Pierce's Disease

Information provided by ANR Communications Services for the University of California Pierce's Disease Research and Emergency Response Task Force. You may download a copy from the Division of Agriculture and Natural Resources web site at http://danr.ucop.edu or from the Communications Services web site at http://danrcs.ucdavis.edu http://ucipm/PMG/r302101211.html - UC Pest Management Guidelines

Sharp shootersGlassy-winged sharpshooter (Homalodisca coagulata) is a serious new pest in California. It is a particular threat to California vineyards due to its ability to spread Xylella fastidiosathe bacterium that causes Pierce's disease. Pierce's disease kills grapevines, and there are no effective treatments for it.


Mature Glassy-winged Sharpshooters

Top View Side View

The Glassy-winged Sharpshooter gets its name from its transparent wings.

Glassy-winged Sharpshooter nymphs

The immature nymphs are wingless.
The immature nymphs are wingless.

Glassy-winged Sharpshooter vs. Bluegreen Sharpshooter

Comparison Actual Size

Glassy-winged Sharpshooters are large insects about 1/2 inch long. 
The Glassy-winged Sharpshooter is shown next to the smaller Bluegreen Sharpshooter.


Fruit White Wash

Watery excrement often collects on either side of the insect, appearing as large white spots.
Watery excrement often collects on either side of the insect, appearing as large white spots.

Egg Masses

Egg mass
Eggs are laid together on the underside of leaves, usually in groups of 10 to 12. the egg masses appear as small, greenish blisters. These blisters are easier to observe after the eggs hatch, when they appear as tan to brown scars on the leaves.

Parasitized Egg Masses

Parasitized egg masses are tan to brown in color with small, circular holes at one end of the eggs.


Glassy-Winged Sharpshooter
Generalized Lifecycle


Glassy-winged sharpshooters overwinter as adults and begin laying egg masses in late February through May. This first generation matures as adults in late May through late August. Second generation eggs masses are laid starting in mid-June through late September, which develop into over-wintering adults.

Additional Site of interest:

http://www.cnr.berkeley.edu/xylella/ - XYLELLA FASTIDIOSA WEB SITE 
http://plant.cdfa.ca.gov/gwss/ - CDFA'S PD/GWSS SITE 
http://ucceventura.xlrn.ucsb.edu/IPM/IPMHome.htm - Phil A. Phillips - Integrated Pest Management