What do Arizona and California have in common? Winegrowers in both states are keeping close watch on the glassy-winged sharpshooter, the insect that carries the dreaded, vine-killing Pierce's disease.
Although California growers have watched the vineyard pest advance northward through their territory over the past several years, the scare is new to Arizona's burgeoning $18 million wine industry. Just this week, Arizona agricultural officials discovered eight adult sharpshooters and two viable egg clusters at a nursery in Sierra Vista, a 45-minute drive from Sonoita, one of the main winegrowing areas in the state's southeastern corner.
"I think everybody is a little nervous about it, but no one is panicking," said Todd Bostock, winemaker at Dos Cabezos WineWorks in Sonoita and secretary of the Arizona Winegrowers Association, which represents 16 wineries. "People around here shop in Sierra Vista as it is the closest place to shop, and it's likely that people could bring back plants from the area."
John Caravetta, the Arizona Department of Agriculture's director of plant services, said that the nursery, located in an Ace Hardware store, is being treated to eradicate any remaining sharpshooters. A door-to-door search in the surrounding residential areas has yielded at least another half-dozen adult insects and a suspected two more egg clusters.
"We are currently in the process of delineating the area of infestation," Caravetta said. "So far, we've detected adults in a three-quarter mile area around the nursery, primarily residential and shopping areas."
State agriculture officials are also currently eradicating an infestation in Tucson, Caravetta said, and a similar infestation had to be eliminated in Phoenix and Scottsdale two years ago.
Caravetta said that nurseries in Tucson and Sierra Vista receive stock from growers in Southern California, an area known to be infested with the glassy-winged sharpshooter. That's where the insect first came to the attention of the wine industry, when in 1998 and 1999 it nearly wiped out wineries and vineyards in the Temecula Valley in Riverside County.
Most of Arizona's wineries and vineyards are spread out in the corner between Nogales on the Mexican border, Tucson to the north and the New Mexico border to the east. Sonoita is the state's only American Viticultural Area. Bostock noted hopefully that the sharpshooter might not be well-suited to long-term survival in the area. "We're at a pretty high elevation, so it might get too cold in the winter for them to get established."