Fig. 30. — Parasitized lar- 

 va of D. myron. (After 

 Riley.) 



Fig. 31. — Micro- 

 gasler which de- 

 stroys larvje of D. 

 niyroii. 



Sphingidse 



Before the caterpillar reaches maturity the grubs emerge from 

 beneath the skin, and attaching themselves to the epidermis, 

 proceed to weave about themselves 

 little white cocoons, in which they 

 are transformed into perfect insects, 

 emerging to repeat the cycle of 

 life. Caterpillars which have been 

 thus parasitized do not survive the 

 ordeal. The accompanying cut (Fig, 30), shows a larva 

 upon which the ichneumon-flies have done their deadly work. 

 The insect, which accomplishes the task 

 of destruction imposed upon it in the 

 economy of nature, is very small. The 

 figure given herewith shows it of its 

 natural size, and also enlarged, so that its 

 structural peculiarities may be more easily 

 recognized. The species which we are con- 

 sidering shares this liability to parasitism 

 with its congeners, as well as with the repre- 

 sentatives of many other genera of the Sphingidtv. I was greatly 

 annoyed a number of years ago by having a large series of the 

 larvae of the beautiful Darapsa versicolor, which I had collected 

 in their early st'i.ges, destroyed by, this ichneumon-fly, and the 

 .following summer, and, in fact, for several summers following, 

 the larvoe of D. versicolor, which haJ been for awhile quite 

 abundant in certain localities known to ^ -e, almost entirely dis- 

 appeared. In one ravine, where I had obtained them" by the 

 hundreds, they were not to be 

 found. 1 account for their dis- 

 appearance by the unusual num- 

 bers of the parasites which had 

 infested them that summer. 



The larva of myron under- 

 goes pupation in a loose cocoon Fig. 32.— Pupa of D. myron 

 of coarsely woven threads of silk, which it spins under leaves at 

 the surface of the ground. In this respect its habits are strictly 

 like those of the other species of the genus. 



(3) Darapsa versicolor Harris, Plate HI, Fig. 13, 6 . (The 

 Hydrangea Sphinx.) 



69 



