PD/GWSS Timeline

10 Years in Perspective


  • 300 acres of grapevines in Temecula infested with the glassy-winged sharpshooter are destroyed and the full extent of the threat the GWSS posed to California agriculture is recognized
  • Riverside County Board of Supervisors declares local emergency
  • CDFA appoints task force to develop strategies and resources to combat GWSS threat
  • Preliminary survey shows GWSS present in eight southern California counties
  • Advisory task force created
  • Federal assistance secured to reduce sharpshooters in Temecula
  • Dr. Triapitsyn of the University of California, Riverside, and Larry Bezark of the CDFA made the first trips to Mexico in search of GWSS egg parasitoids
  • Temecula Valley implements area-wide program that includes trapping and treatments for GWSS


  • Pierce’s Disease Advisory Task Force first meeting
  • The University of California reports that Pierce’s disease transmitted by blue-green sharpshooter destroyed over 1,000 acres of grapevines in Northern California, causing $30 million in damages, since 1994
  • CDFA develops and releases statewide survey protocols and guidelines for counties to use to find infestations of GWSS
  • CDFA develops and activates Web site dedicated to Pierce’s disease and GWSS. The site is visited over 500,000 times during the first year of operation
  • CDFA scientists and the University of California travel to Mexico to search for natural enemies of GWSS
  • Senate Bill 671 signed by Governor Davis establishing the Pierce’s Disease Control Program
  • Single GWSS trapped in nursery in San Joaquin County distant from the infested areas
  • Large scale survey effort helps establish protocol for responding to new sharpshooter discoveries
  • GWSS egg parasitoid, Gonatocerus triguttatus, first released
  • Multiple state and local agencies are mobilized for rapid response
  • Federal government issues declaration of emergency, providing $22.3 million to counter spread of GWSS and support research to find cure for Pierce’s disease
  • CDFA adopts emergency regulations to regulate movement of nursery stock and bulk grapes
  • Statewide compliance programs developed and implemented
  • Survey and detection efforts find additional GWSS infestations in Fresno and Sacramento counties
  • Wasp Pilot project initiated, releases GWSS natural enemy – a tiny wasp from Mexico – in Kern, Riverside and Ventura Counties
  • GWSS infestation discovered in Chico, Brentwood, Fresno and Sacramento
  • GWSS infestations discovered at multiple sites in Tulare and Fresno counties
  • State and local agencies work together to treat over 250 residential properties
  • Environmental Protection Task Force formed
  • Live sharpshooters found in bulk citrus shipments; shipping temporarily suspended until CDFA adopts new emergency regulations for bulk citrus
  • Kern County Pilot Project begins
  • Regional stakeholder meetings in Napa, Orange, Sacramento, San Diego, San Luis Obispo, Stanislaus and Tulare Counties
  • The Environmental Protection Task Force issues recommendations to the Secretary in formal report
  • California Agricultural Commissioners and Sealers Association/Glass-Winged Sharpshooter Advisory Group formed


  • Public scoping meetings held throughout the state to maximize opportunity for public input into the EIR process
  • Assembly Bill 1394 signed, bolstering research and other program activities by providing approximately $5 million per year for five years from an assessment on winegrapes
  • GWSS infestation discovered in multiple sites in Santa Clara County
  • Pierce’s disease and Glassy-winged Sharpshooter Board established to develop recommendations on the use of collected monies
  • Assessment rate set at $3 per $1,000
  • GWSS egg parasitoids, Gonatocerus ashmeadi and Gonatocerus walkerjonesi, first released
  • Emergency regulations governing the movement of bulk citrus adopted
  • First annual Pierce’s Disease Research Symposium
  • First Area Wide control program for GWSS establish in the General Beale area of Kern County


  • Assessment rate lowered to $2 per $1,000
  • Pierce’s disease program draft environmental impact report completed and released for public review and comment
  • First localized GWSS infestation eradicated in Brentwood (Contra Costa County)
  • Pierce’s Disease/GWSS Science Advisory Panel meets in Sacramento to review program and develop recommendations
  • GWSS infestation discovered in Imperial Spa (Imperial County)
  • GWSS infestation (second site) discovered in Sacramento
  • New emergency program regulations filed
  • Structured monitoring protocol put in place at all GWSS egg parasitoid sites
  • GWSS egg parasitoid, Gonatocerus fasciatus, first released
  • Area wide GWSS management program implemented in Ventura County
  • Area wide control program expanded beyond General Beale area north and to Hwy 65 in Kern County.


