Preliminary phylogeny of Tribolium beetles (Coleoptera: Tenebrionidae) resolved by combined analysis of mitochondrial genes

The phylogenetic relationships of the three major species groups of Tribolium (Coleoptera: Tenebrionidae) were inferred using the simultaneous analysis of 642 bp of the most conserved part of mitochondrial DNA (mt DNA) cytochrome oxidase I (COI) and 448-452 bp of mt 16S rDNA. High sequence divergence was observed for both genes even among sibling species. The analysis of the combined segments of COI and 16S rDNA sequences produced a phylogenetic tree with moderate level of confidence. The tree topology showed monophyly of the genus Tribolium whose species were separated into three groups: "brevicornis" group (with T. brevicornis as the only representative), "castaneum" group (with T. castaneum, T. freemani, T. madens and T. audax) and "confusum" group (with T. confusum, T. anaphe and T. destructor). Sibling species pairs T. castaneum - T. freemani and T. madens - T. audax are clearly resolved. The preliminary results presented here give moderate support to the previously proposed phylogeny based on morphological data.