REMEDIAL AND PREVENTIVE MEASURES. 67 
from an ordinary garden sprinkling pot from which the sprinkler 
had been removed and the orifice of the spout reduced in size with a 
plug of wood until the tar came out in a stream about the size of the 
little finger and made a line on the surface of the ground about three- 
fourths of an inch in width. Post holes were sunk along the line 
from 10 to 20 feet apart on the side next to the wheat field, thus prac- 
tically completing the barrier, and the chinch bugs being unable to 
cross the line of tar accumulated in the post holes in vast numbers, 
where they were killed; and those bugs that had already entered the 
cornfield before the barrier was constructed were prevented from 
spreading farther by tar lines between the rows of corn, the infested 
corn itself being cleared of bugs by the application of kerosene emul- 
sion. The same writer states“ that several farmers in Vermilion 
County, Ill., prepared for the coal-tar line by hitching a team to a 
heavy plank and running this, weighted down with three or four 
men, over the ground once or twice until a smooth, hard surface had 
thus been made to receive the tar. If the barrier was to be made in 
sod, a furrow was plowed and the bottom of this made smooth by 
dragging the plank along the bottom. In both cases post holes were 
sunk along the tar lines, and in these were placed cans or jars into 
which the bugs fell in myriads and were destroyed. 
On one farm of 250 acres a coal-tar line 90 rods in length was re- 
newed once each day and killed about 8 gallons of chinch bugs. In 
the case of another farmer there were 300 rods of tar lines with post 
holes, cans, etc., which resulted in destroying about 10 bushels of 
chinch bugs. <A 6-gallon jarful was destroyed in less than half a day 
at one point on the line. In this last instance the lines of tar were 
renewed three times a day, but even then less than a barrel of tar 
was used. Still another farmer, with 120 rods of tar line, used about 
a third of a barrel of tar and did not lose a hill of corn; he caught 
chinch bugs by the bushel. In some of the cases cited the tar line 
was run in a zigzag course, the post holes being situated at the angles, 
and in others leader tar lines were run obliquely to the main tar line, . 
one end terminating at the traphole, but both of these plans were 
afterwards regarded as unnecessary, a single straight line being en- 
tirely sufficient and less expensive. ‘The numerous cases where these 
methods were put into execution with entire success and at small 
expense is the best possible proof of their practical utility. If 
a farmer is situated near town, where refuse tin cans are dumped in 
any locality where they can be got out of the way, he can select the 
larger of these, set them in the post holes and partly fill them with 
kerosene and water. The water being heavier than the kerosene will 
sink to the bottom, leaving a stratum of kerosene on the surface. 
_@ Twentieth Report of State Entomologist of Illinois, p. 39, 1898. 
