The UCCE-Napa viticulture team has a new resource for Pierce's disease: https://ucceviticulturenapa.wixsite.com/uccevitnapa/bgss-live-map
On this website you will find:
Blue-green sharpshooter trap counts from county-wide monitoring program
Guidelines for trapping blue-green sharpshooters
Resources for identifying common vectors
Sharpshooters and spittlebugs are vectors of Xylella fastidiosa, the causal agent of Pierce's disease of grapevines. In 2020, the UCCE-Napa viticulture team, with support from the Napa County Wine grape Pest and Disease Control District, launched a county-wide monitoring program for blue-green sharpshooter (BGSS), the most common vector in the north coast region. Trap data are updated in real time and are accessible via the link above. Trap data are viewable by growing region, by date, and by landscape category (riparian, ornamental, other).