THE ENEMIES OF ALFALFA 217 



the Stubble of the first crop and the half-grown hoppers 

 jump into the pan where the oil coats them over and 

 kills every one that it touches. The hopper dozer works 

 best on level land. On sloping ground the oil and water 

 run to one end and slop over. To prevent this the pan is 

 usually divided into sections by a number of partitions^ 

 The runners should stick out in front of the pan about 

 a foot and one-half, and a piece of chain or heavy rope 

 should be stretched loosely between them to^drag ahead 

 of the machine and make the hoppers jump. On level 

 fields there are no great difficulties in the use of the 

 hopper dozer. Careless driving may spill oil on some 

 alfalfa and kill it. If these machines are to be really 

 effective, they must be used before the grasshoppers get 

 their wings. The first crop of alfalfa should be cut as 

 early as possible, and the hopper dozers should follow 

 the rakes as closely as may be. On the whole, they should 

 be used only where plowing and harrowing have not been 

 done or have failed to keep the grasshoppers in cfieck." 



Of the use of this implement or machine Prof. S. J. 

 Hunter has this to say : 



"The height of the runners depends upon the height 

 of crop to be protected. It is important that there be no 

 timbers in front of the pan, so that its front line may 

 come in contact with the grain passed over. The insects 

 then fall directly into the fluid. When ready for use 

 place two buckets of water and one-half gallon of coal- 

 oil in each pan, and then drive back and forth across the 

 end of the field where the grasshoppers are entering until 

 you have filled the pans; remove the insects, replenish 

 with oil and water, and continue until the field is rid of 

 the pest. 



