ENEMIES OF PLANTS. 



321 



arrangement is to prevent their being eaten by 

 larvae, not only of other insects, l^ut of those of 

 their own family, for they are verital)l(; cannibals. 

 The larvai (Fig. 1 13, <^) are as ugly as the adult is 

 beautiful. They are active, spindle-shaped little 

 fellows with crescent- 

 shaped m a n d i b 1 e s, 

 which never seem to 

 tire of piercing to 

 death all insects they 

 can capture ; but they 

 are particularly de- 

 structive to plant-lice 

 (aphides), and for this 

 reason are often called f^ 

 aphis lions. They 

 hold their prey be- 

 tween the tips of their ^'^'- "4- — ich 



^ POSITING AN EGt 



mandibles, a n d suck 

 the juices through the 

 long tubes formed by a groove along the under 

 side of each mandible and the slender maxilla 

 which fits into it. When this larva reaches its 

 growth it rolls itself into a ball and spins a 

 cocoon of snowy white, from which it comes 

 forth through a circular lid (Fig. 113,/) a 

 wondrously changed creature — the dainty lace- 

 winged fly. 



Another group of our insect friends is the 

 parasitic Hymen.optera, such as the ichneumon- 



NEUMON-Fl.Y DE- 

 G WITHIN COCOON. 



(Slightly magnified.) 



