2 
tion and deposit their eggs, and thus cause several years of abundance. 
In a few sections they are numerous enough to cause great damage only 
three or four years out of every ten. 
This locust is a general feeder, and is especially destructive to hay, 
oats, and wheat, the principal crops grown in these sections. Appar- 
ently the insect dislikes alfalfa, as this crop is usually but little injured. 
REMEDIAL MEASURES. 
The application of remedial measures against this pest depends largely 
on the locality in which the pests are at work, and every possible 
advantage should be taken of the natural surroundings. The breeding 
grounds must be accurately located; and, if there are periods of years 
in which the insects are few in numbers and consist of scattering 
colonies, these colonies should be located and destroyed as a preventive 
measure. Many methods have been devised to combat the insect 
when it has reached the adult or winged stage, but at best these meas- 
ures are very expensive, and are in most cases of little value. If 
success is to be obtained in the destruction or control of this insect, it 
must be attacked in its breeding grounds, either when it is in the egg 
stage or before becoming winged. 
Plowing.—By observing the insects during the egg-laying period, or 
stirring the ground and exposing the eggs, the breeding grounds can be 
easily located. By plowing these grounds in the fall many of the eggs 
are buried so deep beneath the ground that when the young hatch in 
the following spring they perish because they can not reach the surface. 
Others are killed by exposure to the weather, and their numerous 
enemies have a better opportunity to feed upon them. 
Spraying with oil.—In many sections of the West, where crude petro- 
leum can be obtained at very little cost, the method of spraying with 
oil has been found very successful. The petroleum is sprayed over the 
breeding grounds upon the young locusts, which are killed by contact 
with the oil. The effectiveness of this treatment depends primarily 
upon the thoroughness with which it is applied. Additional effective- 
ness can be secured by burning over the ground after it has been sprayed, 
as this will kill those which have escaped the spray. 
Hopperdozers.—Hopperdozers are long, shallow pans of any conven- 
ient dimensions, made of galvanized iron or other material mounted 
upon runners about an inch thick. The pan is partly filled with water, 
a small quantity of kerosene is added to form a film, and a screen is 
placed upright on the back to prevent the locusts from jumping over 
the pan. As hopperdozers are drawn over the ground by either men or 
horses, the young locusts jump into the air, fall into the pan, and are 
wetted and killed by the kerosene. This method has been found to be 
less effective against this insect than against locusts of other species. 
Sage. brush in the breeding grounds often renders it difficult to use the 
