Genus. Ixodes, Latreille.
Ixodes reduvius, L., 1758.338
Syn.: Acarus reduvius and ricinus, L.; Ixodes ricinus, Latreille, 1806.
The males are oval; their length 1·2 to 2 mm.; they are brownish-red or black in colour; the females are yellowish-red, 4 mm. long; when gorged they are lead-coloured, and may attain 12 mm. in length by 6 to 7 mm. in breadth.
The dog tick (fig. 360) lives in thickets on leaves, etc., and attacks sheep and oxen, and more rarely dogs, horses, and human beings, into the skin of which the female bores with the rostrum in order to suck blood; the bite is not dangerous, and sometimes is not even felt. Inflammation, however, is set up if the creatures are forcibly removed from the wound, as the rostrum as a rule is torn off in the process. If left alone or smeared over with some grease—vaseline, oil, butter, etc.—the creatures drop off spontaneously. Sometimes the entire tick bores itself into the skin; they also appear to be permanent inmates of kennels.
[The species I. reduvius is the same as I. ricinus, Latreille. The male is 2·35 to 2·80 mm. long; the body is dark brown, almost black, with a pale, almost white, margin; there are also traces of reddish mottling. Coxæ of the first pair of legs with a short spine. Rostrum much shorter than that of the female; shield oval; anal shield small, about one-third the length of ventral shield. The adult female varies from 2·80 to 3·5 mm. when not distended, but when gorged may reach 10 mm. long. The shield and legs are dark blackish-brown, body deep orange-red with four dark longitudinal lines, paler beneath and light grey in front. When distending it is pale red to grey or white; when fully gorged olive-green, or dark red to black, with irregular yellow streaks on the back and sides just before egg-laying. Sexual orifice opposite fourth pair of legs. The nymph varies from 1·60 to 1·70 mm. long when fasting; the body is olive-white, opaque, with four distinct brown posterior markings and similar anterior ones, leaving a pale centre to the shield. When fully gorged it is 3 mm. long. As the nymph distends, it changes from opaque white to blue-black, and finally black. The little larva is 0·80 to 1·50 mm. long, transparent with olive-green intestinal markings; as it becomes inflated it changes to blue-black, and then black. There are no eyes. It is widely distributed, and chiefly attacks sheep; sometimes it occurs on dogs and also attacks man. Mégnin records it from horses in the nymph stage. Amongst its other numerous hosts are goats, cattle, deer, hedgehogs, moles, bats, birds, and lizards. It is usually known as the grass tick and bottle-nosed tick. This species occurs in Europe, Asia, North Africa, and North America.
[Synonyms.—Considerable confusion exists over the name of this and other common ticks, owing to the same species having been described under a great many names. Observers have taken the same species on different animals and in various stages to be distinct, and have described them accordingly.
[The name Ixodes reduvius, Leach, does not stand, as Leach was describing quite a different parasite. The name I. ricinus, Latreille, 1806, is now substituted by Neumann and Wheler.
[The synonyms given by Wheler are as follow: Reduvius, Charleton, 1668; Ricinus caninus, Ray, 1710; Acarus ricinoides, de Geer, 1778; Acarus ricinus, Linnæus, 1788; Cynorhæstes reduvius, Hermann, 1804; Cynorhæstes ricinus, Hermann, 1804; Ixodes megathyreus, Leach, 1815; Ixodes bipunctatus, Risso, 1826; Cynorhæstes hermanni, Risso, 1826; Crotonus ricinus, Dumeril, 1829; Ixodes trabeatus, Audouin, 1832; Ixodes plumbeus, Dugés, 1834; Ixodes reduvius, Hahn, 1834; Ixodes fuscus, Koch, 1835 (?); Ixodes lacertæ, Koch, 1835 (?); Ixodes pustularum, Lucas, 1866; Ixodes fodiens, Murray, 1877; Ixodes rufus, Ixodes sulcatus, and Ixodes sciuri, Koch.—F. V. T.]
Ixodes holocyclus, Neumann, 1899.
[Under the name I. holocyclus, Cleland (Journ. Trop. Med. and Hyg., 1913, xvi, No. 3, pp. 43–45) says that: “This tick is common in man where there is dense scrub and tropical jungle along the east coast of Australia at certain times of the year. It may cause severe symptoms in children resulting in death.” He records a child being attacked in 1884 which died, and another case from which 200 ticks were removed, the symptoms being weak heart, collapse, syncope, but the patient recovered under treatment; again, in the same journal (pp. 188, 189), the case of a 4 12-year-old girl who was bitten showed widespread muscular paralysis, and other cases resembling conium poison.
