density of this tick is around haystacks and in fallow fields 

 where their immatiire stage host, the European hare, hides and 

 feeds. EJngorged njonphs drop from hares in autumn and overwinter 

 in that stage. They molt in the spring, and adults attack cattle, 

 sheep, horses, and man. The devastation of the Crimea during the 

 war, followed by a" great increase in hares and their ticks, was 

 significant epidemiologic ally in the outbreak of highly virulent, 

 often fatal hemorrhagic fever at that time. 



REMARKS 



Gynandromorphs of H. marginatum have been described and il- 

 lustrated by Pervomaisl^ (1950^ • Tlie same author (19A9) was un- 

 able to secure a complete F]_ generation from parthenogenetic fe- 

 males of this species. 



Schtilze (1932c) illustrated certain of the cuticular sense 

 organs of two of his "subspecies" of this species, also "gyno- 

 tropes**, males with more dense punctations on the scutum con- 

 forming to those of the female scutum in location and distribu- 

 tion. This species has been utilized in a study of sensory phy- 

 siology (Totze 1933). 



When large numbers of ticks (as H. pl-umbeum ) feed on a res- 

 tricted area of the host, the females~and sometimes also males 

 fail to engorge completely and may die; their development is 

 far from normal. When different species are competing for the 

 same feeding area, this additional competitive factor often 

 hinders their normal development (Pavlovsky, Pervomaisky, and 

 Chagin 1954). 



DISEASE RELATIONS 



MAN: H. marginatum is considered to be the chief vector of 

 the virus oT Crimean hemorrhagic fever. The extensive geographic 

 range of this tick and its large population in many areas where 

 it occurs - factors that suggest a high potential as a medically 

 important species _ appear to be generally unappreciated outside 

 of Crimea. This species is not involved in the transmission of 

 Omsk hemorrhagic fever, since it does not occur in that area, 

 so far as is presently known. 



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