Oregon grape growers received some good news and some bad news.
First the good news. The pest found recently in an abandoned vineyard in the Willamette Valley is not the vine mealybug, which is serious pest of grapevines, says Vaugn Walton, horticultural entomologist at Oregon State University in Corvallis.
But the pest is most likely the obscure mealybug, also known as the ground mealybug. Obscure mealybug, which are often found underground on vine roots, also may transmit grapevine leafroll virus.
Vines infected with the virus typically impairs photosynthesis, resulting in lower quality grapes and wine quality, Walton said in a news release.
Scientists used PCR genetic fingerprinting to identify the specimen. Obscure mealybug are different than vine mealybug and typically aren't as invasive.
“Oregon is known for low incidence of scale insects and grapevine leafroll virus, but we are encouraging the industry to remain vigilant and keep alert,” Walton says.
The specimen was an immature, so continued sampling will be conducted in the vineyard.
In addition, the Oregon Wine Board has teamed with OSU and Southern Oregon University to test 28 vineyards in southern Oregon, and is considering statewide monitoring in 2009. Results of the southern Oregon monitoring tests will be known in the next four to five weeks.
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