DNA barcoding of Palaearctic Ulidiidae (Diptera: Tephritoidea): morphology, DNA evolution, and Markov codon models

Abstract

Background: Here, for the first time, we report a barcoding survey of the dipterian family Ulidiidae (with two subfamilies Ulidiinae and Otitinae) coupled with morphology. To date, this is the first comprehensive analysis of the family that relies on molecular data. To reconstruct probable higher-level phylogenetic relationships between the genera of Ulidiidae, we exploited maximum likelihood and Bayesian inference, and additionally, we utilized a modern Markov model of codon substitutions for protein-coding genes coupled with the maximum likelihood approach to establish more realistic evolutionary scenarios connecting Ulidiinae and Otitinae. Results: Though we found morphological synapomorphic characters that clearly distinguish two groups of genera, formerly relating to two subfamilies, the monophyly of the clade Otitinae was not firmly supported by molecular phylogenetic reconstructions. The subfamily Ulidiinae was recovered as the basal likely paraphyletic group with high reliability. Overall, our results suggest the inclusion of the genera Homalocephala and Seioptera into the tribe Seiopterini (Otitinae). Three genera of Ulidiinae (Physiphora, Timia, Ulidia), eight genera of Otitinae (Ceroxys, Herina, Melieria, Myennis, Otites, Pseudotephritis, Seioptera, Tetanops), and the genus of Homalocephala with still unconfirmed systematic status were included in the analysis. Conclusions: On all phylogenetic trees obtained in our survey, there is a clear tendency of clustering at the genus level with separation of (Physiphora + (Timia + Ulidia)) (Ulidiinae) and (Otitinae + Homalocephala). The genus Homalocephala takes basal or subbasal position relatively to Otitinae. Phylogenetic reconstruction based on Markov models of codon evolution provided a good resolution for our limited dataset.