; they become thin, and death frequently
ensues. The Sarcoptes of the goat (Sarcoptes scabiei, var. caprae,
Fiirstenberg) can be transmitted to man, and also to horses,
sheep, cattle, and pigs.

FIG. J2.

Notoedrus murig, parasitic on brown rat (p. 51). — Dorsal view of
female, x 230. (Original.)

Sarcoptic Mange in Camels and Dromedaries.— Sar-

coptic mange is a very common disease of camels in .Egypt and
other parts of North Africa, and causes serious losses if neglected
or improperly treated. If not treated, F. E. Mason says the disease
makes rapid progress and may extend to the whole body. Later
the skin becomes thickened, wrinkled, and covered with thick
crusts. When the disease reaches a more advanced stage the camel

Mites Injurious to Domestic Animals. 31

becomes emaciated, the crusts increase in thickness and extent,
whilst ridges appear on the skin, which is cracked and ulcerated.
A very offensive fluid is discharged by the cracks and ulcers, the
limbs become swollen, etc. The working capacity of camels suffer-
ing from scabies is much reduced, and death may finally take place
through exhaustion or from complications with other diseases.
The variety of Sarcoptes scabiei found on camels is transmissible

FIG. 13.

Cnemidocoptes mutans. — The mite of scaly-leg in fowls (p. 51).
view of female, x 174. (Original.)

Dorsal

to man and also to horses. Mason has used colocynth tar (distilled
from the seeds of Citrullus colocynthus) successfully against sarcoptic
mange in camels, and also in sarcoptic and psoroptic mange in
horses, and against ticks. Before applying this remedy, the camel
should be clipped, washed with soft soap, and the crusts scraped
off with a blunt knife.

Ointments with a fatty basis are apt to become rancid in hot

32 Mites Injurious to Domestic Animals.

•

climates and may cause blisters. For this reason, Curasson recom-
mends an ointment, or rather paste with a white soap as a basis,
for treating dromedaries suffering from scabies. Soap shavings
(600 grams) are dissolved in one litre of warm water, after twenty-

FIG. 14.

Cnemidocoptes mutans (p. 51). — The mite of scaly-leg in fowls. Ventral
view of male, x 305. (Original.)

four hours 300 grams of flowers of sulphur are added, finally
200 grams of cresyl and 150 grams of petrol are slowly poured in,
the mixture being gently stirred meanwhile. The resulting paste is
applied with a brush or by hand and is well worked in with the finger
tips. Next day some of the paste will be found at the end of the

Mites Injurious to Domestic Animals. 33

hairs and should be rubbed into the skin again. On the sixth
day the parts treated should be cleansed with a brush and tepid
water.

Sarcoptic Mange of the Rabbit. — Kabbits sometimes suffer
from sarcoptic mange, besides being liable to notoedric mange and
to otitis due to the presence of Psoroptes. In rabbits sarcoptic

FIG. 15.

Cnemidocoptes laevis, var. gallinae (p. 54).— The mite of Depluming Itch
in fowls. Dorsal view of female, x 210.

mange affects much the same regions as the notoedric kind ; the
legs are, however, first attacked, then the tip of the nose, which
may be transformed into a kind of proboscis. From the nose the
mange spreads on to the face and ears, and sometimes on to the
body. Greyish or yellowish crusts are present on the diseased
parts. This kind of mange may cause great mortality. Railliet

34 Mites Injiirious to Domestic Animals.

and Henry state that treatment is easy ; much washing and bathing
should be avoided ; the fur on the affected parts should be cut
and the crusts well rubbed with black soap ; the diseased places
should then be washed, carefully dried, and treated with some
suitable ointment.

FIG. 16.

Cytoleichus nudus (p. 59). — An internal parasite of the domestic fowl.
Ventral view of female, X 136. (Original.)

The variety of Sarcoptes found on the rabbit can be -transmitted
to the guinea-pig and ferret.

Mange in Horses.— Horses suffer from three different kinds
of mange, viz., the sarcoptic (sometimes called scabies), psoroptic,
and chorioptic (or symbiotic). The first of these is much the

Mites Injurious to Domestic Animals. 35

most serious owing to the burrowing habits of the parasites, which
make it difficult to reach them with acaricidal solutions. Mange in
horses is very common in war time, great numbers of animals being
affected, whilst it is comparatively rare in normal times. All newly

FIG. 17.

Laminosioptes cysticola (p. 59). — An internal parasite of the domestic fowl.C
Ventral view of female, X 376. (Original.)

purchased animals should be carefully examined for symptoms of
mange.

Sarcoptic mange commences by little circular hairless places
and small elevations, accompanied by intense itching ; these little

D 2

36 Mites Injurious to Domestic Animals.

elevations can sometimes be felt if the hand is passed over the
skin. Horses suffering from this kind of mange try to rub them-
selves against any suitable object, and bite those parts of the body

FIG. 18.

Hypopial nymph ("Hypodectes") of Faculifer rostratus (p. 63); from
pigeon, X 80. (After Neumann.)

which they can reach. When the affected parts of the body are
scratched with the hand the animal shows signs of pleasure, moving
the end of the nose in a characteristic manner. Any part of the
body may be attacked, but those parts which come in contact with

Mites Injurious to Domestic Animals. 37

the saddle or harness are usually affected first. The disease often
commences on the withers, spreading afterwards on to the back
and sides. The hair is thin and broken in the rubbed parts of the

FIG. 19.

Megninia sp. (p. 63) — From domestic fowl, in North America. Ventral view
of male. (Original.)

body, and abrasions or excoriations may be present. In advanced
cases the skin is hard and folded, and the animals become very
thin and may die of exhaustion.

38 Mites Injurious to Domestic Animals.

Under war conditions, according to Fayet, sarcoptic mange of
the horse commences on the forehead, parotid regions, base of the
ears, cheeks, intermaxillary spaces, etc., and may be localised for
some time in these regions and on the forequarters. If treated
promptly at this stage the disease can be prevented from invading

FIG. 20.

M egninia columbae (p. 64). — From domestic pigeon,
male, x 154 (Original.)

Ventral view of

other parts of the body. Close clipping enables mange to be readily
detected.

Mr. A. W. Noel Fillers (Notes on Mange, and allied Mites, for
Veterinarians, London, 1921) states that sarcoptic mange can be
distinguished clinically from other types of mange with a fair degree
of accuracy. He says that " the lesion prefers the thinner-skinned
areas ; in addition to encrustation the skin itself is thickened, the

Mites Injurious to Domestic Animals. 39

lesion is diffuse, with intermingling of areas containing hair, and
there are here and there numerous blood points. Early cases are
difficult to diagnose as there are only a number of pimples, diffusely
scattered without loss of hair and which give a positive labial reflex
when the part is rubbed." Mr. Fillers affirms that there is a marked
seasonal prevalence in sarcoptic mange, the disease being usually
at its lowest in warm weather and when there is plenty of sweating
of the skin. There is a gradual increase during October, November
and the following months, until in March it reaches its height. In
the ensuing months it falls slowly, and from June to September

FIG. 21.

(a) Tarsus of fourth leg. (b) Tarsus of third leg, of male of
Megninia columbae (p. 64), greatly enlarged. (Original).

the prevalence of sarcoptic mange is at its lowest. It may justly
be said to be a disease of winter and long and dirty coats.

Sarcoptes can usually be found by soaking scrapings from the
infected animal in 10 per cent, solution of caustic potash. Occasion-
ally, however, it is difficult to find the mites, and it may be necessary
to boil the material in the caustic potash and then centrifuge it ;
after a few turns of the handle of the machine the Acari are generally
to be found at the bottom of the tube.

Sarcoptic mange should be treated at as early a stage as possible,

40 Mites Injurious to Domestic Animals.

and infected horses should be isolated from healthy animals.
According to Moussu, horses which are slightly affected with scabies
should be treated for at least two or three weeks if the cure is to be
complete, and serious cases need at least from two to two and a
half months. Treatment has to be very thorough, particular
attention being paid to areas that are difficult to reach and nooks

FIG. 22.

(a) Posterior end of body of male of Megninia velata (p. 64).

(b) Posterior end of body of male of Megninia cubitalis, var.

ginglymura (p. 64), from English turkey. (Original.)

and corners such as the base of the ears, inner surface of the limbs,
belly, base of tail, etc., otherwise the disease is apt to reappear.
Sulphurated oil is very useful as a remedy. It should be applied to
every part of the body, not merely to the areas in which the mange
is visible. A fresh application of the acaricidal mixture should be
made every four days until the cure is effected. Spraying with lime

Mites Injurious to Domestic Animals. 41

and sulphur is recommended as a preventive and for affected horses
by the Ministry of Agriculture and Fisheries (see Leaflet No. 274).
Noel Fillers gives several formulae for dressings, one of them being

H.ghlty del

FIG. 23.

Pterolichus obtusus (p. 64), a feather mite from domestic fowl.
Female from above, x 160. j

as follows : — Strong calcium polysulphide solution one part = 8 oz.,
water two parts = 16 oz., horse fat two parts = 16 oz., total two
pints. He says that the strong solution of calcium polysulphide may

4?

Mites Injurious to Domestic Animals.

be prepared in small quantities by mixing 2J Ib. of sulphur with
1 Ib. of good quicklime in a bucket, making into a paste, and boiling

r

FIG. 24.

Pterolichus obtusus (p. 64), a feather mite from domestic^
fowl. Male from below, s

in two gallons of water until a dark red-brown solution is formed.
Boiling will take about three hours ; the whole must be kept well
stirred during the process and made up to two gallons at the end.

Mites Injurious to Domestic Animals.

43

About two pints of this oily mixture will be sufficient to dress an
ordinary case.

In war time dipping in specially constructed tanks is used
against sarcoptic mange in horses, and is said to be much the best
method of combating the complaint. Descazeaux gives a plan of
a piscina or tank for bathing horses in Rec. Med. Vet. D'Alfort,
xciv., no. 12, June 30th, 1918, p. 273.

FIG. 25.

(a) Posterior abdominal lobes of male of Pterolichus bicaudatus (p. 64),
a feather mite from ostrich. (b) Posterior abdominal lobes of
Pterolichus sculpturatus (p. 64), from ostrich. (Original.)

Sarcoptic mange of the horse is transmissible to man.

Psoroptic mange in the horse chiefly affects the regions of the
body situated near the long hair, such as the neck, withers, rump,
base of tail, etc., but in advanced cases other parts of the body
may be invaded. There is an accumulation of thick humid crusts
under which the mites live and multiply.

According to Eailliet and Henry (Bull. Soc. Cent. Med. Vet.
Ixxiii., 1920, p. 41) the Psoroptes found in the ears of horses, mules
and asses is distinct from that occurring on the body of these hosts.