[Taylor (Rep. Ent. Aust. Inst. Trop. Med., 1911, p. 21, 1913) refers to this species as the scrub tick of New South Wales. The partially fed female has a dark reddish-yellow scutum and is almost as broad as long, punctations very numerous, equal and confluent in places, long white hairs on the lower half of each coxa. He records it as attacking man commonly, mentioning Kamerunga, Cairns district, Queensland, and Sydney, N.S.W., as localities.—F. V. T.]
Ixodes hexagonus, Leach, 1815.
Syn.: Ixodes sexpunctatus, Koch, 1897; I. vulpis, Pagenstecher, 1861.
Lives in the same manner as the foregoing; especially attacks hounds, but also other mammals and even birds. The difference consists in the shape of the legs, the shorter rostrum, and the larger size of the male. It also occasionally attacks man, but is usually confused with the previously mentioned species.
[The synonyms of this species are as follow:339 Ixodes autumnalis, Leach, 1815; I. erinacei, Audouin, 1832; I. reduvius, Audouin, 1832; I. crenulatus, Koch; I. erinaceus, Murray, 1877; I. ricinus, Mégnin, 1880. Two other synonyms are given above by Braun.
[The female when fully replete is 11 mm. long, when fasting 3·86 mm.; the shield is heart-shaped and punctate, body finely hairy; palpi short and broad; labium shorter, and tarsi of all the legs more truncate than in I. ricinus. The colour of the distended body is drab and somewhat waxy; rostrum, shield and legs light testaceous. The male varies from 3·5 to 4·0 mm. long, and is reddish-brown in colour with lighter legs; the shield is punctate and leaves a narrow margin around the body; the body is elliptical, almost as large in front as behind. There is a spine on the coxæ of the first pair of legs, which is shorter than in the male I. ricinus and longer than in the female. The genital orifice is opposite the interval between the second and third pair of legs. The fasting nymph is 1·76 mm. long, light bluish-grey, margined and transparent, with four large posterior intestinal marks joined together behind the shield and smaller ones extending to the front and sides. When fully distended it is uniformly brownish-white; shield, legs and rostrum pale testaceous. The larva varies from 0·88 mm. when fasting to 1·76 mm. when gorged. Its body is light, but gradually becomes darker, with similar intestinal marks to ricinus.
[This tick is very common, especially on ferrets, stoats and hedgehogs. It is also found on sheep, cattle, etc. The males do not generally occur in company with the females on the host. Pairing probably takes place on the ground.—F. V. T.]
Genus. Amblyomma, Koch.
Amblyomma cayennense, Koch, 1844.
Syn.: Amblyomma mixtum, Koch, 1844; Ixodes herreræ, Dugés, 1887; Amblyomma sculptum, Berlese, 1888.
Characterized by the possession of eyes. The male measures 3·8 mm. in length by 3 mm. in breadth; the female 4 mm. in length by 3 mm. in breadth, but when full of blood may become 13 mm. in length and 11 mm. in breadth. They are common in the whole of Central America (Carrapatas), and attack mammals, amphibious animals and man.340
[This species was described by Fabricius. It occurs in Cayenne, Guiana, in Southern Texas, Florida, California, Mexico, Guatemala, Honduras, Nicaragua, Costa Rica, Panama, Bermuda, Cuba, Jamaica, Trinidad, Colombia, Venezuela, French Guiana, Brazil, Paraguay and the Argentine. It is called the silver tick. It frequently attacks man. Schwarz and Bishopp (Bull. 105, U.S. Dept. Agric., p. 158) heard of one man whose legs were well covered with suppurating sores and who was ill from the attack of these ticks and the wounds produced by scratching, and records other cases of their swarming on man. Newstead (Ann. Trop. Med. and Par., 1909, iii, No. 4, p. 442) records it as the worst pest to man in Jamaica.—F. V. T.J
Amblyomma americana, Linnæus.
