Whiteflies 🐛
Family aleyrodidae
At a glance
- Looks like: Tiny white moth-like insects clustered on leaf undersides
- Tell-tale sign: A small white cloud lifts off when you disturb the plant
- Severity: Moderate to serious — honeydew, yellowing, and fast rebound indoors/greenhouses
How to identify
Whiteflies are tiny sap-sucking insects that sit mostly on leaf undersides. Adults flutter up in a white cloud when disturbed, while the immature stages look like flat pale scales stuck to the leaf. Like aphids and soft scale, they excrete sticky honeydew, which can lead to Sooty Mold.
Damage
Feeding causes yellowing, weak growth, leaf drop, sticky residue, and black sooty mold. Heavy populations can build quickly on warm, sheltered plants.
Treatment (least-toxic first)
Following Integrated Pest Management:
- Rinse leaf undersides to knock down adults and nymphs.
- Vacuum or trap adults with yellow sticky cards.
- Remove heavily infested leaves when practical.
- Insecticidal soap or horticultural oil works only with thorough underside coverage and repeat applications.
- Control ants outdoors if honeydew insects are being protected.
Prevention
Inspect new plants and leaf undersides. Keep plants from being crowded and stressed. Outdoors, avoid broad-spectrum insecticides that remove natural enemies.
Affects (in this guide)
Garden vegetables and ornamentals; warm indoor plant rooms and greenhouse-like spaces