THE ANTS, BEES, AND WASPS 93 



larva by means of its long ovipositor, and the ichneumon 

 larva on hatching moves along in its burrow until it finds 

 its host, when it fastens itself to it and destroys it by sucking 

 its blood. Many of the ichneumon flies are true parasites 

 in the larval stage, the eggs being deposited on the skin 



c\; 



<N -W 





» 



Fig. 60. Gallfly. (Natural size) 



or in the body of the caterpillars, upon the fluids of which 

 the ichneumon larva feeds. The pupal stage is generally 

 passed within the body of its victim. 



Sawflies. The sawflies have the base of the abdomen as 

 broad as the thorax. The ovipositor of the female con- 

 sists of a pair of saws, which are used to make slits in the 

 leaves and stems of plants, in which she deposits her eggs. 

 Fig. 61 shows the American sawfly (Cim'bex america'na), 

 our largest species. The larva looks like the caterpillar of a 

 butterfly or moth, but has more legs. It has the curious 

 habit of coiling the posterior end of its body about a branch, 

 as shown in the illustration. It forms a brown cocoon, in 

 which the winter is passed in the ground. 



Larva? of the currant sawfly (Pteronid'ea ri'besi) fre- 