The so-called long star tick, from the silvery spot on the apex of the scutum of the female. It will attack any mammal and even birds and also man. It occurs in North America, and also in Brazil, Guiana and Guatemala. Its punctures frequently end in suppuration. In the Eastern and Southern States man is more frequently attacked by this species than any other. Moss-gatherers in Louisiana are badly attacked by it.341 It also attacks the milkers in dairies. Attempts to transmit Texas fever failed with this species.
Amblyomma maculatum, Koch.
The so-called Gulf Coast tick, of the Gulf Coast, occurs on birds, mammals and man, especially cattle, and attacks the ears.
Genus. Hyalomma, Koch.
Hyalomma ægyptium, L., 1758.
Syn.: Acarus ægyptius, L., 1758; Ixodes camelinus, Fischer, 1823.
A species frequently found in Africa, particularly in Egypt and Algeria, and which also occurs in France and Italy, as well as in Asia. Male 8 mm. in length, 4·5 mm. in breadth. Female up to 24 mm. in length and 15 mm. in breadth. It infests large and small animals as well as human beings.342
[This is one of the largest ticks, nearly reaching the size of the bont tick. It is known in Africa as the bont leg-tick; all farm stock is attacked, but sheep and goats suffer most. Only one generation appears to occur each year. The male is almost black with a pale marginal stripe; the replete female brown with irregular light blue stripes. It is abundant in parts of South Africa.]
Genus. Hæmaphysalis, Koch.
Hæmaphysalis punctata, Canestrini and Fanzago, 1877–1878.
Syn.: Hæmaphysalis sulcata, Canestrini and Fanzago, 1877–1878; Rhicocephalus expositicius, Koch, 1877; Hæmaphysalis peregrinus, Cambridge, 1889; Herpetobia sulcata, Canestrini, 1890.
[This species does not appear to be common. It occurs on sheep, goats, horses and cattle. I have seen a female taken from man in Britain. The female when fasting is 3·44 mm. long, when gorged 12 mm. long. Colour, reddish-brown, leaden-grey when gorged; dorsal shield deeply indented in front; rostrum, shield and legs brownish; body finely punctate, both above and below; sexual opening opposite the coxæ of the second pair of legs in both sexes. Palpi a little longer than the labium; first segment short and narrow, second and third widened on the dorsal face. Coxæ with a short, broad blunt spine; tarsi short, terminated with a spur on the first pair. The male is 3·10 mm. long. Body rather narrow, yellowish to reddish-brown; dorsal shield nearly covers the whole body; numerous punctures over the whole surface. Eleven indentations on the posterior margin of the body; peritremes lighter in colour, large and comma-shaped. The three anterior pairs of legs with a short spine on the haunches, the fourth with a very long one directed backwards. The nymph varies from 2·5 to 3·0 mm., is oval, and light yellow to dark red in colour. Dorsal shield rounded with few punctations. No spur on tarsi, and sexual orifice nearly obsolete. Larva short and oval. Length 1·20 mm.—F. V. T.]
Genus. Dermacentor, Koch.
Dermacentor reticulatus, Fabricius, 1794.
Syn.: Acarus reticulatus, Fabr., 1794; Ixodes reticulatus, Latreille, 1806; I. marmoratus, Risso, 1826.
This tick is provided with eyes, but it is distinguished from Ixodes and analogous genera by the lack of the abdominal plastron in the male, which measures 5 to 6 mm. in length by 3·5 mm. in breadth. The female may attain 16 mm. in length and 10 mm. in breadth. It is found in the South of Europe, in Asia, and in America; it attacks chiefly oxen, sheep and goats, and occasionally man.343
[This tick sometimes causes much annoyance to human beings. It was once most troublesome at Revelstoke. Specimens have recently been found on fowls, turkeys and pheasants in Kent.
[Other synonyms are as follows: Cynorhæstes pictus, Hermann, 1804; Crotonus variegatus, Dumeril, 1829; I. pictus, Gervais, 1844; Dermacentor albicollis, Koch, 1844–1847; D. pardalinus, Koch, 1844–1847; D. ferrugineus, Koch, 1844–1847; Ixodes holsatus, Kolenati, 1857; Pseudixodes-holsatus, Haller, 1882; Hæmaphysalis marmorata, Berlese, 1887.
