Insect Sttddy 



343 



who do not know that caterpillars never lay eggs, have called, eggs. 

 But the sphinx moths at any stage would have horror of such eggs as 

 these! They are not eggs iaut are httle silken cocoons spun by the 

 larvae of a hymenopterous parasite. It is a tiny, four-winged "fly" which 

 lays its eggs within the caterpillar. The little grubs which hatch from 

 these eggs feed upon the fleshy portions of the caterpillar until they get 

 their growth, at which time the poor caterpillar is almost exhausted; 

 and then they have the impudence to come out and spin their 



silken cocoons and 

 fasten them to the 

 back of their victim. 

 Later, they cut a little 

 lid to their silken cells 

 which they lift up as 

 they com.e out into 

 the world to search 

 for more caterpillars. 

 As soon as the 

 sphinx larva has ob- 

 tained its growth, it 

 descends and burrows 

 into the earth. It 

 does not spin any 

 cocoon but packs the 

 soil into a smooth-walled cell in which it changes to a pupa. In the 

 spring the pupa works its way to the surface of the ground and the moth 

 issues. In the case of the tomato and tobacco sphinx pupa, the enor- 

 mously long tongue has its case separate from the body of the pupa, which 

 makes the "jug handle." The wing cases and the antennte cases can be 

 distinctly seen. In the case of the other species the pupae have the 

 tongue case fast to the body. The larva of the myron sphinx does not 

 enter the ground, but draws a few leaves about it on the surface of the 

 ground, fastens them with silk and there changes to a pupa. 



References — Caterpillars and their Moths, Elliot and Soule; Moths and 

 Butterflies, Dickerson; Moths and Butterflies, Ballard; Manual for the 

 Study of Insects, Comstock. 



A full-grown caterpillar of the Myron sphinx. 



A " cake walk." The caterpillars of the Myron sphinx 



in attitude of defence. 



Photo by M. V. Slingerland. 



