Size-Dependent Cannibalism in Praying Mantids: Using Biomass Flux to Model Size-Structured Populations

Here we investigate how cannibalism, a widespread phenomenon in nature, influences the population dynamics and the differential success of emergence-timing strategies in praying mantids. Relying on an extraordinarily complete data set describing the ecophysiology of a single mantid species, we construct a size-structured model based on "biomass flux" to study how size-dependent cannibalism influences this species' population ecology. Further, we demonstrate how this model accurately predicts mantid developmental patterns under both laboratory and field conditions. We conclude that for mantids, and perhaps generalist ambush predators overall, descriptions of biomass flux can be satisfactorily used to model growth without explicit reliance on encounter rate terms. In particular, this autecological approach to modeling size-structured interactions provides a method for revealing how sensitively development hinges on small differences in emergence time.