Napa County agricultural officials met with counterparts from the United States Department of Agriculture and California Department of Food and Agriculture Thursday, offering an update on the European grapevine moth discovered last week near Oakville.

“We are still gathering information and traps have been placed to try and identify where the insect might be,” Greg Clark, assistant agricultural commission for Napa County, said. “We are still trying to determine the extent of the infestation.”

The European grapevine moth goes dormant in winter, while another pest in local vineyards — the Australian light-brown apple moth — can be trapped throughout the year.

“We do not expect to have a clear understanding of where this new pest is until the spring,” Clark said. “In some ways, that is good because there is no rush to do something right away.”

“In the spring, we need to have enough traps out to get the first flight of the moth and find out where exactly it is,” Dave Whitmer, agricultural commissioner for Napa County said.

The European moth caterpillars larvae feed on fruit as it ripens, ruining grape clusters and increasing the risk of mold affecting vineyards. Last week’s discovery was the first sighting of the European moth here.

Most Napa Valley vineyards are already under quarantine for the light brown apple moth, which is widespread in California but has done little damage. The quarantine requires growers, truckers and wineries to agree to inspections and seek certification from agricultural officials to harvest, deliver and crush the grapes.

The fact that the county already is dealing with one moth will make it easier for the industry to respond to the new one.

“We already have the safeguards in place with this new pest,” Clark said.

So far, there are still only the two confirmed identifications of the European moth.

“Nobody is rushing into anything. We care concerned and following up on every lead and busy submitting samples and checking traps,” Whitmer said.