Posts Tagged: Stephen Vasquez
Anaheim boasted a thriving wine industry in the late 1800s, before an unnamed affliction killed 40,000 acres of the grapevines and put 50 wineries out of business. The problem was later found to have been Pierce’s disease of grapevines. Would Anaheim be wine country today if it weren’t for Pierce’s disease? Probably not, but the sad fate of this Southern California wine industry underscores the importance of controlling the disease and the insects that spread it in California’s thriving grape growing regions.
GWSS has turned out to be a very efficient vector of Xyella fastidiosa, the bacterium that causes Pierce’s disease in grapes. When GWSS made their way to places where scientists believed the bacterium didn’t exist, such as Kern County, grapevines began to express symptoms of the disease. The county agricultural commissioners in the San Joaquin Valley have been working tirelessly over the last 10 years to keep glassy-winged sharpshooters out of grape growing regions to protect a very valuable economic driver. In Fresno County alone, where grapes are the No. 1 agricultural commodity, the crop was worth $961 million in 2011.
Despite the efforts to contain GWSS in Fresno County, the pest is spreading very gradually south and east of the Fresno-Clovis metropolitan area into commercial vineyards and orchards.
“Cooperation by urban residents where we find GWSS has been great,” said Fred Rinder of the Fresno County Agricultural Commissioner’s office. Nevertheless, in 2012, GWSS was found spreading out in Kerman, Parlier, Sanger and Kingsburg.
Stephen Vasquez, UC Cooperative Extension advisor in Fresno County, fears local grape farmers have become complacent about glassy-winged sharpshooter and Pierce’s disease, even though all grapes are susceptible. The best way to control its spread, he said, is to monitor and manage sharpshooter vectors and remove and replace vines that have tested positive for Xylella fastidiosa.
“Be vigilant. Learn the symptoms and train crews and workers,” Vasquez said. “Pierce’s disease has been around for a long time and GWSS has been here more than a decade, but we still haven’t had that marriage of the two. That is potentially devastating.”
BMSB is now found in 33 states. Although not established in California, it has been identified in Los Angeles and Solano counties. BMBS can fly, but they primarily move into new areas by hitchhiking on vehicles and equipment.
Native to Asia, it's thought that BMSB arrived in packing crates shipped to the Eastern U.S. It has a large host range that includes grapes and many of the fruits and vegetables grown in California. Damage can be substantial when BMSB populations are not identified early and managed appropriately.
Apple growers in the Mid-Atlantic states have reported losses of $37 million representing 18 percent of their fresh apple market. Growers and wineries are also concerned that the “stink” from any bugs accidentally crushed in wine or juice grapes could taint the product with off flavors. This insect should concern homeowners as well, since people in the Mid-Atlantic states have reported large populations of BMBS overwintering in their homes and becoming a nuisance.
BMSBs resemble some other California stinkbugs, such as the rough stink bug, a beneficial predator of other insects. If you think you’ve found a BMSB, or any other odd or unique looking insect pest, you should collect it and bring it to your local university advisor, ag commissioner or state ag department entomologist for proper identification. Early identification of invasive pests is critical for protecting California’s billion dollar agricultural industries.
You can learn more about the BMSB and current research here.