Napa Makes Moth Control Mandatory

County requires grapegrowers and winemakers to sign compliance agreements regarding European grapevine moth

by Paul Franson
European grape vine moth
July marks the second generation of EGVM on fruit. Larvae tie berries together using webbing. The University of California recommends that growers separate berries and Look for larvae and entry holes in berries. Photo by Larry Strand/University of California
Napa, Calif. -- Due to continued pressure from the invasive and destructive European grapevine moth (EGVM), Napa County agricultural commissioner Dave Whitmer warned growers and wineries that they will not be allowed to harvest, move or receive winegrapes unless they obtain a compliance agreement issued by his office. Most of Napa County is under quarantine due to the presence of the virulent bug.

Noting that this is a tremendous undertaking, and seeking maximum efficiency, he scheduled mandatory meetings for all growers, harvesters, haulers or receivers (wineries) of winegrapes. At the meetings he will review the EGVM quarantine restrictions and distribute compliance agreements for them to complete. Staff from the commissioner's office will be available to issue compliance agreements to all the attendees.

Whitmer also spoke at yesterday's Organic Grapegrowing Conference, sponsored by the Napa Valley Grapegrowers (NVG), to elaborate on the efforts.

He said, “This is not an easy pest, but we need to get a handle on it. In my experience, if we work together, we can control it.”

He added that he believes the pest was in the valley for some time before it was detected, and likely it was spread by the kind of practices now being restricted. He also thinks the moth was taken to Fresno County this way, probably on some grape stakes that have been identified.

Whitmer warns that green waste of all types is of great concern. Green waste does not include pomace from fermented grapes, because alcohol would kill the pest; pomace from white and rosé winemaking and all leaves, stems and other waste must be handled carefully.

Effective composting will be especially important, and the piles will require aeration and enough water to reach the high temperatures needed to kill the bugs. As a supporter of sustainable agriculture practices, Whitmer noted, “I know that this will also kill beneficial organisms, and I’m sorry about that.”
He suggested that the risk is less this year than last harvest, due to the steps growers have been taking to suppress the moth, including spraying with approved insecticides and mating disruption.

He emphasized that his department is asking for vineyards to use common sense to reduce the risk of spreading the bugs, and it has compromised on some issues such as allowing shipments that aren’t fully covered, in some cases.

At the NVG conference, one grower asked about enforcement, saying he’d heard rumors that sheriff’s deputies would be in charge. Whitmer paused, then stated, “We have no plans for using deputies to stop trucks. This process is in everyone’s interest, and we don’t anticipate problems with compliance.”

The meetings to explain the regulations and distribute the forms are scheduled for:

•    Thursday, July 22 at 6 p.m.
•    Tuesday, July 27 at 9 a.m.
•    Thursday, July 29 at 4 p.m.
•    Tuesday, August 3 at 1 p.m.

All meetings will be held at the UC Cooperative Extension offices at 1710 Soscol Ave. in Napa. The ag commissioner will be issuing compliance documents at these meetings. Phone (707) 253-4357 to RSVP for one of the meetings.

If you cannot attend one of the meetings, contact the ag commissioner’s office to make other arrangements. The forms and a summary of the regulations are also posted at countyofnapa.org/AgCommissioner/EGM/.




Posted on 07.26.2010 - 05:34:22 PST
It appears your commissioner is being seen to be doing something about a situation that cannot be controlled. It's a moth, regardless of what you do, covering loads etc., the larvae will not escape the load. They're happy within the cluster. Those that survive and pupate and emerge as moths, mate and survive to lay eggs will keep the spread moving regardless of what you do. All you can do is manage the pest, just educate the growers about its life cycle and its most vulnerable points, give the growers the info to implement management practices and calm down! Every time Cali ag sneezes, government reacts with a fully fledged Ebola virus containment strategy. Get a grip. It's a moth whose larvae cause fruit damage, if managed effectively, the damage is minimal (unless its table grapes of course, nil tolerance I would imagine). But Crikey guys, it's an insect. It will always win. Manage it and it won't beat you.
Lobethal, OH Australia