44 Mites Injurious to Domestic Animals.

They consider the Psoroptes living in the ear to be a new species
which they describe under the name P. hippotis. Only two of the
longer hairs on the posterior abdominal lobes of the male of P.
hippotis have their bases contiguous, whereas in P. communis, var.
equi, three of these hairs originate quite close together, the bases
of all three being contiguous and on the same level. It seems possible
to the author that P. hippotis may prove to be identical with P.
communis, var. cuniculi, or P. c., var. ovis, both of which have the
hairs on the posterior abdominal lobes of the male disposed in a
similar way (see text-fig. 3, b and c). Professor A. Henry states that

r

FIG. 26.

(a) Posterior end of nymph of Pterolichus bicaudatus (p. 64), from

above, showing shape of dorsal shield, (b) Posterior end of nymph

of Pterolichus sculpturatus (p. 64). (Original).

otocariasis due to Psoroptes is very common in the horse, sometimes
being present in 70 per cent, of the horses examined in France.

At the beginning of the great war all but a very small percentage
of the cases of mange were due to Psoroptes, but this complaint
became quite rare later, and sarcoptic mange became prevalent.

Infection is spread through contact between diseased animals
and also through contaminated harness, grooming implements,
rugs, stable utensils, litter, etc. Anything that has come in contact
with an animal suffering from mange may remain infectious for
several weeks ; hence the need for cleanliness and disinfection
with cresyl or other suitable preparation.

Both sarcoptic and psoroptic mange should be notified to an
inspector (in the London district) or to a police constable (rural districts).

Mites Injurious to Domestic Animals. 45

Chorioptic or symbiotic mange is usually confined to the lower
part of the limbs and root of the tail. Sometimes this complaint
causes horses to stamp when in the stable or to knock their feet
together, and in doing this the coronets of the feet may be damaged.

FIG. 27.

Pterolichus sp., from interior of quills of feathers of North American

fowl, female from below, x 104. (a) Tarsus of second leg of same

greatly enlarged. (b) Denticle on first tarsus very greatly

enlarged. (Original.)

Leaflet No. 274, issued by the Ministry of Agriculture and
Fisheries, should be consulted by those interested in parasitic
mange in horses, asses, and mules. Remedies, symptoms, etc.,
will be found in this leaflet.

46 Mites Injurious to Domestic Animals.

Besides the three kinds of mange described above, pruritus
and other trouble may be caused by Demodex (see page 80).

Genus Notoedrus, Railliet, 1893.
Very similar to Sarcoptes, but with the anus well on the dorsal

FIG. 28.

Pterolichus sp., from interior of quills of feathers of North American
fowl. Male from above, x 216. (Original.)

surface. This genus is not very distinct from Sarcoptes, and should
perhaps be considered only a sub-genus.

Mites Injurious to Domestic Animals. 47

Notoedrus cati, Hering, 1838.

(Figs. 10, 11.)

There are a number of scales grouped together in the middle
of the dorsal surface in this species, but they are not nearly so well
developed as in the species of Sarcoptes, only the posterior edge
being somewhat salient.

Mange in Cats. — Mange in cats generally starts on the neck,

FIG. 29.

Pterolichus sp., from interior of quills of feathers of North American
fowl. Cast skin of nymph, X 160. (Original.)

afterwards appearing on the ears, forehead, and round the eyes;
finally nearly all the head is affected. Greyish crusts are present,
and in advanced cases the skin becomes hard, thickened, and
creased, almost like leather in appearance. In cats mange is usually

48 Mites Injurious to Domestic Animals.

restricted to the head and neck, rarely extending to the body and
limbs.

Craig has reported three cases in which this parasite of the cat
was found in dogs suffering from mange. One of these animals
was known to have associated with a cat affected with notoedric
mange.

FIG. 30.

Freyana chanayi (p. 64). Feather mite from domestic turkey,
North America. Dorsal view of male, x 183. (Original.)

The following case of mange in a dog caused by Notoedrus cati
was observed by the author in July, 1917. The disease occurred
in a puppy aged about three months, and there was no history,
the animal being a stray one found in the streets of London. The

Mites Injurious to Domestic Animals. 49

symptoms were as follows : — The upper part of the face was badly
affected, being greyish in colour and scabby, especially the forehead
and round and between the eyes. A large part of the body was
very seriously affected, the sides and belly being leathery and almost

FIG. 31.

Dermoglyphus elongatus (p. 64). — (a) Male, x 112. (b) Female, -X 120.
Ventral views. (Original.)

hairless. Elbows of front legs leathery and with the hair worn off,
the upper part of the hind legs was also much affected. Irritation
was evidently intense. Specimens of Notoedrus were easily obtained
from all the diseased parts, and could be readily picked out of the
flanks. No specimens of Sarcoptes were to be met with in this

50 Mites Injurious to Domestic Animals.

case. It will be seen from the above that natural infection with
Notoedrus is sometimes found in the dog, and may be intense
and general in character instead of being confined to the
head.

Notoedric Mange of Rabbits. — In the case of rabbits,
Notoedrus usually attacks the face, especially round the eyes,

FIG. 32.

Epidermoptes bilobatus (p. 65), ? , from below, x 268.
(After Neunu

Seumann. )

more rarely attacking the ears. In advanced cases the legs and
genital regions become affected. Scales and crusts are formed on
the diseased parts of the animal.

It is probable that the Notoedrus of the rabbit (N. cati, var.
cuniculi, Gerlach, 1857, figs. 10 and 11) is identical with that of the
cat, or is at most merely a variety of the same species, but it is
difficult to transmit the mite from the cat to this host.

Mites Injurious to Domestic A nimals. 5 i

Notoedrus muris, Megnin, 1880.

(Fig. 12.)

This mite especially affects the ears of its host, the common
brown rat, giving rise to characteristic crusts arid warty excrescences.
Later the face, feet, tail, and genital region may become infected.
When neglected, the disease sometimes terminates fatally. Both
tame and wild rats suffer from this disease.

Genus Cnemidocoptes, Fiirstenberg, 1870.
Without any distinct spines or scales on the dorsal surface,

FIG. 33.
Epidermoptes bilobatus (p. 65), <j , from below, x 300. (After Neumann.)

only a few hairs being present. Both the third and fourth legs
of the male end in a sucker, borne on an unsegmented peduncle
{whereas only the fourth leg has a sucker in Sarcoptes and Notoedrus).

Cnemidocoptes mutans, Robin and Lanquetin, 1859.

(Figs. 13 and 14.)

This mite differs from the allied species, C. gallinae, by the
arrangement of the linear markings on the dorsal surface, which

E 2

52 Mites Injurious to Domestic Animals.

are interrupted in the middle area so as to form raised almost
scale-like sculpturings. A single pair of long hairs is present at the
posterior end of the body.

Scaly-Leg in Fowls. — Scaly-leg in the domestic fowl is

FIG. 34.

Listrophorid mite (unde-
scribed genus occurring on
Cricetomys gambianus),
showing distribution of
tracheal tubes (p. 69).
(After Hirst, Journ.

FIG. 35.
Chirodiscoides caviae (p. 69), Listrophorid

Quekett Microscopical mite, parasitic on guinea-pig. Ventral view

of male, X 268. (Original.)

Club, Nov. 1921.)

caused by Cnemidocoptes mutans. The large scales of the tarsus of
the feet are first affected, becoming raised at the edges by whitish
floury powder, which is sometimes mixed with exuded serum. In
advanced cases the disease assumes a characteristic form, the feet

Mites Injurious to Domestic Animals. 53

FIG. 36.

Hypopial or travelling nymphs of Tyroglyphidae (p. 70), xc. 150.
(After Michael.)

FIG. 37.

Tyroglyphus longior, var. castellanii (p. 71), dorsal and ventral aspects of
male, x 97. (After Castellani and Hirst, Journ. Trop. Med. and Hyg.)

54 Mites Injurious to Domestic Animals.

becoming greatly distorted and covered with thick nodular spongy
crusts. The comb and neck may also be attacked.

Crude petroleum should be applied to the feet, or they can be
dipped into the oil. Another method is to soak the feet of the fowl
in hot soapsuds, removing as much as possible of the infected scales,
etc., and then rub them with ointment containing sulphur or 6 per
cent, carbolic. Scaly-leg is highly contagious, and the fowls suffer-
ing from it should be isolated and their perches and runs disinfected.

Depluming Itch of Poultry. — Cnemidocoptes laevis, var.
gallinae (fig. 15), is the mite present in depluming itch, a complaint
chiefly characterised by the falling out of the feathers over more or

FIG. 38.

Glycyphagusdomesticus(p.ll), x 50. (After Michael.)

less extended areas of the body. If a few feathers are plucked from
the back, top of wing, near the vent, breast, or thighs, the mite will
be found embedded in the tissue or scales at the base of the quill.
According to H. P. Wood, of the U.S. Bureau of Entomology :—
" The damage to the plumage is.very evident. Infested fowls have
a ragged appearance, with a good many broken feathers or perhaps
bare spots. This appearance is more evident in the summer and fall
than it is soon after moulting. It is quite evident that any damage
done to plumage would be detrimental to show birds. We believe
also that more injury is done to poultry generally by this mite than
is commonly supposed. There seems to be some itching, which
may result in feather pulling, causing some hens to become quite

Mites Injurious to Domestic Animals. 55

bare. ..." Depluming itch occurs both in North America and
Europe. Neumann says it is especially prevalent in the spring and
during summer, disappearing more or less completely in autumn,
and usually making its reappearance in March or April. The typical
form of this species (Cnemidocoptes laevis) was described by Railliet
in 1885 from specimens found on a carrier pigeon. Megnin observed

FIG. 39.

Cheyletid Mites, (a) Psorergates musculi (p. 73), parasitic in

skin of house mouse, dorsal view of male, x 3*15. (b) Myobia sp.

(p. 73), a pilicolous mite, dorsal view of male, x 105 J (After

Hirst, Studies on Acari, no. 1.)

a mite causing similar trouble in pheasants, which is, perhaps, a
variety (var. phasiani). Another species (C. prolificus, Railliet and
Henry) occurs on geese in France.

Bishopp and Wood recommend dipping in the following solu-
tion as a cure for depluming itch, for it kills any lice that may be
present on the bird in addition to the mites : — Sodium fluoride
(chemically pure) foz. ; flowers of sulphur, 2oz. ; laundry soap.

56 Mites Injurious to Domestic Animals.

about ^oz. ; water, 1 gallon.* Dipping of poultry is best done during
the summer months, on a warm summer day, so that the fowls will
dry quickly. Windy weather should be avoided. The operation
should be completed a considerable time before sundown, so as to
enable the fowls to become thoroughly dry before going to roost.
The dipping should be done in a large tub filled to within six or
eight inches of the top. In dipping the fowls it is best to hold the

FIG. 40.

