effective for the protection of corn, and there is no doubt that it 
would have been equally so if chinch-bugs had been ten or a hun- 
dred times as numerous. 
A partial failure of the experiment due to the character of the 
weather of the season did not diminish its value as a means of de- 
termining the cost of an effective operation on the scale of actual 
farm practice. It was demonstrated that the coal-tar strip may be 
laid down and maintained for four weeks — the maximum period 
necessary — at a cost of $22 a mile, with the effect to trap all bugs 
approaching the line, where they may be readily and rapidly killed. 
The average cost of making a dusty furrow or ditch sufficient to ar- 
rest and trap all chinch-bugs attempting to cross it was approxi- 
mately three cents a rod, or $10 a mile, for labor only, no materials 
being required. This furrow can not be used, however, except in 
dry hot weather. 
Various methods of preparing the ground for the coal-tar line 
were used in comparison. One of the most satisfactory methods was 
that of plowing a back furrow in the stubble near the edge of the 
field, and packing this with a roller or beating it flat and hard with 
spades. A strip of sod may be prepared to receive the line by scrap- 
ing away the grassy surface with an ordinary farm scraper, after- 
wards leveling and smoothing it carefully with a shovel or hoe. 
A kerosene emulsion prepared by mixing two parts of kerosene 
and one of soap-suds by violently beating with a stick for about five 
minutes, and diluting to contain four per cent, of kerosene, was found 
efficient for the destruction of all the chinch-bugs touched by it, and 
was successfully used for clearing rows of corn along the borders 
of a field which had become infested for lack of effective barriers. 
Stronger kerosene mixtures made in this way commonly proved in- 
jurious to the plant. A barrel of diluted emulsion costs about thirty- 
four cents. It was applied to the corn by hand at an average rate 
of a barrel an acre — five acres per day for each man. A solution 
of whale-oil soap, one half pound to the gallon of water, proved to 
be a safe and sufficient insecticide for corn-field use. Its cost was 
$1.12 a barrel. 
The gasoline blast-lamp, tested on a great variety of insects, 
was found to be only occasionally useful. By two or three suc- 
cessive treatments separated by intervals sufficient to allow the 
chinch-bugs which escape to collect upon the plant, badly infested 
corn might be almost completely cleared of bugs, but serious injury 
to the corn itself was almost certain unless the most painstaking care 
was used. The cost of material is less than that of kerosene, amount- 
ing to only about fifteen cents an acre for each treatment with the 
