Pygmy grasshoppers (Tetrigidae) are a speciose group of complicated taxonomy, with many species requiring clarification on their species boundaries, and more still awaiting discovery. Two new species of Scelimena Serville, 1838 are described: (1) from S. discalis species group S. gombakensis sp. nov. and (2) from S. hexodon species group Scelimena marta sp. nov. Catalogue of Scelimenini genera (15) and species (100) is presented and taxonomy and biogeography of the tribe are discussed. New and resurrected combinations are: Falconius becvari (Buzzetti & Devriese, 2008) comb. nov. (of Gavialidium becvari), Gavialidium carli Hebard, 1930 comb. resurr. (of Bidentatettix carli), Indoscelimena india (Hancock, 1907) comb. nov. (of Scelimena india), Paragavialidium nodiferum (Walker, 1871) comb. nov. (of Platygavialidium nodiferum), Platygavialidium productum (Walker, 1871) comb. nov. (of Gavialidium productum), Scelimena hexodon (Haan, 1843) comb. resurr. (of Hexocera hexodon), Scelimena rosacea (Hancock, 1915) comb. resurr. (of Amphibotettix rosaceus), Tegotettix bufocrocodil (Storozhenko & Dawwrueng, 2015) comb. nov. (of Gavialidium bufocrocodil). New synonyms are: Gavialidium phangensum Mahmood, Idris & Salmah, 2007 syn. nov. (of Eufalconius pendleburyi), Gavialidium philippinum Bolívar, 1887 syn. nov. (of Platygavialidium productum comb. nov.), Hexocera Hancock, 1915 syn. nov. (of Scelimena), Paracriotettix Liang, 2002 syn. nov. (of Scelimena), Paracriotettix zhengi Liang, 2002 syn. nov. (of Scelimena melli), Scelimena mellioides Deng, 2016 syn. nov. (of Scelimena melli), Scelimena wuyishanensis Deng, 2016 syn. nov. (of Platygavialidium sinicum). The genus Scelimena is divided into six species groups. Eucriotettix neesoon Tan & Storozhenko nom. nov. is new name for homonym Eucriotettix guentheri Tan & Storozhenko, 2017. Finally, a tabular key to 15 Scelimenini genera, based on 16 morphological characters, is presented.

Spiky pygmy devils (Tetrigidae: Discotettiginae) are, because of the spiky pronotal projections and widened subapical antennal segments, among the most unique pygmy grasshoppers in Southeast (SE) Asia. The taxonomy of the group was unclear in the past, so this study brings a taxonomic and biographical review of the genus Discotettix Costa, 1864. New terminology of the pronotal projections is proposed for Scelimeninae. All valid species hitherto included in the genus are redescribed; a new genus is established for Discotettix shelfordi Hancock, 1907, Disconius Skejo, Pushkar et Tumbrinck gen. n., so a new combination is established for the species (Disconius shelfordi comb. n.). New synonymy is established: Discotettix selysi Bolivar, 1887 = Discotettix selangori Mahmood, Idris et Salmah, 2007 syn. n. Three new species are described and a key to Discotettix species is provided. The genus now includes seven species (1) Discotettix aruanus Skejo, Pushkar et Tumbrinck sp. n. from Aru; (2) D. belzebuth (Serville, 1838) from Borneo; (3) D. doriae Bolivar, 1898 stat. resurr. from the Mentawai islands; (4) D. kirscheyi Skejo, Pushkar, Tumbrinck et Tan sp. n. from Northeast (NE) Borneo; (5) D. scabridus (Stal, 1877) endemic to Mindanao and Samar; (6) D. selysi Bolivar, 1887 from Sumatra and peninsular Malaysia; (7) D. sumatrensis Skejo, Pushkar et Tumbrinck sp. n. endemic to southern Sumatra. Moreover, Discotettix is again subdivided into two subgenera: Mnesarchus Stal, 1877 stat. resurr. (D. scabridus) and nominotypical one (other species). Widened antennal segments are the only character common to all Discotettiginae genera, but this trait does not have great taxonomic importance, as it is homoplastic, meaning that it appeared in distant Tetrigidae groups independently. Discotettix is herewith transferred to the subfamily Scelimeninae and accordingly, the subfamily Discotettiginae Hancock, 1907 syn. n. becomes a junior synonym of the subfamily Scelimeninae Bolivar, 1887. The tribe Discotettigini stat. resurr., on the other hand, gathers corticolous genera of the Scelimeninae (Austrohancockia Gunther, 1938, Bidentatettix Zheng, 1992, Disconius gen. n. Discotettix, Eufalconius Gunther, 1938, Gibbotettix Zheng, 1992, Paragavialidium Zheng, 1994, Gavialidium Saussure, 1862, and Tegotettix Hancock, 1913), while the tribe Scelimenini becomes restricted to amphibious taxa. All taxa are described and amply depicted with both museum specimens and in situ photographs. An identification key is provided. The morphology and function of widened antennae in Discotettigini are discussed.

