86 



ELEMENTARY LESSONS ON INSECTS 



the silk hardens and then leaves it there, high up out of the 

 way of creeping predatory enemies. 



Fig. 31. — The dobson, Corydalis cornula (after Lintner); A, its larva (known to fishermen as 

 the "hell-grammite"); B, the pupa; C, the adult male; D, the head of the female (note the shorter 

 mandibles). 



The larva that hatches from the egg creeps down the 

 stalk, and at once starts foraging. It is a very useful insect 

 for it eats aphids (whence the name "aphis lion" by which 

 it is sometimes known), and has a big appetite. It is one of 



