|Johnson, Marshall - UNIV OF CA-RIVERSIDE|
|Daane, Kent - UNIV OF CA-BERKELEY|
Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Proceedings
Publication Acceptance Date: December 1, 2004
Publication Date: December 7, 2007
Citation: Johnson, M., Groves, R.L., Backus, E.A., Daane, K. 2004. Spatial population dynamics and overwintering biology of the glassy-winged sharpshooter, Homalodisca coagulata, in California's San Joaquin Valley. Proceedings of the 2004 Pierce's Disease Research Symposium. p. 117-119. Interpretive Summary: The purpose of this project is to define specific environmental constraints (temperature dependent feeding) that influence glassy-winged sharpshooter (GWSS) survival. Adult GWSS feeding and survival under different combinations of host plants and temperatures will be monitored to determine adult feeding activity. Experiments measuring honeydew excretion rates will determine the effects of temperature on feeding rates. Electronic feeding assays are also underway to monitor GWSS adult feeding. Corresponding waveforms reveal the frequency and duration of insect feeding behavior under different conditions. The seasonal survivorship of GWSS will be monitored on selected host plants placed in different regions of the San Joaquin Valley. Results from these experiments will be coupled with climatological data to define where GWSS can be expected to persist and identify where continued management efforts should be directed to limit introductions into non-infested areas of California.
Technical Abstract: The purpose of this project is to define specific environmental constraints that influence glassy-winged sharpshooter (GWSS) population dynamics and overwintering success. We are beginning experiments to determine the temperature-dependent feeding biology of GWSS in temperature-controlled chambers. Experiments are underway in the recently established GWSS Experimental Laboratory on the campus of California State University, Fresno. Adult GWSS feeding and survival under different combinations of host plant type and temperature regimes will be monitored to determine the temperature thresholds for adult feeding activity. Complementary experiments measuring honeydew excretion rates have begun to determine the amounts of excreta collected upon exposed surface(s) of water-sensitive paper and will be compared among different temperature and exposure regimes. Electro-penetration feeding monitoring assays are underway at different temperatures on individually tethered and feeding GWSS adults. Time course examinations of waveforms reveal the frequency and duration of insect feeding behavior under varying environmental conditions. The seasonal population dynamics of GWSS will be monitored on selected host plants placed in different micro-climatic areas of the San Joaquin Valley. 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 should be directed to limit introductions into currently non-infested areas.