(1) Background: The conservation of entomofauna in individual macroregions requires efforts to study the distribution and abundance of insects. For this purpose, databases are created that enumerate this information. Such databases, with the processing of significant factual material, make it possible to objectively assess the status of a species and, if necessary, take measures for its protection. The aim of the paper is to describe the modern Coleoptera fauna in nine regions of Russia on the basis of a recently published dataset. (2) Methods: We conducted our own studies in 1994, 1996, 1998–2003 and 2005–2022. The dataset also includes data from museum specimens from other years. We used a variety of methods, such as sifting through litter, searching under the bark of trees and stumps, trapping by light, soil traps, beer traps, window traps, etc. For each observation, the coordinates of the find, the number of individuals observed and the date were recorded. (3) Results: The dataset contains data on 1469 species and subspecies of Coleoptera from 85 families found in the Volga Region. In total, there are 31,433 samples and 9072 occurrences in the dataset. (4) Conclusions: The largest families in terms of species diversity are Curculionidae (202 species), Carabidae (145 species) and Chrysomelidae (142 species). There are 54 species of Coleoptera with a northern range boundary in the macroregion, two species with a southern range boundary and one species with an eastern range boundary. Twenty-one invasive Coleoptera species have been recorded in the macroregion.

(1) Background: Blattodea and Dermaptera in the temperate forest zone include a limited number of species, some of which are widely distributed and common. However, digital data on their biology remains insufficient. (2) Methods: The surveyed area extends from Kaluga Oblast to Tatarstan and from Vladimir Oblast to Voronezh Oblast. Insects were sampled from 736 plots using various methods, including pitfall traps, beer traps, window traps, pan traps, and sweep nets. (3) Results: The dataset contains 2149 occurrences comprising 18,362 specimens belonging to 5 species of Blattodea and 4 species of Dermaptera. For most occurrences, we recorded the developmental stage (nymph or adult) and the sex (male or female for adults) of the specimens. (4) Conclusions: Three non-synanthropic species are widely distributed and common: Ectobius lapponicus, E. sylvestris, and Forficula auricularia. Ectobius sylvestris is characterized as a true forest species, while E. lapponicus inhabits both forest and grassland habitats. In contrast, F. auricularia is associated with gardens, urban habitats, and some meadows. Ectobius sylvestris exhibits a more pronounced sexual dimorphism concerning the effectiveness of different sampling methods compared to E. lapponicus. Seasonal dynamics of cockroaches and earwigs are described and discussed.

Orthopteroidea is an ecologically diverse group of incompletely transformed insects that includes several insect orders similar in development and structure. Many species from Dermaptera, Orthoptera, Mantodea, and Blattodea are sensitive to anthropogenic influences and are indicators of the external environment. Some species cause damage to agriculture and forestry; others are inhabitants of human dwellings and pests of food supplies. The aim of this study is to describe fauna of some orders of Orthopteroidea in the Republic of Mordovia, in the central part of European Russia. This study was conducted in April–October 1971, 1984, 1995, 1996, 1998, 2000, 2001, and 2004–2023. All possible habitats were studied using a variety of methods (entomological traps, pitfall traps, pan traps, etc.). An acoustic method of species identification was also used. For each observation, the coordinates of location, abundance, and dates were recorded. The dataset contains 4865 occurrences. In total, 16,644 specimens of Orthopteroidea were studied. The dataset contains 71 species including Dermaptera (4), Orthoptera (62), Mantodea (1), and Blattodea (4). Of these, 13 species are identified for the first time in the region; these mainly inhabit steppe areas. The presence of two Orthoptera species has not been confirmed yet during our studies; these species are noted in this paper according an old published paper. The biodiversity of Mordovia includes 73 species from four orders. The biology of numerous species, their seasonal dynamics, and some descriptions of biotopes and number of new species are described.

