37 
and free from clods and weeds. Next, near the center of this pul- 
verized strip a deep dead furrow was made by plowing twice back 
and forth in the same line, — once in each direction with an ordinary 
fourteen-inch plow and once with a small diamond plow, — and in 
the ditch so made, a log eight feet long and eight inches through was 
dragged by a single horse (a mule would have been better) until the 
sides of the ditch were pulverized to the finest dust. This work 
would require, for an eighty-rod line, the labor of two men and a 
team for a little more than half a day. The average cost of a dusty 
furrow constructed as above described, would be practically three 
cents a rod, as shown by the actual labor of man and horse used on 
this eighty-rod line. 
This furrow was finished July 3, and caught and held the chinch- 
bugs generally during that day and the following; but July 5 a heavy 
rain fell which put it out of service, and even the following day the 
ground was too wet to renew it by dragging again with the log. 
Equally heavy rains falling on the 8th and on the nth discouraged 
further work with it, and it was practically abandoned in favor of 
the tar line. 
When in use, some method of destroying the bugs entrapped is 
necessary. In bright summer weather the dust in the bottom be- 
comes so hot as to kill all the chinch-bugs except those with wings, 
and many of these also will succumb. Otherwise, shallow pits may 
be dug with a post-hole digger or spade at intervals in the bottom of 
the furrow, care being taken to restore the dusty surfaces disturbed 
in this operation. The harassed bugs will accumulate here in quan- 
tities, and may be killed by pouring a little kerosene upon them. 
Experiments described on another page of this report indicate that 
the bugs caught in the dusty ditch may also be quickly killed by a 
brief exposure to a kerosene spray or to the flame of a gasoline 
torch. 
DIAGRAM OF CHINCH BUG BARRIER 
,--P<»fHoli.Trap(Diani8m) 
,-•' ,PostHolpTra 
Infested MTheat 
Fig. 2. Dusty furrow, and coal-tar line, with post-hole traps and diagonal ''leaders" of tar 
Preparation of the Coal-tar Line. — To receive the tar line it is 
necessary to have a smooth hard band of earth like a well-beaten 
path, into which the tar will not readily sink. This should be about 
