PHENETIC SIMILARITY AND MÜLLERIAN MIMICRY AMONG DARKLING GROUND BEETLES (COLEOPTERA: TENEBRIONIDAE)

Abstract

Species of tenebrionid beetles in the genera Coelocnemis and Eleodes share high similarity in dorsal features. Similar species are largely sympatric in occurrence, and the distributions of some species pairs are almost identical. These congruences in appearance and geographic distribution are interpreted as evidence of Müllerian mimicry. All these beetles produce quinonoid secretions, presumably used in defense against vertebrate predators. The widespread occurrence of defensive secretions, and the similarities in dorsal silhouette and cuticular sculpturing, suggest that Müllerian mimicry is of general importance among tenebrionid beetles. The common black coloration of tenebrionids probably has an aposematic function, since black contrasts sharply with most substrates under the crepuscular lighting conditions in which tenebrionid activity typically occurs. The suitability of numerical phenetic methods for the description and analysis of convergence and mimicry phenomena is discussed.