INSECTS OF THE FIELD. 



77 



the young caterpillars. Therefore the thorough cleaning of the 

 land after harvest is one means of checking them. 



The army worm also is the caterpillar of a moth, and is so 

 called from its occasional appearance in immense numbers, 

 when they devour nearly every particle of plant food in the 



CHRYSALIS, 



A\OTH 



ARMY (WORM. 



Fig. 29. Army worm, pupa of same, and moth into which it changes. The 

 eggs are seen along the leaf. This is a cutworm. 



course of their march. Then we have other moths, the larvae 

 of which live upon the fibre of clothing, clothes moths. All 

 these are similar in form and in their changes, and all are very 

 destructive. 



Besides the egg we have, in most insects, the three forms or 

 states, namely : the caterpillar, or larva ; the />/'/</, or resting 

 state; and the perfect insect, or imago. All moths, butterflies, 

 bees, beetles, and flies pass through these same three states 

 thus we see that the insects differ from other animals both in 

 their general form or appearance, and also in their method of 

 growth or course of life. In the case of grasshoppers and 

 some bugs there is no pupa or resting state. 



