Description
Mites are minute pests that infest many garden plants. There are many injurious species, some of which are commonly called spider mites. Some mites may injure humans or animals; others are beneficial predators of plant pests. Mites are not insects, but belong to the animal class Arachnida along with spiders, ticks, and several other groups. They have 4 pairs of legs instead of 3, and lack antennae and true jaws. Each mite has a pair of needlelike stylets that pierce plant tissue. The sap and cell contents are sucked out, resulting in leaf stippling. Most mites have many generations each year, often completing a life cycle in 7 to 10 days. Mites, cast skins, eggshells, and webbing may cover the surfaces of leaves or other plant parts. Mites are more numerous on dusty plants. Heavy rains usually limit spider mite populations by washing them and the dust off the plant. Mites also cause more damage to water-stressed plants because the plants are unable to quickly replenish the fluids sucked out by the mites.
Control
Mites can be difficult to control because the egg stage is resistant to most chemical sprays. Chemicals are effective against other stages, however. They must be applied at least 3 times at intervals of 7 to 10 days for effective control. Spray ornamentals with an insecticide containing acephate. Control mites on fruit and vegetables with an insecticide containing diazinon or malathion, or with a horticultural oil spray or an insecticidal soap. Be sure your plant is on the label. Rinse dust off plants with a water spray. Reduce mite damage by keeping plants watered. Use a strong spray of water to knock mites off plants.
