Plant Problem Diagnosis Key / Pests
Pest
Whiteflies
Trialeurodes vaporariorum, Bemisia tabaci
Small sap-feeding insects with white, powdery wings. Adults and the flat, scale-like nymphs feed under leaves and drip honeydew, which grows sooty mold.
Signs
- A cloud of tiny white flies rises when the plant is shaken.
- Flat, oval, translucent nymphs fixed to leaf undersides.
- Sticky leaves, sooty mold, yellowing and slow growth.
What favors it
Greenhouse-grown transplants and indoor plants brought in with eggs and nymphs on them.
Prevention
- Inspect leaf undersides on every new plant.
- Yellow sticky cards at canopy height, counted weekly.
- Control weeds that host them.
Often confused with
Sources
- Whiteflies - VegetablesUniversity of Maryland Extension
- Whiteflies on Indoor PlantsUniversity of Maryland Extension
Treatment by crop
Cultural, biological and chemical options in the order to use them, and notes written for each crop.
Identification is free. Treatment is on the Home and Pro plans.
Questions in the key that lead here
- Look the plant over, leaf undersides included. Are insects, mites, slugs, eggs, webbing or droppings on it?
Yes, something living or its traces - What is on the plant?
Small insects, clustered or flying - Do they fly up when the plant or the soil is disturbed?
Yes, they fly - What do they look like, and where are they?
Tiny, with white powdery wings
Not a match? Start the key or describe what you see.
More photos
More from university Extension: search Extension pages on whiteflies, or find a plant diagnostic lab through your state's Extension.
Other pests
- Aphids
- Bagworms
- Bark beetles of pine and spruce
- Broad mites and cyclamen mites
- Caterpillars
- Cicada and twig-cutting damage
- Colorado potato beetle
- Cucumber beetles
- Cutworms
- Elm leaf beetle
- Emerald ash borer
- Flea beetles
- Fungus gnats
- Galls on leaves and twigs
- Hemlock woolly adelgid
- Japanese beetles
- Lace bugs
- Leafminers
- Mealybugs
- Pine sawflies
- Root aphids
- Root-knot nematodes
- Russet mites
- Sapsucker damage
- Scale insects
- Shore flies
- Slugs and snails
- Spider mites
- Spongy moth (gypsy moth)
- Spotted lanternfly
- Squash bugs and stink bugs
- Squash vine borer
- Tent caterpillars and fall webworm
- Thrips
- Wood borers