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lizards, and of hares and dogs are either incorrect or refer to
a different s cies of tick, most probably H. mar inatumQ7 A.
Sergent (1930 noted a nymph of H. detritum-parasltizing another
nymph of the same species. Host§ of specimens in British Museum
flflatural History) are domestic cattle and camels (Palestine),
dmestic buffalo and pony (India), hare (India), and deer
(Romania).

"H. scu nse“ attacks the see hosts as H. detritum. It has also een ound on the Persian or goitred-gazelle, Cazella sub. tterosa, and on the red deer, Cervus ela hus bactrlanus lPomerantzev 1950). In the Crimean Natio orest_(M5lnlE5va 1953), Hg. scupgnse" is common on red deer and occurs in smaller nubers on roe deer. It is present but not common on hares but absent on squirrels and jays. Wild foxes may also be attacked. Domestic cattle are heavily infested, collections from single animals in various localities in and near the forest averaging from 78 to 756 ticks, with individual maxima ranging from 350 to 5000 ticks per animal. Domestic pigs in the same forest averaged 21 ticks per host. Zolotarev (1934) listed this tick (as H. volgense) from camels.

BIOLOGY

Introduction

Because of the interesting biological and taonomic prim. ciples involved, separate reviews of life cycle and ecology are devoted to H. detritum and “H. scu nse". H. detritum is a two_ host species whose adults fe3d in e summr an w ose nymphs undergo an extensive winter diapause; this feature is common throughout the range of H. detritum though the overwintering habits in Algeria and (usually) in Russia differ markedly; it should be determined what factors account for this variation in habits. H. scu nse is confined to parts of the Soviet Union and possibly to reece and Yugoslavia; it is said to be distinguishable from H. detritum by slight morphological differences through parts of its ggographlc range (see IDENTIFICATION below), and is a one_host

tick whose adults feed in the winter and early spring. Pomerantzev

(1950) considers fg. scup§nse' to be a “biological race" of H. detritum.

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The life cycle of H. detritum (= H. mauritanicum) in Algeria has been studied by Sergen Dona ien;-Parro , and estoquard (l931B and subsequent works). Larvae hatch in the late autumn and feed and molt to nymphs on the same host, remaining attached for appoximately sixteen days. Nymphs hibernate for approximate. 1y eight months either in groups in cracks and crevices of farnu yard walls about six feet above the ground, or under boulders. They are never found in fields without trees and boulders. Hibernation sites are generally those with a warm, sunny exposure, and those nymphs in the warmest places molt earliest in the year (June). Some days after molting, young adults start out in search of a host; they leave their hibernation place at night and travel towards stables, sometimes covering as much as thirty yards a week to reach cattle or horses.

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Adults commence attaching to the host in mid June. They mate and feed there, females dopping off after ten to twelve days. Feeding females are most common in July and August; afterwards fewer are found on animals. Those that feed later do not oviposit the same season. Eggs are laid on the ground near animals and hatch in about six weeks. Females die after laying eggs. There

appears to be quite a little variation from this typical life cycle.

Males remain on the host for a much longer time than fe

males and may move from one host to the other. Nymphs sometimes mve from one host to another.

Note that according to the Algerian reports mentioned above, nymphs hibernate in cracks or crevices of farmyard walls but that almost all Soviet workers, mentioned below, find nymphs alone or with larvae on cattle during the winter. This raises the question whether the Russian and Algerian ticks are actually the same species, and, if so, whether climatic or other factors modify their choice of niches for hibernating in these far-flung areas.

Galuzo (1943) made a special point of the fact that H. detritum is not found in cracks in the walls in southern KerelrstTin._Afi’oTited four paragraphs below, under certain local conditions in.Russia, nymphs may also overwinter off the host. No explanation for these differences in overwintering habits has been found in the Soviet literature.

In southern Kazakstan, Galuzo (l94l,1944) reported H. detritum as a two-host tick with unfed nymphs hibernating on cattle dulng the winter. They engorge and drop from the host in the sping (end of Febuary through April) and olt to adults anywhere from May to August, but mostly in June. Adults disappear in September. Eggs are laid in shaded places in moist meadows, waterside vegetation, or under grass. Larvae aestivate in cracks in the soil or on the surface of the ground until October. Then they ascend grass, attach to grazing cattle, feed, and melt to nymphs on the host. Few nymphs feed and drop from the host before winter.

In Tadzikistan, where H. detritum is most common in irrigated valleys, it has one eneratlon a year (as apparently everywhere else where it occurs%, and the seasonal distribution of feeding of the immatue and adult stages is like that in Khazakstan (Pavlovsky, Galuzo, and Lototslqr 1941).

