Bad News: Moths Detected In Napa, CA

Posted by Christina Herrick|April 27, 2012

According to the California Association of Winegrape Growers, during a conference call Thursday by industry representatives and state and federal plant health officials, the Napa County Agriculture Commissioner reported that three adult male European grapevine moths (EGVM) were detected in two separate traps located east of the city of Napa, CA.

Currently, more than 5,000 traps are placed throughout Napa County and mating disruption materials cover more than 24,000 vineyard acres. In Sonoma County, 7,100 EGVM traps have been placed, but no EGVM finds were reported. EGVM traps have been placed in 17 California counties. Generally, planned treatments for EGVM have been delayed by cool spring weather, but EGVM detections are down from last year at this same time.

Despite this week’s news of finds, officials believe California could see the end of the European grapevine moth in coming years. First detected in Napa County vineyards in 2009, fewer and fewer of the pests are being found in traps. A main reason is the stepped-up fight by growers to control the insect.

Use of mating disruption pheromones and coordinated application of chemical treatments have had the biggest impact on EGVM eradication. For example, when moths were first trapped in Napa County, 100,000 were found. Last year, only 116 moths were found in traps.

To keep the bug battle busy, the USDA’s Natural Resources Conservation Service (NRCS) is offering grants to growers who use environmentally friendly methods, such as softer chemicals or natural treatments like pheromones, to combat the pests. Depending on their cost, growers can be reimbursed up to 75% of what they spend.