Monday, April 30, 2012
The first European Grapevine Moth males of the 2012 season were caught in two traps in the Hagen Rd/Olive Lane area east of the city of Napa. This is close to the Third Avenue area that was heavily infested in 2010. All growers within 500 meters of these finds have been contacted and only two had not yet installed their pheromones for mating disruption. It is very important that all growers in the treatment area install their pheromone dispensers and also spray the first two generations of larvae of EGVM. Pheromones alone will not be effective enough to eradicate this insect. So even if you have not caught moths near your vineyard over the last year you will still need to treat.
The timing for the first spray is at the pre-bloom stage. For very early varieties this will be in 1-2 weeks. For the majority of growers this spray timing is still 2-3 weeks off. Materials of choice for conventional growers are Intrepid or Altacor. Organic growers should use multiple sprays of BT products or Entrust.
From a historical standpoint, in 2010 there were 99,000 moths caught in Napa county in the first flight, In 2011 that number was 96 moths, and so far in 2012 there have only been 3 moths caught. We have come a long way but we still have some work to do if we hope to eliminate this pest.
Napa County EGVM Grower Liaison