CHRYSOMELIDM 



191 



beetles appears in midsummer. These lay eggs, and larvje 

 may be very abundant in late summer, pupate in early fall, 

 and gi^'e rise to beetles that hibernate. Spraying with 

 arsenical solutions is effective in their control. 



Agriculturally a little group of beetles, the Diahrutica, 

 are very important. They present an exception to the gen- 

 eral habit of the family in that they attack roots under the 

 ground. There are three species of interest. The best- 

 known species is the striped squash beetle ( Diahrotica 



Fig. 13S. — -Striped cucumber beetle {Diahrotica vittaia): a, beetle; h, 

 larva; c, pupa; d, egg; a, h, c, much enlarged; d, more enlarged. (After 

 Chittenden, Div. Ent., U. S. Dept. Ag.) 



vitfata), a pest to scjuashes and melons, which is an extremely 

 well-known species. It feeds on stems and leaves close to 

 the ground and, as larva, in the young squashes, and per- 

 haps represents the intermediate stage between stem and 

 root-feeding species. 



Diahrotica kmgicomis, the corn-root worm, is distinctly 

 a root-feeding species. The beetle appears in late summer 

 and autumn and is a rather bright green little beetle with 

 no markings. It is found in late summer on the corn stalks, 

 on^the fall flowers, such as asters, sunflowers, goldenrod, 



