Check plants for:

• Small white-winged insects, about 1 mm long, living on the underside of younger leaves in mid-summer
• In winter, the insect is present as the overwintering scale (nymph) stage. These are black, oval, scale-like objects that are 1 mm long and encrusted with a white waxy powder
• Usually host plant health is unaffected. Occasionally large populations develop which can lead to sooty mould on the upper leaf surface where the insect’s sugary honeydew excrement has accumulated

• This whitefly rarely affects the growth or vigour of host plants and so it can be accepted as part of the biodiversity that viburnum and Arbutus support
• Encourage predators and other natural enemies of whitefly, in the garden, such as birds, ladybirds, wasps and ground beetles

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 (sometimes called larvae) 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.