Section IV., 1915 [225] Trans. R. S. C. 



A Contribution to a Knowledge of Canadian Ticks. 



By C. Gordon Hewitt, D.Sc, 



Dominion Entomologist, Ottawa. 



(Read 25th May, 1915.) 



During recent years our knowledge of the biology and distribution 

 of the ticks has greatly increased owing to the discovery of the economic 

 'importance of this group as carriers of certain serious diseases to 

 man and domesticated animals. In North America we have the 

 North American Fever Tick Margaropus anmilatus Say, the well 

 known disseminator of splenitic or Texas fever of cattle, which is 

 credited with an annual loss of about fifty million dollars to the 

 cattle industry of the southern States, and the Rocky Mountain 

 Spotted Fever Tick, Dermacentor vemistus, the responsible agent 

 for this human disease which has a high rate of mortality. 



With the exception of the work of Dr. Seymour Hadwen, Assistant 

 Pathologist of the Health of Animals Branch of the Dominion Depart- 

 ment of Agriculture and, to a lesser extent, of myself, no serious 

 attempt has been made to study the ticks occurring in Canada. 

 The present account has been prepared with a view to bringing 

 together the hitherto unpublished results of my own work, and those 

 of Hadwen, together with such scattered references as I have been able 

 to find. It is hoped that this information will constitute a basis for 

 further work, and that the comparative meagreness of the records 

 will stimulate others to add to our knowledge of a group which offers 

 problems of unusual interest. 



Except where it is otherwise stated the records in the following 

 account are mine. Hadwen has studied the life-histories of a number 

 of the species and in such cases his results have been given in full or 

 summarized. 



Family ARGASIDAE 



Ornithodoros megnini Dugres. The Spinose Ear Tick. 



(PI. I, Fig. 1.) 



The capture of this species on jack rabbits on October 2, 1912, 



by Dr. A. Watson at Lethbridge, Alta., is recorded by Hadwen (1913). 



This is an unusual record, as the tick is generally found on the ears 



