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Wooly Aphids


Wooly Aphids

Usually appear in

All year

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Caused By:-     Various Insects and their larvae


These are the results of the attack of wooly Aphids. Two of the galls are cut to show the growth of the galls which is solid.
Wooly Aphids are sucking insects that live on plant sap, and whose larvae produces a filamentous waxy white covering which resembles cotton wool and at first sight this may make them appear to be a fungus.
They have a wide range of host including Apple, Cotoneaster, Hawthorn, Pear, Prunus, Pyracantha and Sorbus.
Many of the numerous species of woolly aphids have only one host species, or alternating generations on two specific hosts.
The adults are winged and move to new locations where they lay many of eggs.
Although they appear to be white in their waxy protection, the adults are about 2mm long and a pinkish-brown colour.
They overwinter as young in crevices and cracks in the bark then emerge in the spring to produce a population explosion on new shoots and at pruning cuts where the sap is more easily obtained. Eventually this weakens the tree or plant and lead to early leaf Autumn.
Their sap sucking action causes a callous-like lump or gall to grow, which provides even better access to the plant sap. These galls or swellings remain after the infestation has gone and affected branches do not usually regain their vigour so if possible they should be pruned out.
These galls may split open in the winter frost and other diseases may enter the plant. If a plant is badly infested it may never recover totally and it might be best to replace it.
They also excrete honeydew which can fall on the leaves and allow sooty mould to develop.
See also Mealy Cabbage Aphids, Mealy Plum Aphids, Mealy Bugs, Phormium Mealy Bugs, Root Mealybugs. See also these other aphids Aphids, Blackfly, Cypress, Green Spruce, Honeysuckle, Juniper, Lettuce Root, Lupins, Melon Cotton, Peach, Rose, Rosy Apple, Willow Bark Aphid.


The best way to tackle this pest is to blast off the fluffy, sticky aphid mass with a high-speed jet of water. This won't cure the problem, but deals with the aphids in the short-term.
Then spray with an insecticide and or plant oils.
In winter spray with a winter tar wash or insecticidal plant oil and prune out badly infected galls before spraying.

P_woolyaphid1 P_woolyaphid2 P_woolyaphid3

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