[The female when fasting is 3·86 mm. long by 2 mm. wide. The body is depressed, larger behind and reddish-brown in colour. The shield is very large and extends to the level of the third pair of legs, with a few large and many small punctations, milky white, variegated with reddish-brown. Sexual orifice opposite the coxæ of the second pair of legs. Coxæ of the front legs are deeply bifid, the others with a moderate spine. When gorged light brown, and may reach 16 mm. When depositing eggs the female is mottled with dark brown above and below. The male is like the female. The shield is reddish-brown, variegated with a milky white pattern. Coxæ of the fourth pair of legs three times the size of the third. There is a sharp backwardly pointing spine on the second palpal segment, also seen (but smaller) in the female. Length 4·20 mm.
[According to Mr. Wheler this is a very variable species both in size and colour. It occurs in England on sheep, but not commonly. It has probably been introduced into Britain. Besides the animals mentioned above it is also found on deer.—F. V. T.]
Dermacentor venustus, Banks.
[The Rocky Mountain tick fever tick. This species has been wrongly called Dermatocentor reticulatus var. occidentalis. The correct name of the carrier of Rocky Mountain tick fever is Dermacentor venustus, Banks (Hooker, Bishopp and Wood, Bull. 106, U.S. Dept. Agric., Div. Ent., p. 165).
[The female is from 13·8 by 10 by 6·4 mm. to 16·5 by 11·4 by 6·9 mm. when gorged; the male from 2·1 by 1·5 mm. to 6 by 3·7 by 1·4 mm. The male reddish-brown; scutum with an extensive pattern of white lines, usually but little white on the mid-posterior region, legs slightly lighter than scutum, joints tipped with white. Female with scutum mostly covered with white, abdomen reddish-brown, legs as in male. The nymph when unengorged reddish-brown, when gorged dark bluish-grey; the larva is yellowish-brown when unengorged, slate blue when engorged. The ova light brown, shiny and smooth.
[The chief wild hosts are the brown bear, coyote, woodchuck, rabbit, wild cat, badger and mountain goat for the larvæ; practically all small mammals act as hosts for larvæ and nymphæ, whilst the adults are seldom found on other than large domestic animals; horses and cattle are preferred. It occurs in British Columbia, southward to Northern New Mexico, and from the foothills of the Rocky Mountains in Colorado to the base of the Cascade Range in Oregon and California; abundant in Western Montana, Idaho, Eastern Washington, Oregon, North Utah, West Wyoming and North-west Colorado.
[Of great importance in the Bitter Root Valley of Montana, where a number of cases of fever occur each year, with a mortality of about 70 per cent. In British Columbia this tick causes tick paralysis in man and sheep. Only the adults seem to attack man and animals there (Hadwen and Nuttall, Parasitology, 1913, vi, No. 3, pp. 288–297 and 298–301) according to the Canadian Medical Association Journal, December, 1912. The symptoms are unlike spotted fever. For full details of this tick vide Bulls. 105 and 106, U.S. Dept. Agric.]
Dermacentor occidentalis, Neumann.
This tick only occurs in the Pacific Coast region of the United States. Owing to the fact that it frequently attacks man as well as occurring in great abundance in Oregon and California, it is of considerable economic importance. It is spoken of as the wood tick, and in the regions where found is the most common tick to attack man. Hooker, Bishopp and Wood (Bull. 106, U.S. Dept. Agric., Div. Ent., 1912, p. 189) state that a number of cases have been brought to their notice where the bite of this tick has caused considerable local inflammation, which in some cases required physicians’ attention. It has been supposed to be connected with Rocky Mountain spotted fever, but it is doubtful if it is concerned in its transmission. The engorged female is steel grey, the dorsum with an olive-green surface colour, which covers the grey except in small spots, giving a mottled appearance. The unengorged males and females are reddish-brown, scutum covered with a whitish bloom, interrupted by many red punctures. The female is 9 by 6·1 by 3·3 mm. to 11·8 by 7·6 by 5·6 mm.; the male 2·8 by 1·6 mm. to 4·2 by 2·3 mm. The larvæ are bluish-grey when engorged, reddish-brown when unengorged. The nymph is light brown, sides of scutum darker, and the intestines dark brown. It is confined to the Coast Range and Sierra Nevada Mountains in California and Oregon and the small mountain range to the south-west.
Dermacentor variabilis, Say.
The American dog tick has also been found on man, but it is of little economic importance as it is easily removed from its host.
Genus. Margaropus, Karsch.
