Is this phlloxera

[Snafflebit]

I found this on some leaves in n the vineyard in San Jose

 

[efBobby]

Hmm it’s been a while since I have seen it but I do not think it is grape louse. Not 100% but I remember the “bumps” were uniformly sized and kinda fuzzy up top.

then again these were on natives and may look different on varieties.

 

[NoQuarter]

If it is it is just starting. I would take a leaf to your county extension office and get a pro to advise you as soon as possible.

 

[salcoco]

yes it is. take Sevin and add to our tank mix to spray each interval it will control the spread

 

[efBobby]

Looks more like this:

https://gardening.which.co.uk/hc/en-gb/articles/115005130365-Vine-erinose-mite

 

[efBobby]

Phylloxera Gauls look like this:

https://bygl.osu.edu/node/400

 

[Ignoble Grape]

can

If it is it is just starting. I would take a leaf to your county extension office and get a pro to advise you as soon as possible.

Recommend this course of action. Also recommend the book 'Grapes' 2nd Ed., by Creasy and Creasy if you don't already have a shelf copy.

 

[balatonwine]

Not phylloxera. Phylloxera on the leaf has a more gall like appearance, and no "fuzzy" underside.

As already stated, this is a vine mite. It causes no damage to the grapes. But if you have a large infection it can cause enough leaf damage that it can starve the vine and affect the crop. But that rarely occurs. Sulfur sprays in the spring and a regime of integrated pest management can normally control this mite without much effort.

Some may even think this pest is downy mildew, due to the white "fuzzy" looking underside early in the season (late in the season, they turn brown), but it is not.

https://stcoemgen.com/2013/06/03/downy-mildew-2/

 

[Snafflebit]

Thank you to everyone for the info. These galls look very much like erinose mite. It is found on two vines on a few leaves, so it is not an infestation.

 

[salcoco]

Use Sevin as I suggested and it will take care of either condition