70 



DIPTERA OF MINNESOTA. 



Loew, has been captured at Lake Superior, and Plecia heteroptera, 

 Say, is the fourth species recorded in this state. We also record 

 Dilophus breviceps, Loew, So. Dak. ; Dilophus serraticollis, Walk. ; Sca- 

 topse notata, Linn. Plecia heteroptera is illustrated in color on 

 Plate IL 



SIMULIIDAE, 

 Black Flies, Buffalo Gnats. 



These minute flies, belonging to the single genus, Sinmlimn, are 

 always more or less troublesome in summer to both stock and man in 

 certain localities. Only the females "bite," but many of us can bear 

 witness that each female can do enough mischief for two, and many a 



Fig. 59. Simulium venustum, male. Lugger. 



would-be prospector, surveyor, or fisherman has returned in disgust 

 from the woods, vanquished by the persevering hosts. A clot of 

 blood generally marks the point of the creature's attack. Swarms 

 of them frequently annoy horses during the spring plowing, and when, 

 as sometimes occurs, they attack stock in enormous numbers, serious 

 loss is occasioned. Cloudy weather discourages them, for, like the 

 chinch bug, they want warm sunshine. 



