ATTACUS CECROPIA 257 



all over the body of the caterpillar. Usuall}^ the cater- 

 pillar lives until the cocoons are spun, but in the lat- 

 ter days of its life it is inactive and suffering, does not 

 eat, and writhes painfully. 



These braconids are found on many species of cater- 

 pillars, both sphingid and saturniid, even on the small 

 larvae of some noctuid moths. 



Once in a while a caterpillar is found with only two 

 or three eggs on its skin, and its life may be saved by 

 crushing or removing the eggs with forceps or a knife, 

 if the grubs have not left them for the body of the 

 caterpillar. 



It is not always possible to tell a stung larva, because 

 the egg-shells are east with the molted skin, and the 

 eggs of the ichneumonids are under the skin. Before 

 the braconids come out to spin, however, they may be 

 seen moving about just under the thin skin of the 

 caterpillar. 



These are all hymenopterous flies, but there are also 

 dipterous flies which prey upon caterpillars of many 

 kinds, cecropia among the rest. These are the Tachina 

 flies, which look like very large, hairy house-flies, and 

 their larvae make short, red-brown, round-ended pujDa?. 

 The eggs of these flies are laid on the skin of the cat- 

 erpillar, many on one victim. We have often found 

 the egg-like pupae in the box of a choice and treasured 

 crawler on whom our hopes were set. 



