The most common species of whitefly is the glasshouse whitefly; Trialeurodes vaporariorum . Although tobacco whitefly; Bemisia tabaci is also becoming more common. Whitefly adults penetrate and suck the contents of leaves, turning them yellow. The larvae of the whitefly consume a large quantity of plant sap. This is excreted as Honydrew onto the leaf, which sooty moulds grow on. Whitefly can also transmit plant viruses. The eggs of whitefly are laid on the underside of leaves. Adult whitefly tend to be found mainly at the top of plants and fly up when disturbed. Glasshouse whitefly eggs can survive for a period of time below freezing.