400 ANNUAL REPORT SMITHSONIAN INSTITUTION, 193 3 



the only species concerned in the transmission of this disease in the 

 United States. 



It is found in great numbers in caves in the Southwest from Texas 

 to California and it often inhabits the holes of burrowing animals, 

 and not infrequently invades the habitations of man, particularly in 

 camps. It will undoubtedly feed upon any warm-blooded animal 

 or bird which may come in contact with it, but it is likely that the 

 ticks feed mainly upon rodents or bats. 



The eggs are laid in the hiding places of the tick and hatch in about 

 13 days. The seed ticks, nymphs, and adults are all rather active, 

 and in most cases only a short time is required for engorgement on 

 blood. The females deposit several lots of eggs, each being preceded 

 by one or two meals of blood. 



It is obviously impossible to treat the breeding places of this tick 

 with any degree of success, and since it is only occasionally found in 

 the habitations of man about all that can be done is to destroy rodents 

 near camps and other habitations. Occasionally dwellings become 

 heavily infested with this tick on account of the proximity of suit- 

 able hosts, and in such cases spraying with tick-destroying materials, 

 or fumigating with hydrocyanic-acid gas must be resorted to. 



THE RABBIT TICK 



The rabbit tick, known scientifically as HaeTnaphysalis leporis- 

 palust7'is, is one of the most widely distributed species in this 

 country. It is briefly referred to here because of its importance 

 as a carrier of Rocky Mountain spotted fever and tularemia among 

 rabbits and other animals to which it attaches. It does not attack 

 man and therefore would not transfer a disease directly to him. 

 It is not unusual to find upwards of 1,000 ticks attached to a single 

 rabbit. Undoubtedly the blood loss and irritation due to these 

 pests must have a distinctly adverse effect on the infested animals 

 and birds. This tick also freely attacks quail, meadow larfe, and 

 certain other birds. In the case of birds it usually attaches on the 

 head and neck. On rabbits it is found mainly on the ears and about 

 the head. This tick drops from its host for each molt, and this gives 

 ample opportunity for a specimen to pick up an infection in one 

 animal and transfer it to another. 



Wliile the females do not lay many eggs, the maximum observed 

 being only slightly over 2,000, all of the stages are relatively long- 

 lived, and the fact that they will engorge upon so many different 

 animals and birds maintains the species in goodly numbers. 



Control of the rabbit tick appears impractical on account of its 

 wide distribution and the fact that it feeds exclusively on wild birds 

 and on rabbits. 



