Woolly Aphid
Pest · Commonly affects: Apple, Crab apple, Pear, Cotoneaster, Pyracantha, Ornamental apple
Woolly aphid forms conspicuous cottony colonies on apple trees, especially around pruning cuts, cracks and old wounds. Beneath the white wax are sap-feeding aphids that can cause swollen, lumpy growth and weaken young branches. It is mainly a concern on apples, but regular checks and gentle physical control usually keep a garden infestation manageable without disrupting helpful insects.
How to identify it
Colonies look like fluffy white wool or cotton, often clustered on branches, twigs, pruning wounds and sometimes exposed roots. Brushing the wax aside reveals purplish-brown aphids, about 2 mm long. Affected bark may develop rough, knobbly galls or splits. Unlike ordinary greenfly and blackfly, woolly aphids are covered in waxy filaments and may produce visible white fluff when disturbed. Ant activity and sticky honeydew can accompany colonies.
Damage
Feeding irritates bark and young shoots, causing lumpy galls, cracks and distorted growth. Young apple trees may be checked, and repeated colonies around wounds can make branches more vulnerable to dieback. Honeydew can support sooty mould. Mature, vigorous trees often tolerate limited woolly aphid activity, but nursery stock and newly planted trees need closer attention.
Prevention
Choose healthy trees on suitable rootstocks and plant them in a sunny, well-drained position where they can establish strongly. Prune carefully in dry weather, making clean cuts and avoiding unnecessary wounds. Check bark crevices, pruning sites and root suckers from spring onwards, removing suckers promptly. Encourage ladybirds, hoverflies, lacewings and small birds with a mixed, flower-rich garden and avoid overfeeding trees with nitrogen-rich fertilisers.
How to manage it
Brush or rub off small colonies with a soft brush or gloved fingers, then check the same sites weekly. Prune out badly distorted, heavily colonised shoots if this does not compromise the tree's structure, and dispose of them in household waste. Wash honeydew from reachable foliage with water. Leave predators undisturbed, as ladybirds, hoverfly larvae and lacewings can steadily reduce exposed colonies.
Woolly Aphid: frequently asked questions
How do I identify woolly aphid?
Colonies look like fluffy white wool or cotton, often clustered on branches, twigs, pruning wounds and sometimes exposed roots.
How do I prevent woolly aphid?
Choose healthy trees on suitable rootstocks and plant them in a sunny, well-drained position where they can establish strongly.
How do I get rid of woolly aphid?
Brush or rub off small colonies with a soft brush or gloved fingers, then check the same sites weekly.
General guidance for UK home gardens and allotments, focused on prevention and non-chemical control. For a confirmed diagnosis, the RHS or a local garden centre can help. Page updated 19 Sep 2026.