June 5, 2000

Glassy-winged sharpshooter (Homalodisca coagulata) nymphs and adults were brought to the Fresno County Department of Agriculture by Joe Kretsch with Sun Maid Growers of California. A friend of Mr. Kretsch had called him because this friend had found what he thought was glassy-winged sharpshooter in his backyard grapevine. Mr. Kretsch immediately brought it to the attention of the local county agricultural commissioner’s office.

This find triggered a delimitation visual survey that will continue in southeast Fresno through the remainder of this week and probably into next week. Delimitation trapping will be completed over the next few days with daily trap checks for the first week after initial deployment. The yellow sticky panel traps are being placed in a nine square mile area surrounding the original find location as directed by the California Department of Food and Agriculture.

Based on the delimitation visual survey completed on June 3, 2000, there is an established infestation of glassy-winged sharpshooter in the area southeast of Butler and Minnewawa Avenues in Fresno. Adults, nymphs and egg masses have been collected from the area. The egg masses will be monitored in the lab to see what parasites might emerge from some of the recently laid egg masses.

The glassy-winged sharpshooter adult is approximately -inch long and is dark brown to black with a lighter underside. The wings are partly transparent with reddish veins. When the adults and nymphs are newly emerged, they are grayish to light brown in appearance. The nymphs do not have fully developed wings. They are very efficient vectors of Pierce’s disease. This disease kills grapevines and there are no effective treatments for it.

Glassy-winged sharpshooter feeds on a wide variety of ornamentals and crop plants. They prefer to feed on stems rather than leaves, using their sucking mouthparts to remove fluid from plants. As a result of their feeding, they can transmit various plant diseases including alfalfa dwarf, almond scorch, oleander scorch and Pierce’s disease.

If you think you have found glassy-winged sharpshooter, please do one of the following:

  1. Call Dr. Norman Smith or Wayne Peregrin of the Fresno County Department of Agriculture at (559) 456-7510; OR
  2. Bring the suspect insect to the Fresno County Department of Agriculture at 1730 S. Maple Avenue in Fresno, Monday through Friday between the hours of 8:00 a.m. and 5:00 p.m.
  3. Click here for more on GWSS - http://danr.ucop.edu/news/MediaKit/GWSS.shtml