244 



ELEMENTARY ENTOMOLOGY 



SUBORDER I. THE BORING HVMENOPTERA (TEREBRANTIA) 



In the first suborder the females bear a well-developed ovipositor, 

 with which the eggs are inserted into the food plant or host insect, 

 and the trochanters of the hind-legs consist of two segments. 



1. PLANT-EATING HYMENOPTERA 



The first two families are distinguishable by the base of the ab- 

 domen being broadly joined to the thorax, with no constriction at 

 this point. 



The saw-flies (Tenthredinidae) are so called on account of the saw- 

 like ovipositor. It is toothed at the tip, having a structure which 

 enables the females to insert their eggs beneath the surface of leaves 



d 



FIG. 385. The American rose-slug (Endelomyia rosae] 



a, adult saw-fly ; b, mature larva ; <r, work of larva on rose leaf ; </, piece of rose leaf showing 

 location of egg near margin ; <?, egg. (a, b, c, and e enlarged, d, natural size.) (After Chitten- 



den, United States Department of Agriculture J 



or in the stems of plants. They are medium-sized insects from one 

 fourth to one half of an inch long, usually blackish or yellow-and- 

 black in color, with the wings folded over the back when at rest. 

 The larvae resemble small caterpillars, but usually have a larger 



