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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 #212219

Title: A comparative study on the efficacy of a pest-specific and prey marking enzyme-linked immunosorbent assay for detection of predation

Author
item MANSFIELD, SARAH - FNR, SYDNEY, AUSTRALIA
item Hagler, James
item WHITEHOUSE, MARY - CSIRO, NARRABRI,AUSTRALIA

Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/19/2007
Publication Date: 2/19/2008
Citation: Mansfield, S., Hagler, J.R., Whitehouse, M.E. 2008 A comparative study on the efficacy of a pest-specific and prey marking enzyme-linked immunosorbent assay for detection of predation. Entomologia Experimentalis et Applicata. Vol 127, P199-2006

Interpretive Summary: The efficacy of two different antigen-antibody combinations to detect predation on eggs of cotton bollworm was compared, The first method was an indirect ELISA that detects cotton bollworm egg protein. The second method was a sandwich ELISA that detects an exotic protein (rabbit immunoglobulin G [IgGD]) applied as an external marker to cotton bollworm eggs. The target predators were predatory beetles. Beetles were fed cotton bollworm eggs that had been marked with rabbit IgG and then held at various intervals after prey consumption. Each individual beetle was then assayed by both ELISAs to identify the prey remains in their guts, The two ELISA methods were further tested on field-collected predators. Specifically, protein-marked egg masses were strategically placed in a cotton field. Then, predators from surrounding cotton plants were collected at various time intervals after the marked eggs were exposed and assayed by both ELISAs to detect the frequency of predation on the marked eggs. The rabbit IgG-specific sandwich ELISA had a higher detection rate than the H. armigera-specific indirect ELISA under controlled and field conditions for both predator species. Moreover, a greater proportion of field-collected D. bellulus tested positive for predation than H. variegata. The pros and cons of using prey marking ELISAs instead of pest-specific ELISA and PCR assays are discussed.

Technical Abstract: The efficacy of two different antigen-antibody combinations to detect predation on eggs of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) was compared, The first method was an indirect ELISA that detects H. armigera egg protein. The second method was a sandwich ELISA that detects an exotic protein (rabbit immunoglobulin G [IgGD]) applied as an external marker to H. armigera eggs. The target predators were the predatory beetles Dicranolaius bellulus (Guerin-Meneville) (Coleoptera: Melyridae) and Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae). Beetles were fed H. armigera eggs that had been marked with rabbit IgG and then held at various intervals after prey consumption. Each individual beetle was then assayed by both ELISAs to identify the prey remains in their guts, The two ELISA methods were further tested on field-collected predators. Specifically, protein-marked egg masses were strategically placed in a cotton field. Then, predators from surrounding cotton plants were collected at various time intervals after the marked eggs were exposed and assayed by both ELISAs to detect the frequency of predation on the marked eggs. The rabbit IgG-specific sandwich ELISA had a higher detection rate than the H. armigera-specific indirect ELISA under controlled and field conditions for both predator species. Moreover, a greater proportion of field-collected D. bellulus tested positive for predation than H. variegata. The pros and cons of using prey marking ELISAs instead of pest-specific ELISA and PCR assays are discussed.