Whiteflies

Whiteflies are about 1/16" long.

Found throughout the United States, these tiny, insects feed in large numbers on leaf undersides of tomatoes, cucumbers, lettuce, and other plants by sucking out plant juices. They secrete a sticky, sugary substance called honeydew that may cause the growth of a sooty black fungus on leaves. Eggs laid on leaf undersides hatch into larvae that look like flat, oval, semitransparent scales, which change into adult flies in about a month.

• Spray with a type of oil that's formulated for use on plants, such as or neem oil or paraffonic oil. Make at least two repeat sprays at weekly intervals since different stages of the life cycle are not susceptible to insecticides.
• Whiteflies cannot survive freezing temperatures; in northern gardens they are reintroduced on infected plants each spring. Check purchased plants carefully before setting in the garden.
• Release and attract beneficial insects, such as ladybugs and lacewings.

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