Mitochondrial genomes of Bombyliidae (Diptera): Phylogenetic analysis recovers monophyletic Bombyliidae sister to Asilidae

Bombyliidae (bee flies) is a large family in the order Diptera. Their larvae are predators or parasitoids of several insect orders, such as Coleoptera, Lepidoptera, Hymenoptera and Diptera, some species of the genus Systoechus are predators of grasshopper eggs. The adults visit flowers for nectar and mating, which makes them important pollinators. Their classification and systematic position are still strongly debated. There were only two complete mitochondrial (mt) genomes of Bombyliidae. Mt genomes of Villa fasciata, Bombylius candidus, Heteralonia anemosyris, Ligyra guangdongana, Systropus excisus and Exhyalanthrax afer were sequenced in order to determine the diversity of mt genomes in this family. A comparative mt genomic analysis of these newly sequenced species revealed that the sizes of the mt genome ranged from 15,036 bp to 17,992 bp. All tRNAs had cloverleaf secondary structures, but the dihydrouridine (DHU) arm of tRNASer (AGN) is absent. The phylogenetic analyses based on both Bayesian Inference (BI) and Maximum Likelihood (ML) supported Bombyliidae being the sister group of Asilidae. Within Bombyliidae, the analysis recovered subfamilies Toxophorinae, Anthracinae and Bombyliinae, and Anthracinae is the sister group of Bombyliinae.