(Wines&Vines) - In its ongoing fight against grapevine pests, the Napa Valley Technical Viticultural group brought in the big guns from the University of California, Davis, last week. Andy Walker from the viticulture and enology department gave an update on recent findings about phylloxera, and Jim Wolpert presented evidence of a mysterious new scourge; he asked grapegrowers at the meeting to let him know if they’ve encountered it. A new threat to vines? Called “red blotch” for its distinctive appearance, Wolpert said the new malady is not caused by known viruses or other plant diseases. He said that plants at the Oakville Experimental Station show the condition, and that it seems to be spreading there. It may be localized, but he has also noticed similar symptoms elsewhere in Napa Valley.