Woolly aphid on apples, plums, greengages, damson:
What is woolly aphid?
The woolly apple aphid is different from the other types of aphid. It is easily visible on the trees because the colony develops a white, cotton-like mass on wounds on trunk and branches, which provides protection against predators. The aphid itself is purplish, and it feeds on tender areas of bark. If infestation is heavy, the aphids may descend to the roots, and this can cause serious damage in the case of young trees. The summer generations of woolly aphid are wingless, while in autumn, winged aphids fly to elms on which they lay overwintering eggs.
How to control woolly aphid
Effective insecticides for woolly aphid are no longer available to the gardener or the allotment holder. Using luke-warm water and some detergent, brushing the affected branches will reduce the problem. Repeat the same treatment a month later.