THE FLY AND ITS ALLIES 



67 



wings (Fig. 67). Only the female sucks blood, while the 

 male feeds in flowers. They are powerful and rapid fliers. 

 The larvae are carnivorous and live in the earth or water. 



FIG. GG. Tabanux llmola, white- 

 lined horse-fly. X 1.2. Photo, by 

 W. H. C. P. 



FIG. 67. Chrysops, banded horse- 

 fly. X 1.5. Photo, by W. H. C. P. 



The black-flies (Simuliidse r ) are representatives of the 

 long-horned flies (Nematocera). They are familiar pests 

 in the forests of our Northern country. The females, which 

 alone suck blood, occur in such num- 

 bers and are so active that they render 

 certain places almost uninhabitable to 

 man. Their bite often produces wide- 

 spreading and painful inflammation, 

 accompanied by swelling (Fig. 68). 

 The larvae are aquatic. The Southern 

 black-fly or " buffalo gnat " sometimes 

 causes the death of domestic animals. 



The gall-gnats (Cecidomyidse 2 ) are 

 minute flies which lay eggs on plants, 

 their way into the plant tissue, and cause the further de- 

 velopment of the tissue to be abnormal, so that excrescences 



FIG. G8. Simulium, 

 the black-fly. En- 

 larged. From 

 Packard. 



The larvae make 



1 From simul, together ; or simultas, a hostile encounter. 



2 s, gall-apple ; /tvta, fly. 



