The mitochondrial genome of Ectophasia roundiventris (Loew, 1858), the first representative of subfamily Phasiinae, was sequenced and annotated. So far, there are four Tachinidae mitochondrial genomes, here, all of them are used in Neighbour-Join and Maximum Likelihood analyses. The nucleotide composition of Ectophasia roundiventris mitochondrial genome was 40.4% of A, 39.0% of T, 11.8% of C, 8.8% of G, 79.4% of A + T content. The codon ATG was the most popular start codon. The conservative stop codon was TAA, COX2, and ND5 terminated with an incomplete stop codon T, while the gene ND4 was ended with stop codon TA.

Our understanding of biodiversity patterns comes primarily from described species. Here, we analyze how known biodiversity has increased across living organisms. Past research suggested that the number of new species per year peaked near 1900 and that only ~2 million species exist. We find that overall rates of species descriptions have recently accelerated, with the largest numbers of new species per year all in the past ~20 years (2000 to 2020). The largest groups grew the most quickly during this period, including animals, arthropods, insects, and beetles. However, long-term trends in rates of species descriptions were often unrelated to recent rates and current richness. For example, rates for fungi have recently increased, whereas rates for insects have not. Extrapolating these rates of species descriptions into the future requires considerable caution. Nevertheless, some intriguing patterns are suggested, such as unexpectedly high projected species numbers of plants, fungi, arachnids, malacostracan crustaceans, ray-finned fishes, and amphibians.

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.

Global biodiversity is increasingly threatened, but still poorly known. Preserving higher taxa (e.g., genera, families, orders) is especially important because each higher taxon may represent more genetic, morphological, ecological, and functional diversity than a typical species within a genus. Given this, there has been considerable focus on the loss of clades and their phylogenetic diversity. However, we know little about whether there are also gains of new clades: new higher taxa that are based on newly discovered species. Here, we analyze these newly discovered branches across the Tree of Life. We estimate that >700 new genera, >20 new families, and >3 new orders are described every year, each associated with newly discovered species. The distribution of new genus-level clades largely reflects current species richness patterns among groups. Thus, they are dominated by terrestrial arthropods. At higher taxonomic ranks, the distribution of new clades among groups is increasingly unrelated to the current, known species richness of these groups, and fungi and bacteria predominate. New clades are increasingly microscopic at higher taxonomic ranks and are often marine or host associated. Overall, we suggest that the known Tree of Life is continuing to rapidly expand with many newly discovered clades, not merely contracting with recent extinctions. Discovering and describing these new clades before they disappear should be an urgent research priority. There is also a pressing need to better incorporate phylogenies into the discovery of these new higher taxa.

The long-legged fly Syntormon pallipes belongs to the subfamily Sympycninae of Dolichopodidae. The mitogenome of S. pallipes was sequenced as the first representative of the subfamily. The mitogenome is 15,583 bp long, consisting of 13 protein-coding genes, 2 rRNAs, and 22 transfer RNAs. Syntormon pallipes has the similar gene structures with other published species of Dolichopodidae. The nucleotide composition biases toward A, and T is 78.1% of the entirety. Bayesian inference analysis strongly supported the monophyly of Dolichopodidae, which was inferred from 14 species. It indicated that Sympycninae and Hydrophorinae were assigned to be the sister of the clade of ((Rhaphiinae + Neurigoninae) + (Dolichopodinae + Sciapodinae)).

The known species of the genus Norellisoma from China are reviewed and two new species from Yintiaoling Nature Reserve in Chongqing City, where no other Norellisoma species are recorded, are described: Norellisoma wuxiense sp. nov., Norellisoma yintiaoense sp. nov. A key to the species of Norellisoma from China is provided.