256 CATERPILLARS AND THEIR MOTHS 



English sparrows we have seen eating the moths, 

 though the sparrows had a hard struggle to dispose of 

 the flapping wings, which seemed to bewilder them. 

 When the wings were bitten off, the body was quickly 

 eaten in spite of its furry scales. 



Cecropia caterpillars fall victims to at least three 

 kinds of parasitic flies — Ophion and Cryptus extre- 

 niatus, which are ichneumon-flies, and Microgaster, a 

 braconid genus. 



Ophion deposits one Qgg under the skin of the cater- 

 pillar, and the grub from this egg feeds on the 

 caterpillar's tissues until the larva is ready to pupate, 

 having spun its cocoon. Usually a cocoon spun by a 

 stung caterpillar is thinner and lighter in color than a 

 normal one, but this is not always the case. Comstock 

 says that larvae stung by Ophion do not pupate, but the 

 Ophion larva does, making a large, oblong, round- 

 ended cocoon, very tough and of a rich brown color. 

 We have often found them in the cocoons of cecropia 

 and polyphemiis. The fly has an orange body and 

 iridescent wings. 



Cryptus extrematus is smaller, and lays many eggs in 

 one caterpillar, piercing the skin with her ovipositor. 

 The grubs feed and spin cocoons inside the cocoon of 

 their dying or dead host. 



The little braconid flies deposit their white eggs on 

 the outside of the caterpillar, and often many on one 

 larva. When the grubs hatch they eat through egg- 

 shell and caterpillar-skin into the body of the crawler, 

 and there feast until ready to pupate, when they eat 

 through the skin, stand on their anal ends, and spin 

 little white or yellow-brown cocoons which stand out 



