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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Pest Management and Biocontrol Research » Research » Publications at this Location » Publication #197611

Title: Progress toward developing a novel immunological approach for quantifying predation rates on the glassy-winged sharpshooter

Author
item Hagler, James
item Groves, Russell
item FOURNIER, VALERIE - UC, BERKELEY, CA
item DAANE, KENT - UC, BERKELEY, CA
item JOHNSON, MARSHALL - UC, RIVERSIDE, CA
item MORGAN, DAVID - CDFA

Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Proceedings
Publication Acceptance Date: 12/5/2004
Publication Date: 1/1/2006
Citation: Hagler, J.R., Groves, R.L., Fournier, V., Daane, K., Johnson, M., Morgan, D. 2006. Progress toward developing a novel immunological approach for quantifying predation rates on the glassy-winged sharpshooter. CDFA Pierce's Disease Control Program Research Symposium 321-324.

Interpretive Summary: We just completed the first year of a multi-year research project dedicated to quantifying predation rates on GWSS nymphs and adults and qualifying predation on eggs. There are enough protein/ antibody complexes commercially available that each GWSS in a field cage can be marked with a specific protein. We marked two GWSS adults and two GWSS nymphs, each separately with a unique protein and released them into small field cages placed in a citrus orchard for 8 hours. Each cage also contained a sentinel GWSS egg mass and an assemblage of six potential GWSS predators. The experiment contained a day and night treatment. Observed mortality for each GWSS life stage and predator species was determined by simply counting the number of survivors remaining in each cage after 8 hours. Results showed that GWSS adults were preyed upon three times more frequently than nymphs and mostly during the day light cycle. The gut contents of each predator will be analyzed by four protein-specific ELISAs to determine how many GWSS each individual predator consumed. The gut contents of each predator will be examined by a GWSS egg-specific sandwich ELISA to determine the frequency of predation on GWSS eggs.

Technical Abstract: We just completed the first year of a multi-year research project dedicated to quantifying predation rates on GWSS nymphs and adults and qualifying predation on eggs. There are enough protein/antibody complexes commercially available that each GWSS in a field cage can be marked with a specific protein. We marked two GWSS adults and two GWSS nymphs, each separately with a unique protein and released them into small field cages (N=60) placed in a citrus orchard for 8 hours. Each cage also contained a sentinel GWSS egg mass and an assemblage of six potential GWSS predators. The experiment contained a day and night treatment. Observed mortality for each GWSS life stage and predator species was determined by simply counting the number of survivors remaining in each cage after 8 hours. Results showed that GWSS adults were preyed upon three times more frequently than nymphs and mostly during the day light cycle. Ultimately, the gut contents of each predator will be analyzed by four protein-specific ELISAs to determine how many GWSS each individual predator consumed (note: we are currently conducting these assays). Additionally, the gut contents of each predator will be examined by a GWSS egg-specific sandwich ELISA to determine the frequency of predation on GWSS eggs.