Whiteflies on hibiscus
UConn lists hibiscus as a host of both greenhouse whitefly and silverleaf whitefly, so check which one you have before buying a wasp: Encarsia is for greenhouse whitefly, Eretmocerus for silverleaf. UF/IFAS advises flipping leaves and checking flower buds for whiteflies or sooty mould, treating early with insecticidal soap or oil, and never using malathion on hibiscus. The wasps fly only above about 65 °F (18 °C).
At a glance
- Damage
- Clouds of white adults, sticky leaves, sooty mould
- Type
- Sap feeding
- Settings
- Under glass, Garden, Indoors
- Threshold
- No numeric threshold; UF/IFAS advises treating early, at the first whiteflies or sooty mould
- Release
- Encarsia formosa
- Rate
- 1–10 /m² per release, repeated until control (Koppert)
How to confirm it
Tap the plant: white adults lift off in a cloud and resettle, wings held flat. Flat, pale oval scales sit under the lower leaves; the oldest are raised and fringed with long wax filaments.
Identification, lifecycle, degree days and every control option are on the full Greenhouse whitefly profile. Not sure it is this pest? Answer four questions about the damage.
Work it out
How many do I need?
Carries Encarsia formosa and hibiscus through so nothing is re-entered. Open the calculator →