136 



ENTOMOLOGY. 



large humped thorax; the mouth-parts, jaws, etc., Avell developed, 



the fly giving sometimes a sharp 

 bite, but often leaving behind a 

 clot of blood without giving pain. 

 The larvae live in running streams, 

 and when about to transform make 

 conical pouch-like cases attached 

 to eel-grass, etc., wherein they 

 pupate. The black Ay (Simirfiurn 

 molestum Harris) abounds in the 

 Northern States, and probably ex- 

 tends to the arctic regions. The 

 southern buffalo-gnat (A pecuarum 

 Riley) and the turkey-gnat (8. iiuri- 

 dionale), owing to their severe bite 

 and the great multitudes of the 

 females, occasionally, along the 

 Mississippi River from St. Louis to 

 the mouth of the Red River, kil] 

 mules, horses, cattle, sheep, hogs, 

 dogs, cats, setting turkeys and hens, 

 while three cases of death to human 

 beings are recorded. 



Family Mycetophilidae. — The fun- 

 gus-gnats have a rather slender 

 body, with long legs and coxa8,while 

 the wings have but few veins and no discal cell. Sciara mali (Fitch) 

 lives in apples; the larva of another species of Sciara, called the 



Fig. 164.— Black fly and larva. 



Fig. 165.—Mycetobia ssor- 

 dida. a, larva; b, pupa. 



Fig. 106. — Hessian fly. a, larva; 6, pupa. 

 After Fitch. 



"army-worm," living under the bark of trees, will, when about to 

 pupate, form processions four or five inches wide and ten or twelve 



