50 THE WHITE-FUNGUS DISEASE IN KANSAS. 
the operator should move along fast enough so that the line deposited 
on the ridge is about an inch wide. 
The ridge should be thrown up and the postholes dug before the 
migration begins, leaving the application of the repellent until 
actually needed. 
The oiled-ridge type of barrier has the advantage of not being 
dependent upon a complexity of conditions for its success, and of 
giving immediate results. However, in dry, windy weather, when 
much dust is blowing, the dust is apt to stick to the tar or asphaltum 
in quantities to render it inefficient. For this reason the dust barrier 
is recommended for dry weather. 
After the barrier is formed it should be inspected daily and kept 
in good repair. The tar will have to be renewed occasionally and 
the barrier kept free from straws or débris which might fall or blow 
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Fic. 4.—Diagram illustrating the oiled-ridge type of barrier—b, barrier; p, postholes. 
A partial barrier between the wheat and corn would extend from a to b. (Original.) 
upon the ridge and form a bridge over the repellent stream for the 
chinch bugs to cross. Eternal vigilance will be the price of success. 
The crude oil-straw barrier—An experiment was tried in which 
straw dipped in crude oil was used as the repellent part of the bar- 
rier. It gave promise of success, especially when small fields were to 
be protected. To erect a barrier of this kind the farmer would need, 
besides the straw and crude oil, a tube or barrel mounted on a sled 
or wagon, a pitchfork, and a posthole digger. The oil is placed in 
the barrel or tub and the straw dipped into it and laid in a long 
windrow about a foot wide and from 4 to 6 inches high. This is the 
barrier. Postholes are dug on the wheat-field side of the barrier 
about 75 feet apart and so that the straw somewhat overhangs the 
edges of the postholes. Loose soil or air-slaked lime on the sides of 
the openings facilitates the fall of the bugs into the postholes. 
The advantages of the oiled-straw barrier are its cheapness and 
the fact that it is not easily affected by weather conditions. Heavy 
