Viburnum whitefly has one generation a year.
The adults emerge in mid-summer, when they deposit eggs on the underside of leaves near the shoot tips. These hatch into flat, oval whitish-green nymphs that suck sap from the lower leaf surface.
By autumn, the nymphs have reached the pupal stage, which is black and encrusted with a white waxy powder. Both adults and nymphs produce a sugary excrement, called honeydew, which makes the foliage sticky and can allow the growth of sooty moulds.