Cooley & Kohls : Argasidae of N. America, etc. 31 



In the humid regions the species does not exist since the larva is quite sensitive to 

 humidity. 



While the species may occur in Central America, we have no records from 

 that region. 



It has been reported in Argentina by Aragao (1935), in Brazil by Pinto 

 (1930), and there are specimens from Chile in the Bureau of Animal Indus- 

 try (40809). In South Africa it has been reported by Bedford (1912), and 

 Kingston (1936) reported it from India in the ear of a gelding that had been 

 bred and reared in Queensland, Australia. 



In the United States, O. megnim appears to be rather common in parts of 

 Texas, New Mexico, Arizona, and southern California. We have never made 

 an effort to determine the definitely infested areas in the United States but 

 from the extensive records of occurrence in Hooker, Bishopp and Wood 

 (1912), the Bureau of Animal Industry, the United States National Muse- 

 um, as well as from the records of the Rocky Mountain Laboratory, we are 

 able to map the occurrence of this species in this country in a general way. 

 (See figure 10.) The circular spots on the map indicate records from the 

 Rocky Mountain Laboratory, Bureau of Animal Industry, and the United 

 States National Museum. The species because of its long feeding period is 

 particularly subject to introduction into new areas even over long distances. 

 Occurrences in Northern, Central, and Eastern States are probably the results 

 of livestock shipments. 



We know that it has persisted for at least several years in eastern Mon- 

 tana. On April 27, 1916, Cooley wrote to Mr. Al Young, Kirby, Big Horn 

 County, and received his reply dated May 5, 1916, as follows: 



In reply to yours of April 27 concerning ticks, in February and March 1912 a 

 great many cattle died in this neighborhood. While skinning these we found the ear 

 tick. We talked the matter (over) with our neighbors and one man said he had seen 

 them two years before. I only have his statement for it. But since that time (1912) I 

 know the ticks have been in the ears of our cattle. Ours are native cattle. The ticks 

 I am sending today were taken from the ear of one of my cows. Respectfully yours. 



