Two new species of chitons, Stenosemus moskalevi sp. nov. from the Bering Sea (northwestern Pacific Ocean) and S. merweae sp. nov. from the coastal waters of South Africa (southeastern Atlantic Ocean) are described in this paper: S. moskalevi sp. nov. is distinguishable from other congeneric species by its structures of tegmentum and dorsal spicules; S. merweae sp. nov. differs from many other species of the genus by having many-colored tegmentum and girdle and the structure of dorsal spicules.

For the first time the morphology of the decapodid stage of Neocrangon communis is described in detail. The decapodid can be distinguished from those of the genera Argis, Crangon, and Mesocrangon by the morphology of their telson, antennae, antennulae, and carapace. The main distinguishing features of the decapodid of N. communis were two spines on medial line of the carapace, a short rostrum, relatively wide scaphocerite, characteristic shape and length of the terminal setae on the telson. Drawings of general view and some limbs are presented.

Some questions of classification of the subfamily Landrevinae Saussure, 1878 are discussed: the tribe Odontogryllini Mello, 1992, trib. resurr. is restored from synonymy; the genera Oreolandreva Chopard, 1945, Microlandreva Chopard, 1958 and Creolandreva Hugel, 2009 are included in the tribe Prolandrevini Gorochov, 2005. Some genera of the tribe Landrevini are considered: Duolandrevus Kirby, 1906; Repapa Otte, 1988; Endolandrevus Saussure, 1877; Endodrelanva Gorochov, 2000; Kotama Otte, 1988; Odontogryllodes Chopard, 1969. New taxa (38) from Indonesia, Malaysia, Vietnam, Laos, Philippines, Madagascar and Reunion Island are described: D. (Duolandrevus) bengkulu sp. nov., D. (D.) curup sp. nov., D. (D.) selatan sp. nov., D. (D.) manna sp. nov., D. (D.) lampung sp. nov., D. (D.) kubah sp. nov., D. (D.) sympatricus sp. nov., D. (D.) kalimantan sp. nov., D. (D.) balikpapan sp. nov., D. (D.) spinicauda sp. nov., D. (D.) sabah sp. nov., D. (Eulandrevus) tawau sp. nov., D. (E.) borneo sp. nov., D. (E.) microrarus sp. nov., D. (E.) megararus sp. nov., D. (Bejorama) parvulus sp. nov., D. (B.) firmus tioman subsp. nov., D. (B.) balabacus taytay subsp. nov., D. (B.) doloduo sp. nov., D. (B.) obliteratus sp. nov., D. (Jorama) curtipennis mindoro subsp. nov., R. trusmadi sp. nov., R. denticulata sp. nov., Sulawemina nitida gen. et sp. nov., Endolandrevus halmahera sp. nov., E. saussurei sp. nov., E. biak sp. nov., Endodrelanva tomentosa juara subsp. nov., E. macrorachis sp. nov., E. peculiaris sp. nov., E. chopardi sp. nov., K. incisa sp. nov., O. rotundatus sp. nov., O. angulatus sp. nov. (Landrevini); Striduleva gen. nov., Astriduleva analamazaotra gen. et sp. nov. (Prolandrevini). Neotype for D. (D.) coulonianus (Saussure, 1877); D. (D.) sulawesi Gorochov, 2000, comb. nov. и D. (E.) paradoxus Gorochov, 2001, comb. nov. are transferred from the genus Repapa Otte, 1988 to Duolandrevus s. l. (to its subgenera Duolandrevus s. str. and Eulandrevus, respectively); the former species R. proxima Gorochov, 2004 is considered as a subspecies of the latter species, i. e. as D. (E.) paradoxus proximus stat. nov.; subgeneric position of some old species of Duolandrevus s. l. is established or changed; data on previously unknown females and new localities are also given.

Data on the genera Anabropsis Rehn, 1901, Glaphyrosoma Brunner-Wattenwyl, 1888, Stenopelmatopterus Gorochov, 1988 and Stenopelmatus Burmeister, 1838, belonging to the families Anostostomatidae and Stenopelmatidae, from Mexico, Guatemala, Honduras, Nicaragua, Costa Rica and Colombia are presented. Sixteen new species are described: A. longipenna sp. nov.; A. weissmani sp. nov.; A. kasparyani sp. nov.; A. proxima sp. nov.; A. johnsi sp. nov.; A. chiapas sp. nov.; A. oaxaca sp. nov.; A. apteroides sp. nov.; G. bulbosum sp. nov.; G. beretka sp. nov.; G. tamaulipas sp. nov.; G. pushenkovi sp. nov.; G. dilutum sp. nov.; G. dentatum sp. nov.; G. karnyi sp. nov.; G. anderi sp. nov. Tribe Brachyporini Gorochov, 2001 is restored from synonymy; lectotypes for G. gracile Brunner-Wattenwyl, 1888 and for G. mexicanum (Saussure, 1859) are designated; and new data on distribution of some other species are given.

