Spider mites pierce the undersides of leaves and suck out the contents of individual plant cells. As damaged cells die, leaf surfaces become finely speckled. Although these insects are easy to overlook in small numbers, careful inspection of plant parts with a magnifying lens or a gentle shaking of the leaves and branches over a piece of white paper can reveal mite activity. Adult females lay more than 100 eggs at a time. It takes less than one week for an egg to develop into an adult.
Spider mites thrive under warm and dry conditions.
Spider mites attack a wide variety of plants, including annuals, vegetables, trees, shrubs, houseplants, and greenhouse ornamentals. Dislodge small infestations with strong sprays of water. And since spider mites prefer dry conditions, regular misting will slow or hamper population growth. Light horticultural oil or insecticidal soap can be applied to control mites, and beneficial insects such as lady beetles and predatory mites are also effective. Daniels is curator of butterflies at Butterfly Kingdom Conservatory in Hilton Head, South Carolina.