70 PAPERS ON CEREAL AND FORAGE INSECTS. 
We only know that the higher up the insect punctures the stem the 
more likely is the attack to result only in the transverse rows of holes 
across the leaves, as shown in figure 21 at a. In any case this ridging 
or hilling up would only form a possible slight protection against the 
injurious effects of the feeding of the beetles. Once the larve have 
started to burrow their way downward in the stem there is no way 
whereby they can be reached by any measure likely to seriously 
affect them. The beetles can not be trapped by inducing them to 
hibernate under piles of rubbish prepared for them especially for this 
purpose, because there is excellent proof that they pass the winter 
in fields entirely bare of vegetation. Late planting of the crop, as 
exemplified by repeated replantings, does not offer any encouragement 
in the way of preventing future injuries. As shown by the observa- 
tions of Messrs. Walton and Hyslop, very few of the insects hibernate 
in the roots or old stalks, so that the pulling up and burning of these, 
as in destroying the larger corn stalk-borer, would not be of much 
value against this insect. They probably do not hibernate to any 
extent in their uncultivated food plants. 
Fortunately, however, the farmer has within his reach two most 
practical and efficient measures of prevention. One of these is to 
entirely exterminate from his fields any of the natural food plants of 
this species. Indeed, he should by no means attempt to raise a crop 
of corn while any of this natural vegetation, upon which the insect 
can subsist, is still in existence. The other measure is to follow corn 
or rice with some crop upon which this insect can not feed and never 
to plant corn immediately after corn or rice. On the farms of the 
Messrs. Shannonhouse most convincing illustrations were afforded 
of almost complete protection by rotation of crops. While in no 
case was it possible to find a badly infested field of corn following 
cotton, there were plenty of illustrations of the disastrous effect of 
attempting to raise corn during successive years on the same ground. 
One field offered such an excellent illustration of this phase of the 
problem that Mr. William T.Shannonhouse had it photographed, and 
these photographs are used for illustration in Plates VI to VIII. In 
1910 the eastern portion of this field had been devoted to cotton, 
the western portion to corn. In the year 1911 the entire field was 
planted with corn; as a result that portion on which corn had been 
raised the previous year (see Pl. VI) was almost totally destroyed 
by this insect, while the other portion, where cotton had been grown 
(see Pl. VII), was almost entirely exempt from attack. In order 
to show the abruptness with which this injury terminated and the 
exactness with which this corresponded to the dividing line between 
the two previous crops, the farmer who had himself cultivated the 
field in 1910, and was therefore perfectly familiar with it, was induced 
to stand exactly upon the dividing line between the corn and the 
