April, ’18] 
FLINT: CHINCH-BUG POISONING 
187 
During the winter a number of experiments were made in which adult 
chinch-bugs taken from their hibernating quarters were placed in 
large open boxes in the laboratory. The sides of these boxes were 
chalked to prevent- the escape of the bugs, and small masses of bran 
wet with a solution of sodium arsenite at different strengths were placed 
in some of the boxes, and bran and water in others. The results 
of these experiments proved that at moderately high temperatures the 
bugs would collect on the bran and suck the moisture from it. A very 
high percentage of those in the boxes containing the bran wet with the 
sodium arsenite died in a few hours, while those in the checks lived for 
a number of days. Attempts to make the bran more attractive to the 
bugs by adding corn syrup to the solutions were without results. 
During the spring of 1917, further experiments along this line were 
made in the field. A wheat-field of about fourteen acres, moderately 
infested with chinch-bugs, was selected for this work. As soon as the 
wheat was cut, a barrier was made around the field by cleaning a nar¬ 
row strip of all vegetation and pouring on this a line of crude creosote. 
A number of substances wet with solutions of sodium arsenite, lead 
acetate, and sodium cyanide at strengths of from } ounce to 2 ounces 
per gallon of water, were placed along the inside of this barrier, where 
large numbers of bugs were sure to come in contact with them. 
The solutions of sodium arsenite were not found very effective at any 
of the strengths tried. This substance in solution seemed to have a 
slightly repellent effect on the chinch-bugs. 
Solutions of sodium cyanide were effective in killing large numbers of 
chinch-bugs, but more from the effect of the fumes than as a stomach 
poison. Such solutions would be too dangerous to handle to recom¬ 
mend for general use. 
Solutions of lead acetate at 2 ounces to 1 gallon of water proved the 
best of any of the poisons tested. Fresh corn stalks cut and dried 
for several days were soaked in a solution of lead acetate at the above 
strength, spread along the ground just inside the barrier, and covered 
lightly with straw to prevent rapid drying. After twenty-four hours 
there was an average of 104 dead chinch-bugs to the square inch under 
this material. The dead bugs were removed each morning, but the 
stalks were not wet with the poison solution for seven days. On the 
sixth day there was an average of 11 dead bugs to the square inch under 
this line. This experiment was repeated five times with approxi¬ 
mately the same results. A solution of lead acetate at 2 ounces to 1 
gallon of water was placed in a mason jar sunk in the ground, and a 
wide lamp wick, twenty-four inches long with one end in the solution, 
was laid along the ground and lightly covered with straw. It was 
only possible to keep this wet for about twelve to sixteen inches. 
