A coalition has been launched to persuade California grape growers to vote to continue an assessment on their crop that has been in place since 2001. The money is used to fund research by scientists combating Pierce’s disease, the glassy-winged sharpshooter and other pests that can destroy a vineyard.

The issue has taken on increased importance as a Marin County agricultural inspector discovered an adult glassy-winged sharpshooter on Feb. 26 while checking an incoming shipment of plants from Ventura County. The species damages a wide variety of plants and spreads bacteria responsible for plant diseases, including Pierce’s disease, which is fatal to grapevines.

The California Association of Winegrape Growers, Family Winemakers of California and Wine Institute have created a website — www.YESonPDref.org — to urge grape growers to continue the fee.

The assessment allows for grapes to be assessed up to $3 per $1,000 of crop value. For the past two years, the rate has been set at 75 cents per $1,000.

Growers have previously reauthorized the assessment twice in 2005 and 2010.