Investigating the Relationship Between Dietary Specialization of Caterpillars and Their Risk of Ant Predation in a Forest Community

Abstract

Studies that rigorously measure the effectiveness of anti-predator traits in complex ecological communities are rare. Rarer still are studies that compile the results of these trait analyses in a framework that explains the variation in predation pressure by a predator assemblage. Here the risk of predation by ants is quantified for a community of caterpillar species that employ several putative anti-predator traits that may be constrained by dietary specialization. The effectiveness of these traits in mediating ant predation and their correlation with diet breadth are evaluated in a temperate forest. I utilized three years of field experiments to compile ecologically relevant measures of ant predation risk for twenty-one caterpillar species. I also compared diet breadth, camouflage, warning signals, frequency of behavioral response to physical attack, body size, nocturnal activity, feeding frequency and preferred resting location as determinants of ant predation across caterpillar species.