MEASURING THE SENSITIVITY OF AN INDIRECT PREDATOR GUT CONTENT ELISA -DETECTABILITY OF PREY REMAINS IN RELATION TO PREDATOR SPECIES, TEMPERATURE, TIME, AND MEAL SIZE

The gut contents of three species of insect predators that were fed ei ther a variable or a fixed number of pink bollworm eggs but held at va riable time and temperature regimes were assayed by an indirect enzyme -linked immunosorbent assay (ELISA). The sensitivity and efficacy of t he monoclonal antibody-based ELISA was dependent on the predator speci es examined, Small predators were more immunoresponsive to the ELISA t han large predators. Furthermore, the assay sensitivity was dependent on the number of prey consumed, elapsed time after feeding, and temper ature at which the predators were held, The smaller predator species r etained recognizable traces of prey remains for longer periods than la rger predator species. The ELISA efficacy decreased with increasing am bient temperature, A series of regression equations have been develope d to estimate the median detection interval of prey in a predator's ga t that takes into account the predator species examined, the quantity of prey consumed, and ambient after-meal temperature. (C) 1997 Academi c Press.