Beauveria bassiana for silverleaf whitefly
Silverleaf, sweetpotato and tobacco whitefly are all on the label. UF/IFAS notes that Beauveria is commercialised for field and greenhouse use against Bemisia. In Canadian poinsettia trials, a cutting dip of insecticidal soap plus Beauveria left only 29% of whiteflies alive, and its residues barely affected Encarsia or Eretmocerus. Start early; it will not rescue a heavy infestation on its own.
Before you order
Spores of an insect-killing fungus, sprayed on to the pest. They stick, germinate and grow through the insect's skin, so coverage is everything. It is slow, working over 7–10 days, and must start while numbers are low. It can also infect some beneficial insects. How it works, how to tell it has established and the supplier list are on the full Beauveria bassiana strain GHA profile.
Other controls for silverleaf whitefly
- Amblyseius swirskiiPredatory mite · 25–100 /m² per release (UF/IFAS); Koppert's range runs to 300 /m²; or sachets
- Eretmocerus eremicusWhitefly parasitoid · 1–10 /m² per release, weekly, at least 3 releases
- Delphastus catalinaePredatory ladybird · 10 per infested plant or 100 per hot spot, weekly for 3–4 weeks
- Big-eyed bugsWild predator · wild, attract it
- Dicyphus hesperusPredatory bug · 1–3 adults per plant weekly for 3 weeks (Florida trial)