Two species of the genus Austrohancockia are found in Vietnam. A. orlovi sp. nov. is described from northern and central parts of this country. A key to Vietnamese species of Austrohancockia is provided.

Mirococcus vallis sp. nov. is described and illustrated from Samara Prov. of Russia. Three else species of mealybugs: Fonscolombia amnicola (Borchsenius, 1948), Mirococcopsis subterranea (Newstead, 1893) and Ripersiella poltavae (Laing, 1929) are reported for the first time to the fauna of the Volga Area.

A new species of the genus Pseudotaphoxenus Schaufuss, 1865, P. kazakhstanicus sp. nov., is described from the Aktolagai Mountain Range in Western Kazakhstan and the Koksengir Mountains in Central Kasakhstan.

Based on the examination of the type specimens of Heterocerus kamtschaticus А. Egorov, 1989, described from Kamchatka, the following synonymy is proposed: Heterocerus fenestratus (Thunberg, 1784) = H. kamtschaticus А. Egorov, 1989, syn. nov.

Coccobius barracas Myartseva sp. nov. and C. bacasur Myartseva sp. nov. are described from the Mexican State Baja California Sur. A key to seven species of the genus Coccobius Ratzeburg, 1852 known from Mexico is provided.

Three species of the genus Wockia Heinemann, 1870, which are so far known in Russia are reviewed; their male and female genitalia are illustrated, and a key for identification is provided. Two species, W. koreana Sohn, 2008, and W. magna Sohn, 2014, which were recently described from East Asia, are for the first time reported from Russia. The investigation of the holotype of W. funebrella Heinemann, 1870, discovered in the collection of the Zoological Institute RAS (St Petersburg), confirmed that this species is a junior subjective synonym of W. asperipunctella (Bruand, 1851). The distribution of Palaearctic species of the genus is discussed shortly.

A new species Callopora septentrionalis sp. nov. of cheilostome Bryozoa is described from the collection of the Zoological Institute, Russian Academy of Sciences. The species differs from its congeners by presence on gymnocyst of three types of adventive avicularia: two columnar avicularia with triangular mandible of different sizes as well as large avicularia with spatulate mandible, and by bell-shape and cap-shape ovicells.

Recent studies on mating and copulation in pulmonates have provided a better understanding of a functional relationship between various aspects of their biology and have greatly advanced our knowledge of their reproductive behaviour. Here we describe the mating behaviour, copulatory mechanics and genital anatomy of Hippeutis complanatus (Linnaeus, 1758), a Palaearctic freshwater pulmonates, and compare these results with those from Segmentina oelandica (Westerlund, 1885). In H. complanatus, the individual that initiates mating mounts the shell of the partner and crawls over its basal side to position itself at the shell aperture for intromission. The copulatory connection is achieved by the preputium and its musculo-glandular appendage (preputial organ) that attaches to the shell of the partner. Hippeutis complanatus and S. oelandica share a number of common traits in genital morphology and mating behaviour, most notably the unilateral copulation and the use of the preputial organ as a holdfast. These species also show some significant differences: the opposite orientation of the partners, chemical stimulation in S. oelandica and a significantly longer mating duration in H. complanatus. Overall, the mating behaviour of the two species shows a combination of shared and divergent traits that have potential of being useful as taxonomically informative characters.

The morphology of the soft body of two unique cephalaspid species, Eоscaphander fragilis Habe, 1952 and Cylichna magna Lemche, 1941, having two gizzard plates in their gizzards has been studied. Taxonomic position of the both species is discussed. The morphology of E. fragilis is described and illustrated for the first time. The species belongs to the monotypic genus which was considered previously as a junior synonym of the genus Scaphander. Feeding of E. fragilis on sponges has been noted. A new monotypic genus, Pseudocylichna gen. nov., has been described for Cylichna magna. Morphological differences of the gizzard plates and gizzard walls of the genera mentioned before have been shown. Both genera have been placed in a new family Eoscaphandridae fam. nov. based on their pair gizzard plates and the division of the gizzard wall into four segments by tendons of the connective tissue.

