32 
clover, violets and some other ornamental plants. It has been noticed 
attacking grasses and oats, but does not appear to resort to these 
plants when more choice food is at hand. 
THE WESTERN ARMY CUTWORM. 
( Chorizagroti.^ agrestis Grote. ) 
In 1897 this cutworm, which had hitherto led an unpretentious exist- 
ence in the Missoula Valley, Montana, developed in great numbers, and 
a serious outbreak followed. According to the account given by Dr. 
E. V. Wilcox (Bui. IT, Mon- 
tana Agl. Exp. Sta., 1898), 
this visitation resembled that 
of the common arm}" worm, 
and the list of observed food 
plants shows that it can 
be a very serious vegetable 
pest, since, besides beets, it 
attacks cabbage, horse-rad- 
ish, radish, mustard, turnip, 
pea, tomato, potato, onion, 
celer}", rhubarb, corn, cereals, 
grasses, clover and other for- 
age crops, forest and fruit 
trees, and bush fruits. 
This cutworm (fig. 28) is of 
the ordinary t^^pe, and attains 
a length of 2 inches when 
mature. Its body is nearly smooth, only a few short hairs being 
observable. The color varies from pale green to dark brown. Along 
the sides there are alternating longitudinal light and dark bands. 
The moth is brown with gray markings, has a wing expanse of about 
li inches, and is quite variable." 
The recorded distribution comprises Kansas, Nebraska, Texas, New 
Mexico, Arizona, Colorado, Montana, and California. 
Although the injuries committed in 1897 have not to our knowledge 
been duplicated, reports have reached us of the occurrence of great 
numbers of the species in widely separated localities, the moths 
fl^nng about in such numbers as to become annoying pests in dwell- 
ings. Such reports were received from Missouri in 1902, and from 
Arizona and Colorado in 1903. In Montana a "wild sunflower" 
{Balsamorrhiza sagittata) and avens {Gemn triflorum) are favorite 
food plants, but in other localities it seems probable that the natural 
« This species is so often accompanied by two related forms, more particularly by 
Chorizagrotis introf evens Grote, as to give rise to the supposition that all are colora- 
tional varieties of the same species, the truth of which will probably be established 
by rearing from selected females. 
Fig. 28. — Chorizagrotis agrestis: moth above; larva, dor 
sal view, in center; larva, ventral view, below — some 
what enlarged (original. Division of Entomology). 
