An event of mating between specimens of Corizus hyoscyami and Rhopalus parumpunctatus, registered in the Novgorod Province of Russia is considered. The structure of the aedeagi in their completely inflated state and the female genitalia, as well as the functioning of the genitalia, are described and illustrated. The process of unfolding and swelling of the aedeagi is traced using the method of hydraulic inflation of the membranous parts with glass microcapillaries. The congruence of the genitalia is discussed for each species, and also for the interspecific crosses in both combinations of sexes and species. Structures of insect terminalia are divided into three groups according to their functions: 1) auxiliary structures; 2) structures providing the mutual fixation of the genitalia; and 3) structures directly performing the function of transferring seminal fluid. It is shown that in the considered variants of interspecific crosses, the parts of the genitalia belonging to the second group have almost the same structure and functioning, and most likely cannot perform the function of structural isolation. The structures of the third group have taxon-specific morphological and functioning traits and a high degree of congruence within each species. Schemes of the functioning of the genitalia in interspecific crosses, speculatively showing the impossibility of normal insemination, are proposed.

Phyllobrotica lorestanica sp. nov., from Iran is described, illustrated and compared with closely related P. binotata Ogloblin, 1936 and P. adusta (Creutzer, 1799). Coptocephala fallaciosa Fairmaire, 1884, Radymna nigrifrons (Laboissière, 1914) and Clytra weisei Monrós, 1953 are recorded for the first time from Iran. Habitus and aedeagus of Radymna nigrifrons (Laboissière, 1914) are illustrated.

Six new species of dance flies of the genus Empis (Diptera, Empididae) are described from the Altai Mountains of Russia: Empis (Polyblepharis) altaica sp. nov. (Republic of Altai, Altai Territory), E. (P.) seminskiensis sp. nov. (Republic of Altai), E. (P.) turalae sp. nov. (Republic of Altai), E. (P.) yakovlevi sp. nov. (Republic of Altai), E. barkalovi sp. nov. (Republic of Altai), and E. shebalinensis sp. nov. (Republic of Altai, Altai Territory). A key to species of Empis (Polyblepharis) of the Altai region of Russia is provided.

Hedychridium karakolense sp. nov. and Hedychridium tarbinskyi sp. nov. from Kyrgyzstan are described and illustrated. These outstanding species are among the largest Palaearctic species. Their doubtful placement in known species groups is discussed

At present, 58 species and subspecies of the cricket subfamily Phalangopsinae are registered in Peru, and 25 of them are found in the territory covered by the Peruvian project on invertebrate fauna of the Ene and Tambo River Basins. From this country, ten taxa are here described as new to science: Aclo­gryllus ashaninka sp. nov.; Rumea minispeculum sp. nov.; R. pacaya sp. nov.; Izerskya minutissima gen. et sp. nov.; Kevanacla orientalis zigzag subsp. nov.; Adelosgryllina subtrib. nov.; Adelosgryllus parasimilis sp. nov.; Luzara venado major subsp. nov.; Uvaroviella (Holacla) izerskyi multa subsp. nov. Previously unknown male is described for Modestozara satipo Gor. and for U. (Euacla) grandis (Des.-Grand.). New data on distribution and systematical position of some taxa as well as a brief discussion about Phalango­psinae classification are also given.

A new species of silverfish, Persiatelurina daghestaniana Kaplin, sp. nov., is described from Daghestan. It differs from other species of this genus, P. caucasica (Kaplin, 2016) from Abkhazia and P. farsiana Molero et al., 2018 from Southwestern Iran, by the structure of the legs, maxillae, maxillary and labial palps, pronotum, urotergite X, urosternites II and VII, urocoxites VIII and IX, subgenital plate, and ovipositor.

The pygmy grasshopper subfamily Batrachideinae consists of three tribes: Batrachideini Bolívar, 1887; Cassitettigini Yin, 1984, nom. resurr.; Bufonidini Hancock, 1907, nom. resurr., stat. nov. The Australian pygmy grasshoppers of the tribe Bufonidini are reviewed. Three new genera are described, namely Paraselina gen. nov. (type species Vingselina multifora Rehn, 1952), Anaselina gen. nov. (type species Vingselina minor Sjöstedt, 1921), and Selivinga gen. nov. (type species Selivinga tribulata sp. nov.). Four new combinations are proposed: Paraselina multifora (Rehn, 1952), comb. nov.; P. trituberculata (Sjöstedt, 1932), comb. nov.; P. brunneri (Bolívar, 1887), comb. nov.; Anaselina minor (Sjöstedt, 1921), comb. nov. A key to Australian genera of Batrachideinae is provided.

