As H. marginatum balcanicum and H. marginatum olenevi: Schulze and Schlottke 1930. Olenev 1929A,1931A,C. Kratz 1940. As H. marginatum bacuense (apparently of Schulze, ms.): Olenev 1931A,C. As H. marginatum caspium (apparently of Schulze, ms.): Noted by Olenev 1931A,C, but described by Kratz 1940.

Piontkovskaia

As H. plumbeum plumbeum: Pomerantzev 1950. 1951. Mēlnikova 1953. As H. plumbeum: Shatas 1952. Shatas 1952. Shatas and Bustrova 1954. Pavlovsky, Pervomaisky, and Chagin 1954. Arakian and Lebedev 1955. Pillipenko and Derevi anchenko 1955. Petrishe hevo 1955. Abramov 1955. Zhmaeva, Pchelkina, Mishchenko, and Karulin 1955.

Sharif 1928).

MIDDLE EAST: INDIA (As H. aegyptium f. typica: INDOCHINA (As H. dromedarii indosinensis: Toumanoff 1944).

FAR EAST: ?CHINA: The "H. impressum rufipes" of Chodziesner (1924) is probably H. marginatum according to Kratz (1940, p. 554).7

HOSTS

The common hosts of adult H. marginatum are any domestic animals, especially cattle and horses; also goats, sheep, and camels often serve. In the Crimea, horses have been stressed as hosts by Kurchatov and Sokolov (1940). A typical female taken from a dog at Amman, Transjordan, by Dr. B. Babudieri, has been seen (Hoogstraal, ms.).

Nymphs may also attack domestic animals but are much more frequent on small wild mammals and birds, while larvae feed only on these small animals. Host preferences, especially of immature stages undoubtedly vary somewhat from locality to locality, but the impression of considerable variation between areas appears to be due to incomplete observations by various workers.

In Transcaucasia, birds are said to be the chief hosts of immature stages (Pomerantzev, Matikashvily, and Lototsky 1940). In the laboratory, chickens have been used (Zhmaeva, Pchelkina, Mishchenko, and Karulin 1955).

In Anatolia, adults have been reared from nymphs from hares, hedgehogs, and partridges (Hoogstraal, ms.). Nuttall lot 3278 in BMNH consists of adults reared from nymphs from a hare on the River Tigris, 32°N., November 1917, by Captain P. A. Buxton; H.H. det. A single nymph has been reported from a hare in Iraq (Hubbard 1955).

Hosts in Tunisia are cattle, sheep, porcupines, and hares. Adults are also found in gerbil nests (most probably newly molted, before venturing forth to find a larger host: HH). Nymphs have been taken from "Cochevis" (Galerida cristata) (Colas Belcour and Rageau 1951). In southern Morocco, larvae and nymphs were reported from the nests of jirds, Meriones shawi (Blanc, Martin, and Maurice 1946,1947A,B), while others, presumably adults (same authors 1947B), were found on domestic animals and, at certain times of the year, on the grounds of native markets.

In Egypt, including Sinai, nymphs, which have been reared to typical adults, have been found on two kinds of hedgehogs, Hemiechinus aegyptius auritus and Paraechinus aethiopicus dorsalis, on fat sandrats, Psammomys o. obesus, and on jirds, Meriones shawi and M. crassus. Equally important here are lizards, Acanthodactylus boskianus, while lesser gerbils, Gerbillus g. gerbillus are less frequently found infested by nymphs (Hoogstraal, ms.).

In the Arax valley of Armenia, hosts of immature stages are stated to include reptiles and wild birds (Pomerantzev 1934).

Recent Soviet workers on hemorrhagic fever in Crimea report that adults attack cattle, sheep, horses, and men. Larvae and nymphs infest the European hare, Lepus europaeus transsylvanicus, in Crimea but are not found on hedgehogs, bats, rodents, dogs, or wild carnivores. Some immature specimens were taken from gray partridges, Perdix perdix, prairie larks, Melanocoripha calandria, cranes, Grus grus, and sparrows and domestic chickens (cf. Gajdusek 1953,1956).

