47o THE POPULAR SCIENCE MONTHLY 



term for these insects, but scientifically erroneous, for the species 

 particularly injurious, in that they are the most numerous, belong to 

 the family Acrididce, while the true grasshoppers, having long antennae, 

 and ordinarily more or less sharply pointed heads, belong to the family 

 Locustidce. The common error of calling the periodical cicada and 

 other species of cicada "locusts" adds to the popular confusion. Of 

 the injurious Acridids found in Minnesota only four species are suffi- 

 ciently numerous to warrant our classifying them at this time as a 

 serious menace to crop growing, namely, the lesser migratory locust, 

 Melanoplus atJanis; the two-striped locust, Melanoplus bivitattus; the 



Fig. 10. Spkating for Grasshoppers with Arsenite of Soda. 



red-legged locust, M. femur-rub rum; the differential locust, M. differ- 

 ential's, to which we may add, possibly, the pellucid locust, Camnula 

 pellucida, and the short-winged locust, Stenobothris curtipennis. All 

 of these yielded to a poison spray made by dissolving three pounds of 

 arsenite of soda in 180 gallons of water, and adding to this solution one 

 and one half gallons of cheap molasses. This is essentially the South 

 African formula, though in spraying the veldt a much stronger solu- 

 tion was used in Africa, so strong, in fact, that vegetation was killed, a 

 fact of little import under the conditions in the African campaign, but 

 of the utmost importance where, as in the middle west, pastures or 

 even grain fields have to be treated. We found that at the strength 

 used by us no appreciable injury was evident, and although it took 



