European Grapevine Moth

If you plan to ship winegrapes out of California or out of the country, you must notify the Napa County Agricultural Commissioner’s Office.  Certain time sensitive regulatory requirements must be met prior to such shipments occurring, including removal of mating disruption, and trapping and inspection by Ag Commissioner staff.  If you don’t meet the required time frames for shipping, grapes will need to be fumigated or shipped as must.  If you plan to sell grapes through a broker going out of state, the grower is still required to contact the Ag Commissioner prior to shipping fruit.   

If you plan to ship out of California or the United States, please contact Agricultural Biologist Greg Music: greg.music@countyofnapa.org or (707)253-4357.  Thanks for your cooperation.

As of July 4, 2012, we have accumulated 1594 DDF in Oakville, CA. This is the appropriate time to apply insecticides targeting larvae of the 2nd generation in the regions of Napa that are similar in climate to Oakville. Growers using organic products should make two applications, at 7-10 day intervals. 

As of July 4, 2012, we have accumulated 1341 DDF in Carneros, CA. We should reach 1400 DDF next week. Products with ovicide-larvicide activity can be applied after we reach 1400 DDF (projected next week), in Carneros and other cooler regions of Napa. Products with larvicide activity only should not be applied until we have reached 1550 DDF. 

The Napa County Agricultural Commissioner would like to remind you of the importance of sanitation during the harvest season to minimize the risk of transporting Lobesia. Follow the newsletter link below to read about best practices for this harvest season. 

As of June 20, 2012, we have accumulated 1410 DDF in Oakville and 1180 DDF in Carneros. For areas other than Oakville and Carneros, please refer to the Table of Degree-Day Accumulations for Selected Locations in California.  

What this means for areas of Napa with climate similar to Oakville: 

If you are using an insecticide with ovicide and larvicide activity (such as Intrepid and Altacor), treatments can begin the week of June 24. 

If you are using an insecticide with larvicide activity only (such as organic products and conventional products other than Intrepid and Altacor), we must accumulate at least 1550 DDF before treating. We project this will be during the 1st week of July. 

What this means for areas of Napa with climate similar to Carneros:

If you are using an insecticide with ovicide and larvicide activity (such as Intrepid and Altacor), treatments can begin once we have accumulated 1400 DDF. We project this threshold will be reached in approximately 2 weeks. 

If you are using an insecticide with larvicide activity only (such as organic products and conventional products other than Intrepid and Altacor), treatments can begin once we have reached 1550 DDF. 

Products with ovicide and larvicide activity (Intrepid and Altacor) should be applied after we have reached 1400 DDF (from January 1).

Products with only larvicidal activity should be applied after we have accumulated 1550 DDF (from January 1). Growers using organic products should expect to make 2 applications during the 2^nd generation, at a 7 day interval.

In the warmer areas of Napa County, we expect to reach 1400 DDF during the week of June 25. Cooler regions could be 7-10 days behind.

As of June 10, we have accumulated 1029 DDF and 1230 DDF for Carneros and Oakville, respectively. We will post weekly updates of DDF accumulations for Carneros and Oakville.

If you have weather data from Calistoga, Pope Valley, or any other regions in Napa that differ from Oakville and Carneros, and are willing to share, we can use that information to make more accurate predictions about treatment timing for those regions.

Calculations used to determine treatment timing for 2^nd generation: Lower and upper development thresholds are 50ºF (10ºC) and 86ºF (30ºC), respectively. Start date for degree day accumulations: January 1, 2012.

Heat unit accumulations from the literature (for the 1^st and 2^nd generations): 306 DDF = egg hatch to pupation                                                           234 DDF = pupa development to adult                          &nb

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.