INSECTS INJURIOUS TO BEETS AND SPINACH 



333 



back and one along either side, and marked with numerous 

 black and white tubercles as illustrated. 



Life History. The larvae hibernate over winter an inch or 

 two below the surface of the soil in long silken tubes. In spring 

 they pupate in these tubes and the moths emerge about the middle 

 of May. The eggs are laid on the foliage either singly or in clus- 



FIG. 239. The sugar-beet webworm (Loxostege sticticalis Linn.): 1, moth; 2, 

 eggs; 3, 4, larvae; 5, pupa; 6, winter tube of larva, opened at a to show 

 pupa 1, 3, 4, 5, enlarged. (After Gillette, Colo. Agr. Exp. Sta.) 



ters of from three to ten, one overlapping another. The egg 

 is broadly oval, one twenty-fifth inch long, and of a pale 

 . green color. The first generation of caterpillars feed on pig- 

 weed and alfalfa in Colorado during June. A second generation 

 of larvae occurs about the middle of July and sometimes injures 

 beets, but the third generation about the middle of August is 