  • Permanent program regulations governing the movement of nursery stock, bulk grapes and bulk citrus adopted
  • The Coachella Valley Area-wide GWSS Program begins
  • GWSS infestation discovered in Bombay Beach and Paradise Lane (Imperial County)
  • The program’s Final Environmental Impact Report (Final EIR) completed and released
  • Experiment conducted to test efficacy of pre-shipment treatment of nursery stock at killing GWSS eggs masses and emerging nymphs
  • SB633, the California Table Grape Pest and Disease Control District Law, passes
  • The Program’s emergency regulations become permanent
  • A program underway to help California nurseries with their efforts at keeping nursery stock shipments free of GWSS
  • Second localized GWSS infestation eradicated in Chico (Butte County)
  • GWSS infestation eradicated in Cupertino (Santa Clara County)
  • Fresno County implements area-wide trapping for GWSS in citrus groves
  • Tulare County implements area-wide program that includes trapping and treatments for GWSS
  • Area wide control program that stated with General Beale area expands westward in Kern County
  • Statewide programmatic environmental impact report released for the PDCP


  • Kingsburg area of Fresno County declared eradicated
  • National Academy of Sciences (NAS) releases independent scientific review
  • GWSS infestation in Vacaville, Solano County, detected.
  • The PDCP’s biological control unit acquired a much-needed larger facility in Arvin, Kern County, to increase the production of control agents.


  • GWSS egg parasitoids, Gonatocerus morrilli and Anagrus epos, first released
  • Nursery Treatment Pilot Program begins
  • Second GWSS infestation discovered in Chico
  • The genetic markers (PdR1) for PD resistance in grapevines are discovered at UC Davisdiscovered in June 2005
  • GWSS infestations in Imperial Spa, Bombay Beach and Paradise Lane (Imperial County) are declared eradicated
  • GWSS infestation discovered in Three Flags Area (Imperial County)
  • Winegrape growers demonstrated their continued support for the program when, by a 9 to 1 margin, they vote to continue the winegrape assessment for PD research


  • Assessment to fund research earmarked for PD/GWSS renewed
  • Kingsburg area of Fresno County reinfested
  • Infestation discovered in the Evergreen area of south San Jose in Santa Clara County
  • Statewide Survey and Detection protocols distributed to counties
  • Statewide Survey and Detection biologists provided detection training to 366 county and state personnel
  • Infestation discovered in the Beach Line Area (Imperial County)
  • First annual PD/GWSS Board-sponsored research forum at the American Society of Enology and Viticulture’s annual meeting
  • PD/GWSS Board Selects Nancy Irelan as Research Director
  • PDCP consolidated its research proposal solicitation and review process with the University of California’s Pierce’s Disease Research Grants Program
  • Five counties participate in the Nursery Treatment Pilot Program
  • GWSS infestation in Fowler, Fresno County, is declared eradicated.
  • GWSS infestation in Chico, Butte County, is declared eradicated.


  • Assessment rate lowered to $1.50 per $1,000
  • PD/GWSS Board sets up Research Scientific Advisory Panel (RSAP)
  • The first PD/GWSS Research Scientific Review is released by the RSAP
  • Vacaville, (Solano County) GWSS infestation declared eradicated
  • GWSS infestations in Three Flags area (Imperial County) is declared eradicated
  • Bio-control agents were released in over 13 sites throughout California.
  • 60,600 shipments of nursery stock from infested areas to un-infested areas were inspected.
  • Statewide, no new infestations of GWSS were found and 35 counties were verified as being free of GWSS infestation


  • Assessment rate set at $1 per $1,000
  • Nursery Approved Treatment Program implemented for nurseries in GWSS infested areas.
  • GWSS infestations in Beach Line area (Imperial County) is declared eradicated
  • Infestation of GWSS in 13 counties: Fresno, Imperial, Kern, Los Angeles, Orange, Riverside, Sacramento, San Bernardino, San Diego, Santa Barbara, Santa Clara, Tulare, and Ventura.
  • UC Davis finds the physical location on the genome of the PdR1 gene that provides grapevines with resistance to PD
  • Full-time staffed border inspection stations increased from two to 16
  • “Best Winery in California” thanks PD/GWSS Board for success in Temecula
  • Three adult glassy-winged sharpshooters found in Santa Clara County, prompting a rapid-response survey. These detections lead to the new Capitol area infestation in the city of San Jose, Santa Clara County.


  • Blossom Hill area (Santa Clara County) GWSS infestation declared eradicated
  • Infestation discovered in the Meridian area (Santa Clara County)
  • Foothill Farms area (Sacramento County) GWSS infestation declared eradicated
  • Assessment rate remains at $1 per $1,000
  • SB2 passes and would extend and expand the current Pierce’s Disease Program if growers approve a referendum on the research-oriented program in 2010. If extended, the PD Program could do research and outreach on other invasive pests that affect winegrapes if approved by the PD Board and Secretary of the California Department of Food & Agriculture.

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