New genus and species (Cordela rubra gen. et sp. nov.) are described from Costa Rica. They represent a new tribe of the subfamily Thioniinae (Cordelini trib. nov.) which is based on the unique structure of the hind wing having weak clefts on the terminal margin, the cubitus anterior and cubitus posterior not fused with each other, and the second anal vein simple.

A new species of casebearer moths, Casignetella lastukhini sp. nov., is described from Madagascar.

Four remarkable new species of the genus Probles Förster are described from Vietnam: P. (Euporizon) barycnemiformis sp. nov., P. (E.) diaparsiformis sp. nov., P. (E.) proshchalykini sp. nov. and P. (E.) protoversuta sp. nov.

The genera Megadiestramima Stor. et Gor. and Mimadiestra Stor. et Dawwrueng are considered. Megadiestramima is here divided into three subgenera: Megadiestramima s. str.; Leodiestramima Stor. (in 2014, this subgenus was raised up to generic rank by Storozhenko & Dawwrueng, but in 2015, it was restored in original subgeneric rank by Gorochov & Storozhenko); Neodiestramima subgen. nov. Seven new species and subspecies of this genus are described from Vietnam, Thailand and Cambodia: M. (M.) borealis sp. nov.; M. (M.) abramovi sp. nov.; M. (M.) bilobata sp. nov.; M. (M.) centralis sp. nov.; M. (N.) orlovi lata subsp. nov.; M. (N.) o. khmerica subsp. nov.; M. (N.) brevispina sp. nov. Keys to subgenera and species of Megadiestramima s. l. and Mimadiestra as well as keys to subgenera of Diestramima Stor. and Adiestramima Gor. are given. Eight additional new taxa of the latter genera and of the genus Tamdaotettix Gor. are described from Laos, China and Vietnam: Baculitettix subgen. nov. and Excisotettix subgen. nov. in Diestramima s. l.; D. (B.) propria apicalis subsp. nov.; Hamatotettix subgen. nov. and Ulterotettix subgen. nov. in Adiestramima s. l.; A. (Adiestramima) originalis sp. nov.; T. (Tamdaotettix) ailaoshanicus sp. nov.; T. (T.) minipullus sp. nov. New data on distribution of some species are also given.

Chloropelix canariensis Lindberg, 1936, Paradorydium desertorum Linnavuori, 1964, and P.   spatulatum (Naudé, 1926) are recorded from the United Arab Emirates for the first time. These species were collected from Poaceae and Compositae in northeastern part of the country. Paradorydium desertorum is also recorded for the first time from Israel, and P. spatulatum, from Morocco. Two new synonyms are established: Bumizana deccani Viraktamath et Viraktamath, 1989, syn. nov. = P. spatulatum; Chloropelix indica Viraktamath et Viraktamath, 1989, syn. nov. = Ch. canariensis.

Seven species of the genus Pantolyta Foerster are found to occur in Russia. One species, P. ele­gans sp. nov. from Russia (Kunashir I.) and Japan (Hokkaido I.), is described as new for science. Eight known species of Pantolyta are reviewed and keyed. Colour illustrations are provided to all species.

The Eastern Mediterranean Region of Turkey and Crete Island in Greece are richest in species of the genus Eupholidoptera with ten and eleven reported species, respectively. One additional new species, E. gocmeni sp. nov., from the first region is described and compared with its relatives.

Two new species of the ant genus Myrmecina Curtis, 1829 are described and illustrated based on the worker and queen castes collected in Sumatra, Indonesia under the names M. andalas sp. nov. and M. nitidiuscula sp. nov. Each species displays unique morphological characteristics. Myrmecina andalas sp. nov. is characterized by a combination of the following characteristics: head dorsally sculptured, with the ventrolateral area smooth and shiny; propodeal spine short, triangular, pointing dorsad and with a broad base; propodeal declivity vertical, with the posterodorsal angle almost 90°. Myrmecina nitidiuscula sp. nov. is characterized by a combination of the following characteristics: head dorsum largely smooth and shiny; propodeal spine triangular and pointing posteriad, with a very broad base. Updated key to Myrmecina species of Sumatra is given.

The synonymization of species Chromadorita arctica Gagarin, 1999, syn. nov. from Novaya Zemlya and Ch. fennica Jensen, 1979 from the Gulf of Finland is proposed.

