Of several species, spider mites are important pests of ornamental plants.
Spider mites are general feeders and, when many different kinds of plants are unthrifty, a more detailed search should be made to discover if the spider mite is present. Some of the things to look for are (a) the mites themselves, (b) the web that is frequently present, (c) mottling or bronzing of the leaves and (d) unthriftiness of the plants.
One of the more common is the two-spotted spider mite, which may be found in almost every garden. Outdoors, mites hibernate as adults in the soil, on tree bark, and on leaves. In greenhouses, overwintering survival is no problem.
Spider mites are small. The female is only 1/50 of an inch long and the male is even smaller. They are mere specks when seen crawling on the undersurface of leaves. Young mites are six-legged. After two periods of molting and resting, they become adults and have eight legs. Generations may be completed in 5 to 40 days.
