Knowledge of the diversity and distribution of tardigrades in Mexico is limited. Up to now 79 taxa of limno-terrestrial, freshwater and marine tardigrades were reported (including three species of Milnesium) from the country. We examined a total of 73 specimens of the genus Milnesium collected from mosses and lichens in northeastern Mexico. The analysed specimens represent four species, of which one was previously unknown, and is described in this paper. Milnesium fridaesp. nov. has eyes, claw configuration (CC) [3–3] - [3–3], a wide and short buccal tube (standard width on average 64% of its length), and cuticle with very small pseudopores visible under high magnifications. It differs from other Milnesium species by various morphometric characteristics specified in the paper. Moreover, the ontogenetic variability of CC in new species was followed, observing that there is no variability in this character. In addition, distribution of the Milnesium species in Mexico is also discussed.

We applied an integrative taxonomy approach to describe a new tardigrade species from Pico Island (the Azores Archipelago). Analysis was based on morphological and morphometrical data (using both light and scanning electron microscopy) and combined with multilocus molecular data (nuclear barcode sequence ITS-2 and mitochondrial COI sequence). Molecular data allowed us to determine that genetically (based on COI sequences) Pseudechiniscus lalitaesp. nov. is most similar to Pse. aff. facettalis and the least similar to Pse. indistinctus. The new species differs morphologically from other Pseudechiniscus species, mostly, by the ventral sculpture. Moreover, it differs from other species from suillus-facettalis complex also by some other more subtle morphological and morphometrical characters.

A new species of the genus Xouthous Thomson, 1883, previously known as Idomene, obtained from the 1995–2015 collections, from the coasts of the Korean Peninsula, is described and illustrated. To date 16 valid species of the genus including X. yeonghoonisp. nov. presented herein, have been reported from the Antarctic, Atlantic, Indian, and Pacific oceans. The new species can be easily distinguished from its congeners by the combination of the following characters: 7-segmented female antennule; antenna with 2 exopodal segments; mandibular exopod with 2 lateral strong spines and 4 distal plumose setae; exp-3 of P2–P4 with 2 strong pectinate spines; and P5 baseoendopod with truncate margin, and spatulate and parallel-sided setae. In addition to the description of the new species from Korea, comparisons to 5 closely related congeners (“palisade group”) from the Indian Ocean are also included. Finally, a mini-review on the global distribution of the genus, with a taxonomic revisit to X. laticaudatus sensu Kim (2014), is provided. The new species described herein is the first record of Xouthous from East Asia.

In the present paper four new species records of Gaeolaelaps (Mesostigmata: Laelapidae) mites to the fauna of the the United States including Gaeolaelaps elimatus (Berlese, 1920), Gaeolaelaps praesternalis (Willmann, 1949), Gaeolaelaps subterraneus (Willmann, 1952) and Gaeolaelaps zhoumanshuae (Ma, 1997) have been recorded for the first time. The description of two new species for science belonging to the mentioned genus: Gaeolaelaps klompenisp. nov., and G. americanussp. nov. have been presented based on morphological characters of adult females.

The ant fauna of the State of Qatar is reviewed based on collected material and literature. In total, 23 species, belonging to 12 genera and four subfamilies, were reported from the country. Given that Messor arenarius diabolus Santschi, 1938 is endemic in Egypt, and it was recorded by mistake in Qatar, we excluded it from the country faunal list. Six genera are recorded for the first time from the country, Cardiocondyla Emery, 1896, Crematogaster Lund, 1831, Lepisiota Santschi, 1926, Monomorium Mayr, 1855, Paratrechina Motschoulsky, 1863, and Pheidole Westwood, 1839. Fourteen species are recorded for the first time from Qatar, namely, Camponotus oasium Forel, 1890, Cardiocondyla emeryiForel, 1881, Cataglyphis livida (André, 1881), Cataglyphis arenariaFinzi, 1940, Cataglyphis nigra (André, 1881), Lepisiota bipartita (Smith, 1861), Lepisiota gracilicornis (Forel, 1892), Monomorium abeillei André, 1881, Monomorium areniphilumSantschi, 1911, Monomorium subopacum (Smith, 1858), Monomorium venustum (Smith, 1858), Pheidole sinaiticaMayr, 1862. Tapinoma melanocephalum (Fabricius, 1793), and Tapinoma simrothiKrausse, 1911. Preliminary analysis of the zoogeography of Qatar's ants reveals the remarkable predominance of Palearctic faunal elements (13 species/ ∼57%), followed by minor proportions of Afrotropical (4 species/ ∼17%) and Indomalayan (1 species/ ∼4%) species, while the five invasive species (∼22%) reflect human impacts on the country. Monomorium tumaireCollingwood & Agosti, 1996 is known as endemic in the Arabian Peninsula. No species are considered endemic to Qatar. Ecological and biological notes on species are provided when available.

