THE CHINCH BUG. oA. 
under some conditions the farmer might find it advantageous to apply 
some of the other methods of protection here given. In all of the 
following methods crude petroleum or road oil may be substituted for 
coal tar if the former is more easily obtainable. 
THE SURFACE AND COAL-TAR OR ROAD-OIL METHOD. 
The objections made by farmers to the use of most of these barriers 
is that the most finely pulverized soil soon becomes incrusted by 
even the slightest rainfall and the bugs then pass over it. without 
difficulty, while barriers of boards are expensive. It is feasible to 
eliminate both by simply smoothing off a path along the margin of 
an infested field where such an one adjoins the one to be protected. 
This can be done with a sharp hoe, and as the margins of wheat 
fields usually become compacted, it is but little trouble thus to clear 
off a path a foot or more in width, smooth as a floor, with the sur- 
face almost as hard. Along this path circular post holes are sunk, 
as in the bottom of furrows, and a train of coal tar is run between 
them, being so arranged that it will reach the post hole at the edge 
farthest from the field from which the bugs are migrating. The bugs, 
on reaching the train of tar or oil, will follow along until they reach 
the post hole, while those meeting with the post hole will usually 
divide and, following around it, join with the flow of bugs moving 
along the barrier. The result is that they become congested in the 
acute angle where this barrier is intercepted by the post holes. Those 
in the apex of this angle can not turn back, and thus are continually 
pushed into the post holes by those behind. As the bugs, varying 
from the red larvee of the younger stages to the almost black ones of 
the last stage, mass along the line of coal tar, they have much the 
appearance of a reddish-brown stream running into the holes. From 
these holes there is no escape and here the bugs can readily be killed 
by sprinkling with kerosene. The slightest train of coal tar is suffi- 
cient to obstruct the passage of the bugs, and light rains will not 
affect its efficiency. 
In dry weather these trains of tar or oil, as the case may be, soon 
become covered over with dust and must be renewed; but in showery 
weather there is no dust, and if the coal tar is renewed daily or, at 
most, twice each day, it will accomplish its work and nothing fur- 
ther will be needed than to kill the bugs that have collected in the 
post holes. This measure is inexpensive and can be promptly put 
into operation if the coal tar is at hand. The writer has been able 
in this way effectively to protect a field of corn bordered on two 
sides by a wheat field literally overrun with chinch bugs at harvest 
and during a time when light showers were occurring, frequently 
several times each day. 
