Submitted to: Entomological Society of America Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 6/16/2005
Publication Date: 11/14/2005
Citation: Sikuljak, T., Groves, R.L., Chen, J., Lawson, A. 2005. Seasonal Population Dynamics and Incidence of Xylella fastidiosa Infection in Potential Insect Vectors of the Almond Leaf Scorch Pathogen in California's San Joaquin Valley. Entomological Society of America Annual Meeting. No Volume, issues or page numbers available. Interpretive Summary:
Technical Abstract: In recent years, almond leaf scorch (ALS) disease, caused by Xylella fastidiosa (Xf) has reemerged as a serious disease threat to almond production areas throughout California's San Joaquin Valley (SJV). The vector(s) of ALS strains of Xf, however, have not been as well documented and research is underway to identify potential vectors of Xf responsible for ALS spread. The seasonal population dynamics of sharpshooters (Homoptera:Cicadellidae), and spittlebugs (Hemiptera: Cercopidae) were monitored in permanent, irrigated pastures adjacent to almond with a high incidence of ALS. Green sharpshooters (Draculacephala minerva) were observed to be the predominant known vector species collected in these habitats with population's peak occurring in the summer months (May - September) and comparatively low populations during the winter. Population densities of D. minerva were not evenly distributed throughout sample fields with higher counts consistently collected distant from the irrigation source in areas that remain saturated after flood irrigation. DNA was extracted from field collected insects and single nucleotide polymorphism based, PCR formats used for determining the presence and strain composition of Xf. Preliminary data indicate comparatively high proportions of potentially infectious green sharpshooters collected during the summer months (June-August).