4 FARMERS’ BULLETIN 1752. 
see the full grown, nearly bare, striped caterpillars (fig. 1), his atten- 
tion being called most forcibly to them by the widespread injury 
which they produce. 
WHERE THE FALL ARMY WORM OCCURS. 
During periodical outbreaks the fall army worm is found through- 
out almost the entire United States east of the Rocky Mountains, 
from Texas to Montana in the West and from Florida to Maine in 
the East. (Fig. 2.) It has also occurred recently in the Salt River 
Valley and at Yuma, in Arizona. Ordinarily it is apparently con- 
fined to the Gulf States, but under conditions favorable to its devel- 
opment this pest spreads northward as the summer advances, multi- 
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Fic. 2.—Map showing area sometimes invaded by the fall army worm. In the extreme 
southern portions of this area the fall army worm is always*present. (Original.) 
plying to such an enormous extent as to cause widespread and im- 
mense damage to cultivated crops throughout its range. 
This pest is present every year in Central America, Mexico, and 
the West Indies Islands, and it seems quite possible that our worst 
outbreaks of the insect originate in these regions. 
ECONOMIC IMPORTANCE AND MANNER OF INJURY. 
The economic importance of this periodical invader, in the corn 
and cotton growing sections of the United States, can scarcely be 
exaggerated. The damage done by it in the Southern States during 
1912 alone was enormous. ah 
The caterpillars are exceedingly voracious in their nearly full- 
grown stage and devour stupendous quantities of food, eating almost 
continuously until they are ready to change to the adult form. They 
