ROSS: HOW TO COLLECT AND PRESERVE INSECTS 



43 



unlike the adults and are grublike in form. They are called 

 larvae. The aphid lion, the interesting larva of Chi'ysopa, fig. 

 43, is frequently taken in sweeping. Another interesting larva 

 of this order is the doodlebug or ant lion, of Huckleberry Finn 

 'fame. The adult insects that mature from these ant lion larvae 

 are very similar in appearance to the chrysopids or lacewings. 

 The larva of each of these insects sinks its long, sharp, curved 

 mandibles into the body of its 

 prey and sucks out the body juices. 

 The female Chrysopa has the cu- 

 rious habit of forming a long, 

 slender stalk under each egg ; the 

 bottom of the stalk is fastened to 

 the upper side of a leaf. The 

 stalks are thought to have the 

 effect of keeping the first larvae 

 of a hatch from devouring the 

 eggs placed nearby. 

 When the larva is mature, it spins 

 a globular, silken cocoon or cell 

 around itself and in this changes 

 into a pupa, or quiescent stage. 

 While the pupa itself does not ap- 

 pear active, within it the larval 

 tissues are reorganized into the 

 structures of the adult, including 

 wings and reproductive organs. 

 When this change is completed, 

 the adult insect emerges from the 

 cocoon. 



This order, the Coleoptera, and 

 all the following insect orders 

 differ from the other insect 

 orders in having a pupal stage. 



Fig. 43. — Neuroptera. A larva 

 of the genus Chrysopa. This form 

 uses the long jaws to impale 

 aphids and suck their body juices. 



Megaloptera 



Alderflies 

 Dobsonflies 



mature stages 

 of this order 

 lakes. Typical 



Insects similar in general appearance and 



characters to the Neuroptera. They have 



long antennae, two pairs of similar and finely 



netted wings, chewing mouthparts, and im- 



unlike the adult. All our Illinois representatives 



have immature stages that live in streams or 



of their appearance is the alderfly, Sialis, whose 



