THE LOCUST SAW-FLY. 



369 



color to a paler yellowish green, and its texture is thickened and suc- 

 culent." The same leaf sometimes has two or more of these folds along 

 different parts of its margin. 



The larva is colorless or watery when young, becoming, as it approaches maturity, 

 opaque and milk white, varied more or less with bright yellow. It is long oval, 

 broade'St in the middle and tapering thence to a sharp point anteriorly, the opposite 

 end being bluntly rounded, and is divided into thirteen segments by transverse im- 

 pressed lines. (Haldeman.) 



18. The locust saw-fly. 



Nematus similaria Norton. 



Order Hymenoptera ; family Tenthredinid^ 



Fig. 136. — Locuat saw-fly. a, eggs ; b, c, ■worms ; d, tail 

 of the aame ; c, cocoon ; /, fly. — After Comstock. 



Eating the leaves of the black locust, a small, soft, green worm two-fifths of an 

 inch long, with twenty legs, and a brownish head ; appearing in Washington, D. C, 

 late in August until October; transforming in a dark-brown oval cocoon, and two or 

 three weeks later issuing as a saw-fly nearly one-quarter of an inch long, of a dirty 

 yellow color, with a squarish black patch on top of the head, the sides and front of 

 the thorax black, and a transverse band on top of each abdominal segment. (Com- 

 stock. ) "^ 



This saw-fly inserts its irregularly semi-ellipsoid eggs in a crescent- 

 shaped cut made in the under surface of the leaf by the "saw." In a 

 few days the larva hatches. Professor Comstock thinks there are two 

 and possibly three broods in a season, and that the insect may hiber- 

 nate both in the adult and pupa stages. 1 have found this insect com- 

 mon in the larva state on the leaves of the locust at Brunswick, Me. 

 The head of the worm is amber-colored, rather than " brownish." 

 5 ENT 24 



