ADAPTATION FOR THE SPECIES 143 



caterpillar's back, it punctured the skin with its sting, 

 and deposited eggs within the caterpillar's body. 

 These eggs soon hatched and the little grubs worked 

 their way through the body of its host. The infested 

 victim feeds upon leaves and fills itself with rich food. 

 These parasites eat the food, and, try as it may, the 

 caterpillar does not succeed in getting fat. After the 

 grubs have gotten their full growth, each of them eats 

 its way through a little hole to the outside of the 

 caterpillar's body. Here it spins around itself a little 

 white case, and looks like a rice grain. As the cater- 

 pillar moves about, these seeming rice grains are 

 rubbed off and fall to the ground. Next year there 

 will come up new ichneumon flies to sting fresh cater- 

 pillars and repeat the entire process. 



Another remarkable provision for the young on the 

 part of insects is seen in the behavior of the big 

 sphex wasp, known as the cicada killer. The cicada, 

 it will be remembered, is what is commonly called a 

 locust. The cicada killer is a magnificent big wasp, 

 whose body is nearly an inch long, banded with black 

 and yellow, while the wings are colored a smoky 

 brown. This muscular wasp digs a long tunnel eight 

 or ten inches deep, which ends in a slightly larger 

 room. Having provided the location, he now sallies 

 forth in search of the cicada. The heavy song of the 

 male probably serves as a guide to the wasp in case 



