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Amblyomma nymphs to support a morphological theory). The concep tion of a separate species with unique "half_endo parasitic" habits is not supported by field and laboratory observations. In several Hyalomma species observed in Egypt, long-feeding immature stages become overgrown by the host skin. Poorly developed adult "Hyalom minas" result from these nymphs. If removed early enough, such nymphs may molt into typical though frail adults of recognized species with or without subanal shields. Other larvae and nymphs that attach to the ears, which do not react to the engorging ticks by producing a large amount of tissue, usually develop normally.

On the basis of many such variants among specimens of H. excavatum examined for the present study it is apparent that Delpy's (1949B) synonymy of H. rhipicephaloides under H. exca vatum is correct.

H. lewisi Schulze, 1936, from tropical Africa is the result of similar misinterpretation of H. truncatum by Schulze and his students.

In the present collection, a few specimens of H. truncatum are poorly developed and lack subanal shields. These are similar to specimens (in the Rocky Mountain Laboratory) determined by Schulze as H. lewisi from Kenya and Tanganyika. There is no question but that H. lewisi is a synonym of H. truncatum. Delpy (1949B), probably inadvertently, listed H. Lewisi as a synonym of H. excavatum. Kratz (1940) retained H. Iewisi in the "subgenus Hyalommina" even though he noted that some specimens retained subanal shields while others lacked them.

With regard to H. hussaini Sharif, 1928, the Rocky Mountain Laboratory collections contain enough constant specimens of this species (described below) from India to indicate beyond a doubt that H. hussaini is a valid species. It is coincidental that this species conforms to the criteria proposed for the subgenus Hyalommina; H. hussaini rather than H. rhi picephaloides night, therefore, be considered as the type species of this subgenus. The absence of subanal shields apparently has become a geneticallyestablished character in Indian populations. As stated below, other constant male and female characters also validate this spe_

cies. Thus, recognition of the subgenus Hyalommina would be justi. fied. It is, however, likely that the absence of subanal shields is not a genetic character in Hyalomma populations of Africa and the Near East.

Conclusions on the subgenus Hyalommina may be summarized as follows: Such an entity apparently does exist, but criteria proposed for it apply to a species (H. hussaini and possibly H. kumari) different from that originally proposed as the type For this subgenus (H. rhipicephaloides), this latter species being merely a morphological variant of H. excavatum.

These conclusions are based on study of series of preserved specimens, on field rearing of specimens, and on laboratory ob servations of wild caught subdermal specimens from rodents. More formal laboratory studies on the phenomenon of loss of subanal shields among other species are indicated.

Sharif (1928) also described H. hussaini brevipunctata and H. kumari from Indian populations on the basis of slight difTerences in color, lateral grooves and tarsi. No specimens of these forms have been available for the present study.

Sharif (1928) lists specimens of H. hussaini from the fol lowing India areas: Bihar, Orissa, Central Provinces and Madras and Bombay Presidencies. The subspecies brevipunctata is listed from the same areas as well as from Bengal. H. kumari is also known from the first localities and Assam and Punjab. Hosts are cattle, buffalos, horses, goats, sheep, dogs, tiger, and various kinds of deer.

Sharif (1930) illustrated a specimen of H. hussaini with unequal adanal shields. Material from Portugese India has been reported (Santos Dias 1954J).

Both sexes of H. hussaini have such unique morphological characters that it is difficult to comprehend why Delpy (1949B) placed this species in synonymy under H. excavatum. Sharif's (1928) original description is excellent as are the illustrations of the male. This sex is characterized by large, broad adanal shields, absence of subanal shields; bright, shiny scutum with long, pronounced lateral grooves; long, narrow posteromedian

grooves, shorter and wider paramedian grooves; rarity of punctations that are widely scattered over scutal surface but usually arranged in lines bordering the posterior grooves, and small size (less than 3.00 mm. long and 2.00 mm. wide).

The female also has a smooth, shiny scutum with few punctations, those present are similar to those of the male. Porose areas of the females at hand are notably large and distinct. The genital apron is unique in that it is divided by a medioposterior depression that is either a narrow, median, posterior groove or expanded posteriorly to include the posterior periphery. In outline the genital apron is subrectangular to subtriangular, in profile it is more or less gradually depressed posteriorly. The female size unengorged is only slightly greater than that of the male.

[graphic][merged small][subsumed][merged small][merged small]

Figures 202 and 203, o, dorsal and ventral views
A, spiracular plate, H. dromedarii. B, spiracular plate, H. schulzei.

Specimen from camel, Central Iraq.
Hoogstraal Collection from Dr. G. H. Hall.


illustrations, see PLATE XVIIC



(Figures 202 and 203,337 and 338)


H. Schulzei a hyalomna of restricted geographical range, appears fron male characters to be a giant relative of H. dromedarii. The fe nale genital apron, however, differs so greatly from that of H. drome darii that the relationship of these two species does not appear to be actually so close as previously considered. It is also likely that females associated by Olenev with males of H. schulzei in the original description of the species included some specimens of H. dromedarii.

The geographic range of H. schulzei extends from Iran (Olenev 1931A,B, Delpy 1937) and Afghanistan (Anastos 1954), through Iraq (Hoogstraal, ms.), and Palestine (Schulze 1936C; Kratz 1940, Adler and Feldman_Muhsan 1946,1948) into Sinai and the Eastern and Western Deserts of Egypt some 200 miles west of Alexandria (Hoogstraal, ms.). It is absent in Russia (Pomerantzev 1950) and is not represented in the present collections from Libya, Yemen, coastal East Africa, or Turkey.

Hosts of adults mentioned by all authors and represented in our collections are camels, and Pomerantzev (1950) adds cattle. Hosts of immature stages have not previously been determined. In Sinai and Egypt (Hoogstraal, ms.), nymphs (reared to adults) have been found on hares, Lepus capensis subsp., and fat sandrats, Psammomys 0. obesus. Unfed, newly molted adults have been taken from bur. rows of Jirds, Meriones c. crassus.

The male is large and when engorged measures up to 8.00 mm. in length and 7.00 mm. in width. The extreme width is due to con siderable lateral stretching of the integument during feeding; un engorged specimens are approximately 4.00 mm. wide. The scutum of specimens at hand and previously described has parallel lateral margins while those of H. dromedarii are usually convexly arched. The palpi of available specimens are notably short and robust; the parma is subrectangular; in H. dromedarii it is typically triangular. The most notable distinction between the two species is

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