Injured plants appear water-stressed even though they might be kept well irrigated. Proper choice of potting medium and moderate irrigation can prevent build-up of fungus gnats. Larvae can be controlled with Bacillus thuringiensis var. Greenhouse whitefly , Trialeurodes vaporariorum . The adult holds the wings tent-like above the body.
Adults are white with a fine waxy covering on the body and wings.
Before the bracts color, whiteflies can be controlled with insecticidal soap or ultrafine horticultural oil, which are registered for control of this pest in Connecticut, sprayed on the undersides of the leaves. Biological control is possible with Encarsia formosa , a species of parasitic wasp. Season-long control can be achieved with imidacloprid applied as a systemic taken up by the roots. Consult the label for dosage rates and safety precautions. Silverleaf whitefly , Bemisia argentifolii.