Cheyletiella parasitivorax (p. 73). — A pseudoparasite of rabbit and
domestic cat, x 153. (After Hirst, Ann. Mag. Nat. Hist. xx. 1917.)

wings over the back with the left hand and quickly submerge the
bird in the solution, leaving the head out, while the feathers are
thoroughly ruffled with the other hand so as to allow the solution
to penetrate to the skin on the different parts of the body. The
head is ducked once or twice and the bird is allowed to drain and
is then released. It is not necessary to keep the fowl under the

* See " Mites and Lice on Poultry," by P. C. Bishopp and H. P. Wood,
Farmers' Bulletin no. 801, revised edition, 1919, U.S. Dept. of Agriculture.

Mites Injurious to Domestic Animals.

57

FIG. 41.

(a) Syringophilus bipectinatus (p. 74). — A Cheyletid mite living in the

quills of the feathers of the domestic fowl, x 97. (b) Syringophilus

columbae (p. 75), I from quill of domestic pigeon. Dorsal aspect of

females. (Original.)

58 Mites Injiirious to Domestic Animals.

HijMey dd.

FIG. 42.

(a) Tarsus of leg of Syringophilus bipectinatus (p. 74). (b) Tarsus
of Syringophilus columbae (p. 75). (Original.)

FIG. 43.

Tydeus molestus (p. 76), ? , from below, x 250.
(b) Palp, much enlarged. (Original.)

(a) Leg,

fluid for more than thirty seconds and the head only an instant.
Care should be taken to keep the dip well stirred so as to keep the

Mites Injurious to Domestic Animals. 59

sulphur in suspension. Sodium fluoride solution should not be
allowed to remain in galvanized vessels or tubs for any length of
time or it will damage them.

Two species of Sarcoptid mites (Cytoleichus (=Cytodites) nudus,
Vizioli, and Laminosioptes cysticola, Vizioli) are internal parasites
of the fowl, and both are frequently found in this country.
Cytoleichus nudus (fig. 16) is a minute soft-skinned, smooth, oval
mite, the hairs on its body being few in number and very short.

FIG. 44.

Leptus (Trombicula ?) similis, Hirst (p. 78).— A larval Trombidiid mite
occurring on the domestic fowl in North America, x 130. (Original.)

Numbers of this mite often occur in the air sacs and respiratory
tract of the fowl, pheasant, etc. It is possible that when present
in very large numbers they may affect the health of their host.

Another species of Cytoleichus (C. banksi) is a parasite of squirrels
in California, whilst two specimens of a species of this genus were
found by Castellani embedded in the fat of the omentum of a dead
negro in Uganda.

Laminosioptes cysticola (fig. 17) is a much more elongated species.
Its presence may be detected by the occurrence of calcareous

60 Mites Injurious to Domestic Animals.

nodules or cysts of varying size in the subcutaneous tissues. The
living mites can be found in the tissues and not in the cysts, which
apparently are formed round dead specimens.

Mercier and Lebailly discovered numerous specimens of these

46.

Schongastia americana, Hirst (p. 78). — A larval Trombidiid mite

occurring on the domestic fowl in North America, x 236.

(a) Scutum of same greatly enlarged, (b) A hair greatly enlarged.

(Original.)

two species of mites in a hen which had a cancerous tumour (myxo-
sarcoma) adhering to the wall of, the air-sac near the kidney, and
suggest that Cytoleichus nudus may, perhaps, inoculate the virus
of the disease in much the same way as has already been done
experimentally by means of the needle of a hypodermic syringe:

Mites Injurious to Domestic Animals, 61

FAMILY ANALGESIDAE (Feather Mites}.

The mites of this family are closely allied both to the Sarcoptidae
and Tyroglyphidae, being somewhat intermediate between these

FIG. 46. (See pp. 79-86.)

A. Capitulum of Demodex folliculorum, from above, (a) Labial
sheath of chelicera. (b) Chelicera (upper finger), (c) Spinule
on palp, (d) Epistome. (e) Palp. B. Capitulum of Demodex
folliculorum, from below, (a) Labial sheath of chelicera. (b)
Chelicera (lower finger), (c) Palp, (d) Membranous Capitulum.
(e) Supposed opening of respiratory system. (f) Mouth.
(After Hirst, Studies on Acari, no. 1.)

FJG. 47. (See pp. 79-86.)
Dorsal spinule on capitulum (palp) of Demodex spp. A. of

D. folliculorum. B. of D. canis. C. of D. equi. D. of D. cati.

E. and F. Spinule of D. bovis, showing variation in form. G. of
D. muscardini. H. of D. ratti. I. of D. arvicolae, var. musculi.

(After Hirst, Studies on Acari, no. 1.)

two groups. In some forms there is a lateral vesicle on each side
of the abdomen, as in the Tyroglyphidae. They are found chiefly

62 Mites Injurious to Domestic Animals.
Y-

FIG. 48.

Demodex canis (p. 79). — Ventral view of female, x 328, and capitulum
from above. (After Hirst, Studies on Acari, no. 1.)

'

FIG. 49.

Demodex equi (p.80). —Female from below, x 297, and male from above, x 330.
Also dorsal view of capitulum. (After Hirst, Studies on Acari, no. 1.)

Mites Injurious to Domestic Animals. 63

between the barbules of the feathers of birds or more rarely make
their way into the interior of the quills. The special nymph (Hypo-
dectes, fig. 18) of certain forms (genus Falculifer) penetrates into the
subcutaneous tissue of the pigeon, flamingo, and other birds. These

FIG. 50.

(a) Demodex canis. var. ovis (p. 84), ? , from below, x 456.

(b) Capitulum of same, from above, (c) and (d) Demodex phylloides
(p. 82), 9 (from pig), dorsal and ventral aspects, x 378. (e) Demodex
cati (p. 86), <J , from above, X 566 (After Hirst, Studies on

Acari, no. 1.)

nymphs have also been found in large numbers in the thymus of
pigeons both in Europe and North America.

The anterior legs in the genus Megninia are characteristic, being
armed with large spines (see fig. 19). One of the species of this
genus (M. cubitalis, Megnin), which has the posterior lobes of the

64 Mites Injurious, to Domestic Animals.

male divided into two segments by a transverse line (see fig. 22 b)
is found on the feathers of the turkey, peacock (var. ginglymura),
and fowl, whilst another (M. columbae, Bucnholz, figs. 20 and 21)
occurs on the domestic pigeon, fowl, canary, and certain other
birds ; a third (M . velata, Megnin, fig. 22 a) is found on ducks.

Pterolichus obtusus, Kobin (figs. 23 and 24) is a feather mite
occurring on several kinds of birds, especially on the red-legged or
French partridge (Perdrix rubra), and is sometimes found on fowls.

'

FIG. 51.

Demodex bovis (p. 83).— Ventral view of female, x 335, and dorsal and
lateral views of male, x 324.

The specimens of this mite figured in this pamphlet were taken on
chickens in the United States. Another member of the genus
(Pterolichus bicaudatus, Gervais, figs. 25 a and 26 a) occurs on
ostriches in South Africa and also in California, whilst an allied
species (P. sculpturatus, Hirst, figs. 25 b and 26 b) lives on and inside
the feathers of the South African ostrich in the Transvaal. Another
feather mite (Freyana chanayi, Trouessart) is met with on turkeys
(fig. 30). Two species of Dermoglyphus (D. minor, Norner, and D. elon-
gatus, Megnin) live inside the quills of the feathers of fowls, the latter

Mites Injurious to Domestic Animals. 65

species (fig. 31) is elongated in form like the species of Syringophilus,
which also live inside the quills of various birds (see p. 74, fig. 41).

Several species of feather mites are found on pigeons, viz.,
Megninia columbae, Buchholz, mentioned above, Falculifer rostratus,

in life cycle of Demodex. (a) Young nymph of Demodex
muscardinus. (b) One of the epidermal scales of this nymph
very greatly enlarged, (c) Larva of D. muscardinus. (d) Egg
of D. muscardinus. (e) Large nymphal stage of D. bovis, showing
completely formed adult inside, x 328.

Buchholz, Falculifer cornutus, Trouessart (in America), Analyes
bifidus, Nitzsch, and Pterophagus strictus, Megnin.

Two very minute mites allied to the feather mites (Epider-
moptes bilobatus, Rivolta (figs. 32 and 33), and Rivoltasia bifurcata,

66 Mites Injurious to Domestic Animals.

FIG. 53.

(a) Penis of Demodex cati. (b) Early larva of D. bovis. (c) Tip of
penis of D. bovis, very greatly enlarged, (d) End of same as it
appears when protruding from sexual orifice, (e) Penis of D. bovis,
showing its entire length. (After Hirst, Studies on Acari, no. 1.)

FIG. 54.

Anterior end of Dermanyssus (p. 87), showing chelicerae in situ.
(After Hirst, Journ. Zool. Res., 1916.)

Mites Injurious to Domestic Animals. 67

Rivolta), which have the skin only weakly chitinized, live on the
surface of the skin of the domestic fowl. In some cases of squamous

FIG. 55.

Dermanyasus gollinoe (p. 87). — Dorsal view of female, x 104.
(Original.)

skin diseases (Pityriasis) they have been found in great numbers and
have been accused of causing the trouble.

F 2

68

Mites Injurious to Domestic Animals.

FAMILY- LISTROPHORIDAE,

The mites of the family Listrophoridae live in the fur of
various mammals (bats, shrew mice, weasels, rodents, etc.). The

FIG. 56.

Dermanyssus gallinae (p. 87). — Ventral view of female, X 104.
(Original.)

lips or some of the legs are modified so as to form organs for
clasping the hairs of the host. Many species are compressed

Mites Injurious to Domestic Animals. 69

laterally like the insects of the family Pulicidae (fleas), in order to
enable them to progress rapidly through the fur of the host.
Distinct tracheal tubes are present in some Listrophorid mites
(fig. 34). (See Hirst, Journ. Quekett Club, November, 1921.)

Listrophorus gibbus, Pag., is often very abundant in the fur of

FIG. 57.

Dermanyssus gallinae (p. 87). — Ventral view of male, X 123.
(Original.)

rabbits. Another species (L. mustelae) is found on ferrets. A
minute Listrophorid mite (Chirodiscoides caviae, Hirst, fig. 35)
attaches itself to the hairs on the back of guinea-pigs.

It is said that some of the species of Listrophorus are preyed
upon by species of Cheyletinae, which use the rabbit's fur as a
hunting forest.

/o Mites InJ2irious to Domestic Animals.
FAMILY TYROGLYPHIDAE.

Minute, pale-coloured mites, without any definite respiratory
system, their body is usually rather soft, being weakly chitinized.
They are mostly free-living, feeding on animal or vegetable matter,
especially if in a state of decay. A few species are associated with
mammals, living in their nests, and the travelling nymphs or hypopi

FIG. 58.

