Dispersal of Homalodisca vitripennis (Homoptera: Cicadellidae) from a point release site in citrus.

• Author(s): Blackmer, Jacquelyn; Hagler, James; Henneberry, Thomas; Simmons, Gregory;
• Abstract: : GWSS is an important vector of Xf, a bacterium that has caused substantial losses in the viticulture and ornamental industries in California. Area-wide management programs have been implemented to reduce vector populations and limit the spread of this disease. However, there is still a lack of information on the factors that influence this insects movement within and between host crops. In this study, we used mark-release-recapture (MRR) to examine the dispersal of GWSS in a mature orange grove, Citrus sinensis Osbeck. Insects were doubly marked with chicken or rabbit immunoglobulin G (IgG) proteins and fluorescent dusts to enable monitoring over several weeks. Our objectives were to examine the reliability of IgG protein markers relative to fluorescent dusts, determine how sharpshooter movement differed in this landscape relative to a previous study in an open setting, and develop a better understanding of the biotic and abiotic factors that could influence sharpshooter dispersal. Linear regressions of recapture data with a diffusion model provided significant fits to the data in five out of six releases. Recapture data were fitted to a diffusion model and based on parameters generated with the model, estimated dispersal distances for GWSS at 72 h showed 50 and 99% remained within annuli of 31 and 150 m from the release site, respectively. Flight activity was greatest between 1000 - 1400 h, and no flights occurred between 2200 - 0600 h. Only temperature explained a significant amount of the variability in recapture of GWSS with sharpshooters rarely trapped below 18C.
• Publication Date: Jan 2006
• Journal: Environmental Entomology