Seirinae is one of the most diverse subfamilies of Collembola. To date no detailed phylogeny of Seirinae has been proposed, which leads to difficulties in the understanding of evolutionary patterns regarding this taxon. The main aim of this study is to clarify the phylogenetic relationships within the Neotropical Seirinae, by generating and analysing the mitochondrial genomes of 26 terminal taxa of Entomobryidae, and one species of Paronellidae. Specifically, we first generated Illumina HiSeq 2000 shotgun sequence data from each species, then reconstructed the mitochondrial genome of each species using two methods: MitoZ and MIRA/MITOBim. Using these data, we were able to generate a well-supported phylogeny that combined all the above species as well as three publicly available mitogenomes from other species.Bayesian and maximum likelihood methods were applied using all 13 protein coding genes. In this way, monophyly for the internal groups of Seirinae was obtained based on molecular evidence for the first time, as was the potential validity of three main internal taxa of the subfamily. We furthermore validated that Tyrannoseira is a distinct lineage and propose the elevation of Lepidocyrtinus to genus. Lastly, we anticipate that these newly available mitogenomes will serve as a useful dataset for future studies on the evolution of the Collembola and Hexapoda.

Mitogenomes have been widely used as markers to reconstruct phylogenies of various groups of arthropods, but specifically for Collembola they have not been useful to resolve the relationships between some families, such as Paronellidae and Entomobryidae. Here, we present a phylogenetic study integrating previously published data and 20 new mitogenomes, totalling 54 species of Entomobryoidea and two external groups. Eight of the nine subfamilies were included, with species from the most representative genera. The new mitogenomes were sequenced, assembled and annotated, resulting in sequences with a length of approximately 14,000 bp. Phylogenetic analyses were conducted based on the 13 protein‐ and 2 rRNAs‐encoding genes of the 56 mitogenomes. Both maximum likelihood (with six different datasets/models) and Bayesian inference analyses were performed. Orchesellidae, Seirinae and Lepidocyrtinae were reaffirmed as monophyletic groups, while the phylogenetic relationships between Paronellidae and Entomobryidae remain confused. A complete resolution of the Entomobryoidea phylogeny will require a comprehensive genomic sampling of the most informative nuclear and mitochondrial markers to finally overcome traditional systematic problems.

We herein present the first reliable record of Lepidosira from Neotropical Region. Lepidosira neotropicalis sp. n. from Brazil is described and illustrated in detail, including its complete mitochondrial genome. We perform a Bayesian phylogenetic analysis to place the new species within the Entomobryidae, and at the same time to test previous contrasting hypotheses on Lepidosira position within the Entomobryinae versus Seirinae for the first time. Phylogenetic analyses were based on one mitochondrial and two nuclear genes, Cytochrome Oxidase subunit I, 18S ribosomal RNA and 28S ribosomal RNA, respectively. Lepidosira neotropicalis sp. n. resembles L. sundana Yoshii and Suhardjono and L. nigropunctata (Nguyen) in dorsal chaetotaxy of abdominal segments I and II, but differs from all other species by the combination of head (dorsally and ventrally) and dorsal trunk chaetotaxy, plus empodial complex morphology. Our phylogenetic analyses support the placement of Lepidosira within Entomobryinae, as the sister group of Lepidocyrtoides. Overall, our revision enables a more objective diagnosis to Lepidosira and suggests that the genus is in need of a full revision due to its variable morphology, and lack of data needed to evaluate its monophyly. Finally, we provide an identification key for Neotropical genera of Entomobryinae.