In Neotropical region, the subfamily Andreninae is commonly collected in temperate and subtropical areas with scarce records in tropical areas. Here, we provide a checklist of andrenine bees from Cerrado and describe two new species of Anthrenoides. Twenty-two bee species of Andreninae were recorded. The new species were recorded in the core area of Cerrado, on Brazilan Central Plateau. Anthrenoides kalungasp. nov. is known by a single female specimen from Chapada dos Veadeiros and it is easily recognized by the hairy mesosoma. Anthrenoides urbanaesp. nov. was collected in a grassland area of Cerrado, and is distinguished from other species by glossa and galea longer than compound eyes. A. urbanaesp. nov. is associated with flowers of Alstroemeria gardneri (Alstroemeriaceae) which are used as a source of food and mating sites. The small number of Andreninae bee species recorded on Cerrado is possibly a result of a shortfall of inventories that can be solved by an additional effort to sample these rare bees with specific methods like UV pan traps.

Doddiellini, a monotypic tribe comprising the genus Aneuroscelio Kieffer has been represented until present study by three species – A. dolabella (Kozlov & Lé), A. indicus (Mukerjee) and A. nigricephala (Mukerjee) – in the Oriental region of which the latter two are from India. Nineteen new species of Aneuroscelio are described from India: A. andalsp. nov., A. carinatussp. nov., A. doddisp. nov., A. dronasp. nov., A. durjasp. nov., A. durvasasp. nov., A. ekalavyasp. nov., A. ferrugineussp. nov., A. flavussp. nov., A. glabrussp. nov., A. latimetascutellussp. nov., A. longiflagellumsp. nov., A. nigrumsp. nov., A. parashuramasp. nov., A. preisnerisp. nov., A. purochanasp. nov., A. suvarnussp. nov., A. triangularissp. nov. and A. viracochasp. nov. The concept of Aneuroscelio is expanded by providing additional characters. Keys to the females and males of Oriental species of Aneuroscelio are presented.

A new genus of ricaniid planthopper (Hemiptera: Fulgoromorpha: Ricaniidae), Jeromicanusgen. nov., is described to comprise three species – two species from Vietnam Jeromicanus orientalissp. nov. (type species) and J. vietnamensissp. nov. and one species from Laos – L. laosensissp. nov. Habitus, male and female external and internal genital structures of the new species are illustrated.

The monotypic genus of ricaniid planthoppers (Hemiptera: Fulgoromorpha: Ricaniidae), LambertoniaLallemand, 1950 (type species – L. insignisLallemand, 1950) is redescribed and illustrated for the first time. Habitus, female external and internal genital structures are described and illustrated.

Two new whitefly species of the genus Aleuroclava Singh are described from the Andaman Islands, India. Empty puparia of Aleuroclava aporosaesp. nov. and Aleuroclava jarwaisp. nov. were found on the underside of the leaves of Aporosa octandra (Buch.-Ham. ex D. Don) Vickery (Phyllanthaceae) and Syzygium sp. (Myrtaceae), respectively. Diagnostic characteristics differentiating the new species from the congeners are given. Descriptions of the new species include morphometrics, line drawings, images of habitus on leaf, holotypes and SEM microphotographs.

The genus Cryptochetum Rondani is recorded from Vietnam for the first time with three species described and figured as new to science: C. dicranumsp. nov., C. equitanumsp. nov., and C. proceripalpissp. nov. A key to the species of the genus from Vietnam is presented.

The three larval instars of Hydrocanthus socius Sahlberg, 1844 are described and illustrated for the first time, including morphometric and chaetotaxic analyses of the cephalic capsule, head appendages, legs, last abdominal segment, and urogomphus. Larvae of this species can be separated from those of Hydrocanthus sharpiZimmermann, 1928 by the dorsal color pattern, H. sharpi being entirely brown, and H. socius testaceous with many small dark maculae. Regarding chaetotaxy, H. socius differs from H. sharpi in the length of seta MX11, the position of seta LA3, and the number of additional setae on trochanter. On the other hand, the second and the third instars of H. socius differ from those of H. sharpi in the number of secondary setae on the coxa.

This paper is the first in a series of studies on the genus Habroloma Thomson (1864) from China. The present paper provides discussion on taxonomic characters, indicates the unreliableness for some characters commonly used by previous authors, and proposes new clues for taxonomic studies of this difficult group. Seven species are newly described and illustrated from China: Habroloma attenuatumsp. nov., H. bianpingsp. nov., H. compactumsp. nov., H. elongutumsp. nov., H. hispidumsp. nov., H. latumsp. nov., and H. quadratumsp. nov.

