What's in a genus?: Phylogenetic analysis of Cremastocheilus Knoch (Scarabaeidae: Cetoniinae) based on morphology

The scarab genus Cremastocheilus (Coleoptera: Scarabaeidae: Cetoniinae) currently comprises five myrmecophilous subgenera totaling approximately 45 species. This study presents the first modern cladistic analysis of Cremastocheilus based on 51 external adult morphological characters. The monophyly of C. (Macropodina), C. (Trinodia) and C. (Cremastocheilus) are supported, although species relationships within each respective subgenus remain poorly resolved. Placement of the monotypic C. (Anatrinodia) is problematic, although removal of this species from analysis results in a topology not previously suggested by any previous author. The subgenus C. (Myrmecotonus) is not monophyletic, although several species groups are well supported. The strict consensus, and examination of many equally parsimonious trees suggests that C. (Myrmecotonus) be synonymized with Cremastocheilus sensu strictu. In addition, several characters believed to be tied to beetle-ant relationships show high levels of homoplasy; however, poor knowledge of such interactions limit any conclusions that can be made regarding myrmecophily and its relation to phylogeny.