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Grape Berry Moth and Phylloxera

Aerial Phylloxera. At some sites we are starting to see young leaves with aerial phylloxera.  In many cases, these vineyards will already have developed a large part of their canopy (eg. 12-14 leaves with no phylloxera galls).  If the majority of your leaves are ‘clear’ but you see phylloxera on the shoot tips,  I wouldn’t worry too much about it.  There is very little evidence that phylloxera galls at the shoot tips will compromise your yield or quality.  Its also unknown whether or not spraying them now will help you avoid problems next year.  Lots of factors influence phylloxera problems.  So spend the money if it makes you uncomfortable to see the galls (several insecticides are registered), but be aware that the impact will be small to unnoticeable if you already have a full canopy.

Grape Berry Moth:  According to the GBM forecasting model,  peak egg laying for GBM 2nd generation will occur around July 14.  Current GBM degree days are around 743 (for this generation), and you should hit 810 gdd at July 14-15, which is an ideal time to apply an insecticide if you need to.  Scout vineyards to see if you have any berry moth ‘stings’, recommendation is that if you have around 6% of the clusters infested, a treatment is warranted.


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