Revision of the darkling beetle genus Eurynotus (Blaptinae: Platynotini) and new records of ovovivipary in Tenebrionidae

Abstract

Abstract The taxonomic concepts and monophyly of the southern African genus Eurynotus and its subgeneric components (Biolus and Neosolenopistoma) are tested using cladistic analyses. Seventy morphological characters were scored and analysed using maximum parsimony and Bayesian inference for 26 Eurynotina species, including all Eurynotus. Comprehensive revision of Biolus and Eurynotus resulted in Neosolenopistoma becoming a junior synonym of the genus Biolus stat. nov. (elevated to generic rank), restoration of one species (B. asperipennis stat. res.), recognition of seven new combinations, and descriptions of two new species (Biolus brunoi sp. nov. and Eurynotus privisolum sp. nov.). Lectotypes are designated for previously described species from syntype material, and a key to species of Biolus and Eurynotus is provided. Three species were confirmed as ovoviviparous (two Biolus and one Eurynotus) bringing the number of recorded ovoviviparous Tenebrionidae to 14. Shortened ovipositors are discounted as requisite for ovovivipary based on elongate paraprocts in Biolus and Eurynotus. Principal component analyses were used to examine three lineages of ovoviviparous tenebrionids; however, no single set of climatic variables was correlated with ovovivipary. Southern African, Malagasy, and Guadeloupe lineages of ovoviviparous Tenebrionidae probably have additional and/or separate evolutionary origins and selection pressures to consider when examining this reproductive strategy.