SPATIAL POPULATION DYNAMICS AND OVERWINTERING BIOLOGY OF THE GLASSY-WINGED SHARPSHOOTER IN CALIFORNIAS SAN JOAQUIN VALLEY

• Author(s): Backus, Elaine; Daane, Kent; Groves, Russell; Johnson, Marshall; Lynn-Patterson, Kris; Morgan, David; Son, Youngsoo;
• Abstract: The purpose of this project is to define specific environmental constraints that influence glassy-winged sharpshooter (GWSS) population dynamics and overwintering success. The production of xylem excreta was used as a measure of GWSS feeding rates. GWSS individuals held at 8.3 to 31.1C exhibited a positive linear relationship between xylem excreta per adult and temperature. A low temperature feeding threshold was estimated to be 13.3C. A Logan Type I model described the relationship between temperature and daily excreta production (mg). The percentage of adults that produced xylem excreta was significantly different among tested temperatures (P < 0.0001), but not between sexes. From 24.635.1C, all adults produced xylem excreta, but the percentage of adults producing excreta declined as temperature decreased. At temperatures = 13.3C, only 1 of 41 adults tested produced xylem excreta. Using percent data from 8.324.6C, a linear increase in the percentage of adults that produced xylem excreta was observed and provided a lower threshold temperature of 10.0C, where no xylem excreta were produced. Results from these experiments will be coupled with climatological data to help to spatially define where GWSS can be expected to persist in the agricultural landscape and identify where continued management efforts can be directed to limit introductions into currently non-infested areas.
• Publication Date: Nov 2006
• Journal: 2006 Pierce's Disease Research Symposium