358 



COLLEGE ZOOLOGY 



The Brachycera include the horse-flies, bee-flies, house- 

 flies, bot-flies, and flower- flies. The horse-flies (Tabanid^e) 

 are well-known pests of cattle and horses and often man. The 

 female sucks blood, but the male lives on nectar. The larvae 

 live in the water or in the earth, where they feed on small ani- 

 mals. The bee-flies (Bombyliid^e) look somewhat like true 

 bees. They feed on nectar as adults, but the larva? are car- 

 nivorous, living on the young of bees, wasps, and grasshoppers. 



The house-flies belong to a family (Muscid^e) which contains 

 about a third of all the known Diptera. The house-fly, Musca 



Fig. 293. — Order Diptera. 

 House-fly, Musca domcstica. 

 (From Howard, Circ. 71, Bur. 

 Ent., U. S. Dep't Agric.) 



Fig. 294. — Order Diptera. Horse 

 bot-fly, Gastrophilus equi. a, larva. 

 b, adult. (From Sedgwick's Zoology, 

 after Brauer.) 



domestica (Fig. 293), is dangerous, since it carries disease germs, 

 such as typhoid and tuberculosis, from place to place. Its eggs 

 are laid principally in horse manure and the larvae are called 

 maggots. The adults can be controlled by keeping the horse 

 manure and other filth under cover. The flesh-flies deposit 

 living young in meat or in open wounds. The blow-fly lays its 

 eggs on meat, which is then said to be "blown." The tachina- 

 flies are beneficial, since their larvae are parasitic upon cater- 

 pillars (Fig. 287), often exterminating vast hordes of army- 



