Skip to main content
Sharpshooters & Pierce's disease in Southern California

Department of Entomology

glassy winged sharp-shooter
Sharpshooters & Pierce's disease

The purpose of this site is to provide information on the biology and management of sharpshooters and Pierce's disease, with a focus on Southern California vineyards and surrounding areas.

The blog will be used to post regular updates on the results of the Temecula glassy-winged sharpshooter areawide monitoring program and to occasionally share other information relevant to sharpshooters, Xylella fastidiosa, or Pierce's disease.

For more information, contact Matt Daugherty (matt.daugherty@ucr.edu; 951-827-2246)

Updated GWSS monitoring - late April

There have been three rounds of trapping since the last update. Over that period, GWSS captures have declined down to very low numbers that is more typical of this time of the year than last season. Hopefully, it is an early indicator we'll see much lower GWSS activity than last summer No GWSS adults were...

Train-the-trainer Workshop: CropManage Software

UC ANR staff are organizing a "Train-the-trainer" meeting on March 21st for the CropManage software. More details about the software and event are below ******************************************* The CropManage team and members of the Nitrogen and Irrigation Initiative would like to invite you to learn how to use CropManage, an online decision-support tool for irrigation and nitrogen...

Temecula GWSS monitoring - February 2025

GWSS activity is up again to similar levels as this time last year. Given the warm weather the previous couple of weeks, before the recent rain, this is not unexpected A total of 39 GWSS adults were captured among the 115 traps that were inspected. One trap collected 6 sharpshooters, and 10 others had multiple...

Update Temecula GWSS monitoring - early 2025

GWSS activity increased slightly since the end of the year. This likely reflects a small winter generation of GWSS, which is typical in most years. A total of 18 GWSS were collected on 10 traps among the 71 traps recovered last month. As you can see in the map below, only a handful of traps...

Updated Temecula GWSS monitoring - 2024 summary

Belated happy New Year. Since the last post there have been three rounds of GWSS trapping. The results show sharp declines in the number of GWSS captures, which is typical for this time of year. A total of just 17 GWSS were collected among the 213 total traps recovered over the three censuses (issues with...

Scouting for Pierce's disease

Although things are busy this time of the year with harvest, it is also a good time to keep an eye out for Pierce's disease. Symptoms are strongest this time of year. Try to scout the vineyard as time allows and flag suspected diseased vines for later removal. The following document has some additional details...

New restrictions on neonicotinoid use for glassy-winged sharpshooter?

At the beginning of the year the California Department of Pesticide Regulation ( https://www.cdpr.ca.gov/) placed restrictions on the use of neonicotinoid insecticides, the goal of which are to reduce pollinator exposure. This policy change has the potential to impact the use of certain insecticides (e.g., imidacloprid, dinotefuran, thiamethoxam, clothianidin) that are commonly used for the...

Scouting for Pierce's disease

Although things are busy this time of the year with harvest, it is also a good time to keep an eye out for Pierce's disease. Symptoms are strongest this time of year. Try to set aside some time to scout the vineyard as time allows and flag suspected diseased vines for later removal. The following...

Temecula GWSS Areawide Program is Winding Down

Please note that the Temecula GWSS areawide monitoring will be wrapping up after June 2023. This program has been administered by the CDFA with funding from the USDA for more than 20 years, the goal of which was to support broad-scale monitoring of GWSS populations in the region to guide vineyard pest management decisions. In...

Scouting for Pierce's disease

As things ramp up in preparation for harvest, it is also a good time of the year to keep an eye out for Pierce's disease. Symptoms are strongest this time of year, therefore consider scouting the vineyard as time allows and flag suspected diseased vines for later removal. The following document has some additional details...

How bad a GWSS year is it going to be?

One of the big challenges with managing Pierce’s disease in California vineyards is there can be tremendous variability in vector activity and Xylella fastidiosa spread among locations and over time. They’re moving targets. This is particularly true for the glassy-winged sharpshooter, which has strong seasonal patterns of activity and substantial year-to-year variability in activity. Seasonal...

UC resources for dealing with drought

After a brief hiatus, we are back in drought. Some University of California resources for dealing with drought can be found here: http://ucanr.edu/drought

Welcome back

After a long hiatus due to some university IT stumbles, the blog is back. Keep an eye out here for updates on the Temecula GWSS areawide monitoring program and other information about sharpshooter and Pierce's disease biology and management. Any questions should be directed toward Matt ( matt.daugherty@ucr.edu; 951-827-2246)
Let us help you with your search