SOME REPRESENTATIVE INSECTS 



383 



Coleoptera. — The Colorado potato beetle, Leptinotarsa decem- 

 lineata (cf. Fig. 197 and Fig. 308, p. 551), is representative. Like 

 other beetles, it has the anterior pair of w ings specialized into heavy 

 wing-covers, the elytra, which meet on the median line and fit so 

 tightly together that they seem upon first examination to consti- 

 tute the dorsal side of a wingless body. When, however, they are 

 pried apart, the functional wings are found folded neatly beneath. 

 In flight the wing-covers are widely spread and the wings unfolded 

 to their full length, which is somewhat greater than that of the 



Fig. 197. — Life cj'clo of a blister beetle, one of the Order Coleoptera. 



The larvae of blister beetles are among the most important enemies of grasshoppers 

 (c/. Fig. 173, p. 351). (From Bulletin No. 172, South Dakota Agr. Exp. Sta.) 



covers. This species was originally native to Colorado, feeding 

 upon the sand-bur. With the coming of the early settlers, about 

 1850, it began to attack the potato and gradually spread eastward, 

 causing consternation until Paris green and other insecticides 

 brought it under control. By 1874 it had reached the Atlantic 

 Coast and is now distributed throughout North America wher- 

 ever there is extensive potato culture. In laying, the eggs are 

 fastened to the leaves of the food plant. The larvae hatch as 

 hump backed grubs that feed voraciously and are very destruc- 

 tive to potato vines. When they have reached the end of their 