The former genus Hymenoptila Chopard, 1943 (of mainly African distribution) is placed in the genus Gryllomorpha Fieber, 1853 as its third subgenus (stat. nov.). The following hypothesis about the history of distribution of Gryllomorphinae is proposed: originally, two tribes of this subfamily were geographically isolated from each other by Tethis Ocean (Petaloptilini in South Europe and Asia Minor; Gryllomorphini in North Africa including Arabian Peninsula); later, after the arising of terrestrial contacts between Africa and Eurasia, the Gryllomorphini penetrated to more northern and more eastern territories (Europe and other parts of Southwest Asia) by two ways; but the Petaloptilini was probably not able to go beyond the limits of Europe, Asia Minor and some nearest islands.

Investigation of Eriosomatidae in Belarus started in the 1900s. However, a regional checklist of Eriosomatidae aphids was not published till now. Based on material preserved in the collections of Belarusian State University and the Zoological Institute of the Russian Academy of Sciences, and data scattered across publications we have compiled the first comprehensive list of Eriosomatidae recorded from Belarus and briefly analysed it from the geographical and ecological points of views. The list includes 12 genera and 27 species. Pemphigus passeki Börner, 1952 has been recorded from Belarus for the first time. The registered diversity is less abundant than in the adjacent Poland. In the accordance with the global pattern of aphids host plant connections, a single species permanently inhabit woody plants (monoecious species), the other ones are dioecious and migrate from woody plants to woody (eight species) or herbaceous (12 species) plants. Four species is anholocyclic.

Two Afrotropical scale insect species, Trochiscococcus speciosus (De Lotto, 1961) and Ripersiella aloes (Williams et Pellizzari, 1997), are recorded for the first time in Russia, St Petersburg, under glass on the roots of Gasteria sp. (Asphodelaceae). The first species is morphologically described and illustrated by a standard total coccidological figure and by the photograph; a study of the reproductive biology of this species revealed an obligate ovoviviparity, parthenogenesis (thelytoky) and the chromosomal number 2n=10. The quarantine status for both species is advised on the territory of Russia and neighbouring countries.

The tropical bedbug Cimex hemipterus (Fabricius, 1803) was found for the first time in Russia: in many districts of Moscow in 2015–16, in four districts of St Petersburg, in Moscow Prov., Smolensk and Saransk in 2016. Unusual activity during daytime in autumn was characteristic of individuals of this species in different places of St Petersburg. C. lectularius Linnaeus, 1758 was absent in St Petersburg and Moscow in places where C. hemipterus was found, and apparently the former species is displaced by the latter. In all localities, C. hemipterus is resistant to insecticides used for controlling C. lectularius. It may be expected that C. hemipterus will overwinter successfully in heated facilities in Russia and spread to other regions where it can displace C. lectularius.

The new species Idiasta vanreenensis sp. nov. is described and illustrated from South Africa. This species is compared with the most similar I. curtimembrum Fischer, 2004 from Madagascar.

A braconid endoparasitoid, Protapanteles mygdonia (Nixon, 1973), of the severe pest of box trees, the moth Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae), is re-described and illustrated from the North Caucasus of Russia. This is the first discovery of a native parasitoid of box tree moth in the Western Palaearctic.

Based on a large examined material from several world collections, faunistic records of 87 tersilochine species (including one unidentified species of Palpator Khalaim) belonging to 13 genera from Europe (except Russia), North Africa, Caucasus and Middle East are provided. Palpator turpilucricupidus from Europe, Heterocola linguaria from North Africa and subfamily Tersilochinae from Jordan and Syria are recorded for the first time. First colour photographs of the genus Palpator are given.

Three species of adventive beetles, Arthrolips fasciata (Erichson, 1842) from the family Corylophidae, Silvanoprus cephalotes (Reitter, 1876) and Psammoecus trimaculatus Motschulsky, 1858 from the family Silvanidae, are recorded from the Caucasian region and from Russia for the first time. Psammoecus trimaculatus is the first recorded from Europe, and A. fasciata and S. cephalotes are first recorded from Eastern Europe.

