CLASSIFICATION AND DESCRIPTION OF COMMON INSECTS 257 



The Ox Warble Fly {Hypoderma bovis DeG.).— This bot-fly is also 

 European and is found in several provinces of Canada and in several 

 states. It is more dreaded by cattle than lineaium, and causes much 

 panic due largely to the insect's persistence and manner of egg-laying. 

 More robust than H. lineatum. Body hairs yellow, except those on 

 scutellum and base of abdomen which are yellowish-white, and at apex 



Fig. 163. — The ox warble fly {Hypoderma bovis). Enlarged. {After Hadwen.) 



of abdomen which are bright lemon yellow (see Table given above 

 for structural differences between bovis and lineatum) (Fig. 163). 



The adults of H. bovis appeared in B. C. from May 31st to August 

 2d as extremes (Hadwen). Carpenter says that most of the maggots 

 emerged from May 2 7 th to June 1 7 th. The pupal period has an average 

 duration of about 35 days varying according to temperature. One 

 egg is laid at a time, often when the cattle are running, besides not 



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