THE COLEOPTERA OR BEETLES 



53 



to the one it formerly preyed upon. The species then be- 

 gan to spread rapidly toward the east. In a few years 

 it crossed the Mississippi, and in a few more years spread 



FIG. 43. The twelve-spot- 

 ted cucumber beetle, Diabro- 

 tica i2-punctata Oliv. (After 

 Essig.) 



FIG. 44. A "cut worm killer," 

 Calosoma calidum, and its larva. 



throughout all the middle and eastern states. The beetle 

 is particularly destructive, since it feeds upon the leaves 

 of the potato in the larval as well as in the imago stage. 

 Its eggs are laid in masses on the leaves and they soon 



FIG. 45. The round-headed apple-tree borer, a, larva; b, pupa; c, adult. 

 (After Riley.) 



hatch into reddish, fleshy larvae which eat and grow 

 rapidly. There are commonly two, and sometimes three 

 generations a year. The mature insect passes the , winter 