Great medieval scientist-polymath Abu Rayhan Al-Beruni (973–1050) wrote in his book “Pharmacognosy” about some kind of “worms” inhabiting willows in Azerbaijan and Southern Iran and used by native people for producing of a red dye. It was unclear during one thousand years which organisms Al-Beruni noted as those dye-producing “worms”. Some modern authors even suggested that the relevant medieval text was partly erroneous. To the contrary, in the present paper we, for the first time, consider some species of the felt scale insects (Coccinea: Eriococcidae) as the organisms, which have probably been used for the production of the red dye in the medieval countries of Western and Central Asia. These insects are several species from two closely related genera Acanthococcus Signoret, 1875 and Gossyparia Signo­ret, 1875. The review of biological characters, identification key, new figures and colour photographs are provided for the species of Acanthococcus and Gossyparia associated with Salix spp. in the Asiatic Region. Acanthococcus turanicus Matesova, 1967, syn. nov. is placed in synonymy with A. salicis (Borchsenius, 1938), and A. altaicus Matesova, 1967, syn. nov. is placed in synonymy with A. spiraeae Borchsenius, 1949. Earlier discovered synonymy of A. melnikensis (Hodgson et Trencheva, 2008) with A. aceris Signoret, 1875 is discussed. Some other dye-producing scale insects and their pigments are also briefly considered.

A complex of morphological features of the genera Dictyonota Curtis, 1827, Kalama Puton, 1876 and Derephysia Spinola, 1837 (Heteroptera: Tingidae: Tinginae), inconsistent with the characters of the tribe Ypsotingini Drake et Ruhoff, 1965, is discussed. The common morphological features of these genera together with those of Acalypta Westwood, 1840, which do not correspond to the characters of Tingis Fabricius, 1803, as the type genus of the tribe Tingini Laporte, 1832, are presented. The data on the sex chromosome system X0/XX of these four genera, radically different from that of all the other 17 so far karyotyped Tinginae genera (XY/XX), are summarised. The closely related genera Acalypta, Dictyonota, Kalama and Derephysia are united in a tribe under the resurrected valid name Acalyptini [Acalyptaini; ICZN Case 3813, in press] Blatchley, 1926 according to the principle of priority (ICZN, Article 23). A diagnosis of the resurrected tribe Acalyptini based on morphological and karyological characters and an improved key to the genera Acalypta, Dictyonota, Kalama and Derephysia are given.

Tetracoelactis ioran gen. et sp. nov. is described from abyssal depths of the NW Pacific and assigned to the family Exocoelactinidae. The genus is unique in having of only four meristematic zones, the lowest number among all species of Actiniaria.

The following four representatives of Histeridae are recorded for the first time from the territory of Abkhazia: Plegaderus sanatus gobanzi J. Müller, 1903, Platysoma (Cylister) cornix Marseul, 1861, Margarinotus (Ptomister) terricola (Germar, 1824), and Gnathoncus communis (Marseul, 1862). The first two species were found for the first time throughout the Caucasus.

The type material of five species of the flat moths described by Aristide Caradja from the Russian Far East and originally placed within the genus Depressaria Haworth, 1811 were examined. Four of these species now belong to the genus Agonopterix Hübner, [1825] and one to Exaeretia Stainton, 1849. Three new synonyms are established: Agonopterix pallorella (Zeller, 1839) = Depressaria divergella Caradja, 1920, syn. nov.; Agonopterixmultiplicella (Erschoff, 1877) = Depressaria sutschanella Caradja, 1926, syn.nov.; and Exaeretia exquisitella (Caradja, 1920), comb. nov. = Exaeretia amurella Lvovsky, 1990, syn. nov. A new systematic status is proposed for Depressaria rimulella Caradja, 1920 as Agonopterix liturosa rimulella (Caradja, 1920), comb. nov., stat. demotus.

The Cercyon shinanensis species group with two included species is erected within the nominotypical subgenus of Cercyon Leach, 1817. This group is compared with other Palaearctic species groups of Cercyon s. str. The little-known C. shinanensis Nakane, 1965 from Japan (Honshu) is redescribed and its diagnostic features are given. Cercyon sundukovi sp. nov. is described from the Russian Far East (Kunashir Island).

A new data on distribution of 19 species of Tersilochinae (Ichneumonidae) belonging to the genera Allophrys Förster (four species), Aneuclis Förster (five spp.), Diaparsis Förster (eight spp.) and Tersilochus Holmgren (two spp.) in the Afrotropical Region are provided. Tersilochus abyssinicus Khalaim, 2006, syn. nov. is synonymised with T. moestus Holmgren, 1868. The subfamily Tersilochinae is recorded from Benin, Côte d’Ivoire, Mozambique, Niger, Nigeria, Sierra Leone, Togo, Zambia and Yemen for the first time.

