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BIOLOGY

Judging from its considerable geographical range, this spe cies is able to adjust to marked climatic variations only partially modified by protected cave environment.

I. vespertilionis is rare on bats in Equatoria Province east of the Nile. Over a thousand bats, representing almost every spe cies in Eastern Equatoria, have been carefully searched without finding more than the single specimen listed above. There has been little opportunity to examine carefully many caves.

Males have been collected only from caves and other retreats in which bats assemble. No males have been found on bats. Nuttall and Warburton (1911) postulated that males may either feed very rapidly and then leave the host or that they may not feed at all Neumann (1916) believed that the various degrees of engorgement in which male specimens are found might not necessarily prove that males do feed but rather may be an indication of degree of nymphal feeding. This conclusion is based on the atrophy of the male hypostome in comparison with its robust development in fe males and in immature stages.

Neumann (loc. cit.) mentioned the preponderance of numbers of males in relation to females and immature stages in collections and surmised that this may be due to the conspicuousness of the male's vagabond search for females. Females secrete themselves between stones of the caves to digest their blood meals. They probably oviposit in these niches, though this is not certain. Engorged nymphs are sometimes found in similar situations.

When females are found on the host, immature stages are frequently found with them. Feeding is probably comparatively rapid, otherwise it is logical to assume that females and nymphs would have been more frequently reported from bats.

Arthur's (1956A) comparison of data from Switzerland and from Macedonia leads him to believe that, because there is a reasonably high catch of partially and fully engorged ticks be tween October and January and a number of unfed nymphs and fe males during the summer, feeding is accomplished mainly during

the winter months. This picture, possibly modified by the host's seasonal breeding cycle and activity, requires further observation.

RDMARKS

The exceptionally long legs of this species is a character shared by many chiropteran parasites, notably the Streblidae and Nycteribidae (Diptera) and Argas bousti (cf. Figures 33 and 34). This feature is, however, not shared by all bat parasites, es pecially those which are strongly appressed laterally, as fleas, or appressed dorsoventrally as bugs of the families Cimicidae and Polyctenidae. Except for Argas boueti, all the known chiropteran. infesting Argas species have normal length legs, and indeed some, as for instance Argas transgariepinus White, 1846 (cf. Hoogstraal 19521), have comparatively short legs.

Certain morphological peculiarities of adults and immature stages have been briefly mentioned by Arthur (1953A). The halleris organ is described by Arthur (1956B); it is like that of I. simplex subspp.

Schulze (1938A, figure 28) has utilized this species to il lustrate the thesis of morphological indicators due to pressure within the developing nymph..

The subgeneric position of this species has been discussed by Neumann (1916), but this is moot; Arthur (1956A), the out standing contemporary specialist on this genus, disregards it until further study can be undertaken.

IDENTIFICATION

Both sexes and the immature stages of I. vespertilionis are unique in the extreme elongation of the legs. The long anal grooves of both sexes are open; those of the male slightly con verge posteriorly, but female anal grooves are parallel. The male scutum has a few large punctations in three rows and nu merous fine, scattered punctations; the female scutum bas nu merous small, shallow punctations.

The larva and nymph were partially illustrated and briefly described by Nuttall and Warburton (1911) but Arthur (1956A) provides complete descriptions of both sexes and of the immature stages.

MARGAROPUS

INTRODUCTION

The genus Margaropus, closely related to Boophilus and con fined to Africa and Madagascar, consists of only two species, M. winthemi Karsch, 1879, of southern Africa and Madagascar, and M. reidi sp. nov. of the Sudan. Earlier assertions that M. winthemi is a South American tick apparently are erroneous.

Usual remarks in the introductory sections for each genus treated in the present work are, in the case of Margaropus, in corporated into the text below and do not require repetition here.

Illustrations of nymphal M. reidi sp. nov. and of M. winthemi, together with a review of the latter species, are given in the APPENDIX, pages 896 to 905. The mexpected circumstance of the very recent acquisition of the new species necessitates this treat ment.

KEY TO THE GENUS MARGAROPUS*

MALES

Six pairs of hair tufts and ventral hook
on posterior body margin; a caudal pro
jection present when engorged. Adanal
shields sharply pointed distally, acces
sory shields absent. Scutal outline
convex laterally and bluntly rounded
posteriorly. Free segments of leg IV
as wide as long. (South African winter
horse tick).

....M. WINTHEMI Figures 359 and 360,

363 to 367

*The characters provided in the key, together with those in the generic key, are sufficient to comprise an adequate diagnosis for each species in this genus.

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