Several species of mealybugs pose problems for gardeners across North America. Host plants include citrus, apples, peaches, grapes, potatoes and a number of tropical plants — including houseplants. These tiny insects appear in clusters on the undersides of leaves and clumped in the forks of twigs and branches where they suck plant juices. As they feed, some species inject toxins that damage plant tissues.

 

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Mealybugs are oval in shape, with a grainy, dusty looking surface that is actually a protective waxy coating. Large clumps of mealybugs may resemble fur or lint attached to a plant. Symptoms of their presence include yellowing leaves and dark, dirty patches on leaves, which is actually sooty mold growing on the sweet mealybug excretion called honeydew.

In regions without freezing winters, mealybugs are present year round. In colder climates, there may be two to three generations per year. The pests overwinter as eggs in cottony egg sacs or as tiny nymphs (the juvenile stage, commonly called crawlers).

 

Control

Controls include insecticidal soap and horticultural oil. Natural enemies include the mealybug destroyer (a kind of ladybug), lacewings and the mealybug parasite (a tiny wasp).

About National Gardening Association (NGA)

The National Gardening Association (NGA), founded in 1973, is a nonprofit leader in plant-based education. NGA actively works to promote “best practice” principles that result in healthy lawns, gardens and gardeners. They provide tools and resources needed to support gardening as an enjoyable, satisfying and environmentally responsible activity. Visit www.garden.org.