Abstract. The Asian species of Bironium are reviewed and three new species are described: B. lobatumsp. nov. and B. yunnanumsp. nov. from South China and B. sulcatumsp. nov. from Thailand. Bironium atripenne (Pic) and B. amicale Löbl are placed in synonymy with B. grouvellei (Achard) and B. elegans Löbl, respectively. Lectotypes are designated for B. atripenne (Pic), B. distinctum (Achard), B. grouvellei (Achard) and B. sumatranum (Achard). Redescriptions are provided for B. biplagatum (Achard), B. feai (Achard), B. grouvellei (Achard), B. minutum (Achard), B. nigrolineatum (Pic), B. rufonotatum (Pic), B. sumatranum (Achard), and B. tonkineum (Pic); otherwise, original descriptions are appended with new characters. New collecting records significantly expand the known distribution ranges of many species. A key to the Asian species is given. A cladistic analysis based 27 characters that included all but four species of Bironium (29 species) rooted with Baeocera and Birocera was poorly resolved but indicated that there were at least three dispersal events from mainland Asia east through Wallacea towards Papua New Guinea (PNG). One potential dispersal event is represented by a clade that includes an undescribed species from Sulawesi, and others that may have undergone subsequent vicariance. The PNG fauna is represented by two lineages, one dispersal that involves B. flavapex Löbl, the only known species from the Moluccas that is the sister taxon of B. maculatum Löbl from PNG and B. nepalense Löbl from Nepal; the other is a monophyletic lineage of PNG species placed within a paraphyletic group of mainly mainland Asian taxa.

Examination of a series of Adelaidia rigua Blackburn, the type species of Adelaidia Blackburn and a new species A. queenslandicasp. nov. from Queensland, allowed for clarifying the systematic placement of this enigmatic genus. It was found to be a member of Attageninae, Attagenini, not of Megatominae, the subfamily in which it was placed by previous authors. Five Asian species formerly classified in Adelaidia are removed from Adelaidia to a new genus Adelaidellagen. nov. (type species Adelaidia unicolorMroczkowski, 1966) and the following new combinations are established: Adelaidella unicolor (Mroczkowski, 1966) comb. nov., A. haucki (Háva, 2000) comb. nov., A. rufa (Háva, 2002) comb. nov., A. splendida (Háva, 2012) comb. nov., and A. thailandica (Kadej & Háva, 2016: 596) comb. nov.

Trictenotoma davidi Deyrolle, 1875 and T. formosanaKriesche, 1919 are the only insular Palaearctic Trictenotomidae. Both species are related and T. formosana was originally defined on the basis of unstable morphological features and originally described as a subspecies of T. davidi. In this paper, a detailed redescription of T. formosana is provided, male and female genital organs are described and illustrated for the first time and the lectotype is designated. Hainan (China) records of T. davidi are presented and morphological variability of this taxon is discussed. The first observation of Trictenotomidae mating behaviour is briefly described.

The taxonomic position of Penichrus blapstinoidesChampion, 1885 (type species of PenichrusChampion, 1885) within Tenebrionidae is discussed based on the analysis of both type material and comprehensive internal and external morphology. The species was formerly classified within Opatrini (subfamily Blaptinae); however, this hypothesis is hereby rejected as this species does not share any of the diagnostic characteristics proposed for that tribe. A detailed analysis of other phylogenetically crucial features (including male and female terminalia, defensive glands, antennae, and abdominal ventrites) places Penichrus within Tenebrioninae. However, a more detailed assignment is not currently possible given the present circumscriptions of tenebrionine tribes. The genus is hereby placed as incertae sedis within Tenebrioninae. A morphological analysis and discussion of current tribal concepts is presented, which exposes the weakness of the currently accepted classification system, and highlights a need for extensive comparative morphological studies within Tenebrioninae and related subfamilies. A lectotype for Penichrus blapstinoides is designated. Distolinus impressicollisFairmaire, 1892 is reinstated as a junior synonym of Penichrus blapstinoides. A revised checklist and key to the genera of Opatrini known from mainland North America are provided.

Endemic species Archaeoglenes slipinskiisp. nov. is illustrated and described from Lord Howe Island (Australia), as well as a new monotypic genus Sepilokusgen. nov. (Tenebrionidae: Archaeoglenini) with S. tenenbaumisp. nov. (type species) from Sepilok Forest Reserve (Borneo). Morphology and anatomy of the genus Archaeoglenes is investigated using micro-CT techniques. The world catalogue of all known taxa belonging to Arachaeoglenini is presented.