Economic entomology for the farmer Economic entomology for the economicentomolo00smit_0 Year: 1896 THE INSECT WORLD. 119 wonderful power of reproduction make the scale especially dan- gerous. In the genus Diaspis the scales are more oval, and the cast lar\-al skins are at or near the margin rather than toward the middle, while the males are long and Fig. 89. slender. A common example is the Di- aspis ros(Z, found on roses and other plants belonging to the same natural family. The scale is pure white and very conspicuous, measuring nearly an eighth of an inch in diameter. Yet more ova
Economic entomology for the farmer Economic entomology for the economicentomolo00smit_0 Year: 1896 THE INSECT WORLD. 119 wonderful power of reproduction make the scale especially dan- gerous. In the genus Diaspis the scales are more oval, and the cast lar\-al skins are at or near the margin rather than toward the middle, while the males are long and Fig. 89. slender. A common example is the Di- aspis ros(Z, found on roses and other plants belonging to the same natural family. The scale is pure white and very conspicuous, measuring nearly an eighth of an inch in diameter. Yet more oval, with the cast larval skins at the smaller extremity, are spe- cies of Chionaspis, and a good exam- ple is the '' scurfy scale,'' C. furfu- rus, common on pear and apple. A similar species is found on pine and spruce throughout the United States. These species may have one or two gener- ations, according to latitudes, but ususally winter in the egg state. Some of the species have the curious habit of boring under bark, thus passing a large part of their life out of sight, becoming more dangerous by that fact, since trees may be badly infested and the cause of sickness not even suspected by the farmer. It is practically impossible to even mention all the injurious scales of house, conservatory, or orchard plants, and it is not San Jos^ scale on a California pear, natural size ; the scale itself enlarged at b.
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