REPORT OF THE SOCIETY 31 



WARBLES AND BOTS. 



By A. E. Cameron, M.A., D.Sc, F.E.S., Technical Assistant, Entomolog- 

 ical Branch, Department of Agriculture, Ottawa. 



(This address was illustrated by many original lantern slides. — Ed.) 



Warbles are confined to the bovine race and bots to horses. Exceptionally, 

 they are found in man causing "cutaneous myiasis." 



WARBLES 



There are two species, HypodermabovisDeG., and Hypoderma lineaHimViWers, 

 both affecting cattle and generally distributed throughout the world wherever 

 domestic breeds are kept. From the similarity of their habits and general ap- 

 pearance, there seems to have been much confusion in their discrimination in the 

 older literature, but much of the difficulty has been eliminated by the researches 

 of Curtis^ and Schaupp^ in the United States, Carpenter and Hewitt^ in Ireland 

 and Hadwen ^-^ in Canada, not forgetting the splendid work of Bracy Clark^° 

 in 1815 in his "Essay of the Bots of Horses and Other Animals. Osborn^^ 

 has also made a valuable contribution to the study. 



Briefly, the characters distinguishing the two species may be stated as follows: 

 H. lineatum is a less robust and more slender fly than bovis, and, whereas the 

 dense yellow hair on the anterior dorsal region of the thorax partially obscures the 

 presence of four lines in bovis, in lineatum these lines are quite distinct. In bovis 

 the investing body hairs are predominantly yellow with the exception of those on 

 the scutellum and base of the abdomen, which are yellowish white. On the apex 

 of the abdomen they are a bright lemon yellow. In lineatum the body hairs are 

 yellowish white except those on the posterior extremity of the body which are 

 orange red. In both species the ground colour is black, appearing prominently 

 as a band on the posterior region of the thorax and middle region of the abdomen. 

 In the wings, the veins of bovis are not so dark as those of lineatum, and the tarsi 

 of the former are more sparsely endowed with bristles than are those of the latter. 

 Of the two, the resemblance of bovis to a honey-bee is much more pronounced than 

 lineatum. 



Entrance of Host by Larvae. 



Previous to the discoveries of Curtice \ who presumed to have proved that 

 the normal course of entrance {lineatum) within the body of the host is by way of 



