Cross-Level Trade-Offs: An Integrative Model of Trait Investment in \u3cem\u3eCallosobruchus maculatus\u3c/em\u3e

Abstract

Life-history theory aims to understand how different environments result in differential investment in fitness associated traits. While previous research has demonstrated trade-offs between traits from the same phenotypic level (e.g. two morphological traits), many studies show positive or no correlation between pairs of costly traits. One hypothesis that may explain the inconsistency of trade-offs in the literature is that trade-offs may occur across phenotypic levels (e.g. morphology versus behavior). In turn, this study aims to identify the presence of cross-level trade-offs in the bean beetle, Callosobruchus maculatus. In this experiment, copulatory behaviors and morphology were analyzed for both males and females. While trade-offs were reported between copulatory behaviors and morphology for both males and females, traits, subjected to trade-offs, only covaried when analyzing cross-level relationships. This study is the first to report the novel finding that trade-offs may be the result of cross-level investment