8 FARMERS’ BULLETIN 634. Be 
successful proportion will be greatly decreased by persistent crop — 
rotation. 
Another remedy, probably the best for this insect, is the thorough 
destruction, some time before the period of emergence of the maths 
in the spring, of all the stalks and stubble remaining in the field from 
the preceding crop. If all this trash can be disposed of before the 
opening of spring, the numbers of the pest must be greatly diminished 
if not almost exterminated, for the only form in which the insect 
passes the winter is that of the caterpillar, and the only known loca- 
tion is in the lower tip of the corn root, snugly hidden. Some few 
may, however, be found to survive in the roots of the larger grasses 
mentioned above, and care should be taken in such cases to treat 
these in the same way. The method employed im disposing of the 
stubble and stalks will depend largely on the conditions in individual 
cases. If the stubble is cut low and the land is moderately heavy, a 
thorough deep plowing may suffice, an inch or two of well-settled soil. 
being sufficient to prevent the escape of the adult moths. Bringing 
the stubble to the surface where it can dry will kill some of the con- 
tained larve, but this method depends too much on the state of the 
weather to be trusted. By far the most effective plan is to remove 
the stubble from the field with a rake and burn it. 
In the cane field the methods of treatment must be adjusted to 
correspond with the methods of handling that crop.. The larve com- 
monly spend the winter in the trimmings and tops which have been 
discarded at harvest time because of immaturity. This refuse, left 
on the ground throughout the winter, becomes dry and inflammable 
and, if thoroughly burned before spring, enough larve will be killed 
to insure at least temporary relief from the ravages of the borer. - 
Any method which will insure the complete destruction of the over- 
wintering larve, if persisted in and carried out simultaneously over 
large sections of the country, will effectually preclude serious damage 
from the insect. 
WASHINGTON : GOVHRNMANT PRINTING OFFICH : 1914 
