Plants like us humans seem to be afflicted by a very wide range of pests and diseases. Some you don’t really need worry about too much and others that you most certainly do.
Grape Vine Blister Mite falls into the first category. A tiny two-legged creature that is almost invisible to the human eye is very easily identified by the unsightly damage that this sap sucking creature causes to the underside of the leaf. Whilst the gall-blisters on the upper side of the leaf look unsightly, they do very little damage to the plant or the fruit and so control measures are not worthwhile.
For those of you that do need perfect leaves for those rather daring Adam and Eve costumes for the neighbours Summer fancy dress party, then adequate control can be found by drenching the dormant vine in early spring just as the leaf buds swell with a sulphur wash. The over wintering adults have spent the Autumn and Winter months in the cracks and crevasses of the vine bark, so you need to control them before they make their move to the new and very tasty young leaves. For the rest of us who prefer to dress a little more modestly to a fancy-dress party, I suggest that the control is unnecessary as the fruits are completely unaffected.
It's worth noting that some varieties of grape seem completely immune to the gall-mite and this may be to do with the smoother bark of certain varieties. The mite also has its own enemies in the form of predatory creatures that much away at the gall mites. So, its worth trying to create a balance of good and bad on your vine . Remember, there will be no more goodies if the baddies are all gone!