Vol. XLVI. LONDON, JANUARY, 1914 No. 1 



THE OCCURRENCE OF THE WARBLE FLY HYPODERMA 

 BOVIS DE GEER IN CANADA. 



BY C. GORDON HEWITT, D.SC, F.R.S.C, DOMINION ENTOMOLOGIST, 



OTTAWA. 



In the early writings on the Warble Fly occuring in the United 

 States, the species was constantly referred to as Hypoderma bovis 

 of de Geer, which was supposed to be the species common to 

 Europe and North America. Curtice, in 1891, concluded that the 

 American species was H. lineata Villiers, and not H. bovis, and 

 Riley in the following year (Insect Life, Vol. 4, pp. 302-317, 1892) 

 discussed the question fully, and concluded that "the older Ox 

 Bot-fly, Hypoderma bovis, hitherto supposed to be a common species 

 of both America and Europe, is in reality either a very rare insect 

 in this country, or possibly does not occur here at all." Aldrich 

 (Catalogue of North America Diptera, 1905) states that bovis is 

 not positively known from North America. 



Subsequent workers on this continent have been accustomed 

 to refer only to H. lineata in speaking of the North American species. 



Brauer described H. lineata Villiers as H. bonassi from the 

 larva only, specimens having been obtained in Colorado from the 

 American buffalo. Besides being generally distributed through 

 the United States, according to Riley, it also occurs commonly in 

 Europe. Walker described it from Nova Scotia in 1853 as Oestrus 

 < up pi ens. 



During the summer of 1912 Dr. Seymour Hadwen, in charge 

 of the Branch Laboratory of the Health of Animals' Branch of the 

 Dominion Department of Agriculture located at Agassiz, B.C.. 

 carried out a series of experiments on Warble Flies, and his im- 

 portant contribution to our knowledge of the biology of these in- 

 sects has now been published (Bull. No. 16, Health of Animals' 

 Branch Dept. of Agriculture, Ottawa). Dr. Hadwen made the 

 interesting discovery that the common species of fly under observa- 

 tion was H. bovis, and all the full-grown larvae collected at Agassiz, 



