210 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



more than one year for completing the cycle. It has also been found 

 that nymphs show less inclination to attach to hosts as the temperature 

 declines in the fall. 



It must be concluded, therefore, that the possibility of the comple- 

 tion of a cycle in one season is very remote in the Bitter Root Valley. 

 In the more southern range of the tick there is more likelihood of some 

 ticks, which hibernate as adults, being able to complete the cycle in 

 one season. It should also be pointed out that at the rate of develop- 

 ment which has been observed in the Bitter Root Valley, it is easily 

 possible for ticks to take three years to complete a cycle. 



Results of Tick Attack on Man (Other than Spotted-fever) 



A considerable number of curious cases of paralysis, more or less 

 complete and in some cases fatal, have been reported as being produced 

 by Dermacentor venustus. Nine cases of this trouble, in each of which 

 a tick (in one case two ticks) was found attached in the hair below the 

 occipital prominence, have been reported to us by Dr. I. U. Temple of 

 Pendleton, Oregon. All of these cases occurred in or near the Wallowa 

 Valley in northern Oregon. A similar case has been reported from 

 Wyoming, and Professor Cooley has heard of one or two cases in 

 Montana. The affliction as reported, first manifests itself as a partial 

 paralysis of the lower limbs, the paralysis advancing to the upper part 

 of the body and arms, ultimately affecting speech, deglutition and 

 respiration. The symptoms subsided rapidly after removal of the 

 tick. The point of attack seems to be an important factor in produc- 

 ing these symptoms. These observations by no means show conclu- 

 sively that the condition has anything to do with the presence of the 

 tick.i 



Local, itching sores frequently follow at the point of attachment, 

 especially if infection is introduced by scratching. Swelling of a limb 

 and lameness have been known to persist for weeks following the bite 

 of a spotted-fever tick which was left attached for some time. 



Nymphs Attaching to Man 



In two instances, one in the Bitter Root Valley and the other in 

 Colorado, a single nymph of this species has been found attached to 

 man. Although this must occur very rarely its importance should not 

 be overlooked, owing to the fact that the nymphs of this species have 

 been shown to be capable of transmitting Rocky Mountain Spotted- 

 fever. 



I Since this paper was submitted for publication an article by Dr. J. L. Todd 

 (Canad. Med. Journ., Vol. 2, p. 1118-1119) records from British Columbia a 

 number of cases analagous to that described. 



