Common Houseplant Pests: Identification, Prevention, and Control

Stressed or new plants are pest magnets. Isolate new arrivals 3 weeks. Common pests:

Major Pests

Two-Spotted Spider Mites

Tiny, crawl between plants. White flecks on leaves → gray-bronze discoloration → webbing. Heavily infested leaves drop. Hard to control—discard badly infested plants. Wash small plants repeatedly with water jet. Maintain optimal conditions.

Greenhouse Whiteflies

Gnat-like, white-waxed adults on hibiscus, lantana, vegetables. Suck sap → reduced vigor, sticky honeydew. Trap adults with yellow sticky cards. Vacuum small plants. Neem, horticultural oil, insecticidal soap for nymphs.

Mealybugs

Soft, cottony, on jade, poinsettia, coleus, cactus. Suck sap → leaf drop. Visible on leaves, but often in roots. Swab with alcohol/soap. Systemic insecticides (disulfoton, imidacloprid) as soil drench.

Fungus Gnats

Tiny dark flies on soil surface. Nuisance, minimal damage. Larvae eat decaying matter. Dry soil surface between waterings. Yellow sticky cards for adults.

Other Common Pests

• Aphids: Sap-feeders, cause wilting. Biological control (predatory midge).
• Thrips: Silvery leaf patches. Oils/soaps; sticky tape for adults.
• Soft Scales: On twigs/leaves. Spray oils best (waxy cover blocks contact sprays).
• Armored Scales: Round with central spot. Horticultural oils. Systemics ineffective.
• Springtails: Tiny gray/cream in soil. Annoying, little damage. Reduce watering.

Integrated Control Methods

• Water jets for aphids/spider mites
• Hand-picking for large pests (mealybugs)
• Vacuuming for whiteflies
• Yellow sticky cards for flying pests
• Beneficial insects (lacewings, predatory mites)
• Alcohol, insecticidal soaps, horticultural oils, neem extracts
• Systemic insecticides as last resort

Healthy plants resist pests best. Optimal light, water, and humidity are your first defense.