Virginia Creeper Leafhopper: Fairyfly to the Rescue

How do you get rid of an invasive leafhopper that destroys acres of vineyards?

In Hopland yesterday, growers in Mendo, Lake and other counties met to hear the latest recommendations from U.C.'s Cooperative Extension researchers studying and learning how to combat invasions of the non-native Virginia Creeper Leafhoffer, a bug that has been plaguing North Coast vineyards.

This leafhopper has been particularly devastating to organic growers, a number of whom have abandonned organic practices in order to stay in the vineyard business, according to UCCE Farm Advisor, Glenn McGourty, who serves in the Mendocino and Lake county region. But, as the latest research shows, there's hope they could return to organic wine grape growing.

At the July 7th tailgate event in the vineyard, Berkeley Post-Doctoral Researcher Houston Wilson presented the latest findings on improved methods on combatting the Virginia Creeper Leafhopper (Erythroneura ziczac).

Virginia Creeper Leafhopper
Credit: Mike Poe, UC ANR Communications

Researchers found a parasitoid, Anagrus daanei, a member of the fairyfly family, one of the tiniest flying insects. A particular strain that exists in the Sacramento Valley is effective in keeping Virginia Creeper Leafhopper populations in the North Coast in check.

The parasitoid also lives in Mendocino, but local specimens have not been going after the Mendocino Virginia Creeper Leafhoppers, which only recently invaded the area.

Virginia Creeper Leafhopper eggs parasitized by the Anagrus daanei

A 2015 pilot program, conducted with the initial support of the American Vineyards Foundation and Fetzer, was successful enough to win funding from the California Dept. of Pesticide Regulation's Pest Management Alliance grants program for the purposes of rolling out significant numbers of Anagrus daanei to a larger number of vineyard growers.

"We started our initial releases in July 2015 with 2,000 Anagrus daanei, and they spread into the vineyard blocks," Wilson said. Now in 2016, his group has started a much larger release program, with four vineyards in Mendocino and one in Lake County. "And we're looking for new targets," he added.

Houston Wilson

The release program has continued with one release per month at each site. "We've done 13 releases so far," Wilson said. Researchers have been breeding Anagrus daanei in the lab to provide releases of more of the fairyflies.

Wilson said the fairyflies reproduce up about 10 times per season, faster than the leafhoppers.

Use of the parasitoids to control the Virginia Creeper Leafhopper will reduce the amount of pesticides used in fighting the invasive non-native species as well as reduce pesticide costs for both conventional and organic growers.

For more information, or to find out how to participate in the program, visit the project's web site at http://ucanr.edu/sites/vclh/.