(1) Background: Carabidae is one of the most diverse families of Coleoptera. Many species of Carabidae are sensitive to anthropogenic impacts and are indicators of their environmental state. Some species of large beetles are on the verge of extinction. The aim of this research is to describe the Carabidae fauna of the Republic of Mordovia (central part of European Russia); (2) Methods: The research was carried out in April-September 1979, 1987, 2000, 2001, 2005, 2007–2022. Collections were performed using a variety of methods (light trapping, soil traps, window traps, etc.). For each observation, the coordinates of the sampling location, abundance, and dates were recorded; (3) Results: The dataset contains data on 251 species of Carabidae from 12 subfamilies and 4576 occurrences. A total of 66,378 specimens of Carabidae were studied. Another 29 species are additionally known from other publications. Also, twenty-two species were excluded from the fauna of the region, as they were determined earlier by mistake (4). Conclusions: The biodiversity of Carabidae in the Republic of Mordovia included 280 species from 12 subfamilies. Four species (Agonum scitulum, Lebia scapularis, Bembidion humerale, and Bembidion tenellum) were identified for the first time in the Republic of Mordovia.

(1) Background: Beetles in the superfamily Scarabaeoidea are one of the most important groups of Coleoptera. They are found in various ecosystems all over the world and belong to coprophagous, necrophagous, saproxylophagous, phyllophagous and rhizophagous types. The aim of the study is to describe the fauna and distribution of Scarabaeoidea in the Republic of Mordovia (central part of European Russia); (2) Methods: The study was conducted from 2003 to 2023. Collection material (specimens from 1972 and 1986) was also used. Specimens were collected using traditional Coleoptera collecting methods (manual collecting, light trap, collection of rotten remains and pitfall traps). For each observation, the coordinates, number of specimens and dates were recorded; (3) Results: The dataset contains 3198 occurrences. We examined 11,011 specimens of Scarabaeoidea. The dataset contains information on 88 species of Scarabaeoidea. Of these, five species (Aphodius pedellus, Nobius serotinus, Phaeaphodius rectus, Planolinus fasciatus and Onthophagus medius) are listed for the region for the first time. Another seven species are additionally known from others taken from the literature (but were not found during the present field survey); (4) Conclusions: Species diversity of Scarabaeoidea of Mordovia accounts for 95 species from 4 families (Geotrupidae, Trogidae, Lucanidae and Scarabaeidae). Ten species (Protaetia marmorata, Anoplotrupes stercorosus, Cetonia aurata, Protaetia cuprea volhyniensis, Oxythyrea funesta, Platycerus caraboides, Serica brunnea, Melolontha hippocastani, Trichius fasciatus and Protaetia fieberi) constitute the main population of Scarabaeoidea fauna given in the dataset. The species diversity of Scarabaeoidea of the Republic of Mordovia is roughly similar in number of species to that of neighboring or more northern regions.

(1) Background: Phoridae is a relatively large and understudied family of Diptera. Species within this family occupy diverse ecological niches across a wide range of habitats. (2) Methods: The dataset is based on Phoridae specimens collected in the Republic of Mordovia (European Russia). Sampling was conducted from 2019 to 2024 using six collection methods: hand-held sweep nets, pitfall traps, beer traps, pan traps, Malaise traps, and window traps. (3) Results: The dataset includes 4713 occurrence records from the Republic of Mordovia, comprising a total of 15,701 Phoridae specimens. It provides data on 271 species. The highest species richness was recorded in the Mordovia State Nature Reserve (226 species, 83.4%). Fewer species were documented in the fauna of the National Park “Smolny” (177 species, 65.3%), with comparable diversity observed in other parts of the region. Ten species were dominant in the dataset (Megaselia pusilla, Triphleba opaca, Megaselia angusta agg., Diplonevra funebris, Megaselia brevicostalis, Megaselia plurispinulosa, Megaselia minuta, Megaselia lutea, Megaselia lactipennis, and Megaselia flavicans). A total of 139 species were represented by fewer than ten specimens each. Seasonal dynamics varied across habitats: in the Mordovia State Nature Reserve, both species richness and specimen abundance were already high in April, peaking in June. In contrast, in the National Park “Smolny”, peak values were observed in August. (4) Conclusions: We have listed 151 new recorded species from Russia in this list. Currently, the Phoridae fauna of the Republic of Mordovia is among the best-studied in Russia. The distribution of many species has become clearer, with the Mordovia State Nature Reserve demonstrating the highest biodiversity compared to other areas of the region.