Microrhagus nikitskyi sp. nov. and M. vicarius sp. nov. are described from the Russian Far East. Based on the holotype, Balistica elongata Fleutiaux, 1923 is re-described. The following new combinations are proposed: Clypeorhagus elongatus (Fleutiaux, 1923), comb. nov. (= Balistica elongata Fleutiaux, 1923) and Dirrhagofarsus ferrugineus (Reitter, 1889), comb. nov. (= Dirrhagus ferrugineus Reitter, 1889). A new synonym is established: Dirrhagofarsus Fleutiaux, 1935 = Pseudorhacopus Olexa, 1975, syn. nov. Lectotypes of Microrhagus pyrenaeus Bonvouloir, 1872 and Dirrhagus ferrugineus Reitter, 1889 are designated; status and distribution of these species are discussed.

The larger black flour beetle, Cynaeus angustus (LeConte, 1851), is recorded from Russia (Belgorod Province) for the first time. It is also first recorded in the literature from Ukraine (Lugansk and Kharkov Provinces), known previously from the Kharkov Province from the record in the Internet. Its economic importance, historical and contemporary distribution are discussed.

New synonymies in the genus Scolytus Geoffroy, 1762 are established: S. koltzei Reitter, 1894 = S. yablonianus Murayama, 1943 = S. shanhaiensis Yin et Huang, 1980; S. ventrosus Schevyrew, 1890 = S. trispinosus Strohmeyer, 1908. Scolytus kononovi Kurentsov, 1941 is justified as a distinct species from S. semenovi (Spessivtsev, 1919). The synonymy of S. formosanus Eggers, 1939 with S. frontalis Blandford, 1894 is confirmed.

Four species (Rhyparida spiridonovi sp. nov. from Penang Island and Singapore, Tricliona trimaculata sp. nov. from Penang Island and Malay Peninsula, T. suratthanica sp. nov. and T. trangica sp. nov. from Thailand) are described. A key to the species of the genus Tricliona from Indochina and Malay Peninsula is given. Rhyparida faitsilongi nom. nov. is the new replacement name for Rhyparida megalops (Chen, 1935), comb. n., transferred from the genus Tricliona; Tricliona tonkinensis (Lefèvre, 1893), comb. nov. and Tricliona episternalis (Weise, 1922), comb. nov. transferred from the genera Phytorus and Rhyparida, accordingly. Lectotypes of Rhyparida episternalis Weise, 1922 and Phytorus tonkinensis Lefèvre, 1893 are designated.

A new species, Buvatina dubatolovi sp. nov., closely related to the East European B. iremella Junnilainen et Nupponen, 1999, is described from the Botchinskiy Nature Reserve (Sikhote-Alin Range) at the Russian Far East.

The Palaearctic species of the genus Trichardis Hermann, 1906 are reviewed. A new species, T. lehri sp. nov., is described. A new synonymy is established: T. leucocoma (van der Wulp, 1899) = T. afanasievae Lehr, 1964, syn. nov. The male of T. mongolica V. Richter, 1972 is described for the first time. External features and the male genitalia of T. lehri sp. nov., T. leucocoma (van der Wulp, 1899) and T. mongolica V. Richter, 1972 are illustrated with photographs.

An updated checklist and a revised key to the males of Palaearctic species of the genus Medetera including all 180 species and 3 subspecies are provided; 27 species are included in the key for the first time. Medetera belgica Parent, M. bilineata Frey, M. kowarzi Negrobov, M. miki Negrobov, M. peloria Negrobov, M. sphaeropyga Negrobov, M. tarasovae Negrobov, and M. thunebergi Negrobov, stat. resurr., are removed from synonymy based on the differences in the male genitalia.

The rare Palaearctic species Tipula apicispina Alexander, 1934 and T. stenostyla Savchenko, 1964 are recorded for the first time from Russian Karelia. The new data on their bionomics are given. The adults were collected with trunk eclector set on a recently fallen aspen trunk. The larvae develop under moss growing on fallen trunks, bases of old standing trees and stumps of hardwoods, as well as on the ground near tree bases.

The first data are presented about the Sciomyzidae of Iturup, the largest of the Kuril Islands. A total of ten species are recorded. Limnia setosa Yano is recorded for the first time from Russia; Tetanocera montana Day and T. phyllophora Melander are recorded for the first time from the Kuril Islands. Photographs, comments on diagnostic characters and adult habitats of poorly known species are given.