A Monoclonal Antibody to Pink Bollworm (Lepidoptera: Gelechiidae) Egg Antigen: A Tool for Predator Gut Analysis
ABSTRACT We describe the development, selection, and application of a monoclonal antibody (MAb) to eggs of pink bollworm, Pectinophora gossypiella (Saunders). We tested this MAb against all pink bollworm life stages and the egg stage of 10 other insect species using an enzyme-linked immunosorbent assay (ELISA). In all cases, the MAb was highly specific to pink bollworm egg and adult female antigens. A Western blot analysis showed that the MAb reacted with two egg polypeptides with molecular weights between 46 and 60 kDa. Predation studies were conducted in the laboratory to test the usefulness of this MAb for studying predator-prey interactions. Most predators fed either one or two pink bollworm eggs responded positively to the MAb in a serological analysis of gut contents. These data suggest that this MAb can be used as a diagnostic probe for gut content analysis of potential predators of pink bollworm eggs under field conditions.
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ABSTRACT: Immunological methods have been widely used to identify key predator species and qualitatively evaluate predation of target prey. However, despite the quantitative nature of many immunoassays, the translation to number of prey attacked has been problematic because of the many factors that confound interpretation of the strength of the immunoassay response. We developed a new predation model that couples the proportion of predators positive for prey remains determined by enzyme-linked immunosorbent assay (ELISA), predator density, and predator functional response to prey density for estimating total prey attacked. We used single cotton plant arenas in the greenhouse to develop functional response models for two generalist predators, Geocoris punctipes (Say) and Orius insidiosus (Say), preying on Pectinophora gossypiella (Saunders) eggs. The model was validated and compared with other immunologically based predation models in multiple plant/multiple predator arenas. Our predation model was relatively accurate in predicting the total number of prey attacked by both predator species and was a significant improvement over previous models that rely on simple assumptions regarding predator attack rates. The model also improves the predictive capacity of the functional response model alone by correcting for the number of predators actually consuming prey. Sensitivity analyses indicated that model performance was most sensitive to accurate measurement of input variables such as temperature and the proportion of individuals positive for prey antigens by ELISA and less sensitive to changes in estimates of prey density. Accurate estimation of the functional response parameters is also important, especially for the behavioral parameter defining the decline in plant leaf area searched with increases in prey density. Limitations of the model and application to the field are discussed.02/2001;
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ABSTRACT: A two-year study was conducted in a citrus orchard, Citrus sinensis L., to determine frequency of predation on glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar). A total of 1,578 arthropod predators, representing 18 taxa, were collected and assayed for the presence of GWSS egg protein by an enzyme-linked immunosorbent assay using a Homalodisca-species and egg-specific monoclonal antibody and then by polymerase chain reaction using a H. vitripennis-specific DNA marker. The gut content analyses revealed the presence of GWSS remains in the gut of 2.28 % of the total arthropod predator population, with 3.09 % of the spiders and 0.59 % of the insect predators testing positive. Moreover, a comparison of the two assays indicated that they were not equally effective at detecting GWSS remains in predator guts. Low frequencies of GWSS detection in the gut of predators indicated that GWSS are not a primary prey and that predators may contribute little to suppression of this pest in citrus.BioControl 58(3). · 2.22 Impact Factor