BEET AND SPINACH INSECTS 97 



The Su(;ar-Beet Webwohm 



Loxostege sticticaUs Linnaeus 



Although the sugar-beet webworm has attracted more atten- 

 tion as an enemy of the sugar-beet, it also attacks a large num- 

 ber of garden and field crops. It is widely distributed through- 

 out Europe, Asia and North America and is particularly 

 injurious in southeastern Europe. It did not attract notice in 

 the United States until the beginning of the development of 

 the sugar-beet industry. It has been destructive only in the 

 Mississippi Valley and westward to the Rocky INIountains. 

 In addition to the sugar-beet, it has been reported feeding on 

 the following : pea, bean, potato, cabbage, onion, squash, 

 pumpkin, cucumber, alfalfa and vari- 

 ous grains and grasses. Its favorite 

 wild food plants are pigweed (Ama- 

 ranthus) and lamb's quarters. 



The winter is passed by the full- 

 grown caterpillars in silken tubes in 

 the soil. In late spring thev trans- Fig 05. - The sugar-beet 



^ ^ • webworm moth (X 1|). 



form within the tubes to yellow-brown 



pupae about ^ inch in length. In about eleven days the moths 

 emerge. The moth has an expanse of about an inch. The 

 front wings are smoky brown with faint darker markings, a 

 straw-colored spot below the middle of the front margin and 

 a similarly colored band along the outer margin. The hind 

 wings are paler with two blurred bands (Fig. 65). The 

 females deposit their pale, pearly green or yellow, oval eggs 

 about ^ inch in diameter, singly or in overlapping rows of 

 two to ten, usually on the underside of the leaves. The egg 

 is flattened below and very convex above. Each female lays 

 from 200 to 250 eggs. The eggs hatch in three to five 

 days. The young whitish larvae with black heads feed at 



H 



