38 



oping on weeds related to beets and invading corntields and vegetable 

 gardens when the i;upply of wild food plants and weeds is scant. 

 Still a third sjiecies, the imported cabbage webworm, occasionally 

 occurs on beets, but, as its name indicates, it is a cabbage pest, prop- 

 erly speaking, and does not resort to other plants when Cruciferai are 

 available. 



THE SUGAR-BEET WEBWORM. 



[Loxostege sticticalis Linn.)" 



Although primarily a sugar-beet insect, this species, like many 

 others that have been treated, is a periodical pest, and, as it is an 

 introduction from abroad and widening its range, there is likelihood 

 that it will in time assume greater economic importance. It is cousin 

 to the native garden webworm, but the moth is larger, darker col- 

 ored, and the markings are somewhat more pronounced. With the 



Fig. Zi.— Loxostege sUcHcalis: a, moth, twice natural size; b, larva, less enlarged; c, upper surface of 

 first proleg segment of larva; d, side view of same; c, d, more enlarged (reengraved after Insect 

 Life, Division of Entomology). 



wings fully expanded it measures nearly an inch and is of a purplish 

 brown color, with darker and paler bands, as shown in figure 34, a. 



The pale-yellow eggs are laid singly or in rows of two to five or 

 more, overlapping like scales. The young webworms are whitish, 

 with polished black head and piliferous spots. Mature caterpillars 

 (h) are darker than the garden webworm, with a preponderance in 

 longitudinal markings. 



It is an inhabitant of western and central Europe and northern Asia, 

 and has evidently, like the beet army worm, been introduced from the 

 Orient on the Pacific coast, and is now slowly but steadily pushing its 

 way eastward. In 1869 it came under observation in Utah, and b}^ 

 1873 had found its wa}^ to Missouri. It occurs southward to Kansas 

 and as far north and east as Michigan, but the major portion of 

 reported injuries have occurred in Kansas and Nebraska. 



Practically all that is known of the biology of this webworm is from 



«Eiley & Howard, Insect Life, Vol. Y, pp. 320-322; Vol. VI, pp. 369-373; Chit- 

 tenden, Bui. 33, new series, pp. 46-49. 



