Phenotypic analysis of aposematic conoderine weevils (Coleoptera: Curculionidae: Conoderinae) supports the existence of three large mimicry complexes

Abstract

AbstractThe Conoderinae (Coleoptera: Curculionidae) are one of the most distinctive Neotropical weevil groups in behaviour and appearance, attracting numerous hypotheses regarding the evolution and function of widespread apparent mimetic convergence. Conoderines have a poorly documented natural history, and a large fraction of the diversity of the group remains undescribed, presenting challenges to their study. In this analysis, 128 species of conoderine weevils previously or herein hypothesized to belong to three mimicry complexes are analysed in the first quantitative test of conoderine mimicry. Fifteen continuous and categorical characters describing the size, shape and coloration of these weevils were analysed using non-metric multidimensional scaling while statistically testing the resulting clusters in ordination space. Three similar, putatively mimetic complexes are recognized: (1) the ‘red-eyed fly’ complex of weevils, which are hypothesized to be evasively mimetic on various species of red-eyed flies; (2) the ‘striped/spotted’ complex, composed of weevils with a brightly coloured pronotum and red to white elytral stripes or spots; and (3) the ‘shiny blue’ complex of species with iridescent blue to blue–green pronotal scales. Each of these groups covers a wide geographical distribution and has evolved independently in multiple genera, although the red-eyed fly complex appears to be both the most species rich and widely distributed phylogenetically. Groupings were found to be statistically significant, although variation within each group suggests that the similarity in appearance of species in each group could be attributable to independent convergence on different, but phenotypically similar, models. Several avenues for future research on conoderine mimicry are discussed.