120 



AGRICULTURE FOR BEGINNERS 



and this, like the other parts, is composed of joints. The 

 insect breathes through openings in the abdomen called 

 spiracles (see Fig. 107). 



An examination of spiders, mites, and lice shows eight 

 legs; therefore these do not belong to the true insects, nor 

 do the thousand-legged worms and their relatives. 



The chief classes of insects are as follows : the flies, 

 with two wings only; the bees, wasps, and ants, with four 

 delicate wings; the beetles, 

 with four wings, two hard, 

 horny ones covering the two 

 more delicate ones. When 



FIG. 109. THE HOUSE FLY 



a, egg; l>, larva, or maggot ; c, pupa; d, adult male. (All enlarged.) From Hodge's 

 " Nature Study and Life," Ginn & Company 



the beetle is at rest its two hard wings meet in a straight 

 line down the back. This peculiarity distinguishes it from 

 the true bug, which has four wings. The two outer wings 

 are partly horny, and in folding lap over each other. 

 Butterflies and moths are much alike in appearance, but 

 differ in habit. The butterfly works by day and the moth 

 by night. Note the knob on the end of the butterfly's 

 feeler. The moth has no such knob. 



