The mitochondrial genome of Formicosepsis sp. (Diptera: Cypselosomatidae)

Phylogeny and Evolutionary Timescale of Muscidae (Diptera: Calyptratae) Inferred from Mitochondrial Genomes

House flies (Muscidae) comprise the most species-rich family of the muscoid grade with over 5000 described species worldwide, and they are abundant in various terrestrial and aquatic ecosystems. The high number of species, varied appearances, complex feeding habits, and wide distributions have hindered researchers from understanding their phylogeny and evolutionary history. Here, we newly sequenced fifteen mitochondrial genomes and reconstructed the phylogenetic relationships and divergence time among eight subfamilies of Muscidae (Diptera). The best phylogenetic tree, which was inferred by IQ-Tree, recovered the monophyly for seven out of eight subfamilies (except for Mydaeinae). Based on phylogenetic analyses and morphological characteristics, we prefer the subfamily status of Azeliinae and Reinwardtiinae, and separate Stomoxyinae from Muscinae. Genus Helina Robineau-Desvoidy, 1830 was synonymized with Phaonia Robineau-Desvoidy, 1830. The divergence time estimation indicated Muscidae originated at 51.59 Ma (early Eocene). Most subfamilies had originated around 41 Ma. We provided a mtgenomic viewpoint on the phylogenetic relationships and divergence time estimation of Muscidae.

The complete mitochondrial genome of Ornithomya biloba (Diptera, Hippoboscidae)

The mitochondrial genome (mitogenome) of Ornithomya biloba (Dufour 1827) was first sequenced and annotated in this study as the first representative of the genus Ornithomya. The complete mitogenome is 18,654 bp in length and contains 37 genes (13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and control region). The phylogenetic analysis based on 13 PCGs in IQ-TREE supports the monophyly of Hippoboscidae, which was a sister group of Streblidae. Families Hippoboscidae and Streblidae formed the monophyletic Hippoboscoidea clade.

The mitochondrial genome of Nemalecium lighti (Hydrozoa, Leptothecata)

The hydrozoan species Nemalecium lighti (Hargitt, 1924) is widely distributed in tropical marine waters around the world. Here we report the complete linear mitochondrial genome of N. lighti from Sint Eustatius (Lesser Antilles). The mitochondrial genome with a length of 14,320 bp encodes for 13 protein-coding genes, two tRNA genes, and two rRNA genes. Gene arrangement differs from that found in other species of the same taxonomic order and a phylogenetic analysis shows that based on mitochondrial genes, N. lighti clusters outside of the Leptothecata, rendering the order paraphyletic.

The mitochondrial genome of Syneches medoganus (Diptera: Empididae)

The mitogenome of one dance fly species, Syneches medoganus, was sequenced as the new representative of subfamily Hybotinae. The nearly complete mitogenome was 16128 bp totally, consisting of 13 protein-coding genes (PCGs), two rRNA genes, and 22 tRNA genes. The nucleotide composition biased toward A and T, and the overall A + T was 78.1% of the entirety. All the PCGs started with codon ATT, ATC or ATG, except CO1 using TCG as an initiation codon. Most PCGs terminated with stop codon TAA or TAG except CO2 with an incomplete stop codon T. Bayesian analyses indicated that the monophyly of Hybotinae subfamily group is strongly supported. Subfamily Hybotinae is the sister group of subfamily Tachydromiinae.