Knowledge on the pygmy grasshoppers of Australia is, despite the numerous endemics being described from this unique continent, still scarce. Of interest is the Vingselina genus group, including genera Anaselina Storozhenko, 2019, Paraselina Storozhenko, 2019, Selivinga Storozhenko, 2019 and Vingselina Sjostedt, 1921. The systematic position of this group, currently assigned to Batrachideinae (Bufonidini), is probably not correct. In this study new records are presented of Anaselina minor (Sjostedt, 1921), Paraselina brunneri (Bolivar, 1887), P trituberculata (Sjastedt, 1932), and Selivinga tribulata Storozhenko, 2019, all except A. minor the first records of the species since their original descriptions. The first photographs of living specimens of A. minor, P. brunneri, P. trituberculata and S. tribulata are provided and their habitats described. All the records were compiled by citizen scientists who use online social media, such as iNaturalist. Lastly, P. multifora (Rehn, 1952) syn. nov. represents a junior synonym of P. brunneri.

The COI gene is widely used as a DNA barcode in animals that can assist in the identification of species. One of the widely used aggregators of DNA barcodes is the Barcode of Life Data System (BOLD Systems), which contains around 2500 sequences of Tetrigidae, an understudied orthopteran family with unresolved taxonomy and species that are difficult to identify. In this paper, we provide a summary of the metadata provided with the COI sequences and present a phylogenetic analysis of photographically vouchered sequences using Maximum Likelihood and Bayesian analysis. We found that (1) the subfamily Tetriginae is disproportionately represented in the dataset, (2) most of the records are not identified beyond the family level, (3) most regions, except for Costa Rica, are undersampled, (4) most of the sequences do not have photographic vouchers, and (5) the taxonomic backbone of BOLD is out of date. The phylogenetic analysis showed that the clusters of COI barcodes mostly correspond to species, but some clusters remain ambiguous. The deeper nodes in the phylogenetic trees are not well-supported, indicating that this gene has a very weak phylogenetic signal beyond the specific level.

In a recently published paper on colour polymorphism in a Pygmy grasshopper from China (Zhao et al 2016) an unidentified Paratettix sp. was misidentified as Tetrix bolivari. This case highlights the need for correct species identification and provides an opportunity to recommend some aspects of Good Taxonomic Practice (GTP) in Tetrigidae to reduce the number of erroneous identifications.

Modern accounts of eukaryogenesis entail an endosymbiotic encounter between an archaeal host and a proteobacterial endosymbiont, with subsequent evolution giving rise to a unicell possessing a single nucleus and mitochondria. The mononucleate state of the last eukaryotic common ancestor (LECA) is seldom, if ever, questioned, even though cells harboring multiple (syncytia, coenocytes, and polykaryons) are surprisingly common across eukaryotic supergroups. Here, we present a survey of multinucleated forms. Ancestral character state reconstruction for representatives of 106 eukaryotic taxa using 16 different possible roots and supergroup sister relationships, indicate that LECA, in addition to being mitochondriate, sexual, and meiotic, was multinucleate. LECA exhibited closed mitosis, which is the rule for modern syncytial forms, shedding light on the mechanics of its chromosome segregation. A simple mathematical model shows that within LECA’s multinucleate cytosol, relationships among mitochondria and nuclei were neither one-to-one, nor one-to-many, but many-to-many, placing mitonuclear interactions and cytonuclear compatibility at the evolutionary base of eukaryotic cell origin. Within a syncytium, individual nuclei and individual mitochondria function as the initial lower-level evolutionary units of selection, as opposed to individual cells, during eukaryogenesis. Nuclei within a syncytium rescue each other’s lethal mutations, thereby postponing selection for viable nuclei and cytonuclear compatibility to the generation of spores, buffering transitional bottlenecks at eukaryogenesis. The prokaryote-to-eukaryote transition is traditionally thought to have left no intermediates, yet if eukaryogenesis proceeded via a syncytial common ancestor, intermediate forms have persisted to the present throughout the eukaryotic tree as syncytia but have so far gone unrecognized.