Mimicry Diversiry, Evolution and Ecology of Ithomiine Communities

Mimicry Diversiry, Evolution and Ecology of Ithomiine Communities

Their hypothesis is that different mimicry complexes occur in different microhabitats, i.e. ridge tops or stream sides, where distinct predator species occur, so that predators rarely encounter more than one kind of color pattern and thus the selection for convergence of different mimicry complexes is weak. The microhabitats where butterflies occur may be constrained by the microhabitats where their food-plants grow, so they are rearing ithomiines to identify host-plant usage. They are also mapping the height and microhabitat distribution of butterflies, plants and insectivorous birds to quantify niche space for these groups. Finally, they are deriving molecular and morphological phylogenies for certain ithomiine genera to test whether adaptive shifts in warning color pattern, host-plant or microhabitat have been important in speciation.

Understanding how such diverse communities coexist is a central goal of evolutionary ecology, and ithomiines are an ideal study group. Ithomiine caterpillars feed almost exclusively on plants of the family , and each ithomiine species is usually confined to a single hostplant species. There is evidence of adaptive radiation, with more diverse plant clades supporting more diverse groups of ithomiines. Ithomiines are also notable for being unpalatable to predators and thus warningly colored, and extensively involved in mimicry rings. However, rather than all species converging on a single warning color pattern as predicted by mimicry theory, there are diverse complexes of mimetic species occurring together. Drs. Keith Willmott and Julia Robinson Willmott are thus working with colleagues from Edinburgh and Cambridge Universities, UK, to try to understand how mimicry diversity is maintained in two distinct ithomiine communities in eastern .