Tyranonoseira is revised and new diagnostic characters to the genus and its species are proposed. The genus is now characterised by distinct chaetotaxic patterns of head, in lacking M2, S1, S4, S5 macrochaetae and Th II to Abd IV with 21–27, 7, 0, 3, 1 and 8–10 central macrochaetae, as well as anterior legs of males with modified chaetae. The five species of the genus are redescribed based on type material: T. raptora Zeppelini & Bellini, T. bicolorcornuta Bellini & Zeppelini, T. diabolica Bellini & Godeiro, T. gladiata Zeppelini & Lima and T. sex Bellini & Zeppelini. We include an identification key and comparison of the species. The dorsal chaetotaxy is similar for all species. Characters omitted from the original descriptions such as chaetotaxy of the clypeus, labral papillae, collophore chaetae and manubrial formula are now used to distinguish species more clearly. We compare the morphology of Seira and Tyrannoseira using dorsal chaetotaxy and the modified chaetae on anterior legs of males.

The taxonomic comprehension of Brazilian entomobryids had several contributions during the last decade, but the absence of detailed chaetotaxic schemes to most of endemic species difficult identifications and probably hides undescribed species in surveys across the country. Herein we describe two new species of the family and provide detailed dorsal chaetotaxy of them, in hope to guide future identifications and descriptions within the genera in Brazil and Neotropical Region. Lepidocyrtus sotoi sp. nov. is possibly more related to L. biphasis due to the lack of antennal and leg scales, but presents a unique dorsal head chaetotaxy among the Neotropical species of the genus. Entomobrya bahiana sp. nov. presents an uncommon color pattern and dorsal chaetotaxy in Th. II-III, Abd. II and IV when compared to other Entomobrya spp. from Neotropical Region.

Three new species of Seira Lubbock, Seira jiboiensis sp.nov., Seira primaria sp. nov. and Seira harena sp.nov. from Neotropical Region are described and illustrated. All species were collected from humid areas of Caatinga Biogeographic Domain, northeastern Brazil. Seira jiboiensis sp.nov. shows some similarities with S. mendoncea Bellini & Zeppelini and S. ritae Bellini & Zeppelini, while S. primaria sp.nov. resembles S. pseudoannulata Bellini & Zeppelini and S. paraibensis Bellini & Zeppelini in dorsal chaetotaxy in some aspects. Seira harena sp.nov. belongs to a subgroup of Seira originally described in the subgenus Lepidocyrtinus Börner, which has modified macrochaetae on distal manubrium and proximal dens, like S. prodiga (Arlé), S. xinguensis (Arlé) and S. nigrans (Arlé).

Two new species, Seira coroatensis sp. nov. and Seira diamantinae sp. nov., from different areas of Caatinga Biome, Northeastern Brazil, are described and illustrated in this paper. Seira coroatensis sp. nov. share some similarities with Seira mendoncae Bellini & Zeppelini and Seira ritae Bellini & Zeppelini, but presents a very distinct pattern of setae on dorsal head and mesothorax. In the other hand, Seira diamantinae sp. nov. is the fifth neotropical species described bearing modified blunt macrosetae on distal manubrium and proximal dens. The detailed dorsal chaetotaxy of S. paraibensis Bellini & Zeppelini and S. glabra Godeiro & Bellini are presented with some notes regarding the original descriptions of the species.

A new species of Seira from Koh Rong Sanloem Island, Cambodia, as well as its mitochondrial genome information, are herein described. Seira sanloemensis sp. nov. has a similar colour pattern compared to nine other species of Seira worldwide distributed, but the dorsal chaetotaxy is more similar to S. arunachala Mitra from India, S. camgiangensis Nguyễn from Vietnam, and S. gobalezai Christiansen & Bellinger from Hawaii. However, the new species differs from these species by dorsal chaetotaxy of head, Th II–III and Abd II, collophore chaetotaxy, and morphology of the empodial complex. This is the third Collembola species described for Cambodia. Its assembled incomplete mitogenome from MGI reads, has a length of 13,953 bp, and contains all protein-coding genes except for tree tRNAs missing; the gene order is the same of the Pancrustacean ancestral gene order. Based on the alignment of the 13 coding genes, a maximum likelihood phylogenetic tree of medium bootstrap values suggested that the Asian Seira species can represent a different lineage from the Neotropical Seirinae, but further biogeographic and divergence estimation analyses plus the inclusion of more Asian taxa are necessary to test such hypothesis.