Monday, December 10, 2007
D0207

Secondary spread of Pierce's disease in central Texas vineyards

F. Mitchell, f-mitchell@tamu.edu1, Jeff Brady, jbrady@ag.tamu.edu1, Blake Bextine, bbextine@uttyler.edu2, and Isabelle Lauziere, ilauziere@tamu.edu1. (1) Texas Agricultural Experiment Station, 1229 N. Hwy 281, Stephenville, TX, (2) University of Texas - Tyler, Department of Biology, 3900 University Blvd, Tyler, TX

Evidence is presented that suggests the secondary spread of Pierce's disease in central Texas vineyards. Results from trapping studies, species distributions and molecular examination of captured insects from 2003 - 2006 are compiled to illustrate the point. Three insects are implicated - Homalodisca vitripennis, Graphocephala versuta and Clastoptera xanthocephala. Xylella fastidiosa amplifications from these insects are genotyped to determine which are Pierce's disease strain and which are not.


Species 1: Hemiptera Cicadellidae Homalodisca vitripennis (glassy-winged sharpshooter)
Species 2: Hemiptera Cicadellidae Graphocephala versuta
Species 3: Hemiptera Cercopidae Clastoptera xanthocephala (sunflower spittlebug)