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Pest NameDescription 
Scale insectsScale insectsSeveral species of scale insects may infest indoor plants. They are quite small, usually ranging from 1/16" to 1/8" in diameter. The scale is actually a hard shell which protects the female insect and eggs from physical and chemical damage. The shell may be brown, black or grayish with various markings on it. It can be flattened or rounded in profile, or look like an oyster shell (oystershell scale). The insects themselves are soft-bodied and feed by sucking sap from the plant. Adults do not move around the plant once they are established and form the scale covering. Young scales ("crawlers") lack the hardened shell and are more mobile. The crawlers are usually grayish to brownish in color, flattened, and smaller than adults. Damage caused by scale insects may resemble that of aphids, with wilting, yellowing, and overall decline of the plant common. Heavy scale infestations can kill plants. Some scale species produce large amounts of honeydew, coating leaves and nearby surfaces with a shiny, sticky residue. Black sooty mold may grow on the honeydew. While the mold is not a direct threat to the health of the plant, it is unsightly and may become a problem on household surfaces.