Margaropus annulatus australis, Fuller.
The so-called Australian cattle tick. Newstead344 reports this as a great pest to man in Jamaica in its larval stage. Its chief hosts are cattle, horses, goats, sheep, dogs and rabbits.
Margaropus microplus, Canestrini.
Recorded by Aragão (Mem. Inst. Oswaldo Cruz, 1911, iii, fasc. 2, p. 163) as occurring in larval stage on man in Brazil.
Genus. Rhipicephalus, Koch.
Rhipicephalus sanguineus, Latreille, 1804.
Syn.: Ixodes sanguineus, Latr., 1804; I. rufus, Koch, 1844; Rhipicephalus limbatus, Koch, 1844; Rh. siculus, Koch, 1844; Rh. stigmaticus, Gerstäcker, 1873.
Spread over almost the entire tropical and sub-tropical regions, occurring in Europe in the South of France and in Italy; it infests dogs and more rarely sheep; oxen, cats, foxes and human beings are also attacked.345
Neumann’s Table of Species of Argas.
| 1 | Body elliptical (sides curved) | 2. | |
| Body oblong (sides straight), ending anteriorly in a point | 7. | ||
| 2 | Body transversely oval | vespertilionis. | |
| Body elongate oval | 3. | ||
| 3 | Margin of body striated | 4. | |
| Margin of body formed by quadrangular areolæ | PERSICUS. | ||
| 4 | Body flat, integument plainly wrinkled | 5. | |
| Body tumid, elongate; integument finely wrinkled; coxæ of fourth pair of legs near anterior third of body | hermanii. | ||
| 5 | Body oval, narrowed anteriorly | REFLEXUS. | |
| Body elliptical, blunt, hardly narrowed anteriorly | 6. | ||
| 6 | Body twice as long as broad | cucumerinus. | |
| Body hardly longer than broad | transgariepinus. | ||
| 7 | Dorsal integument with large polygonal depressions; tarsi appearing bifid | BRUMPTII. | |
| Dorsal integument almost smooth; tarsi not appearing bifid | æqualis. |
The Argantinæ are distinguished from the Ixodinæ by the head, which in the former is situated on the inferior aspect of the cephalothorax, while in the Ixodinæ it projects freely; also by the very short proboscis, the small club-like palpi, the lack of suckers on the legs, as well as by the scutellum, which covers the entire back and is bent up round the borders. Two genera are distinguished: Argas, Latreille, 1796 (Rhynchoprion, Hermann, 1804), and Ornithodorus, Koch, 1844. The species live on mammals, but more especially on birds.
Genus. Argas, Latreille.
Argas reflexus, Fabricius, 1794.
Syn.: Acarus reflexus, Fabricius, 1794; A. marginatus, Fabricius, 1794; Rhynchoprion columbæ, Hermann, 1804.
Fig. 361.—Argas reflexus: from the dorsal surface, the intestine showing through the integuments. (After Pagenstecher.)
The European marginated tick, Argas reflexus (length of male 4 mm., breadth 3 mm., length of female 6 to 8 mm., breadth 4 mm.), is of a yellowish colour and has yellowish-white legs. The ingested blood shows red or brown through the intestine, which is provided with blind sacs. It lives in dovecots. It remains hidden during the day and at night crawls on to the sleeping pigeons to suck their blood. It has been observed in France, England, Italy, Germany, and Russia. Persons sleeping near infected dovecots, or in apartments formed from pigeon-lofts, are also attacked, even when the room in question has not been used for sheltering pigeons for years, as “marginated ticks” can live in a fasting condition for a very long time. The bite sometimes gives rise to serious symptoms, such as general erythema and sudden œdema.
[This pest more often feeds on the blood of man than is imagined. Blanchard states that he has received them from men’s clothes in Strasburg. Boschulte, of Westphalia, records these parasites in a bedroom inhabited by children and connected with a pigeon-house. The children were bitten during sleep on the hands and feet. The result of the bite was intense itching along the nerves, the bite only being marked by a red spot. In a girl of 14 or 15, vesicles were formed similar to those produced by burns, and in an old man an ulcer formed. Others record painful punctures and persistent œdema produced by this pigeon pest. It was once abundant in Canterbury Cathedral, and often caused much annoyance, I am told, to the worshippers; the ticks falling down from the roof, where they were living, derived from the numerous pigeons that breed in the towers. This Acarus has enormous powers of vitality, living without food for months at a time.—F. V. T.]
