April, ’24] HASEMAN & BROMLEY: CHINCH BUG AND CALCIUM CYANIDE 329 
material too expensive. This is further attested to by the fact that 
the Missouri Farmers Association, an independent organization of some 
70,000 Missouri farmers have just recently contracted for a minimum 
of twenty tons for their 1924 chinch bug campaign. 
Summary 
(1) Calcium cyanide flakes used in a properly prepared furrow at the 
rate of one pound to sixty linear feet once a day proved an effective 
chinch bug barrier in Missouri. The material in such a barrier cost 
about four dollars a day for a fourth of a mile of barrier. 
(2) For best results it should be applied in the early afternoon or 
when the daily migration begins. 
(3) A narrow, deep furrow with a vertical wall next to the crop to 
be protected proved to be the best type of furrow in which to apply the 
calcium cyanide flakes. 
(4) Other type of furrows or methods of applying the chemical did 
not prove so effective. 
(5) Temperature, moisture and wind are factors influencing the 
success of such a barrier. 
Question : What is the cost per mile of treating such a furrow ? 
Mr. Leonard Haseman: About $4 per day for a quarter mile. It 
depends upon the rapidity with which the gas cleans up the infestation. 
That really determines the total cost. 
Mr. J. J. Davis: I want to make a brief statement regarding the use 
of calcium cyanide in controlling chinch bugs. The results obtained in 
Indiana are not sufficient to permit definite recommendations and I 
wish at this time simply to bring out the fact that we must look to 
cheaper calcium cyanide or more efficient methods of application to 
make its use practical under Indiana conditions. Mr. Haseman recom¬ 
mends it at the rate of one pound to 60 linear feet, which, at 18 cents a 
pound would cost $3.96 per quarter mile per day or $55.44 for material 
to treat a quarter mile furrow for 14 days, the minimum period of chinch 
bug migration. By using the creosote barriers, which Mr. Flint has 
found to be very effective in Illinois, and which we have also found to 
be effective in Indiana, the cost for material per quarter mile for the 
entire period of chinch bug migration is $6.00 or $7.00. The difference 
in cost is too great to consider calcium cyanide as a practical chinch bug 
control at the present time. 
