Agriculture: Dry Beans Pest Management Guidelines

Whitefly (Sweetpotato)

Description of the Pest

Sweetpotato whiteflies (previously silverleaf whiteflies) are tiny, 0.06 inch (1.5 mm) long, white insects about the size of a pinhead. The body and wings of adults are covered with a fine, whitish powdery wax, opaque in appearance. Whiteflies colonize the underside of leaves. Adults and eggs are commonly found on the lower surface of younger leaves, while the scalelike nymph stages are usually on somewhat older leaves. Clouds of small white insects fly up when plants are disturbed.

Damage

Sweetpotato whiteflies generally are not a serious problem in beans. When present, infestations are frequently restricted to small areas and field edges. Infested leaves will be slightly curled and covered in honeydew, resulting in a sticky, shiny appearance.

Management

Biological Control

Several parasitoid wasps, such as Encarsia and Eretmocerus species, parasitize most species of whiteflies. In addition, bigeyed bugs, lacewing larvae, and lady beetles prey upon many species of whitefly nymphs. Plant habitat that attracts natural enemies and avoid the use of broad-spectrum pesticides known to harm natural enemies.

Organically Acceptable Methods

Use biological control for an organically certified crop.

Treatment Decisions

Pesticide applications are not recommended for sweetpotato whitefly on dry beans because this insect rarely reaches economically damaging levels. Outbreaks are usually associated with the use of broad-spectrum pesticides that negatively impact natural enemies that help control this pest.

Text Updated: 06/18