Title: Annual report of the Pennsylvania Department of Agriculture ..
Identifier: annualreportpe81penn (find matches)
Year: 1896- (1890s)
Authors: Pennsylvania. Dept. of Agriculture; Pennsylvania. State Board of Agriculture; Pennsylvania Horticultural Society
Subjects: Agriculture -- Pennsylvania
Publisher: Harrisburg, Pa. : The Dept.
Contributing Library: New York Botanical Garden, LuEsther T. Mertz Library
Digitizing Sponsor: The LuEsther T Mertz Library, the New York Botanical Garden

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238 ANNUAL. REPORT OF THE Off. Doc. bat thej remain so for a few days only. Additional waxy material is added at the edges, the scale enlarges, becomes darker iu color, more flattened, and reaches the gray stage. From ibis the color changes to black and later, as it becomes mature, it again lightens and the yellow centre becomes obvious. In about four weeks full growth is attained and the female is sexually mature. Jf we follow the insect beneath the scale, we find that as the covering increases, the antennae and legs disappear and, when the first larval skin is cast, no appendages remain. The cast skin is made to form part of the centre or nipple of the scale, and in the female, a second cast is added before the insect is sexually mature. The male at its next change differs totally from the female and forms a true pupa, from which we get in a few days, a very minute, frail, two-winged fly with long stout feelers, long legs and a long anal style or process. This male is so small and inconspicuous that it is almost impossible to see it without a magnifying glass, and so frail that the least puff of wind carries it off; nevertheless, it succeeds in impregnating the fe- male and then dies.
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Pig. 3.—Adult male, Aspidintiis pernioiuHun: greatly enlarged. (From Hoiwi/d, Circ. ,3, 2d so:, DLv. Eat., U. S. Dept. Agr.) Breeding begins in the latitude of Philadelphia about June 10, and continues throughout November in ordinary seasons. During that time a single pair may, if absolutely unchecked, produce a progeny of over one thousand million (1,000,000,000)! This number is so enormous as to be almost incredible; but from the facts given it may be easily figured out by any one with a mathematical turn of mind. It has been stated that breeding continues until very late in the fall, but those insects that start late never live over until the fol-

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