Beetles 



279 



tive agencies combined." The beetle, \ inch long, is reddish yellow with 

 black spots on head and prothorax, and a thick black stripe on each elytron. 

 From orange-yellow eggs laid on the under side of the leaves hatch larvae 

 which, when full grown are inch long, flattened, marked with blackish 

 and yellow. They skeletonize the leaves. When ready to pupate they 

 crawl down into the ground. The beetles themselves after issuance fly back 

 to the tree-tops and eat holes in the leaves. There are two broods a year, 

 and the adult beetles of the last brood hibernate in concealed places. 



FIG. 384. The elm-leaf beetle, Galerucetta luteola; eggs, larvae, pupa, and adults. (After 

 Felt; eggs greatly magnified; larvae, pupa, and adults about twice natural size.) 



Four species of the genus Diabrotica are common over the country and 

 very injurious: D. viltata, the striped cucumber-beetle, is greenish yellow 

 with two black stripes on each elytron, and feeds on cucumber-, pumpkin-, 

 squash-, and melon-vines, the larva also burrowing into the stems and roots 

 of the same plants; D. 12-punctata (Fig. 385) is greenish yellow with six 

 black spots on each elytron, and feeds on a great variety of plants, the larva 

 often being injurious to corn in the South; D. longicornis, the corn-root- 

 worm beetle, is grass-green with spots or stripes, and its underground larva 

 is very destructive to corn by burrowing into its roots; D. soror (Fig. 386)^ 

 of the Pacific coast, the flower-beetle or "diabrotica," yellowish green with 