Argas persicus, Fischer de Waldheim, 1824.
Of oval form and brownish-red colour. The male measures 4 to 5 mm. in length by 3 mm. in breadth; the female 7 to 10 mm. in length by 5 to 6 mm. in breadth. It frequents the entire north-west and north-east of Persia (the gerib-gez or malleh of the Persians, the miana bug of travellers). It lives concealed in houses and attacks man at night to suck his blood. Its bite is much dreaded, but the serious results may probably be attributed to unsuitable treatment of the wound or its invasion by bacteria.
[This tick, sometimes called the tampan and wandlius in South Africa, is mainly a fowl parasite. Fowls and ducks frequently die under its attack, particularly young ones, death being due to loss of blood. This tick remains attached to its host during its larval stage for about five days; it then leaves and moults in concealment. In its subsequent stages it visits its host by night and remains for about an hour only, during which time it distends itself fully with blood. As a nymph it moults twice, not once as do the cattle ticks. This tick and other Argas become larger with each moult, but retain their same general appearance. The female visits the host every now and then, and, between, deposits eggs in sheltered crevices. About fifty to 120 are deposited at once. Four weeks seems a necessary period to intervene between visits to the host, and the interval may be extended to upwards of a year according to Lounsbury.346
[It is found in the Sudan, where Balfour has found granules derived from the segmentation of spirilla in their digestive tract. Fantham and Hindl have confirmed this. It has been assumed that these granules carry infection.
[This so-called Persian tick, the miana, which is such a scourge to travellers in Persia, appears to infest the huts of natives in that country. It has been sent me from Quetta, where it has invaded houses to such an extent the natives cannot live in them. The virulence of its bite is probably due to the tick transmitting fever germs from natives, probably inured, to strangers, who would be susceptible.—F. V. T.]
Argas brumpti, Neumann.
[Found in Somaliland, by Brumpt, and in the Sudan. This tick attacks man as well as wild animals and produces a painful swelling according to King,347 but as pointed out by that naturalist it probably relies on other than human food.—F. V. T.]
Argas chinche, Gervais, 1844.
This Acarus, a native of the temperate parts of Colombia, is very troublesome to man. It is probably identical with A. americanus, Packard, which infests domestic fowls and turkeys, and occasionally also cattle, and is differentiated from A. reflexus by the sculpturing of the cuticle.
Genus. Ornithodorus, Koch.
Neumann’s Synopsis of the Genus Ornithodorus is as follows:—
| 1 | Hypostome unarmed; integument in nymph stage and partly in adult spinulose | MÉGNINI. | |
| Hypostome armed with recurved teeth; integument not spinulose | 2. | ||
| 2 | Camerostome with movable lateral flaps | TALAJE. | |
| Camerostome without movable lateral flaps | 3. | ||
| 3 | Anterior border of distal segments of legs with tubercles or festoons | 4. | |
| Anterior border of segments of legs without tubercles or festoons | 8. | ||
| 4 | Body not much contracted anteriorly | 5. | |
| Body pointed anteriorly | 7. | ||
| 5 | Tubercles of distal segments of legs higher than broad, distant | 6. | |
| Festoons of distal segments of legs as broad as high, contiguous | pavimentosus. | ||
| 6 | Eyes present | SAVIGNYI. | |
| No eyes | MOUBATA. | ||
| 7 | Eyes present | coriaceus. | |
| No eyes | TURICATA. | ||
| 8 | Integument with fine radiating wrinkles | lahorensis. | |
| Integument granular | 9. | ||
| 9 | Tarsi appearing bifid at apex | furcosus. | |
| Tarsi not appearing bifid at apex | 10. | ||
| 10 | Tarsi of first pair of legs with three dorsal tubercles, of other legs with one | canestrinii. | |
| Tarsi without dorsal tubercles or with only one | 11. | ||
| 11 | Tarsi of last three pairs of legs with pronounced dorsal protuberance | tholozanii. | |
| Tarsi of legs with indistinct dorsal protuberance | erraticus. |
Ornithodorus moubata, Murray, 1877.
