temperature survival of vmfed immature stages increases vdth 

 higher humidity. In laboratory tests, larval longevity varied 

 between two and 21^ days (mean 1.25 and 162.6 days), nymphal 

 longevity between ten and 2Z^6 days (mean 6.8 and IA.9.2 days). 

 The author considered that tinder undisturbed natursil conditions 

 sxirvival would have been longer than in these tests in which 

 daily counts were made. 



Nymphs are less susceptible than larvae to low humidity. 

 The length of nymphal life increeises directly with humidity and 

 inversely with temperature. Other life history and hibernation 

 studies by Feldman-Mtihsam (19^9) are of interest, but since they 

 apply to frigid Palestinian winter conditions that do not occur 

 in the area under consideration this work is not presently per- 

 tinent . 



Serdyukova (1946A) observed ticks detaching from their hosts 

 at night; larvae and nymphs mostly between nine and eleven o'clock 

 in the evening. A number of larvae and nymphs placed on a calf 

 in the morning became fully engorged during the day but 'remained 

 on the calf when darkness set in. This behavior, probably an 

 adaptation to local climatic conditions, protects the ticks from 

 exposure to the direct rays of the sun, which are fatal to them. 

 They are apparently inactive diiring the hot part of the day, and 

 attach to hosts at night as has been recorded for other Hyalomma 

 species under desert conditions. In an isolated plot only 

 slightly over five percent of a counted number of unfed ticks 

 attached to calves between noon and sunset. 



H. excavatum is obviovisly a tick of xeric regions not neces- 

 sarily associated with domestic animals although populations are 

 considerably larger where these animals occur. Experience in the 

 comparatively lightly-vegetated desert areas of the Mediterranean 

 littoral of Egypt, where it infests rodents in their burrows, 

 indicate this tick's habits away from large, dense flocks of 

 domestic animals. 



In Transcaucasia, H. excavatvcn (= H. anatolicum ) is typical 

 of various desert, semiHesert, and steppe formations , but does 

 not occur in forested zones (Pomerantzev, Matikashvily, and 

 Lototsky 19^0) . This agrees with observations in Anatolia (Hoog- 

 straal, ms.). With respect to altitudinal distribution in Trans- 



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