194 PESTS OF GARDEN AND FIELD CROPS 
that caused by adults and young on the grains to which the adults 
have migrated in the spring. This is especially evident where corn 
shocks have been left standing in fields seeded to small grain. 
Meaures of control are various, and must be thorough and timely. 
The most important measure is destruction of all hibernating places 
where the bugs are accustomed to spend the winter. 
Clumps of grass should be raked up and burned; fence corners 
cleaned out; all places that harbor bugs looked after. If plowing is 
depended on to destroy hiber- 
nating bugs, it must be done 
with great thoroughness, else the 
bugs will succeed in reaching the 
surface of the ground. 
Invasions of the bugs from 
newly harvested fields can be 
prevented by suitable barriers, 
among which the following is 
known by experience to be prac- 
ticable and effective: A strip 
Fic. 242. — The Chinch-bug. Enlarged : 
andaiatural size. Odsinal. of ground along the side from 
which the invasion threatens is 
smoothed and compacted by dragging over it a heavy plank. 
Along the center of this path a narrow line of coal tar or road 
oil is poured. The line of oil need be only half or three quarters 
of an inch wide. At intervals of three or four rods post holes are 
dug, the edge of the hole nearest the field to be protected just inter- 
cepting the line of oil. The invading bugs, when they reach this line, 
travel along it until they come to the angle of the oil line and the hole, 
when they are crowded into the hole and are unable to get out. They 
can then be killed easily by sprinkling with kerosene or kerosene emul- 
sion, or by crushing witha pole. In dusty weather the oil line will need 
renewal every day or so, while the invasion threatens. 
If a field of wheat is seen to be beyond reasonable hope, it is best to 
plow it under at once, harrow thoroughly, and plant to potatoes, alfalfa, 
soy beans, garden truck, or whatever is seasonable. 
