METAPOPULATIONS OF FOUR LEPIDOPTERAN HERBIVORES ON A SINGLE HOST PLANT,LOTUS CORNICULATUS

Abstract

Multispecies metapopulation models generally make the assumption that the interacting species occupy the same habitat network as one another. We examined the spatial distribution, metapopulation structure, and habitat network of four lepidopteran herbivores feeding on a single host plant, Lotus corniculatus, in a patchy landscape in North Wales, UK. The four species showed contrasting spatial distributions despite the fact that they feed on the same host plant. Information on dispersal rates and population turnover suggest that each species is likely to exhibit metapopulation dynamics, but with different relative contributions of local and regional processes. Detailed analyses of habitat requirements suggest that habitat networks were species-specific, and their degree of occupancy a function of the number of patches in the system. These results do not support the idea that patchiness promotes regional coexistence through multispecies metapopulation dynamics. Rather, each species appeared to act as a largely independent metapopulation system in its own specific habitat network. The results also suggest that conservation recommendations must be based on detailed analysis of the requirements of each key species in order to understand their spatial dynamics.