Second nymphal stage (deutonymph) of Dermanyssus gallinae (p 87),
from below. (Original.)

of these forms usually have a special apparatus on the ventral'
surface of the body for grasping the hairs of the host (fig. 36). The
travelling nymphs of other species bear discs provided with suckers
in the same position, enabling them to attach themselves to insects
(fig. 36).

Several species]of Tyroglyphids occur accidentally on the skin of

Mites Injurious to Domestic Animals. 71

horses — for instance, Aleurobius farinae, Tyroglyphus longior (fig. 37),
Glycyphagus domesticus, G. cadaverum, and G. ornatus. Hypopial
nymphs of several tyroglyphid mites have also been found on horses.

Aleurobius farinae, De Geer, 1778.
This species is a well-known^ pest of grain and is sometimes also

FIG. 59.

Dorsal view of first nymph (protonymph) of Dermanyssus
gallinae (p. 87), X 146. (Original.)

found in cheese and other substances. It is said by Shipley to
occur frequently on the red grouse (Lagopus scoticus).

Glycyphagus domesticus, De Geer, 1778.

C. J. Davies records the presence of a Tyroglyphid mite in the
ear of tame rabbits. The mite has been determined by A. W. N.
Fillers as Glycyphagus domesticus, De Geer (fig. 38).

72 Mites Injurious to Domestic Animals*

SUB-ORDER PKOSTIGMATA.

FAMILY TROMBIDIIDAE.

Sub-Family CHEYLETINAE.

Many of the mites in this family have the palpi greatly enlarged.
The male sexual orifice is often situated dorsally.

FIG. 60.

Protonymph of Dermanyssus gallinae (p. 87), from below, X 14-6.
(Original.)

Some of the Cheyletinae (Cheyletus, etc.) are free-living, predatory
forms, being found amongst detritus and elsewhere preying on
Tyroglyphid mites or other small arthropods, or they may occur on
birds or mammals, either preying on the Analgesid or Listrophorid

Mites Injurious to Domestic Animals. 73

mites of those animals, or being sometimes themselves parasitic or
pilicolous (Psorergates fig. 39 a, Myobia fig. 39 b, etc.).

Genus Cheyletiella, Canestrini, 1886.

In the genus Cheyletiella the palp is stout, ending in a prehensile
claw, used to grasp the feathers or hairs of the host.

FIG. 61.

Larva of Dermanyssus gallinae (p. 87), x 154; drawn from living

specimens. Note the minute conical tooth at posterior end of

body used for piercing the egg-shell. (Original.)

Cheyletiella parasitivorax, Megnin, 1878.

Apparently C. parasitivorax (fig. 40) is the only species that
lives on mammals. It can readily be distinguished from the other
members of the genus] by the absence of claws, which have dis-
appeared, for there are only combs at the end of the feet.

74

Mites Injurious to Domestic Animals.

The fur of the rabbit and hare is the normal habitat of this
species. It is said to feed on the minute pilicolous Acari (Listro-
phorus, etc.) found on these rodents. In 1917 specimens of this
mite were found by the author on a domestic cat in London.
Cheyletiella parasitivorax has also been observed more recently on
cats in Denmark by Lomholt and others.

Several other species of Cheyletiella are found upon birds.

FIG. 62.

Dermanyssus muris (p. 87), x 40. — A widely distributed parasite of rats.

(a) Ventral aspect, (b) Dorsal aspect.

(After Hirst, Bull. Ent. Res. 1914.)

Genus Syringophilus, Heller, 1880.

Body very elongated and furnished with a number of long hairs.
Chelicerae stiliform. Palpus and first leg normal, not being modified
to form clasping organs. Feet with two claws and also with two
combs, each composed of a series of setae.

Syringophilus bipectinatus, Heller, 1880.

(Figs. 41 a and 42 a.)

Body very elongated, the female being almost vermiform, in
but the male somewhat shorter and stouter.

Mites Injurious to Domestic Animals. 75

This mite lives inside the quills of the feathers of the fowl, and is
often present in great numbers. It is said to feed on the internal
cones of the feathers. It occurs both in Europe and North America.

Syringophilus columbae, Hirst, 1920.
(Figs. 41 b and 42 b.)

Closely allied to the preceding, but there are only two quite
short hairs on the front end of the anterior scutum, and the modified

FIG. 63.

Dermanyssus sanguineus (p. 87), x 39. (a) Ventral aspect, (b) Dorsal
aspect. (After Hirst, Bull. Ent. Res. 1914.)

hair on each side of the claws of the feet is much wider, being scale-
like. A smaller species .than S. bipectinatus.

S. columbae lives inside the quills of the feathers of the domestic
pigeon.

Genus Cheletoides, Oudemans, 1904.

Differing from Cheyletus in the absence of the comb from the
chelicerae (mandibles).

7 6 Mites Injurious to Domestic Animals.

Cheletoides uncinata, Heller, 1880.

A much less elongated form than the two species of Syringophilus
figured above. It lives in the quills of the feathers of the peacock
(Pavo cristatus).

Sarcopterinus, Railliet, 1893.

Sarcopterinus ( = Harpirhynchus)nidulans, Nitzsch, 1818, lives in
colonies in the follicles of the feathers, and gives rise to tumours

FIG. 64.

t, (b) Dorsal

Dermanyssus aegyptius (p. 87), x 47. (a) Ventral aspect,
[aspect. (After Hirst, Bull. Ent. Res. 1914.)

or cysts in the skin. It occurs in a number of birds, including
pigeons.

Sub-family EUPODINAE.
Genus Tydeus, C. L. Koch, 1842.
Tydeus molestus, Moniez, 1889.
This mite is described by Moniez as occurring in very large

Mites Injurious to Domestic Animals.

77

numbers for many years at an isolated farm in Belgium and causing
great irritation by its bite to human beings and domestic animals
(dogs, cats, fowls, guinea-fowl, and ducks). It,is supposed to have
been imported in guano from Peru. Fig. 43 of this mite is drawn
from some of Moniez' original preparations now in the collection
of the Faculty of Medicine of the Paris University.

Harvest Bugs (Leptus, etc.)
Harvest bugs are the larval forms of various Trombidiid mites.

FIG. 65.

Liponyssus bacoti (p. 89), x 64.— A widely distributed parasite of

the brown rat, sometimes attacking man. (a) Ventral aspect.

(b) Dorsal aspect. (After Hirst, Bull. Ent. Res. 1914.)

Owing to the fact that the adult stage is usually not known, it is
necessary to allot provisional specific names to these larval mites.
Both wild and domestic animals are sometimes molested by
harvest bugs. For instance, cats and dogs are often attacked
during the warmer seasons of the year by our common Leptus
(Trombicula ?) autumnalis^Sh&w. According to Oudemans, Meta-
thrombidium poriceps, Oudemans, also attacks dogs. Harvest bugs
also molest man, horses, cattle, sheep, and goats. Similar mites have
also been found on domestic poultry both in England and on the

7 8 Mites Injurious to Domestic Animdls.

Continent ; they are said to be very injurious to young chickens
in the United States, sometimes causing death when present in large
numbers. Two of the forms occurring on American poultry are
figured in^this pamphlet (figs. 44 and 45).

Another larval Trombidiid mite (Leptus (Microtrombidium?)
guineense, Bruyant and Joyeux, 1913) occurs on poultry and
monkeys at Kouroussa on the Niger in Upper French Guinea.

FIG. 66.

Liponyssus bursa (p. 89). — A fowl mite with a wide distribution in

the warmer regions of the world. Dorsal view of female, x 100.

(After Hirst, Bull. Ent. Res. 1915.)

SUB-ORDER VEKMIFOKMIA.
FAMILY DEMODICIDAE.

These mites are allied to the Cheyletinae (Prostigmata), espe-
cially to the genus Psorergates, Tyrrell, the species of which, like

Mites Injurious to Domestic Animals. 79

Demodex, are internal parasites, but are very different in shape,
being almost circular in outline. Demodex agrees with Psorergates and
certain other Trombidiid mites (Myobia, etc.) in having the sexual
aperture of the male on the dorsal surface, and also in the structure
of the appendages of the larvae and nymphs which are quite rudi-
mentary, merely consisting of an epimeron supporting a circular
disc crowned with minute denticles (fig. 52). It is probable, there-
fore, that the Demodicidae are descended from pilicoloua mites like
Myobia, living at the base of the hairs of the host, and have subse-
quently become internal parasites, the very small size and elongation
of the body being special adaptations to this mode of life. Besides
the forms of Demodex mentioned below as causing skin trouble in
domestic animals, Demodex occurs in man, bats, hedgehogs, moles,
badgers, foxes, deer, rabbits, field mice, rats, house mice, etc.

FIG. 67.

(a) Sternal plate of Liponyssus bursa, ? (p. 89). (b) Sternal plate of
L. sylviarum, 9 • (Original.)

Genus Demodex, Owen, 1843.

Demodex canis, Leydig, 1859.

(Fig. 48.)

An elongated species, usually more than six times as long as
wide. Spinule on capitulum very short and pointed.

D. canis is present in the skin disease called demodectic or
follicular mange, a very serious complaint which is most difficult
to cure. In typical cases the mites are found in enormous numbers,
and are associated with a bacterium (Staphylococcus pyogenes albus
or some allied form). The mite plays an important part in the /
disease by preparing the ground for the invasion of the bacterium
by dilating the follicles and sweat glands, and possibly also carries
and introduces the germ. The clinical symptoms of follicular
mange vary very greatly ; sometimes it assumes a pustular form
characterised by numerous pustules accompanied by various crusts,
etc. ; in other cases it is a squamous affection with numerous
epidermal pellicles, and sometimes the irritation is not very great

So Mites Injurious to Domestic Animals.

in this variety. There is also a form of the disease with circular
patches accompanied by large pustules. In a typical case there
are small hairless patches, together with reddish pimples and
pustules, skin hot and thickened in the affected places, etc. Dogs
suffering from follicular mange have a characteristic odour which
is very foul and disgusting. The complaint can easily be confused
with sarcoptic mange and also with certain fungoid affections, but
the presence of the mites in large numbers is a distinguishing feature.
(For a more detailed account of the structure of the mite and of the
symptoms see Hirst, Studies on Acari No. 1. The genus Demodex,
Owen, 1919, 44 pp., 13 pis., and 4 text-figs.).

FIG. 68.

(a) Posterior end of dorsal shield of Liponyssus bursa, $ (p. 89).

(b) Posterior end of dorsal shield of L. sylviarum, ? . (Original.)

Demodex equi, Kailliet, 1895.
(Fig. 49.)

The Demodex found on the horse is a rather wide species, the
width being about a third of the total length. Spines on capitulum
slender, rod-like, and blunt at the end.

