Pest library
Houseplant Pest Identification
Identify six common houseplant pests, what damage they cause, and how to get rid of them using integrated pest management (IPM) methods cited from university extensions.
- Spider MitesTetranychus urticaeSpider mites (Tetranychus urticae) are tiny arachnids that pierce leaf cells and feed on the contents, leaving a stippled or sandblasted look on foliage. Webbing along leaf undersides is a tell-tale sign of an established infestation. They thrive in warm, dry conditions — typical indoor air in winter.
- MealybugsPseudococcidaeMealybugs are soft-bodied sucking insects covered in a white waxy coating that looks like cotton tufts. They cluster in leaf axils, along stems, and at the base of the plant. Untreated infestations weaken the plant and produce sticky honeydew that attracts sooty mold.
- Fungus GnatsBradysia spp.Fungus gnats are small dark flies (about 1/8 inch long) whose larvae live in the top 2–3 inches of moist potting media, feeding on organic matter and fine roots. The adults are mostly a nuisance; the larvae can damage seedlings and stressed plants. They indicate consistently overwet soil.
- Scale InsectsCoccoideaScale insects are armored or soft-bodied sucking pests that attach to stems and leaves and feed on plant sap. Adults look like small brown or tan bumps and don’t move once settled. Heavy infestations weaken the plant and produce honeydew that attracts sooty mold.
- ThripsThysanopteraThrips are slender, minute insects (less than 1/20 inch long) that rasp leaf surfaces and suck out the contents, leaving silvery streaks, deformed new growth, and black fecal specks. They breed quickly and are commonly introduced on new plants.
- AphidsAphidoideaAphids are small pear-shaped soft-bodied insects that cluster on new growth and the undersides of leaves, sucking sap and excreting honeydew. They reproduce rapidly indoors and can transmit plant viruses, but are also the easiest of the common pests to knock back.