Asymmetric interactions and their consequences for vital rates and dynamics: the smaller tea tortrix as a model system

Asymmetric interactions among conspecifics can have diverse effects on population dynamics including stabilization, generation of cycles and induction of chaotic fluctuations. A difficult challenge, however, is establishing the link between the impact of asymmetric interactions on life history and the consequences for population dynamics. The smaller tea tortrix, Adoxophyes honmai, is a good example. Larval instars differ dramatically in size and have a tendency for cannibalism, which suggests the potential for strong asymmetric interactions among instars. Yet whether these asymmetries have any role in generating the distinct single-generation cycles observed in the field and laboratory is unclear. Here we report on the development of a new experimental approach to characterize the impact of asymmetric interactions on life history that can be directly embedded into stage-structured population models. The experiments use donor-replacement protocols in which focal individuals are challeng...