Andrew asks;
I am curious about how to tell the difference between grapevine mites? I have a Uni project to do on pest and disease and this would be of assistance.
Many thanks.
A= Mites are tiny, about 1/10th of a millimetre long and we generally only become aware of them when their activity causes symptoms on grapevines during the growing season.
There are three common types of mite pest in South Australian vineyards. Grapevine Rust Mite, Grapevine Blister Mite and Grapevine Bud Mite.
Rust Mite affected shoots are common. The photo below is from the Blewitt Springs district of McLaren Vale during mid-spring.
Slow and distorted growth caused by Rust Mite.
Rust mite is seen as shoots with slow and perhaps stunted shoot growth with distorted leaves. It is too late for spraying to be effective this season. Rust mite levels can be reduced by a sulphur (and Canola Oil) spray at Chardonnay 10% budburst.
Bud Mite are found in most vineyards.
Grapevine Bud Mite.
Bud mite damage causes shoot to have no growing tip and only produce one or two crinkled leaves. Bud mites generally don't cause economic damage and levels under 1 per 100 shoots are considered minor. Bud mite cannot be easily controlled by fungicide spraying.
Blister Mite can look severe, but rarely causes mature vines any trouble. Blister mite can be an issue in nurseries though.
Grapevine Blister Mite.