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According to Pomerantzev (1950), when_§. detritum is reared in the laboratory nymphs drop from the host any time Between October and April. Yet they all undergo the typical winter diapause and molt to adults from May to Juky, mostly in June. Thus, nymphs that begin life as larvae in October require eight and a half months to become adults, but those that commence feeding as larvae (under experimental conditions) in April require‘ only two months to reach the adult stage. Furthermore, females may fast for six or seven months and feed, between May and August, for from seven to 27 days, average eleven days. After dropping from the host, females commence oviposition in six to 31 days. Eggs number from 5000 to 7000. Larvae appear 25 to sixty days after the eggs have been laid, and may fast for seven or eight nnnths. They (normally) attach to the host about a week after hatching, feed for eleven das, and molt on the host about eleven days later. There is one generation a year.

Pomerantzev (1950) notes that in Middle Asia, (overwintering) nymphs may be found under cattle dung (stored for fuel), and also in the walls of stables (Pavlovsky). Metamorphosis from nymph to adult may oocu in buildings and stables thus increasing the importance of the species in the spread of disease.

Life Cycle pf TH. scuggnse"

Knuth, Behn, and Schulze (1918, p. 254) first noted, in their studies of tick.borne diseases in Greece, that TH. scupgnse" is a single.host tick.

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According to Pomerantzev (1950), "H. scu nse' (which occurs in the Kursk and Saratov areas, lower Vdlga, UE¥ainia, Crimea, Caucasus, Kazakh, Tadzhik, and Yugoslavia, Central Asia, and the rayon of Kogen) is a single.host tick. Adults appear in the winter from January to April and rarely until June. Larvae feed in November, nymphs from November to March.

In the laboratory Gnarkov, Abramov, and Dzasokhov 1940, as H. vol ense), females begin to oviposit from 45 to 85 days after leaying e host and continue to lay eggs for thirty days. Larvae hatch from 45 to ninety days after commencing oviposition and en. gorge in six or seven days. They molt to nymphs on the host, conn mence feeding after several days, and feed for four to six days. Nymphs molt to adults, on the same host, ten days afterwards.

In nature, unfed larvae begin to attack cattle in October and molt to the nymphal stage during the same month. The maximum number of nymphs are found in December, when young adults begin to appear. Adults move to different parts of the host and pass the winter on the host. Adults commence feeding early in March. Early in Apil large numbers of adults leave the hosts. Oviposi. tion and development of the eggs occurs during the summer. Z-Note the long summer period of oviposition and embryological development, whereas the larval and nymphal development is rapid57 Unfed adults and fed nymphs may undergo a winter diapause. Some engorged nymphs that do not molt remain attached to the host until February. From December to March, adults wander over the host's body but do not start feeding till early spring. The cycle re. quires one year.

In northern Caucasus, larval "H. scu nse" infest cattle in October and overwinter on the mmIs.~ appear early in spring (Markov, Gildenblat, Kurchatov, and Petunin 1948). These workers confirm the single..host life cycle of this tick as does Alfeev (1951) and Melnikova (1953), in his study of the ticks of the Crimean National Forest. There, adults are found on cattle and wild ungulates from September through April but rare individuals may be collected on deer during the summer (May to June). All stages occur on deer during the winter (November. December) butin January and February only nymphs and adults are found, and by the second half of March all nymphs have molted to adults. In April and the first half of May, only males and greatly engorged females are found on wild ungulates.

Ecology of H. detritum*

In eastern Transcaucasia, H. detritum inhabits various types of desert and step areas, des'<':ri5ed E Pomerantzev, Matikashvily, and Lototslq (l9l.0))e(see six par aphs below). In the Arax val. ley of Armenia, Pomerantzev (1934 found this tick only in saline,

marshy types of grassland pasture areas, not in Artemesia semi. desert areas.

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It appears that H. detritum infests a selected variety of semidesert areas, and also steppe and other grassy areas, but not forest zones. It still requires to be explained why H. detritum, which seems to be ecologically more limited than "_H. scugnse", should have a so much more extensive geographical

range n H. scufinse" .

Larvae, since they attach to cattle in the cool months of October and November in Tadzhistan and eastern Uzbekistan, select those parts of the host body most exposed to the sun. Summer..feeding adults attach on the shaded undersides of the

host (Galuzo 191.3) .

Among the enemies of these ticks are wagtails (Motacilla spp.), one of which may eat as many as a dozen engorge e e ticks from a cow. This bird, and the heron, are considered of importance in the control of _I_{. detritum in Spain (Miranda.

Entrenas 1951.). i

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See also life cycle of this form above, and ecology of "H.

scup_e_nse" below.

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