Grape Berry Moth

[dwhill40]

Year five on my experiment is done and the wine is cooking. A wet year with much lower than average temps. Harvest came in on the same day as a dry hot year last year. I noticed this year much more sour rot on the tight cluster varieties. Monster Zin clusters had to be tossed. Reisling failed miserably. Looser clustered Cab Sauv did well but I see the small holes and and internal damage that indicates the GBM and of course the follow on sour rot.

Understanding regular Sevin will control GBM here is my question - is there a time in the life cycle of the GBM to spray a few times and limit spraying?

I drip apply imidacloprid once in the spring and have maintained a healthy population of beneficial insects. This has been the only pesticide i have used so far.

TIA

 

[TonyR]

The only time i have had a problem with grape berry moths was very early in the season, talking flower time. I sprayed with sevin and problem eliminated.

 

[grapeman]

In NY we have a Grape Berry moth model on the NEWA site. You base sprays on set growing degree days past when wild grapes bloom. Also since you had a lot of sour rot you may have a population of spotted wing drosophila. The females have a serrated ovipostitor and lay their eggs directly in the grapes. The larvae hatch and feed inside the grapes and leave a path for sour rot to infect. This even happens in France which is where Il earned about the correlation between sour rot and SWD.

http://newa.cornell.edu/

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5383864/

 

[dwhill40]

Thanks for the info. I'll attempt to use the degree day chart and catch those moths at their first hatching maybe. Muscadines grow in abundance in the area so there will always be pressure from them.

I found a "safe" product that eliminates fruit flies overnight. I only sprayed a few times this year but I will use it diligently next year. Bull's-eye bioinsecticide with the spinosad seems to really wipe them out. I haven't spotted the spotted fruit flies yet but each year brings a new pestilence.