COOLEY & KOHLS: ARGASIDAE OF N. AMERICA, ETC. 



The Medical and Veterinary Importance of the Argasidae 



Several species of the Argasidae are of known medical or veterinary im- 

 portance. 



Five species of Ormthodoros in this hemisphere, hermsi, tuncata, parkeri, 

 talaje, and rudis, are proved vectors of relapsing fever spirochetes. O. hermsi 

 is present in California, Nevada, Idaho, Oregon, and Colorado. O. tuncata is 

 found in California, Arizona, New Mexico, Texas, Oklahoma, Kansas, Colo- 

 rado, Utah, Florida, and in Mexico. O. parkeri is present in Washington, 

 Oregon, California, Idaho, Nevada, Montana, Wyoming, Utah, and Colo- 

 rado. O. talaje is present in California, Arizona, Nevada, Texas, Kansas, 

 Florida, and Central America. O. rudis is known in Panama, Mexico, and 

 South America. 



Other species may prove to be of importance as disease vectors. Davis has 

 reported (Section VII, Sixth Pacific Science Congress, Berkeley, Calif., July 

 1939) the experimental transmission of Rocky Mountain spotted fever by O. 

 parkeri and has also demonstrated similar transmission of this disease and 

 American Q fever by O. hermsi. 



O. coriaceus, of California and Mexico, while not known to be a vector of 

 any specific disease agent, readily attacks man. Its "bite" is quite painful. 

 Herms, who has studied this species, considers it to be one of the most venom- 

 ous of our ticks. 



O. nicoltei, a Mexican species of which we have one record from the 

 United States (from snakes in a St. Louis, Missouri, zoo), was reported by 

 Mooser as occurring in native huts and feeding on man in Mexico. 



Brumpt was unable to transmit iuricata strains of relapsing fever spirochetes 

 with nicollei but found that the species would transmit experimentally the 

 telapsing fever of Turkestan. 



Very little is known concerning the several species in the Southwest recent- 

 ly described from bats and bat retreats. One of these, O. stageri, promptly 

 attacks man when opportunity permits. While its "bites" are rather severe, the 

 species is not known to be concerned in the transmission of any disease. An- 

 other, O. kelleyi, probably primarily associated with bats, has been found in 

 houses in Minnesota, Iowa, Wisconsin, Illinois, New York, and Pennsylvania 

 but is not known to attack man. Further settlement in Western States may 

 increase the possibilities of association of the various bat-infesting species 

 with man. 



Argas persicus, of almost world-wide distribution in warm climates, is a 

 notorious pest of poultry. It is the vector of avian spirochetosis in many Old 

 World regions and in the New World the disease has been reported from 

 Brazil, Panama, and Cuba. Brown and Cross (1941) published results of 

 experiments indicating that the species may be a vector of fowl paralysis in 

 Texas. 



Otobius megnini, the spinose ear tick, is a serious pest of cattle in most of 