New and interesting records of 60 Diptera species in ten families, namely Anisopodidae, Blephariceridae, Campichoetidae, Dixidae, Drosophilidae, Limoniidae, Lonchopteridae, Pediciidae, Psychodidae and Scatopsidae, are presented in this paper based on the specimens collected in Azerbaijan and Georgia. A total of 26 species are recorded for the first time for Transcaucasia, 32 species for Azerbaijan, and 33 species for Georgia. In addition, the first or updated checklists of the above ten families are given for these countries.

The genus Geogryllus Otte et Perez-Gelabert, 2009 is recorded from South America. Three new species of this genus are described: G. mezai sp. nov. and G. doderoae sp. nov. from Peru as well as G. nubilosus sp. nov. from Ecuador. These species differ from other congeners mainly in the structure of male tegmina and male genitalia as well as in some peculiarities of the body colouration and the shape of head.

The recent catalogues of the family Dolichopodidae considered Syntormon pallipes (Fabricius, 1794) and S. pseudospicatus Strobl, 1899 as separate species. In this study, we used three approaches to estimate the significance of differences between the two species: molecular analysis (COI and 12S rRNA sequences), analysis of leg colour characters and geometric morphometric analysis of wing shape. The morphological data confirmed the absence of significant differences between S. pallipes and S. pseudospicatus found in the DNA analysis. Significant differences in the wing shape of two species have not been revealed. Hence, according to our data, there is no reason to consider S. pseudospicatus as a distinct species.

New genus and species of cockroaches of the subfamily Epilamprinae, Coriaceolamprodes rubidus gen. et sp. nov., are described from the Malaysian state of Sarawak (Borneo Island). This genus is closely related to the genera with asymmetrical armament of tarsi: Calolamprodes Bey-Bienko, 1969, Pseudocalolampra Roth et Princis, 1971, and Paracalolamprodes Anisyutkin, 2015.; however, it readily differs from these genera by the nearly symmetric hypandrium and the unique pressbutton-like shape of the apex of sclerite L3 of the male genitalia.

Aphis sibirica sp. nov. is described by apterous and alate viviparous females collected in the Irkutsk and Novosibirsk provinces of Russia at Euphrasia pectinata Ten., Odontites vulgaris Moench, Pedicularis palustris subsp. opsiantha (Ekman) Almq., Rhinanthus serotinus subsp. aestivalis (N.W. Zinger) Dostál (all four from the family Orobanchaceae), Elaeagnus rhamnoides (L.) A. Nelson (Elaeagnaceae), and Medicago sp. (Fabaceae). Diagnostic characters that distinguish the new species from its congeners inhabiting the same plants, and from other polyphagous species of Aphis are discussed.

Based on the large examined materials of Tersilochinae from the Zoological Institute of the Russian Academy of Sciences (St Petersburg) and other world collections, faunistic records from the Palaearctic Region (mainly from Russia) for 87 tersilochine species belonging to ten genera are provided, including ten species recorded for the first time from Russia. Two new species, Probles smaragdites Khalaim, sp. nov. and Tersilochus turpiculus Khalaim, sp. nov., are described from the Russian Far East. Gelanes tootsae Khalaim, 2002 syn. nov. is synonymised with G. cuspidatus Khalaim, 2002. Tersilochus kerzhneri Khalaim, 2007 is excluded from the fauna of Europe. The male of Tersilochus impunctator Khalaim, 2012 is recorded for the first time. Specimens of Tersilochinae, deposited in the Zoological Institute RAS (St Petersburg) and the Zoological Museum of the Moscow State University (Moscow) and briefly mentioned from the former USSR by K. Horstmann in his revisions (1971, 1981), are found, re-examined, and their complete label data are provided.

The parasitic louse fly Ornithomya comosa (Austen, 1930) (Diptera, Hippoboscidae), known from the Oriental Region (India, Thailand, Nepal and Peninsular Malaysia) and Asian part of the Palaearctic Region (Kazakhstan, Kyrgyzstan, West Siberia of Russia and Japan), is found for the first time in Europe and in the western part of Russia (Curonian Spit). Flies were collected from the swallow species Hirundo rustica (Linnaeus, 1758) and Delichon urbica (Linnaeus, 1758) (Hirundinidae). Two possible narratives for the occurrence of this fly in Europe are discussed.