An abundant African tick which is one of the carriers of the spirillum of African relapsing fever and can also carry Filaria perstans (Christy). Its body is oval, yellowish-brown when young, greenish-brown when mature. The integument is covered with mamillose tubercles. No eyes and the stout legs granular above, the tibiæ and tarsi fringed with tubercles on the upper side. Pocock348 records it from Uganda and German East Africa, Congo and Angola, to Namaqualand and the Transvaal in the south. It is called bibo in Uganda, moubata in Angola, and tampan on the Lower Zambesi. It feeds on animals and birds as well as man. Its bite is very painful. This tick is found in native huts, living in cracks and crevices and in the thatch roofs.
The female tick infected with the spirillum transmits the infection to the eggs and the next generation. They appear to be able to live without food a long time, and probably live for years. They lay their eggs in masses on the ground or in crevices, and when they hatch they are in the nymph stage with four pairs of legs. O. moubata also occurs in Madagascar with recurrent fever (Lamoureux, Bull. Soc. Path, exot., 1913, vi, No. 3, pp. 146–149).
Ornithodorus savignyi, Audouin, 1827.
At one time considered the same as the preceding species, but can be easily separated by the presence of two pairs of eyes. It is widely spread over Africa and has been found in South India and at Aden. In the Sudan it occurs in large numbers. King349 records that a few miles N.N.E. of Khartoum 370 specimens were collected in two hours under a single tree by a well. It is found in Somaliland, where relapsing fever occurs and no O. moubata, which it probably replaces as a transmitter (Drake-Brockman, “Rep. Col. Office,” April 6 and April 16, 1913). It also occurs in Tunis, where the natives call it “tobbiah” (Weiss, Arch. de l’Inst. Pasteur de Tunis, 1912, pt. 4, p. 226).
Ornithodorus coriaceus, Koch.
Found in Mexico, Paraguay and California. Attacks man.
Ornithodorus talaje, Guerin, 1849.
An eyeless species with somewhat elongate pentagonal body found in Mexico and South America, called the “chinche.” A variety of it (coniceps) is found at Venice, etc., and another variety on various islands in the Indian Ocean and South Atlantic. Its bite is very painful to man.
Ornithodorus turicata, Dugès, 1876.
Without eyes. Indigenous in Central America; attacks human beings and pigs. The bite is painful and is often followed by serious consequences.
[So virulent is this species that pigs put in an infested sty often die in a night. This “turicatas” of Mexico often reaches 6 mm. in length.—F. V. T.]
Ornithodorus tholozani, Laboulbène and Mégnin, 1882.
Syn.: Argas tholozani, Lab. and Még., 1882.
Without eyes. Males 4 to 6 mm. in length and 2 to 4 mm. in breadth; females 8 to 10 mm. in length and 4 to 5 mm. in breadth. It especially attacks sheep. Native of Persia and Asia Minor.
[This species is reputed as being very dangerous to man. It is locally know as the kéné, or sheep-bug. In its fully gorged state it is deep violet.—F. V. T.]
Ornithodorus mégnini, Dugès, 1883.
Syn.: Argas mégnini, Dugès, 1883.
Length 8·5 mm., breadth 5·5 mm. Native of Mexico.
[Another synonym for this species is Rhynchoprion spinosum, Marx. The adult males and females are grey to dark brown, the male somewhat the smaller; female 5 by 3·5 by 2·5 mm. to 10 by 6 by 3·5 mm. The larvæ at the seed tick stage are dark grey, turning to pink, then to a whitish grey when engorged. The nymph when young is blood-red in front, rest pearly white; later they turn reddish-brown.
[Intense pain may be caused by its presence in and around the ears.
[Two specimens in the nymphal state were taken from the ears of a visitor to Cambridge by Dr. J. Christian Simpson. They were supposed to have entered the ears when the gentleman was camping out in Arizona (Lancet, 1901, i, No. 4,052, p. 1198, fig. 3).
[This species attacks the horse, ass, dog, cats and oxen, generally around the ears, and also attacks man. It is well known in the United States as infesting the ears of children (New York Ent. Soc. Journ., 1893, pp. 49–52).
[It occurs in Texas, Arizona, New Mexico and California as well as Mexico, Brazil, and possibly many parts of South America; and recently Bedford (“Sec. Report Div. Vet. Res., S. African Union,” 1912, pp. 343, 344) has shown it to occur at Vryburg and Fauresmith, in the Transvaal, on stock. It also occurs in the Sudan.—F. V. T.]