An exceptionally interesting study of H. marginatum (= H. p. plumbeum) in the Crimean National Forest Reserve has recently been reported by Melnikova (1953), whose chart is reproduced below.

Host

No. Hosts No. Hosts

No. No. No. No. Max. No. Mean Per Examined with Ticks Larvae Nymphs ở doo Ticks on Host

As is easily seen, jays, chickens, and hares are the chief hosts of immature stages in the Crimean forest. Cattle, pigs, and red deer are important adult hosts, and hares may be of some im portance. The absence of ticks on the roe deer is noteworthy.

Melnikova (loc. cit.) noted that unfed larvae enter the audi tory canals of jays and chickens and molt there to nymphs and to adults; he found 118 immature ticks in the ears of a single bird. In Eastern Anatolia (Hoogstraal, ms.) partridges with larvae and nymphs of this tick similarly tightly packed in their ears have been observed. The comparative ease with which these birds were shot or even caught by hand suggested that the heavy tick infesta tion impaired the birds' keenness. Infested birds seemed muddled and confused and ran in staggering circles rather than flying or dashing off as did most of the flock.

BIOLOGY

Life Cycle

Life cycle studies of "H. aegyptium reported by Nuttall (1913B) were undertaken with H. marginatum. Specimens resulting from this work are at present in the Nuttall collection at the British Museum (Natural History). Nuttall found that H. margi natum may act as a two-host or as a three host tick; he believed that the "peculiar two-host life cycle, when nymphs were fed on

hedgehogs, was due to larvae remaining entangled among the spines. This is, however, probably the typical life cycle in nature.

This period Nuttall believed to be the shortest time required for completion of the life cycle. From 4300 to 15500 eggs were laid by single females; the higher number probably approximates the more common figure in nature. Females may remain alive as long as 26 days after oviposition; males live much longer. The longevity of the various stages, presumably unfed, in these experiments was 345 days for larvae, 89 days for nymphs, and over 421 days for some adults. Hosts were hedgehogs, guinea pigs, and rams.

Subsequently, Nuttall (1915) noted that some adults were still alive 759 days after emerging. Females that had fasted for 817 days were fed on a ram, mated with males that had fasted over 210 days, and were ovipositing when the report was written. Three times as many females (253) as males (83) were counted in the progeny of a single female.

Four years later, Nuttall (1919) observed that males may remain attached to one spot of the host for as long as 122 days. More commonly, however, after preliminary feeding for periods ranging from five to 29 days, they start wandering about in search of females. After mating, when females leave the host, males do

little if any wandering. If a female is placed near a male, con siderable excitation is caused. A male may copulate with several females, but females apparently accept only a single male. Copu lation may be very swift or may apparently extend over several days. Females do not move from their feeding site until they drop from the host.

Ecology

See also section on HOSTS above.

In Algeria, adults are rarely seen in winter but begin to appear in March and continue till October, maximum densities being reached in April, May, and June (Algerian seasons are comparable to those of southern United States). Nymphs are found mostly during the summer. With slight variation, this seasonal picture is typical for H. marginatum wherever it oc

curs.

In the Crimean forest (Melnikova 1953) adults are found during the summer, March to September, but rare individuals (?mostly males) may be seen at any time of the year. Larvae and nymphs infest hares from the end of June to the first half of September. Nymphs are most common on hares in the latter part of August; for example, a hare on 2 August yielded 100 nymphs while another on 17 August yielded 390 nymphs. In this forest reserve, H. marginatum (= H. p. plumbeum) occurs in all ecological zones and in all types of forest. In pure stands of conifers, it is, however, comparatively rare. The most favorable habitats appear to be valleys with small open fields between the mountains.

In Transcaucasia, this species occurs equally in both highland and forest zones and in desert and steppe formations and is found in every type of landscape in that area (Pomerantzev, Matikashvily, and Lototsky 1940). In Armenia, it occurs in the Artemesia semidesert of the Arax valley (Pomerantzev 1934) and at altitudes of 6500 feet and over (Lototsky and Popov 1934).

On the Crimean steppes, adults are and June according to Kurchatov 1940A).

most common in July (May There, the greatest