New insect vectors of grapevine Pierce’s disease (Xylella fastidiosa) in North Carolina (US)
Grapevine Pierce’s disease caused by Xylella fastidiosa (EPPO A1 List) occurs in North Carolina (US) but field data about its primary insect vectors was still lacking. In 2004 and 2005, yellow sticky traps were placed in vineyards of the eastern Piedmont and Coastal Plain regions of North Carolina. Among potential insect vectors, the most abundant species caught were: Oncometopia orbona, Graphocephala versuta, Paraphlepsius irroratus, and Agalliota constricta (all Homoptera: Cicadellidae). Adults were tested for the presence of X. fastidiosa by nested-PCR. Results showed that 27 % of O. orbona, 28% of G. versuta and 33% of P. irroratus tested positive for the bacterium. Transmission experiments then showed that both O. orbona and G. versuta were able to transmit X. fastidiosa to grapevine. Although further studies are needed on the biology of these two insect vectors, it seems that O. orbona is likely to be the primary vector of X. fastidiosa because it enters vineyards early in the spring and feeds on shoots, thus allowing X. fastidiosa more time to colonize grapevine.
Sources
Myers A, Sutton TB, Abad JA, Kennedy GG (2007) Pierce’s disease of grapevines: identification of the primary vectors in North Carolina. Phytopathology 97(11), 1440-1450.