European Grapevine Moth

We found 2, 1st instar larvae on Monday, 14-May. 

Of the eggs that we found, 19% had already hatched, 19% were ready to hatch (black cap), and 41% were in the yellow stage. 

This is the time to be treating for the 1st generation of Lobesia in Napa.  

It is time to treat for 1st generation Lobesia larvae in Napa County. Treatments should be applied between now and May 26.

A Napa Napa County trap deployed between Apr 24 and May 8 caught a total of 33 moths, confirming that peak of the 1st flight occurred towards the end of April. 

On May 9, we detected 66 eggs; 47% of these eggs were in the yellow stage, roughly mid-way through their development. Of the remaining eggs, 33% were white, 12% orange, and 8% black cap. We also found one larva (1st instar). This confirms that treatments will be effective if applied during the next 2 weeks. 

Please submit your Pesticide Use Reports for mating disruption by today's deadline. This critical information is used in many ways, and is of special interest to members of the Technical Working Group, who deliberate and make recommendations about the Lobesia program in California. As a member of the TWG, I can assure you that we do use this information, so please take a moment to provide it. 

 

It is time to treat for the 1^st generation of Lobesia larvae.  Ideally treatments should be applied between cluster elongation and the beginning of bloom. Applications should be made before 5% bloom.

Starting May 7, in Napa Valley and a week later in cooler areas, treatments can be combined with fungicide sprays anytime during the next 3 weeks. Hillside vineyards that are behind Oakville vineyards can be treated at the later end of the 2-3 week period, depending upon cluster development.  Organic growers will need to make multiple applications, at 7 to 10 day intervals.

We are inferring that the peak of the 1^st flight of Lobesia in Napa occurred during the week of April 23. This is based on recent trap catches, degree-day model calculations, and our experience with Lobesia over the last 2 years.  

Most eggs are laid during the peak flight period. We expect these eggs to hatch in 118 DDF. From April 25 to May 2, we accumulated 93.22 DDF in Oakville. Once most eggs start hatching, there will be a window of 2-3 weeks to control small larvae.

For those following degree-days, here are historical numbers for Napa (Oakville CIMIS) for the peak of the 1^st flight:
          2010: April 19 (485 DDF)
          2011: April 19 (572 DDF)
          2012: week of April 23 (588 DDF). 

UC Treatment Guidelines for the 1st generation of 2012 are now available on the UC Cooperative Extension, Napa County website.

Also, if you missed the Industry meetings in Napa County this week, my presentation is also available.

The Technical Working Group for Lobesia botrana has released their report, from meetings held Dec 13-15, 2011 in Sacramento, CA.

The report provides recommendations for regulatory policy and management practices for Lobesia botrana in California. Staff of USDA and CDFA use these recommendations to develop regulatory policy.

The Ag Commissioner's office will be holding three meetings to address the EGVM program in Napa County for 2012. The format will be identical for each meeting, so you need plan to attend only one. BUT, YOU SHOULD PLAN TO ATTEND, or send a representative, to learn about the recommended treatment program for 2012.

Yountville Community Center on Tuesday, Feb 14, 10 am to noon.
Tucker Farm Center (Calistoga) on Wednesday, Feb 15, 10 am to noon
Rutherford Grange on Thursday, Feb 16, 2 pm to 4 pm

Pre-registration is not required, but any questions regarding the meeting should be directed to the Ag Commissioner's office: 707-253-4357.

CDFA crews will be working in the RESIDENTIAL AREAS of Napa and American Canyon. They will not be working in any commercial vineyards. They will be removing mating disruption dispensers. They plan to start work on November 7, and hopefully finish by November 23. There will be seven 3-person teams removing the dispensers.

Questions? Please contact John Cooledge, in the Ag Commissioner's office:   (707) 253-4357 or john.cooledge@countyofnapa.org

We caught one male today (9-September) in a Napa County vineyard trap. This is a male of the 3rd flight that was forecasted to start at the end of August in Napa.  

Any moths trapped after 2350 degree-days Fahrenheit (DDF) are considered moths of the 3rd flight. As of August 28, we had accumulated 2367 DDF in Oakville (Oakville CIMIS station data).

Treatments for the 3rd generation were not recommended by the Technical Working Group, except in the case of obvious damage or populations. 

USDA-APHIS, CDFA, and California Agricultural Commissioners released a Situation Report on Lobesia botrana on August 27, 2011.

2011 catches in Napa County detection traps, by month:
April: 31 males
May: 60 males
June: 0 males
July: 15 males
Aug: 1 male

The Napa County Agricultural Commissioner and Staff have issued a progress report on EGVM activities in Napa. 

The report contains critical information on Compliance Agreements for the movement of fruit both within California and out-of-state. You must have an active compliance agreement to move or receive fruit grown in a quarantined area. Compliance agreements from 2010 are still in effect, unless you received an updated exhibit from the Agricultural Commissioner's office.

There are unique requirements for fruit moving out-of-state from the quarantined area. These are detailed in the newsletter file.

If you have any question on Compliance Agreements or fruit movement, please contact the staff of the Agricultural Commissioner: 253-4357