34 



V_^ 



lighter moth. The distribution of this species is wide, including 

 the territory from Massachusetts to the Gulf, and westward to Cali- 

 fornia, but it occurs in greater numbers southward. In the northern 

 portion of its range it is occasionally killed off b}- exceedingly cold 

 winter temperatures, as happened in 1899. The laryje are found 

 abroad from April to November. As with other species which have 

 apparently come northward from the Gulf region, this species is 

 most destructive in the autumn of the year. It is credited with being 

 double-brooded, and possibly three generations are produced in the 

 South. Larvae have been observed b}- the writer to complete their 

 development in a month, and the pupal period varies from 12 to 25 

 days. The winter is evidently passed in the pupal condition, in which 

 respect this species differs from the ordinary cutworm. 



THE GREEN BEET LEAF- WORM. 



{Peridroina incitis Guen. ) 



In certain j^ears and localities, as in Illinois in 1899 and 1900, this 

 species is more abundant on beet leaves than any other caterpillar. It 

 feeds on both surfaces of a leaf, and has been o))seryed eating purslane, 



which is doubtless its nat- 

 ural food plant. 



The larva, also called 

 green cutworm, is green 

 with a white or pinkish 

 stripe on each side of the 

 body. The species is gen- 

 erally distributed, and quite 

 common in Illinois and Ken- 

 tucky, where it is appar- 

 ently double-brooded. 



NATURAL ENEMIES. 



Cutworms are exposed to 

 a great variety of natural en- 

 emies, but as a rule these are 

 not efficient checks except 

 when the cutworms appear in great numbers and travel like the army 

 worms. At such times manj' species of predaceous and parasitic insects 

 and predatory mammals and birds, wild and domestic, destroy them in 

 great numbers. Of the predaceous enemies ground beetles are most 

 abundant, while the parasites include numerous species of ichneumon 

 and tachina flies and a few chalcis flies. A common species of tachina fly 

 is shown in figure 31. Cutworms are also subject to a fungous disease 

 Empusa aullcce. Among birds which are beneficial by feeding upon 

 cutworms are robins, crows, the bluebird, and the bluejay, and among 

 domestic animals are chickens, ducks, turkeys, Guinea fowls, and hogs. 



Fig. Z\.—Euphrocera claripennis, a common cutworm par 

 asite: adult with puparium at right and enlarged an 

 tenna at left (from Howard, Division of Entomology). 



