Page:Popular Science Monthly Volume 81.djvu/471

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465
MODERN WARFARE AGAINST GRASSHOPPERS

MODERN WARFARE AGAINST GRASSHOPPERS
By Professor F. L. WASHBURN

MINNESOTA EXPERIMENT STATION, STATE UNIVERSITY, MINNEAPOLIS

IN all probability there will never be in the middle west a repetition of such uneasiness and alarm as prevailed during the early seventies in the states of the upper Mississippi and Missouri valleys, on account of the so-called Rocky Mountain grasshopper, Melanoplus (Caloptenus) spretus. Entomologists living in the area bounded by the Rockies on the west and the Mississippi Valley on the east report that for many years they have been unable to collect a baker's dozen of this long-winged locust east of the western plains, which represent occasional breeding grounds of this at one time destructive species, or in the foothills of the Rockies, believed to be the source and permanent breeding grounds of the pest, although it is reported that a few individuals have recently been captured in the Rocky Mountain districts. The passing of this insect may be in slight part due to the settling up of much of the country formerly utilized by them as breeding grounds, either temporarily or permanently. But so suddenly has it disappeared, and so markedly has been the increase of an allied shorter-winged form, M. atlanis (the lesser migratory locust), closely resembling M. spretus, that a suspicion exists that the latter may have been a varietal and, we may say, a sporadic form of the first named. Farmers, however, and others in the region indicated, must rid themselves of the idea that the winged visitor from the Rockies which, years ago, laid waste their fields, is the one grasshopper to be dreaded. Indeed, they are beginning to realize that in the rapid increase of some of our common species, which we may refer to as "native" species, there exists a serious menace to successful farming. Any grasshopper or locust is injurious in proportion to its abundance, and during the last three years a marked increase of a few of our common forms, and the accompanying and yearly increasing injury to crops, constitute a "writing on the wall," as it were, well calculated to rouse citizens from a feeling of absolute security to an appreciation of the need of practical measures of control. This menace is of interest not only to farmers, but naturally also to business men in any community so afflicted, since the business prosperity of a locality depends very largely on the prosperity of the farmers.

The farmer living in a neighborhood under complete cultivation, containing but a small amount of unfilled land, has little to fear, but