Demodex equi is often present in horses which are apparently free
from disease. It seems clear, however, that this species can cause
a distinct pathogenic condition of the skin, characterised either by
pruritus, varying greatly in intensity, or by definite lesions ; these
symptoms may occur together or separately. The clinical effects
are as follows : — The coat is poor, with the hair very sparse in places,
and there are peculiar bare-looking spots (rather like the marks
made by the bites of horse-lice) occurring chiefly where the hair is

Mites Injurious to Domestic Animals. 81

short ; the hair on the spots is very thin, but not entirely absent.
This disease usually commences on the saddle or neck of the animal.
It does not appear to be at all infectious. The disease may also
occur in a pustular form. The Demodex of the horse is often found
in skin complaints due to other causes, especially in sarcoptic
mange.

Williamson and Oxspring (Vet. Journ., Ixxvi, p. 376, 1920)

FIG.

(a) Liponyssus bursa (p. 89), <5 , from below, x 92.

(After Hirst, Bull. Ent. Res. 1915.)
(b) L. sylviarum (p. 90), S , from below, x 110. (Original.)

state that in no case does demodectic mange of the horse show such
marked symptoms as are commonly met with in the dog, but the
majority of cases show obvious lesions which one would be far from
justified in neglecting. There seem to be two stages in the disease.
In the first stage, which includes the most benign and usually the
more recently infected cases, there is no pustular formation, but
there is always very strong pruritus. Certain areas of the skin
are more irritable than others ; these are generally on the neck,

G

82 Mites Injurious to Domestic Animals.

withers and croup, the lower parts of the belly being rarely affected
at this stage. The lower third of the neck is the usual site of
origin. Little can be seen, but epidermal scales will be noticed to be
more numerous than is usual on a well-groomed horse.

In the second or more advanced stage the presence of pustules is
the most striking symptom. Cutaneous irritation is very much less
marked, but a certain thickening of the skin will always be noticed.

FIG. 70.
Protonymph of Liponyssus bursa (p. 89), dorsal aspect, x 101.

Demodex phylloides, Csokor, 1879.
f (Fig. 50, c and d.)

The Demodex of the pig is rather wide, the female being only
about three and a half times as long as the width of the cephalo-
thorax ; the posterior end of the body is abruptly narrowed so as to
form a short tail. Tubercle on capitulum very short and incon-
spicuous

D. phylloides causes a pustular skin disease in pigs, the pustules
varying from a grain of sand to a walnut in size. They are often
very numerous, and may be situated close together ; sometimes
they become confluent, and may rupture and cause sores and ulcers
on the skin. Large numbers of the parasites are present in these

Mites Injurious to Domestic Animals. 83

pustules. The parasites are only found in places where the skin
is fine in texture. The disease usually spreads from the snout,
over the neck, the under part of the chest and abdomen, and over
the flanks and inner parts of the legs. Some of the pustules are
embedded deeply in the skin. In the pig, demodectic mange spreads
very slowly, and only a few animalsi n the herd are infected.
Usually the general health of the animals is not affected.

FIG. 71.

Laelaps echidninus (p. 91). — A widely distributed parasite of the brown

rat. Female, from below, x 66. (a) Chelicera.

(After Hirst, Bull. Ent. Res. 1913.)

Demodex bovis, Stiles, 1892.

(Fig. 51.)

A fairly wide species, the female being usually from three to
three and a half times as long as wide. Abdomen distinctly pointed
at the end, especially in the male.

The demodectic mange of cattle Ms been reported from Nyasa-
land and the Belgian Congo. Nodules or pustules varying in size
from the head of a pin to that of a fowl's egg are present on the
skin, occurring principally round the ears, on the sides, shoulders,

G 2

84 Mites Injurious to Domestic Animals.

intercrural space, etc. Numerous specimens of Demodex in various
stages of development are to be found in the cheesy or fluid contents
of the nodules. The pustules or nodules may be situated in the
thickness of the skin instead of on the surface. A large number of
animals in a herd are sometimes found to be suffering from demo-
dectic mange ; hence it would seem to be infectious. According
to Van Saceghem, the general health does not usually seem to be
much affected. It is probable that the more serious cases of disease
in cattle attributed to Demodex by Geoffrey and one or two other

FIG. 72.

Raillietia auris (p. 91). — A Gamasid mite living in the ear of cattle.
Dorsal view of female, X 47. (Original.)

observers, are really due to infection with some bacterium. Stiles
states that the damage to the hides due to the enlarged holes caused
by Demodex bows lessens their value very considerably. The
disease seems fairly common in the United States.

Demodex cam's, var. ovis, Eailliet, 1895.

(F]g.50a.)

The Demodex of the sheep is a slender, elongated form very
similar to D. cam's (and perhaps, indeed, the same species), but

Mites Injurious to Domestic Animals. 85

slightly shorter and with the capitulum rather wider. Spinule on
capitulum as in D. canis.

Probably this form is a common parasite of sheep, but appa-
rently it does not usually give rise to disease.

Dr. W. Klein has described, however, a serious form of demo-
dectic mange occurring in sheep in Germany. Two large flocks were
affected, nearly every sheep in one flock of six hundred seemed to
be suffering from the complaint, the fleece being torn and missing

FIG. 73.
Raillietia auris (p. 91).— Ventral view of female, X 47. (Original.)

or hanging loose in places.. In advanced cases the animals were
in moderate condition as regards nourishment, the wool had disap-
peared from the flanks, back, neck, and sides of the body, and the
skin became hard as a board, thickened, and strongly wrinkled in
the region of the neck. In the badly affected cases pruritus was
intense. A slender form of Demodex, very similar to that of the
dog, was present in numbers in these sheep.

Judging by the symptoms given by Klein one would imagine

86 Mites Injurious to Domestic Animals.

that Demodex was in this case associated with a skin complaint due
to some other mite such as Sarcoptes or Psoroptes.

Demodex cati, Megnin, 1880.

(Fig. 50 e.)

Body elongated, the abdomen of the male pointed at the end.
Demodex cati occasionally causes a skin disease very like that of
the follicular mange of the dog. It may also be present in notoedric
mange or in cases of parasitic otitis due to the mite called Otodectes.
Specimens have been found in the skin of cats which were appa-
rently quite healthy and showed no sign of any skin complaint.

Demodex caprae, Railliet, 1895.

The demodectic mange of the goat is characterised by little
pustules varying from the size of a pea to that of a walnut. Some-
times they are placed on the surface of the skin, but in other cases
they are situated deeply and are not visible on the surface. These
pustules contain a greyish matter with numerous specimens of
Demodex in all stages of development. The more deeply situated
nodules are only visible when the skin is taken off (for they are
situated on the inner surface) ; when the skin is being tanned holes
appear at the places where the nodules occur and greatly lessen its
value. In certain parts of Germany, according to Rissling, the
goats of the race of Saanen are especially affected with this com-
plaint ; in many villages the majority of the goats have con-
tracted it, whilst in other localities it is unknown.

SUB-ORDER MESOSTIGMATA.
FAMILY GAMASIDAE (PARASITIDAE).

These mites usually have rather strongly chitinized plates on
the body. There is a well-defined linear peritreme running down
each side of the body, the stigmal opening being placed close to
the basal joint of the last pair of legs,, Many of the mites of this
family are free-living, often predatory forms ; others attach them-
selves to beetles and other insects for transport ; others are para-
sitic on small mammals, often living in the debris of the sleeping
place or nest of the host, others are found on birds or reptiles.

The species of Halarachne live in the bronchial passages of seals,
whilst those of the genus Pneumonyssus inhabit little cysts or
tubercles in the lungs of old-world monkeys.

Mites Injurious to Domestic Animals. 87

Genus Dermanyssus, Dugs, 1834.

This genus is chiefly characterised by the thin stylets (chelicerae)
which are of considerable length in the female sex, being well
adapted for piercing the skin of the host (fig. 54). Only five species are
known, two of them being found on birds and three on rats. One
of the species found on birds (D. gallinae, figs. 55-61) is the common
red mite of poultry and cage birds ; the other (D. passerinus) is a
parasite of the common sparrow and apparently restricted to that
host.

One of the species of Dermanyssus parasitic on rats (D. muris,
Hirst, fig. 62), chiefly found on the black rat, is widely distributed,
having been recorded from Egypt, Arabia, India, Ceylon, and

FIG. 74.

Raillietia auris (p. 91). (a) Second leg of male, (b) Chelicerae
of male. (Original.)

Formosa. The other two (D. sanguineus, Hirst, fig. 63, and D.
aegyptius, Hirst, fig. 64) have so far been found only in Egypt.

Dermanyssus gallinae, Redi, 1674.

(Fig. 55-61.)

The colour of this well-known pest of poultry varies from whitish
to dark red, according to the amount of ingested blood. The
larva can transform itself into the next stage (first nymph) without
taking any nourishment. The complete life cycle from egg to
adult is said to take about seven days.

Dermanyssus gallinae is of considerable economic importance,
being very abundant' in many fowl-houses in Europe and North

88 Mites Injurious to Domestic Animals.

America. Both poultry and cage birds are greatly weakened by
loss of blood due to its attacks. It is nocturnal in habits, coming
out at night to suck the blood of the birds. During the day time
the mites conceal themselves in crevices, under boards, and in
similar obscure places. Sometimes they live in the hollow perching-
bars of cages or in the ornamental tops of metal cages. They are
capable of living many days without feeding. Red mites (pre-
sumably D. gallinae) have been proved by Mayer to transmit
spirochaetosis (Spirochaeta gallinarum) in canaries, but it is not
certain whether infection is due to the bites of the Acari or to their
being swallowed by the bird.

Bishopp and Wood point out that the mites can continue to
infest the poultry houses long after the fowls have been removed.
D. gallinae is able to live for a long time without sucking blood.
In some test experiments made by the authors mentioned above
some of the mites were still alive after being separated from the
host for 113 days or more. Their tests showed that when the
mites were supplied with a certain amount of moisture they lived
longer than when kept under very dry conditions. The author
has kept specimens of D. gallinae in tubes and cardboard boxes
without food, but with a little moisture supplied occasionally, and
one or two mites were still living after eighty-two days.

Fowl houses infested with D. gallinae should be sprayed with
crude petroleum either employed alone or diluted with kerosene at
the rate of one part of kerosene to three parts of petroleum. Com-
mercial carbolineum (a high grade anthracene oil) has been used as
a spray with still better results in the United States. It is advisable
to repeat the spraying after a month's interval. Creosote has also
been successfully used against this fowl mite.

Solutions of commercial disinfectants made up to double the
usual strength recommended for domestic use can be applied by
means of a watering-oan with a fine rose to the interior of the fowl-
house, the soil of the runs, dust bath, etc. If this be done weekly
the parasites become reduced in number and gradually disappear.

