Grapevine peril

It appears that (hold your breath) perhaps California agriculture has dodged a major catastrophe this year with the early control of the European grapevine moth, Lobesia botrana.

Results from early-summer monitoring programs are very encouraging to agriculture officials. However, the quarantines, fruit inspections and trapping programs will continue at least until spring, which is the earliest that the monitoring could show that the insect is under control.

Key Points

• Early European grapevine moth control may have paid off.

• Quarantines and inspections will continue until spring.

• The tiny moth first appeared in late fall 2009 in Napa County.

Napa find

The tiny moth, only ¼-inch long as an adult, appeared in late fall 2009 in Napa County. The discovery prompted state and federal officials to implement a statewide monitoring system when the grape-growing season began in 2010. It was not an easy task. The number of grape-growing acres in California is huge, but the moth is very small and it is difficult to identify, requiring an entomologist in a laboratory to confirm its identity.

“We did some initial survey work very late in the 2009 season,” Larry Hawkins, a USDA spokesman, says.

“A few samples in the Napa area were confirmed positive. We arranged to do a survey in the spring, in all of the grape-growing areas within California. So, working with the California Department of Food and Agriculture and county agricultural commissioners, we now have 49,000 traps around the state,” Hawkins adds.

Wilcox writes from Sanger.

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identity CHECK: CDFA inspector Pao Vang examines a small moth found in a trap in the Fresno area to see if it is a European grapevine moth.

This article published in the August, 2010 edition of CALIFORNIA FARMER.

All rights reserved. Copyright Farm Progress Cos. 2010.