Calaveras County is exploring new methods of monitoring potential winegrape pests as a result of layoffs in the agriculture department.
The department will go without its team of several seasonal extra-hire workers. Those workers monitor 180 traps set up in vineyards to detect the presence of the glassy-winged sharpshooter or European grapevine moth.
While neither of the insects have been located in Calaveras or Tuolumne counties, they have been found nearby and can have a disastrous impact on a crop worth more than $3.5 million in the Mother Lode if they gain a foothold.
The European moth was previously thought to be too cold-weather weary to make its way to the Sierra foothills, but was discovered in Nevada County earlier this month, prompting a quarantine.
“They’re thinking that it over-winters here possibly,” said Calaveras County Chief Deputy Agriculture Commissioner Kevin Wright.
Its presence in neighboring San Joaquin County means people bringing home grape vines, leaves or other detritus from grapes in the back of a pickup are a constant concern for local officials, Wright said.
In addition to the European moth, the glassy-winged sharpshooter is another insect that causes concern, with Calaveras and Tuolumne counties both listed by the California Department of Food and Agriculture as “at-risk” from the insect and the harmful Pierce’s Disease it carries.
Sharpshooters have been found as far north as Butte County, but the general infestation is limited to areas south of Santa Clara and Madera counties, according to the CDFA.
They are a greater worry because of the amount of damage they can do, according to Calaveras Winegrape Alliance President Matt Hatcher. When the sharpshooter eats grape leaves, it leaves a disease behind that destroys the entire plant. The moth, meanwhile, opens plants up to bunch rot while allowing the plant as a whole to survive, Hatcher said.
Hatcher said he has spoken with county Agriculture Commissioner Mary Mutz about the invasive pests. A meeting is tentatively scheduled the first week of July to educate local growers about the European grapevine moth, what its expanding presence in California means and measures to take to monitor for the harmful insects, he said.
“It’s good to be proactive. I think everybody in our small county, all the wineries, are going to be at that meeting,” Hatcher said. “I think we, as the wine industry, are going to be monitoring some of the traps ourselves. Whatever it takes for us to get together to take care of these problems.”