D. gallinae is also found in the nests of sparrows, pigeons,
swallows, wrens, and of a few other species of birds. Horses and
other mammals are sometimes molested by this mite.

Genus Liponyssus, Kolenati, 1859.

The genus Liponyssus is characterised by the rather short
mandibles (chelicerae), the fingers of which are separate and smooth
or with obsolete teeth. The body is often bilobed posteriorly.

Mites Injurious to Domestic Animals. 89

There are a number of species of Liponyssus, most of them
being parasitic on bats and rodents, a few on reptiles and on birds.
Two species (L. bursa and L. sylviarum) are parasitic on the domestic
hen. Another species (L. bacoti, Hirst, fig. 65), is parasitic on rats,
and is widely distributed in the warmer parts of the world, some-
times attacking man.

Liponyssus bursa, Berlese, 1888.
(Figs. 66, 67 a, 68 a, 69 a and 70.)

The tropical fowl mite apparently replaces Dermanyssus gallinae
in the warmer regions of the world. It is very widely distributed

FIG. 75.

Sternostomum rhynolethrum (p. 92). — A mite living in the nasal cavities
of geese. Female from above. (After Berlese.)

in Africa, also occurring in Mauritius, the Comoro Islands, China,
India, Texas, the Bahamas, Colombia, Buenos Aires, and in
Australia. Sometimes it occurs in very large numbers on nesting
hens. Several cases of this fowl mite attacking man have been
recorded. L. bursa has been found on the common sparrow, and,
like L. sylviarum, possibly it is conveyed from one locality to
another by this host. When the name Dermanyssus gallinae is
met with in reports by entomologists dealing with the parasites of
the domestic fowl in tropical countries, it is probable that L. bursa

90 Mites Injurious to Domestic Animals.

is really the species concerned. Numerous batches of Gamasid
fowl mites from tropical regions have been forwarded to the British
Museum (Natural History), but, with the exception of a few
examples from Palestine and from the Kenya Colony, and an
example found on Gecinus vaillantii at Tangiers, there have not been
any specimens of D. gallinae amongst them. It would appear,
therefore, that the European red mite of poultry does not thrive
in tropical and sub-tropical countries.

L. bursa is closely allied to L. sylviarum, of which perhaps it is
a variety.

Liponyssus sylviarum, Canestrini and Fanzago, 1877.
(Figs. 67 b, 68 b, and 69 b.)

Liponyssus sylviarum is very closely allied to L. bursa, but has
only a single pair of long hairs at the posterior end of the dorsal
scutum instead of two pairs as in that species. There are only two
pairs of hairs on the sternal plate instead of three. Ventral plate
of male with a transverse line posteriorly in front of the anal plate,
this line being absent in L. bursa. (Text fig. 69.)

This Gamasid mite occurs on several kinds of birds in Europe,
including sparrows and pigeons, but it is not a very common species
in England. In the United States it has recently been found on
sparrows and in their nests, and also attacking poultry in several
localities. It sometimes spends its entire life cycle on the fowl,
all stages being found amongst the feathers. Egg production is
much reduced in birds infested by it. Fortunately, this parasite
seems to have been introduced into only a few localities in the
United States, and, owing to the prompt and energetic measures
taken against it, has probably been stamped out.

Owing to the fact that this mite can live and breed on the fowl,
it is necessary to apply some substance which will kill the mites
without injuring the host. Fumigation by nitro-benzol has been
successfully employed for this purpose at the Purdue University
Agricultural Station, Lafayette, Indiana. This method should not
be used in the case of laying hens, as the fumes affect the unlaid
eggs to such an extent that they cannot be used for domestic
purposes. Dusting with flowers of sulphur is also said to be a
useful remedy.

The mite described by Megnin in 1891, under the name Lophoptes
patavinus as causing a special acariasis in Paduan fowls, is possibly
L. sylviarum.

Another species of Liponyssus (L. suffuscus, Railliet) is said to

Mites Injurioris to Domestic Animals. 91

have been found on rabbits, but little is known about the structure
or habits of this mite.

Some of the mites of the genus Laelaps, C. L. Koch, are parasitic
on rodents, moles, and other small mammals. One species
(L. echidninus, Berlese, fig. 71) is parasitic on the brown rat and,
like its host, is probably cosmopolitan ; another species (L. nuttalli,
Hirst) is common both on the black rat and brown rat in
tropical regions. The species of Haemogamasus, Berlese, suck the

FIG. 76.

Sternostomum rhynolethrum (p. 92). — Female from below.
(After Berlese.)

blood of various small mammals such as moles, field mice, etc. ;
and one species (H. oudemansi, Hirst) is found on the brown rat in
this country.

Genus Ratllietia, Trouessart, 1902.
Raillietia auris, Leidy, 1872.

(Figs 72-74.)

In general appearance this mite resembles a Dermanyssus or
Liponyssus. Second leg of male very characteristic, being armed

92 Mites Injiirious to Domestic Animals.

with, knob-like protuberances, like those present in certain non-
parasitic Gamasid mites (Gamasus, etc.). It measures slightly over
a millimetre in length.

This interesting mite lives in the external ear of cattle, appa-
rently feeding on the waxy secretions. It is found both in North
America and Europe (France, Austria, etc.). In some localities it
seems to be fairly common.

FIG 77.
Holothyrus sp. (p 93)., from below x 13. (After Thorell.)

Genus Sternostomum, Trouessart, 1895.
Sternostomum rJiynolethrum, Trouessart, 1895.

(Figs. 75 and 76.)

This mite has been found living in the nasal cavities of geese in
France. It feeds on the blood of the host and may set up severe
inflammation of the nasal passages. Another species (Sternostomum

Mites Injurious to Domestic Animals. 93

cryptorhynchum, Berlese and Trouessart) is parasitic on the com-
mon sparrow. An allied mite (Ptilonyssus nudus, Berlese and
Trouessart) occurs in the nasal cavities of the common sparrow,
whilst others (Rhinonyssus, etc.) are parasitic in various birds both
in Europe and elsewhere.

FAMILY HOLOTHYRIDAE.

The Holothyridae are rather large reddish mites with the upper
surface of the body convex and shining, the integument being hard.

According to some recent authors these mites should be regarded
as forming a distinct family, but in general appearance, position
of the stigmata, etc., they are very like Gamasid mites, and are
regarded by some authors as being closely allied to that family.

Genus Holothyrus, Gervais, 1842.

(Fig. 77.)

Holothyrus coccinella, Gervais, 1842.

This species lives in the Island of Mauritius. It secretes an
irritant poison, and is sometimes swallowed by ducks and geese,
causing their death ; for this reason it is called " touille canard " by
the inhabitants. Children have suffered ill effects through putting
the mite in their mouths, or from meddling with it and afterwards
touching the mouth with the fingers.

APPENDIX.

ON THE ACAEINB DISEASE OF HIVE BEES.

SUB-ORDER HETEROSTIGMATA.
FAMILY TARSONEMIDAE.

Genus Acarapis, Hirst, 1921.

The genus Acarapis is closely allied to Tarsonemus, from which
it differs as follows : — Second and third legs of larval stage very
short (almost rudimentary) and without either claws or sucker
(figs. 82 and 83 c), whereas, in the larva of Tarsonemus, these legs are
about as long as the first and are provided with paired claws and
a sucker (fig. 84).

The female of Acarapis lacks the club-shaped pseudostig-
mata present between the first two pairs of legs in that sex in
Tarsonemus, and the fourth leg is shorter and wider, being provided
with more numerous hairs (in this last respect somewhat resembling
the fourth leg of Scutacarus).

Acarapis woodi, Rennie, 1921.

(Figs. 78-83.)

For a longtime the " Isle of Wight Disease " of bees was thought
to be due to a protozoon parasite (Nosema apis). But Rennie,
White, and Miss Harvey (Trans. Roy. Soc. Edinburgh, LIL, 1921 ,
pp. 737-779) have found a Tarsonemid mite constantly present in
the thoracic tracheal tubes of bees suffering from -this disease.
Loss of the power of flight is one of the chief distinguishing features
of " Isle of Wight " Bee Disease, and another is the great mortality
that occurs amongst infected bees. " Crawling " bees are usually
present in numbers in diseased stocks. According to Rennie crawl-
ing appears to be intermittent. Apparently on very warm days an
excessive amount of crawling may occur, ridding the hive of the
bulk of the heavily infected individuals and lowering the proportion
of sick bees in the hive. New bees are being produced in large
numbers at certain times of the year, and even if some of them become
94

Mites Injurious to Domestic Animals. 95

infected early in their adult life, they may continue to fly and work
for a long time. A false impression of recovery from the disease may
thus be conveyed. The mite has been found in workers, drones,
and queens, but the young stages of the bee do not seem to
harbour it. It also occurs sometimes in apparently healthy bees,
but in these the disorder usually makes its appearance at a
later date. In some instances, however, the mite seems to
be present without causing the disease, and heavily infested bees
may be capable of flight. All stages of the life cycle of the parasite
are found in the tracheal tubes of the thorax and sometimes of the

FIG. 78.

Tracheal tube of honey bee infested with Acarapis woodi.
(Photo by the Rev. G. H. Hewison.)

head, and apparently the mites are restricted to this part of the
respiratory system. Acarapis woodi is oviparous, the eggs being
of very large size, when compared with the mite itself, and bean-
or kidney-shaped. They are laid in the tracheal tubes of the host.
The mite emerges from the egg in the form of a six-legged larva
(fig. 82), which subsequently develops into the adult. Adult mites
of either sex are frequently to be met with fully-developed but still
enclosed in the larval skin. Apparently infection takes place through
the thoracic stigmatal openings. The mites, no doubt, set up ill
effects through blocking the tracheal tubes, and probably also
through sucking the blood of their host. It has been suggested

g6 Mites Injurious to Domestic Animals.

that the metabolic products of the mite may perhaps cause toxaemia
(see " Bee World," October, 1920— April, 1921, p. 59). White has
pointed out that pathological changes take place in the tubes
infested by them ; whilst the muscles concerned with flight also show
degenerative changes. The tracheal tubes of bees are normally pale,

FIG. 79.

Acarapis woodi. — Female from above, x 405.
(After Hirst, Ann. Mag. Nat. Hist., June, 1921.)

but in advanced cases of the disease they become brownish or
blackish, and this makes it easy to recognise the malady, for if the
tracheae of a bee are discoloured the mite is invariably present. This
change in the colour of the tracheal tubes is accompanied by hardness
and brittleness of their walls. White has shown that if one of the
thoracic stigmatal openings of a bee is closed with wax, the insect loses

Mites Injurious to Domestic Animals. 97

the power of flight and becomes a crawler. So far apparently
Acarapis woodi * has been found only in English bees. It is obvious
that this mite has long been a specialised parasite of the honey bee
or some allied insect, and it is very remarkable that its presence in
the tracheal tubes has so long been overlooked by workers on the

PIG. 80.

