. California greenhouse pests and their control. Insect pests; Greenhouse plants. ARMORED SCALES Importance: Armored scales are very serious pests of ornamental plants. They not only suck the plant sap, but their feed- ing is often accompanied by a toxic ef- fect to the plant. No honeydew is excreted. Appearance: Armored scales are char- acterized by possessing a hardened shield, or scale, above the body. The shields are more or less flattened, usually about 1/12 to 1/8 inch in diameter. They are circular in shape, or else elliptical or oystershell- like. Development: Reproduction may be by eg
. California greenhouse pests and their control. Insect pests; Greenhouse plants. ARMORED SCALES Importance: Armored scales are very serious pests of ornamental plants. They not only suck the plant sap, but their feed- ing is often accompanied by a toxic ef- fect to the plant. No honeydew is excreted. Appearance: Armored scales are char- acterized by possessing a hardened shield, or scale, above the body. The shields are more or less flattened, usually about 1/12 to 1/8 inch in diameter. They are circular in shape, or else elliptical or oystershell- like. Development: Reproduction may be by eggs, from several dozen to several hundred being laid beneath the shield over a period of a month or two. In some cases, living young are produced. The newly emerged crawlers are active for several hours or for a day or two. After settling down, they lose their legs and re- main stationary for the rest of their de- velopment. There are commonly from 3 to 7 generations a year. In the course of female development, the discarded skin of the settled crawler forms the nipple of the shield. The cover- ing of the second stage forms a ring around this. The larger part of the shield ordinarily is secreted by the third stage which becomes the mature female. The shape, color, and texture of the shield, together with the position of the nipple and comparative sizes of the rings, are useful in recognizing the species. The nipple, together with the secretion of the second immature stage, forms the covering of the male. Adults of this sex emerge as delicate, winged insects. The male shields are smaller and more elon- gate than those of the female. They either resemble the female shield in color and texture or else they are cottony white with three longitudinal ridges. Important Greenhouse Species Ivy scale (oleander scale), Aspidiotus hederae (Vallot). The shield of the female is more or less circular, flattened, whitish in color, and with the nipple more or less central. Shield of the male is
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Keywords: ., bookcentury1900, booksubjectgreenhousepl, booksubjectinsectpests
