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(Figures 331 to 334)


This species occurs in EGYPT and probably extends eastward and westward from here.


Adults feed on camels; immature stages on lizards, Acantha dactylus and Agama. In the laboratory, rabbits serve as host for all stages and man has been utilized to feed adults.


This is a fairly common tick locally on Egyptian desert lizards.

Life cycle and other biological data will be pre sented subsequently (Hoogstraal, ms.).


Although probably already described, we are not yet certain which name applies to this species. The male runs to H. excava tum in the Delpy (1949A) and in the present (page 397) keys. The female superficially resembles that of H. detritum but is morphologically distinct from all others. In size, both sexes are considerably larger than H. excavatum. Adults, reared from nymphs removed from Egyptian lizards, have produced uniform F1 adults, thus indicating the validity of this species. All specimens are remarkably similar, a phenomenon seldom seen in this genus. However, further search of field collections and addi. tional rearing will probably reveal more variable individuals. Means to separate this species from "H. species no. 2 near excavatum" may be found on page


Male. The scutum measures from 3.94 mm. to 4.37 mon. in length and from 1.95 mm. to 2.90 mm, in width; specimens with a scutum measuring less than 4.10 mm. long and 2.66 mm, wide are uncommon.

The scutum of H. excavatum measures from 3.52 mm. to 4.18 mm. Tong and from 2.00 mm. to 2.19 mm. wide, but seldom exceeds 3.75 mm. in length and 2.09 mm. in width.7 The appearance is that of a strong hyalomma in comparison with the typical frail guise of H. excavatum. The shiny dark brown scutum is in contrast to the Eypically yellowish brown scutum of H. excavatum. Scutal puncta tions are few; minute but distinct punc

ctations are widely scattered over the entire surface and become dense in the characteristically triangular caudal depression; large punctations number no more than those on the specimen illustrated (Figure 331) and may be even rarer. Lateral grooves are strictly confined to the posterior third of the scutum where they are deep and distinct. The caudal depression is an approximately equilateral triangle (margins curved in H. excavatum) bounded by a ridge that is not so elevated as in H. excavatum; the apex of the depression is level with the apex of the lateral grooves; the posteromedian groove is poorly devel oped and does not extend beyond the depression, the paramedian grooves are faint, rounded depressions extending as faint grooves to the middle of the third pair of festoons. The posterior margin of the scutum is bluntly rounded while that of H. excavatum is more narrowly rounded. The adanal shields are strong, broad, and quadrate posteriorly (Figure 332), and the subanal shields, that lie directly posterior of them, are larger than is usual in H. excavatum. The spiracular plate (Figure 332G) is distinguished from that of H. excavatum (Figure 332F) especially by the narrowly tapered, very slightly curved tail (the tail of H. excavatum is wider and curves more abruptly apically).

Female. Scutal measurements in most specimens are approx imately 2.30 mm. in length and 2.38 mm. in width; the minimum is 1.95 mm. by 2.00 mm.; the maximum 2.71 mm. by 2.52 mm.; the out line is subcircular and the surface is smooth with very few, large, widely scattered punctations, thus being similar to that of H. detritum (the typical outline in H. detritum tapers more abruptly from the level of the eyes and is narrower posteriorly). The genital apron (Figure 334A to D) is similar to that of H.

truncatum and might easily be confused with it (cf. Figure 189A to D and page 503); its deeply depressed profile and wide outline is in strong contrast to the gradual slope and narrower outline in H. detritum and to the strongly convex profile and subcircular or more narrowly triangular outline in H. excavatum.

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Figures 333 and 334, o, dorsal and ventral views.
Figures 335 and 336, 2, dorsal and ventral views.

A, 4, genital area. B to D, , genital area outline and profile.

B, unengorged. C, partly engorged. D, fully engorged.


Reared Egyptian Specimens





(Figures 335 to 338)


EGYPT, including Sinai, and LIBYA (H.H. collection). PALES. TINE (various lots in BMNH identified as "H. excavatum large race", HH det.). MOROCCO (Lot 0823-12_13 in BMNH, HH det.). CANARY ISLANDS (Nuttall lot 3226 in EMNH, HH det.). YEMEN (HH, ms.).


Known hosts of adults are camels and cattle. In Egypt, im mature stages (reared to adults) have been taken from spiny mice, Acomys russatus, at 5000 feet altitude in Sinai; lesser gerbils, G. &. gerbillus, near Cairo; and fat sandrats, Psarmmomys o. obesus, in satine desert areas on the Mediterranean littoral and beside the Nile Delta.


Biological and life history data will be presented separately (HH, ms.). It is notable that in Egypt we find this species only in certain desert situations from sea level to 5000 feet elevation but never in cultivated areas.


"Species number 2w is a large race or species closely related to H. excavatum but differing from it in color and size. The size is even greater than that of "species number 1" but the color is similar.

Recently Mr. Glen M. Kohls of the Rocky Mountain Laboratory kindly sent us the Schulze collection of "H. anatolicumle for study. The bulk of this material conforms exactly to Hyalomma species no. 2 near excavatum". Although a surprising mixture of

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