INSECTS 



245 



Make a drawing of the beetle, natural size, to show as many of the above 



parts as possible. 



The Life History of a Beetle. —The June bug (May beetle) and 

 potato beetle are excellent examples. May beetles lay their eggs in 

 the ground, where they hatch into cream-colored grubs. A grub 

 differs from the larval fly or maggot in possessing three pairs of 

 legs. These grubs live in burrows in the ground. Here they feed 

 on the roots of grass and garden plants. The larval form remains 

 underground for from two to three years, the latter part of this 

 time as an inactive pupa. During the latter stage it lies dormant 

 in an ovoid area excavated by it. Eventually the wings (which 

 are budlike in the pupa) grow larger, and the adult beetle emerges 

 fitted for its life in the open air. 



Economic Importance. — ■ Among the beetles which are of 

 economic importance is the potato beetle which destroys the po- 

 tato plant. This beetle 

 formerly lived in Colo- 

 rado upon a wild plant 

 of the same family as 

 the potato and came 

 east upon the introduc- 

 tion of the potato into 

 Colorado, evidently pre- 

 ferring cultivated forms 

 to wild forms of this 

 family. The snout 

 beetles or weevils do 

 much damage to stored 

 grains and fruits. Other 

 beetles known as the 

 borers produce larvae 

 which bore into trees 

 and then feed upon the sap of the tree. Many trees in our Adiron- 

 dack Forest Reserve annually succumb to these pests. Most fallen 

 logs will repay a search for the larvae which bore between the bark 

 and wood. Among the most destructive of all in city homes are 

 the carpet beetles. 



Cotton-boll weevil; o, larva; b. pupa; c, adult. From 

 photograph, enlaiged four times, by Davison, 



