258 



ECONOMIC ENTOMOLOGY 



SO many laid about the hoof as with lineatiim. SwelHng is more rounded 

 and more raised than that of lineatum, and exudes less serum. 



Control. — When practicable dip every lo days and treat the larvae 

 with arsenic. Remove the larva from the warble in spring. 



Larvae of a species of Uypoderma have been obtained from the 

 backs of horses. 



Box Flies 



These flies are probably of European origin but little is known 

 of their introduction. 



Horse Bot Fly {Gastrophilus intestinalis DeG. = equi Fab.). Adult. 

 — A large brownish hairy bee-like fly, % inch long; head brown with 



Mil^Sii. 









■"T 2. 



1/ 



Fig. 164. — Larvce of horse bot flies: i, G. hcemorrhoidalis; 2, G. inleslinalis; 3, G. 

 nasalis. {After Dove, Bur. Ent., U. S.) 



three rows of black spots; wings with dark spots or bands; abdomen brown 

 with spots and conical. July-August. 



Eggs. — Yellow, conical, attached by female without alighting to 

 hairs of fore-legs, shoulders and under side of body; |f 6 inch long; 

 hatch most readily lo to 15 days after deposition, with the aid of 

 warmth, friction and moisture. 



Larva. — ^Licked into the mouth of the horse, thence into the stomach, 

 where it attaches itself to the wall. Remains in stomach 8-10 months. 