Acarapis woodi. — Ventral view of female, X 443.
(After Hirst, Ann. Mag. Nat. Hist., June, 1921.)

diseases of bees. So far no one has succeeded in finding Acarapis as
a parasite of any other insect, but the possibility that this is
the case should be borne in mind. It is not known how infection

* According to Vitzthum, Dr. Ellinger of Weimar has reported that the
disease has made its appearance in Germany also (Bayerische Bienenzeitung ,
April, 1921).

98 Mites Injurious to Domestic Animals.

takes place— possibly by bees visiting the same flower or drinking-
place. or perhaps the mite is introduced by strange bees or drones
drifting into a hive, or is acquired by healthy bees whilst robbing an
infected colony.

FIG. 81.

Acarapis woodi. — Dorsal view of male, x 650.
(After Hirst, Ann. Mag. Nat. Hist., June, 1921.)

There is no nymphal stage either in Acarapis or in Tarsonemus,
this stage being entirely suppressed. It is probable, therefore,
that the disease spreads by transference of adult mites. After the
death of the bee the mites continue to live for several days, and the
great majority of them seem to die without leaving the body of

Mites Injurious to Domestic Animals. 99

the host. Occasionally a few adult female mites may be seen
wandering about on the dead body of their host. Rennie states
(" Bee World," May, 1921, p. 144) that adult females of the mite
may be found creeping amongst or clinging to the hairy covering
of infected bees, and that when bees carrying such mites move
about in the cluster, the mites are transferred from bee to bee.
Fertilisation had, no doubt, already taken place before the female
mite left the inside of the tracheal tubes of its host. It is too early
as yet to be able to estimate the exact degree of importance

FIG. 82.

(a) Larva of Acarapis woodi. (b) The same in the egg-shell.
(After Hirst, Ann. Mag. Nat. Hist., June, 1921.)

of the discovery of this Tarsonemid mite as an internal parasite
of the honey bee. It is probable, however, that it is the causal
agent of the deadly malady usually called " Isle of Wight Bee
Disease." As mentioned above, the protozoon Nosetna apis was
once thought to be the cause of this disease, but apparently the
disease set up by it is a distinct one. The possibility that other
diseases with similar symptoms may occur should also be borne in
mind, for bees are sometimes found crawling and dying in large

H 2

roo Mites Injurious to Domestic Animals.

FIG. 83.

Acarapis woodi. (a) Fourth leg of female, (b) Egg. (c) Posterior

leg of larva, (d) First leg of larva.
(After Hirst, Ann. Mag. Nat. Hist., June, 1921.)

FIG. 84.

Larva of Tarsone.rn.us, and end of second leg of same.
(After Reuter.)

Mites Injurious to Domestic Animals. 101

numbers when neither Acarapis nor Nosema can be found in the
stock.

Besides Acarapis woodi, which is an internal parasite, examples
of Tarsonemus occasionally occur on bees. A species found on
British hive bees has been described by Dr. Kennie under the name
Tarsonemus apis (fig. 85). The author has found specimens
of Tarsonemus on Apis dorsata and Apis florealis (both Indian

Tarsonemus apis. — Ventral view of female, (a) Last leg of male
of same. (Original.)

species of bees) and on Apis mellifica, var. indica (from Singa-
pore). It is probable that the presence of these mites of the
genus Tarsonemus (sensu stricto) on bees is due to the migratory
instinct, the bee being merely used for the purpose of transporta-
tion, thus increasing the area of distribution of the mite. It is
improbable that pseudoparasites of this type are injurious to the
health of the bee, whereas Acarapis is undoubtedly parasitic and
very injurious to its host. Specimens of Tarsonemus (sensu stricto)

IO2 Mites Injurious to Domestic Animals.

apparently may sometimes, however, gain access to the respiratory
system of the bee, for the author found a specimen of a male
Tarsonemus in one of the thoracic tracheae of a healthy hive bee
from Golders Green.

The Joint Committee on Research in Animal Nutrition of the
University of Aberdeen and the North of Scotland College of
Agriculture has issued a leaflet containing the following " Instruc-
tions for the Control of Acarine Disease " (see " Bee World,"
October, 1920— April, 1921, p. 108) :—

"1. Weak stocks which crawl in spring should be examined for
Tarsonemus woodi. If found, the stock should be destroyed. This
may be done by burning sulphur within the hive. Such procedure
will, at the same time, disinfect the hive, frames and quilts.

2. Owners of stocks weak from any cause should adopt every
possible means to prevent robbing.

3. For the present, it seems desirable to exercise the greatest
caution in purchasing bees. These should be obtained only from
apiaries with no recent history of disease. With regard to bees
offered for sale from districts where the disease is prevalent, it
should be borne in mind that Acarine disease may be present in a
stock, while as yet collective crawling has not developed.

4. With a view to preventing, as far as possible, the mingling
of bees of different stocks, avoid placing hives of similar appearance
in rows. If this is done the hives should show some distinctive
colouring.

5. General advice : —

(a) Do not attempt to winter stocks known to be diseased.
(6) If the disease show in summer before or during the

honey flow —
(i) Do everything to stimulate breeding, requeen if thought

desirable,
(ii) Use a crawler trap, empty it daily, burn the dead bees ;

never return crawlers to the hive,
(iii) If the stock become weak, prevent robbing and destroy

as soon as foraging shows failing signs,
(iv) Control as far as possible the entrance of Drones to
hives.

NOTE. — The only reliable test for the presence of Acarine
disease is the finding of the infective organism itself, within the bees.
If reported present, the procedure to be adopted must be deter-
mined by the proportion of infected bees in the stock, the season of

Mites Injurious to Domestic Animals. 103

the year, the age and qualities of the queen, the district and amount
of disease prevalent within it, the proximity of other stocks either
in the same or other apiaries. The advice of experts should be
taken in estimating the particular importance to be attached to
these matters."

Investigations on the treatment and prevention of this disease
are being carried on at the University of Aberdeen and elsewhere.
The instructions given above are therefore necessarily of a pre-
liminary nature. As our knowledge of the malady increases
improved methods will be discovered.

Traps for crawlers, although no doubt very useful, only help in
the elimination of very heavily infected bees. Many bees which
have the mites in their tracheal tubes are still capable of flight.

During the height of the season, bees from neighbouring stocks
when bringing in nectar sometimes attempt to enter the wrong hive,
and, if laden, are usually admitted. It is difficult to imagine any
way by which this intermingling could be entirely prevented. Drones
also visit strange hives, and although they can be prevented from
entering, the devices used for this purpose are not very practical, in-
asmuch as they interfere with the normal life of the bee community.

Mites are very resistant to chemical fumes, and it seems very
unlikely that any method of fumigation can be discovered that
will kill the mite without injuring the health of the bee. It seems
probable that drastic methods, such as compulsory notification and
destruction of all diseased stocks, will finally have to be adopted in
dealing with this malignant disease of bees.

ON MOUNTING MITES FOR EXAMINATION
UNDER THE MICROSCOPE.

For ordinary research purposes it is best to mount mites in
glycerine jelly or in glycerine diluted with water. Owing to its
higher refractive index, balsam is not a very suitable medium for
mounting Acari, for it is difficult to see delicately chitinized plates,
etc., when it is used. In order to study the external morphology
of mites it is usually necessary to destroy as far as possible the
muscles and other internal structures by soaking in 10 per cent,
caustic potash solution. Spirit specimens of parasitic Gamasid
mites often contain coagulated blood, which is very difficult to
dissolve ; they should be pricked with a very fine needle and well
boiled in caustic potash, the blood when sufficiently softened being

IO4 Mites Injurious to Domestic Animals.

pressed out with the help of blunt needles. After treating with
potash, neutralize with strong acetic acid (50 per cent.), then wash
in water and pass into glycerine jelly. Glycerine jelly preparations
should be ringed with gold size, twenty-four hours after mounting,
and finally ringed again with some suitable cement. Soft bodied
mites such as Tyroglyphidae are best examined in liquid media such
as very weak glycerine, and slides with a hollow cell should be used
for this type of mount, for built-up cells are liable to leak. For per-
manent preparations, euparal is very suitable. Specimens should
be passed through alcohols of increasing strength into absolute
alcohol and then into euparal. Whilst in alcohol they can be
stained with picric acid or Congo red, or other suitable chitin stains.
Farrant's medium is also very suitable for mounting mites, and
so are the various combinations with gum Arabic as a base (see
Lee's Microtomist's Vade-Mecum).

LITERATURE.

Owing to considerations of space only works of a comprehensive
nature are given below : —
Banks, Nathan. THE ACARINA OR MITES. A Review of the

Group for the use of Economic Entomologists. Report

No. 108. Office of the Secretary, U.S. Dept. Agric. 1915.
Berlese, Prof. A. ACARI, MYRIOPODA ET SCORPIONES HUJUSQUE

IN ITALIA REPERTA. 1882-1903.
Id. GLI INSETTI, LORO ORGANIZZAZIONE, SVILUPPO, ABITUDINI

E RAPPORTI COLL' UOMO. Vol. ii, FASC. 1-6, 1912-13.
Canestrini, G. PROSPETTO DELL' ACAROFAUNA ITALIANA. In 8

parts, 1885-1899.
Canestrini, G., and Kramer, P. DEMODICIDAE UND SARCOPTIDAE.

" Das Tierreich," 7 Lieferung, 1899.
Hirst, Stanley. STUDIES ON ACARI. No. 1. The Genus Demodex,

Owen. 1919.

Megnin, P. LES PARASITES ET MALADIES PARASITAIRES. 1880.
Neumann, Prof. L. G. TRAITE DBS MALADIES PARASITAIRES NON-

MlCROBIENNES DBS ANIMAUX DOMESTIQUES.

Id. PARASITES ET MALADIES PARASITAIRES DBS OISEAUX DOMES-
TIQUES. Paris. 1909.

Id. PARASITES ET MALADIES PARASITAIRES DU CHIEN ET DU
CHAT. Paris, 1914.

Railliet, Prof. A. TRAITK DE ZOOLOGIE MKDICALE ET AGRICOLE.
2nd Edition. Paris, 1895.

INDEX.

