UC's Pierce's Disease Research and Emergency Response Task Force has just completed a brochure on the disease's most threatening vector, the glassy-winged sharpshooter, to help growers and others identify the insect. The brochure will be available from UC farm advisors working in viticulture at county Cooperative Extension offices throughout the state.

"The glassy-winged sharpshooter, with its ability to spread Pierce's disease, poses a very serious threat to viticulture throughout California," according to Ed Weber, UC Cooperative Extension farm advisor in Napa County and a member of the task force. "It has the potential to take what has been a localized disease problem and spread it across entire viticultural regions."

Pierce's disease, first discovered in the late 1800s, has caused millions of dollars in damage to the state's vineyards. The disease is caused by bacteria that choke off the plants' water and nutrient supplies. Scientists have long known that the disease-causing organism is transmitted to grapevines by blue-green sharpshooters. More recently, however, the glassy-winged sharpshooter emerged as a more formidable threat because of its wide host range and ability to spread rapidly. The new pest has severely affected grapevines in the Temecula area of Riverside County.

"We hope to enlist the support of growers throughout the state to begin a monitoring program for glassy-winged sharpshooters," says Weber. "The new brochure should help in this effort by providing excellent photographs, life history information and useful tips for identification."

County offices of UC Cooperative Extension are listed in most phone directories under the University of California. An online version of the brochure and additional information about Pierce's disease and the glassy-winged sharpshooter are available from the UC Division of Agriculture and Natural Resources at http://danr.ucop.edu.