Cockroaches, Locusts, Grasshoppers, and Crickets 137 



Melanoplus spretus. The invasions of the grain-growing Mississippi Valley 

 states by this species have been already mentioned. In 1866, 1874, and 

 1876 such invasions occurred, and before these still others. "Kansas grass- 

 hoppers" had gained a notoriety which spelled ruin to the state. But, 

 strangely, these grasshoppers, or locusts, not only were not Kansas born, 

 but could not even adopt Kansas as a home. The Rocky Mountain locust 



FIG. 168. FIG. 169. 



FIG. 168. The lesser migratory locust, Melanoplus atlanis, female. (After Lugger; 



natural size indicated by line.) 

 FIG. 169. The differential locust, Melanoplus differentials, female. (After Lugger; 



natural size indicated by line.) 



has its permanent breeding-grounds on the plains and plateaus of Colorado, 

 Idaho, Wyoming, Montana, and British Columbia, at an altitude of from 

 2000 to 10,000 feet above sea-level, and while able to maintain itself for 

 a generation or two in the low, moist Mississippi Valley, cannot take up 

 any permanent residence there. But in those days there were few ranches 

 and farms on the great plains, and succulent corn and wheat were not at 



