Research Update from Activity #17A, August 25, 2020
Grape Phylloxera Detection and Control
Tom Lowery, Summerland Research & Development Centre, Agriculture & Agri-Food Canada
Grape phylloxera (Daktulosphaira vitifoliae), an aphid-like pest of grapevines, was recorded on Vancouver Island apparently for the first time this summer from leaf galls on a hybrid grape variety. Native to eastern North America, grape phylloxera is now found in most major wine-producing regions, including in the southern interior of British Columbia since 1961. The roots of European vinifera varieties are particularly susceptible to this pest, and the accidental introduction of grape phylloxera to Europe in the 1850’s devastated the industry within 25 years. The wine grape industry was saved by grafting susceptible varieties onto resistant rootstocks derived from American Vitis species or hybrids.
Grape phylloxera have a complex biology. The natural life cycle on native Vitis species involves both leaf-galling forms and root-infesting forms, asexual and sexual reproductive stages, and winged and wingless adults. Like most aphids, several generations are produced each season. The sexual forms and ability to create leaf galls has been lost in some areas where grapevines susceptible to the leaf-galling forms are not present. In other regions, biotypes or races have adapted the ability to feed and develop on rootstocks that were previously resistant to phylloxera feeding. Because of this variability and adaptability, phylloxera remain on the Canadian Food Inspection Agency (CFIA) quarantine list, requiring that grapevine nursery material receive a hot water treatment prior to importation.