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Page:Popular Science Monthly Volume 7.djvu/724

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THE POPULAR SCIENCE MONTHLY.

THE COLORADO POTATO-BEETLE.
By Prof. C. V. RILEY.

FEW insects have done more serious injury, or attracted greater attention, than this, even in America, where insect depredations attain a magnitude scarcely dreamed of in this country. Feeding originally on the wild Solanumr ostratum in the Rocky Mountain regions of Colorado and other Territories, it fell upon the cultivated potato as soon as civilized man began to grow this esculent within its reach. With large fields of palatable food, instead of scattered plants of the wild Solanum to work upon, it multiplied at a marvelous rate, and began to spread from its native home toward the East. Reaching a point 100 miles west of Omaha, Nebraska, in 1859, its progress has been carefully recorded each year since, until last year it reached the Atlantic coast at a number of different points in Connecticut, New Jersey, New York, Pennsylvania, Delaware, Maryland, and Virginia. The present year we hear of it being still more numerous on the Atlantic coast, and of its swarming around New York City, and covering the nets of fishermen. It has thus, in sixteen years, spread over 360 geographical miles, in a direct line; and, if we consider the territory

PSM V07 D724 Colorado potato beetle.jpg
Fig. 1.—Colorado Potato-Beetle

a, a, Eggs; b, b, b, larvae of different sizes; c, pupa; d, d, beetle; e, left-wing: cover magnified to show lines and punctures; f, leg enlarged. Colors: of egg, orange; of larvæ, Venetian-red; of beetle, black and yellow.

actually invaded, which includes the States of Kansas, Nebraska, Missouri, Iowa, Minnesota, Wisconsin, Illinois, Indiana, Kentucky, Michigan, Ohio, Ontario (Canada), New York, Vermont, Massachusetts, Pennsylvania, Maryland, and Virginia, it has overrun an area of 800,000 square miles. The natural history of the species was first