Capital Press

There's another invasive moth threatening California's grapevines.

An adult and larva of the European grapevine moth, Lobesia botrana, was found by a grower in the Oakville area of Napa county last week. State scientists confirmed its identity on Oct 12. It was the first known detection of the moth in the United States.

The European grapevine moth is a known pest in Europe, the Mediterranean, southern Russia, Japan, the Middle East, Near East and northern and western Africa. It is known to feed on a list of additional fruits, including olives, blackberries, cherries, nectarines, persimmons and pomegranates.

The moth's larva bite into grapes, especially varieties with dense clusters, and feed on the inside, said Greg Clark, assistant agricultural commissioner in Napa County.

"We're working with sate and federal government to determine where exactly this pest is," Clark said.

That's being done through "delimitation trapping," which involves setting traps in a pattern of spokes extending from a central hub, Clark said.

"There is a sense of urgency," Clark said. "We need to find out as much as we can about this pest now, before winter."

Unlike the light brown apple moth, the European grapevine moth overwinters in its pupa stage, making it difficult to detect until spring, Clark said.

No regulatory action has been imposed yet on growers, who are still harvesting the year's crop. Researchers are first trying to get a handle on the moth's range, Clark said, and the picture will likely change quickly.

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