Whitefly is a group of tiny insects that damage plants. Whiteflies stunt plant growth and limit fruit production by sucking sap from the leaves. They also secrete a sticky substance that causes an unsightly mold to grow on fruits. In addition, some species (kinds) spread viruses. There are more than 1,000 species.
A type of whitefly called the silverleaf whitefly has severely damaged crops in south-central California’s Imperial Valley. This whitefly measures only about 1/10 inch (2.5 millimeters) long. The insects have been difficult to control because they resist most pesticides and have few natural predators. They feed on many different plants, including broccoli, citrus fruits, cotton, lettuce, and melons. A species called the greenhouse whitefly infests tomatoes and other plants in greenhouses and gardens throughout North America.
The female whitefly lays her eggs on the underside of a plant’s leaves. The eggs hatch into wingless young called nymphs or crawlers. The nymphs stick their mouthparts into a leaf vein and remain there, sucking out the sap, until they mature. The adult whiteflies also feed on plants occasionally.
