Cotton wool like substance growing on your apple tree what is it?

The white, cottony substance growing on your apple tree is likely to be woolly apple aphid (Eriosoma lanigerum). This is a common pest of apple trees, and it can cause significant damage to the tree if left untreated.

Woolly apple aphids feed on the sap of the tree, and they can also transmit diseases. The white, cottony substance that they produce is a protective covering that helps to keep them safe from predators and parasites.

If you have woolly apple aphids on your tree, it is important to treat them as soon as possible. There are a number of different ways to treat woolly apple aphids, including:

- Insecticides: There are a number of different insecticides that can be used to kill woolly apple aphids. Some common insecticides include malathion, carbaryl, and acephate.

- Biological control: You can also use beneficial insects to control woolly apple aphids. Some common beneficial insects that eat woolly apple aphids include ladybugs, lacewings, and parasitic wasps.

- Pruning: You can also prune away the affected branches of your tree. This will help to remove the aphids and prevent them from spreading to other parts of the tree.

If you are not sure how to treat woolly apple aphids, you can contact your local agricultural extension office for assistance.