204 



AGRICULTURE ON THE PACIFIC SLOPE 



across the field. A light pole running before it causes 

 the grasshoppers to jump, and an upright screen 

 behind it prevents them from jumping over it. Even 

 those which at once jump out of the pan usually get 

 enough of the crude oil on them to kill them. Burn- 



FIG. 116. Grasshopper. (Enlarged.) 



ing and plowing the places where they breed and feed 

 helps greatly to keep them in check. (California Ex- 

 periment Station, Bulletins 142, 170, and 192 ; Idaho, 

 41; Nevada, 57; New Mexico, 63, 68.) 



A wingless grasshopper known as a " cricket " has 

 done much damage in the Northwest. (Idaho Experi- 

 ment Station ; Bulletin 41; Nevada, 56; Wyoming, 

 32.) 



