992 Farmers’ Bulletin 1223. 
in the 34 pounds of additional soap liquid and the nicotine sulphate, 
and start the agitator. Then pour in the emulsion while the agitator 
is running. In case a 50-gallon barrel pump is used this will make 
two sprayer loads, 5 gallons being added to 45 gallons of water and 
12 pounds of soap liquid previously placed in the sprayer barrel. 
While pouring the mixture into the sprayer the agitator should be 
kept moving. 
A modification of the formula, in which the strength of the oil is 
increased by one-third, and the nicotine sulphate omitted, may be used 
with good results. In that case the stock mixture should be added to 
sufficient water to make 66 gallons instead of 100 gallons of spray, 
using additional soap liquid, as before, at the rate of 34 pounds per 
100 gallons. 
Cost. 
The cost of spraying operations for destroying the chinch bug is 
relatively high. The following statement of costs is the result of 
work done during the era of high prices prevailing in 1919. 
Cost’ of oil-per100-callon tank.» = ben te ee ae eee $0. 368 
Costiofsoap pertl00:callomitamnkk— freee tee ee eee . 653 
Cost of nicotine per A00-callontank= = eee . 952 
STO CE— Spbeat sigh el ES Oe hy ee - a $1. 97 
Costcot insecticide er vacre: 2. ee ee ee ee $29. 55 
Cost:of labor per acre_--.2 2 ee ce ee eee 10-138. 00 
WOtalo kus ee ee $39. 55-42.55 
In view of the considerable expense involved, the use of this 
method must necessarily be restricted to comparatively small areas, 
such as the borders or edges of newly infested fields and stubble fields 
or other small areas from which the bugs are migrating in large 
numbers. 
The grower should consider well, before attempting to spray, the 
question of whether the expense involved will be justified by the 
results to be obtained. The price of suitable oils has fallen con- 
siderably since the estimate given above was prepared. 
SPECIAL BARRIER DRAGS. ' 
A dust path or oil-line barrier, laid about harvest time, between 
the wheat or other small-grain field which the bugs are about to 
leave, and the corn or other row-crop field which they threaten to 
attack, is one of the best means of destroying the bugs. By this 
means, corn planted near a small-grain field can be protected from 
destruction by the spring issue of bugs while still under 18 inches 
in height. This highly important lot of bugs being destroyed, dam- 
age from the second uprising may possibly be prevented by un- 
favorable weather. 
