Viburnum tinus and Arbutus are a host of a small sap sucking insect known as the viburnum whitefly.
Latin name Aleurotuba jelinekii
Plants affected Viburnum tinus and Arbutus spp.
Main symptoms Small white-winged insects on foliage in summer, black and white scale-like pupae on underside of leaves in winter
Caused by A sap-sucking insect
Timing All year
What is viburnum whitefly?
Viburnum whitefly feeds on the underside of the leaves on Viburnum tinus and sometimes on strawberry trees, Arbutus spp. Often with no noticeable effect on the host plants health. This insect should not be confused with other species of whitefly such as glasshouse whitefly which rarely affects these plants or cabbage whitefly which is only found on brassicas.
Check plants for;
- Small white-winged insects, about 1mm 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 1mm 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 insect can usually be accepted as part of the biodiversity that viburnum and Arbustus support, it rarely affects the health of its hosts.
Check Viburnum tinus and Arbutus frequently from early summer onwards so if necessary action can be taken before a damaging infestation has developed. When choosing management options you can minimise harm to non-target animals by starting with the methods in the non-pesticide control section and avoiding pesticides. Within pesticides the shorter persistence products (that are usually certified for organic growing) are likely to be less damaging to non-target wildlife than those with longer persistence and/or systemic action. Pesticide treatments are likely to kill natural enemies and are only likely to be successful if the entire plant can be reached.
- This whitefly rarely affects the growth or vigour of host plants and so it can be accepted as part of the biodiversity these plants support.
- Encourage predators and other natural enemies of whitefly, in the garden, such as birds, ladybirds, wasps and ground beetles.
Pesticide controlThe RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, cultivar selection, garden hygiene and encouraging or introducing natural enemies, should be the first line of control. If chemical controls are used, they should be used only in a minimal and highly targeted manner.
- Organic sprays, such as natural pyrethrum (e.g. Bug Clear Ultra 2, Neudorff Bug Free Bug and Larvae Killer) or plant oils (e.g. Vitax Plant Guard Pest & Disease Control, Bug Clear Fruit & Veg, Vitax Rose Guard) can give good control of whitefly. These pesticides have a very short persistence and so may require reapplication to keep whitefly numbers in check. Plant oil and fatty acid products are less likely to affect larger insects such as ladybird adults
- Plant invigorators combine nutrients to stimulate plant growth with surfactants or fatty acids that have a physical mode of action against aphids (e.g. Ecofective Bug Control, Growing Success Bug Stop, Rose Clear 3 in 1 Action SB Plant Invigorator and Westland Resolva Natural Power Bug & Mildew). These products contain some synthetic ingredients and so are not considered organic
- More persistent contact-action insecticides include the synthetic pyrethroids lambda-cyhalothrin (e.g. Westland Resolva Bug Killer), deltamethrin (e.g. Provanto Ultimate Fruit & Vegetable Bug Killer, Provanto Sprayday Greenfly Killer) and cypermethrin (e.g. Py Bug Killer)
- A systemic containing the active ingredient Flupyradifurone (Provanto Smart Bug Killer) is available for use on ornamentals and selected edibles
- The systemic neonicotinoid insecticide acetamiprid (e.g. Bug Clear Ultra) is also available
Plants in flower should not be sprayed due to the danger to bees and other pollinating insects.
Inclusion of a pesticide product does not indicate a recommendation or endorsement by RHS Gardening Advice. It is a list of products currently available to the home gardener.
Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)
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.
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