Acarapis, 94 ; A. woodi, 94
Acarine disease, of bees, 94
Aleurobius farinae, 71
Analges bifidus, 65
Analgesidae, 11, 13, 61

Bee disease, Acarine, 94

Camel ; sarcoptic mange of, 30
Cancer in hen, 60
Canker in cat, 23 ; in dog, 23
Cat, canker or parasitic otitis of,
23 ; mange of, 47 ; pseudo-
parasite of, 56 (fig.), 74
Cattle, Chorioptic or symbiotic
mange of, 23 ; Demodex and
demodectic mange of, 64 (fig.),
83 ; ear mite of, 84 (fig.) 91, 92 ;
Psoroptes and psoroptic mange
of, 16, 17 (fig.), 21 ; sarcoptic
mange of, 25
Cheese mites, 71
Cheletoides, 75 ; C. uncinata, 76
Cheyletiella, 73 ; C. parasitivorax,

56 (fig.), 73
Cheyletinae, 69, 72,
Cheyletus, 72

Chirodiscoides caviae, 52 (fig.), 69
Chorioptes, 15, 16 (fig.), 22 (fig.)
Chorioptic mange, 23, 34, 45
Cnemidocoptes, 51; C. laevis, 55 ;
C. laevis, var. gallinae, 33 (fig.),
54 ; var. phasiani, 55 ; C. mutans,
31 (fig.), 32 (fig.), 51 ; C. pro-
lificus, 55

Cytoleichus nudus, 34 (fig.), 59, 60;
C. banski, 59

Dairyman's itch, 25

Demodectic mange, of cat, 86 ; of
cattle, 83 ; of goat, 86 ; of horse,
80; of pig, 82; of sheep, 85

Demodex, 11, 61 (fig.), 79 ; D. bovis
64 (fig.), 65 (fig.), 66 (fig.), 83 ;
D. canis, 25, 62 (fig.), 79 ; D.
canis, var. ovis, 63 (fig.), 84 ; D.
caprae, 86 ; D. cati, 86 ; D. equi,
46, 62 (fig.), 80 ; D. phylloides, 63
(fig.), 82

Demodicidae, 13, 78

Depluming itch, 54

Dermanyssus, 66 (fig.), 87 ; D.
aegyptius, 76 (fig.), 87 ; D. gal-
linae, 67 (fig.), 68 (fig.), 69 (fig.),
70 (fig.), 71 (fig.), 72 (fig.), 73
(fig.), 87, 89 ; D. muris, 74 (fig.),
87 ; D. passerinus, 87 ; D. san-
guineus, 75 (fig.), 87

Dermoglyphus elongatus, 49 (fig.),
64 ; D. minor, 64

Dog, canker or parasitic otitis of,
23 ; follicular or demodectic
mange of, 62 (fig.), 79 ; noto-
edric mange of, 48 ; sarcoptic
mange of, 25

Dromedary, sarcoptic mange of, 30

Epidermoptes bilobatus, 50 (fig.), 51

(fig.), 65
Eupodinae, 76

Falculifer, 63 ; F. cornutus, 65 ;
F. rostratiis, 36 (fig.), 65

Feather mites, 11, 61

Ferret, parasitic otitis of, 23

Follicular mange, 79

Forage mites, 70

Fowl, depluming itch of, 54 ;
feather mites of, 61, 64 ; internal
parasitic mites of, 59 ; red mite
of, 67 (fig.), 87 ; scaly leg of, 31
(fig.), 52 ; Syringophilus of, 57
(fig.), 74, 75

Freyana chanayi, 48 (fig.), 64

io6

Index.

Gamasidae, 11, 13, 86

Qamasus, 92

Glycyphagus cadaverum, 71 ; O.

domesticus, 54 (fig.), 71 ; #•

ornatus, 71
Goat, Chorioptes of, 23 ; demodectic

mange of, 86 ; Psoroptes and

psoroptic otitis of, 17 (fig.), 21 ;

sarcoptic mange of, 29
Goose, nasal parasite of, 89 (fig.),

91 (fig.), 92
Grain mites, 71
Guinea-pig, pseudoparasite of, 52

(fig.), 69 ; Sarcoptes of, 25

Haemogamasus, 91 ; H. oudemansi,

91

Halarachne, 86

Harpirhynchiis, 76; H. nidulans, 76
Harvest bugs, 77
Holothyridae, 13, 93
Holothyrus, 92 (fig.), 93 ; H. coc-

cinella, 93
Horse, Chorioptes or Symbiotes and

chorioptie mange of, 23, 45 ;

Demodex and demodectic mange

of, 46, 62 (fig.), 80; Psoroptes

and psoroptic mange of, 17 (fig.)

44 ; Sarcoptes and sarcoptic

mange of, 26 (fig.), 34
Hypodectes, 36 (fig.), 63
Hypopial nymphs, of Faculifer, 36

(fig.), 63 ; of Tyroglyphidae, 53

(fig.), 70, 71

Insecta, 11

Isle of Wight Bee Disease, 94

Laelaps, 91 ; L. echidninus, 83

(fig.), 91 ; L. nuttalli, 91
Laminosioptes cysticola, 35 (fig.), 59
Leptus, 77; L. (Trombicula ?) au-

tumnalis, 11 ; L. (Microtrom-

bidium ?) guineense, 78 ; L.

(Trombicula ?) similis, 59 (fig.),

78
Liponyssus, 88 ; L. bursa, 78 (fig.),

79 (fig.), 80 (fig.), 81 (fig.), 82
(fig.), 89 ; L. sylviarum, 79 (fig.),

80 (fig.), 81 (fig.), 89, 90; L.
suffuscus, 90

Listrophoridae, 13, 68
Listrophorus, 69 ; L. gibbus, 69 ;

L. mustelae, 69
Lophoptes patavinus, 90

Megninia, 37 (fig.), 63 ; M. colum-
bae, 38 (fig.), 39 (fig.), 64, 65;
M. cubitalis, 63 ; M. cubitali*
var. ginglymura, 40 (fig.), 64 ;
M. velata, 40 (fig.), 64

Metathrombidium poriceps, 11

Mounting mites, 104

Myobia, 55 (fig.), 73

Myxosarcoma, 60

Nosema apis, 94, 99

Notification of mange in horses, 44 5

of scab in sheep, 20
Notoedric mange, in cat, 47 ; in

dog, 48 ; in rabbit, 50
Notoedrus, 46 ; N. cati, 47 ; N.

cati, var. cuniculi, 28 (fig.), 29

(fig.), 50 ; N. muris, 30 (fig.), 51

Otacariasis, of cat, 23 ; of ,dog,

23 ; of goat, 21 ; of horse, 43 5
of rabbit, 21

Otodectes, 15 (fig.), 23

Otodectes cynotis, var. canis, 23

24 (fig.) ; 0. cynotis, var. fells'
15 (fig.), 23

Parasitic otitis, of cat, 23 ; of
dog, 23 ; of goat, 21 ; of horse,
43 ; of rabbit, 21

Parasitidae, 11

Pig, Demodex and demodectic
mange of, 63 (fig.), 82 ; Sar-
coptes and sarcoptic mange of,
25, 28

Pigeons, depluming itch of, 55 ;
feather mites of, 63, 65 ; Syringo-
philus, of, 57 (fig.), 75

Pilicolous mites, 7, 68, 72, 74

Pityriasis, 67

Pneumonyssus, 86

Psorergates, 55 (fig.), 73, 78

Psoroptes, 11, 15, 16 (fig.), 43 :
P. communis, 16 ; P. communis,
var. bovis, 17 (fig.) ; var. caprae,
17 (fig.), 21 ; var. cermnae, 17

Index.

107

(fig.) ; var. cuniculi, 17 (fig.), 21,
44 ; var. equi, 17 (fig.), 44 ;
var. ovis, 17 (fig.), 18 (fig.),
19 (fig.), 44; P. hippotis, 44;
P. natalensis, 16, 17 (fig.)

Psoroptic mange, in cattle, 21 ;
of goat, 21 ; of horse, 34, 44 ;
of rabbit, 21 ; of sheep, 17

Pterolichus bicaudatus, 43 (fig.), 44
(fig.), 64; P. obtusus, 41 (fig.),
42 (fig.), 64 ; P. sculpturatus, 43
(fig.). 44 (fig.), 64; Pterolichus
sp. 45 (fig.), 46 (fig.), 47 (fig.)

Pterophagus strictus, 65

Ptilonyssus nudus, 93

Rabbit, Cheyletiella of, 56 (fig.),
74 ; Listrophorus of, 69 ; Noto-
edrus and notoedric mange of, 28
(fig.), 29 (fig.), 50 ; Psoroptesand
psoroptic mange of, 17 (fig.), 21,
44 ; Sarcoptes and sarcoptic
mange of, 33

Raillietia, 91 ; R. auris, 84 (fig.),
85 (fig.), 87 (fig.), 91

Rats, 30, 51, 74, 77, 79, 87, 89, 91

Red mite of fowl, 87

Rhinonyssus, 93

Rivoltasia bifurcata, 65

Sarcopterinus, 76 ; 8. nidulans 76
Sarcoptes, 11, 24,i39 ; S. scabiei, var.

cams, 25 ; var. caprae, 30 ;

var. equi, 26 (fig.), 27 (fig.), 34;

var. ovis, 29 ; var. suis, 28
Symbiotes, 15, 16 (fig.), 22 (fig.)
Sarcoptic mange, of camel, 30 ;

of cattle, 25 ; of dog, 25 ; of

dromedary, 30 ; of goat, 29 ;

of horse, 34 ; of pig, 25 ; of
rabbit, 33 ; of sheep, 28
Sarcoptidae, 13, 15
Sarcoptoidea, 15
Scab in sheep, 17
Scaly-leg, 52

Schb'ngastia americana, 60 (fig.), 78
Scutacarus, 94

Sheep, Chorioptes or Symbiotes of,
22 (fig.), 23 ; Demodex and demo-
dectic mange of, 63 (fig.), 84 ;
Psoroptes and psoroptic mange or
scab of, 17 (fig.), 18 (fig.), 19
(fig.), 44 ; Sarcoptes and sar-
coptic mange of, 28
Spirochaeta gallinarum, 88
Staphylococcus pyogenes albus,lQ
Sternostomum, 92 ; S. cryptorhyn-

chum, 93

S. rhynolethrum, 89 (fig.), 91 (fig.), 92
Symbiotes, 15, 16 (fig.), 22 (fig.)
Symbiotic mange, 23, 34, 45
Syringophilus, 11, 65, 74 ; S. bipecti-
natus, 57 (fig.), 58 (fig.), 74, 75 ;
S. columbae, 57 (fig.), 58 (fig.) 75

Tank for dipping horses, 43
Tarsonemidae, 13, 94
Tarsonemus, 94, 100 (fig.), 101 ;

T. apis, 101 (fig.)
Tracheal tubes of Otodectes, 15

(fig.) ; of Listrophoridae, 52 (fig.),

69

Trombidiidae, 13, 72
Tropical fowl mite, 89
Tydeus, 76 ; T. molestus, 58 (fig.), 76
Tyroglyphidae, 13, 61, 70, 71
Tyroglyphus longior, 7 1 ; T. longior,

var. castellanii, 53 (fig.)

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