Phylogenetic analysis of the myrmecophilous Cremastocheilus Knoch (Coleoptera, Scarabaeidae, Cetoniinae), based on external adult morphology

Abstract

The genus Cremastocheilus (Coleoptera: Scarabaeidae: Cetoniinae) is a myrmecophilous group of approximately 45 species distributed throughout North America. Authors previously recognized anywhere between two and five subgenera. We present the first cladistic analysis of Cremastocheilus based on 51 external adult morphological characters. The monophyly of the subgenera Macropodina, Trinodia and Cremastocheilus is supported. Cremastocheilus (Anatrinodia) wheeleri is most closely related to other C. (Cremastocheilus). The three species groups comprising C. (Myrmecotonus) are paraphyletic with respect to C. (Cremastocheilus). The pronotum, which bears most of the glands that enable beetles to interact with ants, provides important characters, while characters associated with setae and tomenta are homoplastic. Based on examination of the strict consensus of 24 equally parsimonious trees C. (Myrmecotonus) and C. (Anatrinodia) are synonymized with C. (Cremastocheilus).