The Black Flies and Buffalo Gnats 



bubble of water quickly arises to the surface of the water and 



flies away instantly, , , 



the silky pubescence 

 keeping it from get- 

 ting wet. The first 

 generation having ap- 

 peared in early May, 

 successive generations 

 are produced from 

 this time on during 

 the summer and part 

 of the autumn. All 

 of the flies captured 

 from the first brood in 

 one instance were fe- 

 males and this may be 

 the rule but towards 

 autumn the males 

 began to appear in 

 greater numbers and 

 towards the last of 

 August nearly all of 

 the specimens taken 

 were males. On Sep- 

 tember 2, 1888, the 

 present writer cap- 

 tured fifty specimens 

 of this fly at Ithaca 

 and all were males 

 with the exception of 

 one. Adults were 

 observed on the wing as late as the 10th of October. 



Fig. 73. — Simulium ornatum, early stages. 

 (After Riley.) 



123 



