Many houseplants enjoy time outdoors during summer. However, it’s a tough world out there and more than a few plants develop insect or mite infestations while they are basking in the summer sun. A few weeks indoors can allow pests to increase while the plants adjust to indoor conditions, and symptoms become more apparent.
Common culprits include aphids, mealybugs, scales, spider mites, thrips, and soil-dwelling fungus gnats. Pressure washing, hand picking, and pruning are among the quickest and easiest ways to deal with some problems; others require a long-term approach.
Your options and the likelihood of a happy outcome depend in great part upon the resilience of the plant and the type of pest that is involved. Plants suspected of being infested should be isolated from other plants to reduce the chances of an expanded infestation. Inspect plants carefully to determine if an insect or mite is causing the problem, and identify it or get help from your county extension office.
In some cases, an insecticide may be the best way to bring an infestation under control. Products with the following active ingredients (and example brand names) are labeled for a variety of houseplant pests: bifenthrin, cyfluthrin (Bayer Rose & Flower Insect Killer Ready-to-use), permethrin (Eight) , pyrethrins (Spectracide Bug Stop for gardens), Insecticidal soap (Garden Safe Brand Insecticidal Soap), and neem (Bon-Neem).
More information on houseplant insect control can be found in ENTfact 406, Houseplant Insect Control.
By Lee Townsend, Extension Entomologist