35 2 



The Two-winged Flies 



is a yellowish winged species common on owls, some hawks, and the ruffed 

 grouse. Swallows are often infested, and I have taken bird-ticks from half 

 a dozen other kinds of birds. A careful search for these curious insects 

 will certainly make known numerous new species. 



FIG. 501. A horse-tick or forest -fly, Hippobosca equina. 



length \ to J inch.) 



(After Lugger; natural 



The genus Lipoptena includes a few known species found on mammals 

 which are winged for awhile, but later cast or bite off the wings. They 

 probably fly about in their search for a host, after finding which they remove 

 their wings and remain for the rest of their life on this host individual. Lip- 

 optena cervi is a species found en deer. 



FIG. 504. 



FIG. 502. FIG. 503. p IG> 503 . Bat-tick, Nycterlbia sp. 



FIG. 502. Sheep-tick, Melophagus ovinus. Nat. size ^ in. 



FIG. 504. A bee-louse, Braula sp. (After Sharp; much enlarged.) 



The bat-ticks, Nycteribiidas (Fig. 503), are curious long-legged, wingless, 

 small spider-like creatures about -^ inch long or less, which look as if the 



