210 AGRICULTURE 



they molt, or cast, that skin and grow a new one. They repeat 

 this process several times until they are full-grown. 



Pupa. The insect next enters the pupa state. The larva 

 ceases to eat ; it does not move. You would think it dead. But 

 it is only asleep, and in its sleep a wonderful change takes place. 

 The creeping, crawling worm changes to an imago, a winged 

 creature. 



Imago. It waves its wings to and fro, and flutters from flower 

 to flower. Who would ever guess that it was once a dull worm, 

 that fed on the leaves of plants ? Instead of feeding greedily on 



J-N-B 



A FULL-GROWN GRASSHOPPER 



leaves, it sips nectar from flowers. It lays its eggs in a protected 

 place where its young can find suitable food. Soon after it lays 

 its eggs, it dies. This is the life history of a perfect winged insect, 

 such as the butterfly. Moths resemble butterflies in appearance, 

 but fly abroad chiefly at night, or in the dusk, instead of by day, 

 as do butterflies. 



Nymphs. Every insect does not pass through all these stages. 

 Some, such as bugs and locusts, or grasshoppers, have only three 

 stages, egg, nymph, and a dult'. The nymphs resemble the 

 adults, and attain their growth by molting, without entering the 

 pupa state. 



Larvae. It is as larvae that insects are usually most injurious 

 to crops, but it is often easier to kill them in other stages. If we 



