Threshold for controlling leaf phylloxera?

[user 36973]

I don't generally have major issues with phylloxera damage to leaves in the vineyard, but they little buggers seem to really like the frontenac. I've been treating the issue as a nuisance but at some point in severity it must begin to impact the leaf's ability to photosynthesize and ultimately for the plant to grapes to ripen sufficiently and winterize. For those of you who spray to control phylloxera, how does the photo below compare to your threshold for needing to control it?

 

[BigH]

I added Assail to my rotation for JB and have not seen any phylloxera this year. Last year it was really bad, to the point that the lost leaf area was a concern for some varieties like La Crosse.

idk if the difference is due to weather differences or if the Assail wiped them out early.

 

[salcoco]

major issue I lost vines during winter because of leaf loss. I just added Sevin to tank mix once start to see any infestation. Actually best pracise I found was to add Sevin each time I sprayed.

 

[user 36973]

major issue I lost vines during winter because of leaf loss. I just added Sevin to tank mix once start to see any infestation. Actually best pracise I found was to add Sevin each time I sprayed.

I spray Sevin during the season to control japanese beetles and grape berry moth but it doesn't seem to control the leaf phylloxera for me. I'll have to look into other insecticides like Assail to rotate next season

 

[treesaver]

My frontenac looked just like your pic, last year on my vines. This year they are just starting on the ends with new growth. I'll keep an eye on your thread Mr Miller!

 

[Dennis Griffith]

I've not seen any signs of phylloxera since I started using Sevin (not Carbaryl, but Zeta Cypermethrin based). I'm down to only 2 uses this year.