Bui. 885, U. S. Dept. of Agriculture 
The Black Fly. 
A, Egg, -with enlarged view of polygonal markings of egg; B, pupal spine immediately after 
molting; C, same, showing variation in outer' sheath; D, pupal spine just before changing 
color; E, male genitalia: F, antenna of female; G, distal portion of segment in in the male 
antenna; H, distal portion of segment in in the female antenna; /, f orewing of adult female 
showing costal margin at base of wing; J, same, showing variations in markings; K, forewing 
of male. 
* 
