Phylloxera Biotype B is a newer mutant of Phylloxera which suddenly appeared in Napa and Sonoma vineyards in the mid 1980s. It successfully attacks and destroys the AXR-1 rootstock (and any fruiting variety grafted onto it), thus killing many of the California North Coast's most valuable vineyards. It will have been the reason for at least 60,000 acres of prime Napa, Sonoma and other California vineyards being pulled out and replanted to other rootstocks by the year 2000. Fortunately, there are many other rootstocks available, many of which are superior to the old AXR-1 in viticultural attributes besides being immune to attack by Phylloxera Types A and B. (Wine/Other)