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Page:Popular Science Monthly Volume 81.djvu/476

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470
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 Acrididæ, while the true grasshoppers, having long antennae, and ordinarily more or less sharply pointed heads, belong to the family Locustidæ. 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 sufficiently numerous to warrant our classifying them at this time as a serious menace to crop growing, namely, the lesser migratory locust, Melanoplus atlanis; the two-striped locust, Melanoplus bivitattus; the

PSM V81 D476 Spraying for grasshoppers with arsenite of soda.png

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

red-legged locust, M. femur-rubrum; the differential locust, M. differentialis, 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 solution 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