Q how do I recognise vine erinose mite?

A Raised, blister-like patches develop on grape leaves from mid-spring onwards as the minute mites feed. The concave area beneath each raised patch has a dense covering of creamy white hairs, which darken as the season progresses. The upper surface of the leaves may also become discoloured.

Caption: Erinose mite causes blister-like patches on grape leaves.

Q What can do if my grapevine has vine erinose mite?

A  If only a small number of leaves are showing symptoms of vine erinose mite, it may be worth removing them in an attempt to limit the infestation. But as this pest causes no significant harm, removing too many leaves would probably cause the grapevine more stress.

Q How can I prevent vine erinose mite?

A  There is no known method to prevent an infestation, but the feeding damage seems to have no significant effect on the grapevine's general health or its ability to crop.