THE HUMMINGBIRD MOTHS 



283 



A Myron caterpillar that has been para- 

 sitized. The white objects upon it are 

 the cocoons of the little grubs which 

 feed upon the fatty parts of the cater- 

 pillar. 



which the blood flows and is purified ; no insect breathes through 



its mouth. These caterpillars, like all others, grow by shedding 



the skeleton skin, which splits down the back. 



Often one of these caterpillars is seen covered with white objects 



which those who do not 

 know that caterpillars 

 never lay eggs, have called, 

 eggs. But the sphinx moths 

 at any stage wotdd have 

 horror of such eggs as 

 these! They are not eggs 

 but are little silken cocoons 

 spun by the lar\'as of a 

 hjinenopterous 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 tmtil 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 little lids to their silken cells which they lift up as 



they come out into the world to search for more caterpillars. 

 As soon as the sphinx lar\^a has obtained 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 groimd 



and the moth issues. In 



the case of the tomato 



and tobacco sphinx pupa, 



the enormously long tongue 



has its case separate from 



the body of the pupa, which 



makes the" jug handle. ' ' The 



wing cases and the antennae 



cases can be distinctlv seen- 



The pupa of the common tomato sphinx 



caterpillar 



Note that the part encasing the long tongue is 



free and looks like the handle of a jug. 



Photo by M. V. SUngerland. 



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 



