Some sort of insect on a vine

Anyone know what this leaf infestation is, and what (if anything) to do about it?





It's a well established (20 years old) Vitis purpurea. The plant itself seems to be happy enough.

 

Its well advanced for this time of the year?

Nice Agave, BTW.

Think I had something similar on one of my grape vines last year, most of the flowers aborted and the leaves had strange bumps.
I'm guessing insect, but what insect remains a mystery to me.

 

It's what the French call 'mildiou' (mildew) which doesn't necessarily correspond to the English version. It's a fungal disease. You could try taking off the worst affected leaves, dispose of them carefully, and treat the vine with Bordeaux mixture.

 

Thanks. I put mildiou vigne into google and came up with this

Plasmopara viticola - Wikipedia

It’s clear that it’s a big problem for grape production, but hopefully it’s not going to significantly weaken my plant, which only rarely produces grapes and then inedible ones.

Nevertheless I’ll spray as advised.

 

I’m not sure that the window cleaner agrees!

 

Interesting @noisette47 , is it the same as this, just one of my vines was infested last year.

 

Can you still buy Bordeaux mixture?

 

That looks like the early stage, @pete. Mine get it every year 'cos I don't follow my own advice and spray Whether it's mildiou or oïdium, the treatment's the same. No idea now whether BM is banned or not It's classed as OK for organic gardening but there were rumours of it being banned anyway

 

My picture was taken in August, the flowers never opened in june and the buds dropped off, but there was no visible fungus.

 

I'll see if I can copy your photo and description to a Frenchie (with your permission) who's far more knowledgeable than me about vines

 

bordeaux mixture online

 

BM was banned a couple of years ago wasn’t it? It just so happens I bought a few before the ban That said, I’ve never needed it since. Don’t seem to get blight here.

 

Well, well....you were absolutely right, @pete! The verdict is l'érinose de la vigne. Gall Blister mite. Grapevine blister mite / RHS Gardening It doesn't explain why the flowers dropped, though. Drought? Cold/wet?

 

I believe BM was among several horticultural and agricultural chemicals banned under EU regulations.

BM was featured in the Victorian Garden series. Gardeners of that era used to make their own. It is highly dangerous.