THE DEVELOPMENT AND CHARACTERIZATION OF AN ANTI-HEMOLYMPH ANTISERUM FOR THE DETECTION OF MOLLUSK REMAINS WITHIN CARABID BEETLES

Molluscan haemolymph was evaluated as an antigen for the detection, by enzyme-linked immunosorbent assay (ELISA), of mollusc proteins within the crop contents of carabid beetles, using an anti-haemolymph antiserum. The value of using a narrow range of prey-specific immunogens, rather than whole-body macerates, was discussed. Predators and potential prey were tested by a quantitative indirect ELISA, with separate evaluation of antigen reactions with non-specific and specific antibodies. The assay proved to be capable of detecting less than 1 ng of haemolymph protein and the antiserum reacted strongly with all molluscs tested. Initial cross-reactions with earthworms were effectively eliminated by absorption. A range of invertebrates was tested, and a significance level established relative to the invertebrates giving the strongest cross-reaction, which proved to be wolf spiders, Pardosa sp. Harvestmen (Opiliones), that initially gave strong reactions to the antiserum, were shown to have fed upon molluscs. Laboratory tests on the crop contents of slug-fed beetles demonstrated clear detection for at least 4 days after feeding.