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Submitted to: Integrated Pest Management Symposium Workshop Proceedings
Publication Type: Proceedings Publication Acceptance Date: 2/1/2009 Publication Date: 3/24/2009 Citation: Hagler, J.R. 2009. The Use of Protein Markers to Pinpoint Predation Events. Integrated Pest Management Symposium Workshop Proceedings. 19.4 pg 35. Interpretive Summary: Identifying the feeding choices and amount of prey consumed by insect predators is difficult. Often the only evidence of arthropod predation is in the stomach contents of predators. The most effective method for analyzing stomach contents for prey remains is by molecular gut analysis. State-of-the-art predator gut content assays are similar to those used in the medical field to detect disease, pregnancy, genetic anomalies, etc. These assays include prey-specific enzyme-linked immunosorbent assays (ELISA) for the detection of prey-specific proteins and polymerase chain reaction (PCR) assays for the detection of prey-specific DNA. However, prey-specific assays are difficult, costly, and time consuming for wide scale use and they cannot quantify predation. These shortcomings were the impetus to develop a new technique for predator gut analysis. Specifically, prey items can be marked with foreign proteins. Predators exposed to marked prey can be assayed by a series of protein-specific ELISAs to detect individual predation events. The prey marking technique can be employed to quantify three aspects of arthropod predation that are impossible to study using prey-specific gut content assays. Specifically, prey marking can quantify predation and identify cannibalism and scavenging events. Prey marking for studies of predation is an untapped resource. The advantages and disadvantages of immunomarking (a.k.a., protein or prey marking) prey over prey-specific gut assays will be discussed. Technical Abstract: Identifying the feeding choices and amount of prey consumed by generalist predators is difficult. Often the only evidence of arthropod predation is in the stomach contents of predators. Currently, the state-of-the-art predator stomach content assays include prey-specific enzyme-linked immunosorbent assays (ELISA) for the detection of prey-specific proteins and polymerase chain reaction (PCR) assays for the detection of prey-specific DNA. However, pest-specific antibody development for the ELISA is too difficult, costly, and time consuming for wide scale use. PCR assays are less expensive, easier, and faster to develop than MAb-based ELISAs, but the assays are technically demanding, tedious, and time consuming. Finally, neither type of assay is quantifiable. These shortcomings were the impetus to develop a new technique for predator gut analysis, applying the protein marking technique used to mark insects for dispersal studies. Specifically, prey items can be marked with foreign proteins. Predators exposed to marked prey can be assayed by a series of protein-specific ELISAs to detect individual predation events. The prey marking technique can be employed to quantify three aspects of arthropod predation that are impossible to study using prey-specific gut content assays. Specifically, prey marking can quantify predation and identify cannibalism and scavenging events. Prey marking for studies of predation is an untapped resource. The advantages and disadvantages of immunomarking (a.k.a., protein or prey marking) prey over prey-specific gut assays will be discussed. |
