Napa County Winegrape Pest & Disease Control District

Agendas & Minutes

Agendas are available prior to the meetings. Minutes are available following approval.

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About the District

GWSS trap hanging on vineyard endpostThe Napa County Winegrape Pest and Disease Control District’s purpose is to provide funding for the inspection, detection, prevention, and education of Pierce's disease, glassy-winged sharpshooter, vine mealybug, and other potential pests of winegrapes. Currently, the District collects annual assessments $9.15 per planted acre of winegrapes (for parcels with one or more planted acres.) The local assessments help fund activities that benefit the local agricultural industry in Napa County. Local projects have included vine mealybug (VMB) trapping, VMB educational seminars and other education and outreach materials and events, VMB biocontrol releases, and regional VMB mating disruption trials in 2010 - 2012; the inspection of plant material for glassy-winged sharpshooter life stages, and glassy-winged sharpshooter vineyard trapping; sentinel pest trapping; and various UCCE research trials and projects.

Pest District SurveyPest DIstrict Survey QR Code

Please help us gauge grower awareness and support of the Pest District activities, and determine the priorities and concerns of grapegrowers by taking this short Napa County Pest District Survey. This voluntary survey is being conducted by the University of California Cooperative Extension (Napa County) and responses are anonymous.

Pest District Highlights

Vine Mealybug Biocontrol ReleasesVial of Anagyrus wasps on a vineyard wire

This summer the Ag Commissioner’s Office, in partnership with the Napa County Winegrape Pest and Disease Control District, implemented our VMB biological control program for a tenth year. The use of biocontrol is one component of an integrated pest management program that may include ant control, mating disruption, cultural practices, and the application of insecticides. We release Anagyrus - a tiny parasitoid wasp that lays its eggs inside female VMB, where the larvae grow and develop inside the mummified VMB skin.

Staff released live wasps and hung vials with Anagyrus mummies at approximately 160 sites throughout the County, releasing 1,500 – 2,000 wasps per site. Release sites were selected utilizing past trapping data, the UCCE chronically-infested data, and grower-identified infestations. Any vials left in your vineyard will be marked with a bright green Pest Detection Program - 2022 sticker and can be removed and recycled after harvest.

Grapegrowers are encouraged to release their own Anagyrus to augment the County's releases; potential sources are found here.

Vine mealybug trap on a grapevine

Other Activities Supported by the Pest District