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Corn Earworm as an Enemy of Vetch. 17 
will pass to other fields and destroy crops growing there. Cotton 
and corn growing next to vetch have been completely overrun by 
caterpillars acting in this manner. If a deep furrow is made with 
a turn plow (fig 13) in the path of advance the caterpillars, in their 
endeavors to cross the ditch, will fall into it and become entrapped. 
They may then be sprayed with kerosene or crude oil, or a log may 
be dragged through the furrow to crush them. Holes may be sunk 
at frequent intervals in the bottom of the furrow for entrapping the 
worms. Where the worms attempt to cross a smooth, hard road in 
Fic. 13.—Plowing a furrow around a field to be protected from corn earworms on the 
march. The man in the foreground is digging post holes at intervals to entrap the 
worms. 
going from an infested field to a new field, a field roller run up and 
down the road gives excellent results in destroying them. 
SUMMARY OF CONTROL MEASURES. 
(1) A practical spraying outfit or duster should be kept on hand; 
also standard insecticides. 
(2) In the spring watch carefully the vetch crop, and at the first 
sign of caterpillars apply the control measures recommended in this 
bulletin. 
