9 FARMERS’ BULLETIN 131. 
it is known in some of the extreme Southern States. The latter in- 
sect always originates in the South and travels northward as the 
summer advances. The western army cutworm? also is occasionally 
mistaken for the true army worm, but it occurs in destructive abun- 
dance only throughout the regions west of the Mississippi River. 
Both of the latter insects will be treated in a separate publication. 
GENERAL DESCRIPTION. 
The fully developed parent of the army worm (figs. 2, a@,and 5) isa 
moth or “miller” measuring about 14 inches across the expanded 
wings. It is brownish-gray in color, having a single small white 
spot near the center of the front pair of wings, the hind wings being 
somewhat darker along the hind edges. Although these parents of the 
worm sometimes are very numerous, they fly only at mght and are 
therefore often entirely overlooked by the farmer. The stage of the 
insect most familiar to him is the full-grown, striped, nearly naked 
caterpillar (figs. 1 and 2, >), usually discovered in the act of devour- 
ing his crops and in most cases after having already destroyed the 
greater portion of the infested crop. 
WHERE THE ARMY WORM OCCURS. 
The true army worm is probably a native of North America, 
although it is also found in South America. It occurs throughout 
most of the United States east of the Rocky Mountains, including the 
States bordering the western banks of the Mississippi and the 
Missouri Rivers. It also has been found in New Mexico, Arizona, 
and California. It is not known from the Rocky Mountain Plateau 
region. (See fig. 3.) 
ECONOMIC IMPORTANCE AND MANNER OF INJURY. 
The loss in money to the farmer by army worms in the past has 
been exceedingly great, and although no exact estimate is possible, it is 
safe to say that in the Eastern States alone many millions of dollars’ 
worth of grain and forage crops have disappeared down their throats 
during the past 30 years. 
1 (Chorizagrotis) Euxoa auciliaris Grote. 
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