Glassy-Winged Sharpshooter (GWSS) Control Projects
What to Know
The invasive glassy-winged sharpshooter attacks hundreds of plants, including many used in landscaping, and spreads Pierce’s disease, which is deadly to grapevines. With everyone's support, we can protect neighborhood greenery, landscape plants and crops. Without treatment, GWSS could cause major damage to the environment and the economy.
Current Eradication Projects
Working with county agricultural officials, the Pierce’s Disease Control Program (PDCP) coordinates trapping, surveying, treatment and biological control to find and eradicate new GWSS infestations outside of generally infested areas.
The PDCP is currently overseeing GWSS eradication efforts in five counties. See more details below.
Eradication projects can span several years. Infestations are declared eradicated when there have been no GWSS finds in the area for about two years since the last treatment. The PDCP has eradicated 18 GWSS infestations since 2001.
Treatments are conducted by licensed pest control operators under the supervision of the local county agricultural commissioner, or by trained personnel from the agricultural commissioner’s staff. More information about products that may be used during GWSS treatments:
- Merit® – English | Spanish
- Tempo® – English | Spanish
- CoreTect® – English | Spanish
- Altus® – English | Spanish
GWSS/Pierce’s Disease Notice of Treatment & Proclamation of an Emergency Program
El Dorado
The El Dorado Hills infestation was found in October 2024.
Status for 2026: January – March
- Detections: 36 adults, 4 nymphs and 43 egg masses
- Properties treated: 253
- Biocontrol Wasps Released: 0
Previous Year
| Detections | 2025 |
|---|---|
| Adults | 465 |
| Nymphs | 241 |
| Egg Masses | 142 |
| Properties Treated | 907 |
| Biocontrol Wasps Released | 6480 |
Proclamation of an Emergency Program (PEP) / Public Meetings
- PEP (GWSS): El Dorado Hills 2, December 18, 2025
- Map Only: El Dorado Hills 2, December 18, 2025
- PEP (GWSS): El Dorado Hills, January 10, 2025
- Map Only: El Dorado Hills, January 10, 2025
Fresno
In addition to area-wide treatments, urban treatments are ongoing in the areas of Kerman, Highway 41, Selma-Kingsburg, rural western Fresno County, Del Rey, Fowler, Kingsburg, Parlier, Reedley and Sanger to suppress GWSS populations in Fresno County.
Proclamation of an Emergency Program (PEP) / Public Meetings
- PEP (GWSS): West Fresno, February 20, 2025
- Map Only: West Fresno, February 20, 2025
- PEP (GWSS): East Fresno, February 20, 2025
- Map Only: East Fresno, February 20, 2025
Kings
The Hanford infestation was found in July 2025.
Status for 2026: January - March
- Detections: 2 adults, 0 nymphs and 0 egg masses
- Properties treated: 640
- Biocontrol Wasps Released: 0
Previous Year
| Detections | 2025 |
|---|---|
| Adults | 34 |
| Nymphs | 0 |
| Egg Masses | 0 |
| Properties Treated | 413 |
| Biocontrol Wasps Released | 2390 |
Proclamation of an Emergency Program (PEP) / Public Meetings
- PEP (GWSS): Hanford, October 10, 2025
- Map Only: Hanford, October 10, 2025
Madera
In addition to area-wide treatments, urban treatments are ongoing in southeast Madera County to suppress GWSS populations.
Proclamation of an Emergency Program (PEP) / Public Meetings
- PEP (GWSS): Southeast Madera County, August 12, 2025
- Map Only: Southeast Madera County, August 12, 2025
Santa Clara
The Morgan Hill infestation was found in September 2025.
Status for 2026: January - March
- Detections: 12 adults, 1 nymphs and 0 egg masses
- Properties treated: 929
- Biocontrol Wasps Released: 0
Previous Year
| Detections | 2025 |
|---|---|
| Adults | 29 |
| Nymphs | 17 |
| Egg Masses | 7 |
| Properties Treated | 0 |
| Biocontrol Wasps Released | 1440 |
Proclamation of an Emergency Program (PEP) / Public Meetings
- PEP (GWSS): Morgan Hill, November 6, 2025
- Map Only: Morgan Hill, November 6, 2025
Solano
The Vacaville infestation was found in 2021, and the likelihood of eradication is high.
Status for 2026: January - March
- Detections: 0 adults, 0 nymphs and 0 egg masses
- Properties treated: 208
- Biocontrol Wasps Released: 0
Previous Years
| Detections | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|
| Adults | 51 | 78 | 13 | 5 | 1 |
| Nymphs | 8 | 12 | 6 | 0 | 0 |
| Egg Masses | 43 | 54 | 213 | 105 | 10 |
| Properties Treated | 86 | 953 | 872 | 842 | 845 |
| Biocontrol Wasps Released | 0 | 4300 | 5190 | 6580 | 7630 |
Proclamation of an Emergency Program (PEP) / Public Meetings
Stanislaus
The Turlock infestation was found in August 2024.
Status for 2026: January - March
- Detections: 3 adults, 0 nymphs and 0 egg masses
- Properties treated: 165
- Biocontrol Wasps Released: 0
Previous Year
| Detections | 2025 |
|---|---|
| Adults | 168 |
| Nymphs | 4 |
| Egg Masses | 7 |
| Properties Treated | 3506 |
| Biocontrol Wasps Released | 7000 |
Proclamation of an Emergency Program (PEP) / Public Meetings
Tulare
In addition to area-wide treatments, urban treatments are ongoing in the areas of Dinuba/Reedley, Exeter, Tulare and Visalia to suppress GWSS populations in Tulare County.