Russian Journal of Biological Invasions

2026, issue №3

CONTENTS

RECORDING A POSSIBLE CASE OF ADOPTION IN THE NON-NATIVE MYSID LIMNOMYSIS BENEDENI (CRUSTACEA: MYSIDA) - Alexandrovich P., Lipinskaya T. - Two cases (≈2.30% of females with broods) of Limnomysis benedeni (Czerniavsky, 1882) from the site of the Pripyat River were recorded in which a single female’s marsupium contained a larva at a later stage of development while other larvae in the same marsupium were at an earlier stage; in one case the “older” larva had an atypical body configuration. These observations may correspond to the phenomenon of adoption, but are probabilistic in nature due to data origin. The article includes a literature review on the synchrony of embryonic development and the phenomenon of mysids’ adoption, and alternative explanations for the observed patterns are also discussed.

NATURAL CENOPOPULATIONS OF PRUNUS ARMENIACA L. (ROSACEAE) AS OBJECT OF SECONDARY INVASION BY THE PHYTOPATHOGEN WILSONOMYCES CARPOPHILUS (LEV.) ADASK.) (BOTRYOSPHAERIACEAE) IN THE NATURAL CONDITIONS OF MOUNTAINOUS DAGESTAN - Anatov D.M. - The new data on the spread of shot-hole disease (Wilsonomyces carpophilus (Lev.) Adask.) in apricot natural coenopopulations (Prunus armeniaca L.) of Intramountainous Dagestan are given. The influence of the main abiotic environmental factors affecting the spread of shot - hole disease was analyzed in fruit and leaves and assessed in 17 coenopopulations and 468 trees. It has been found that fruit are more highly injured by the pathogen (3.2 points) than leaves (1.3 points). As revealed, the altitude above sea level is the main limiting factor facilitating an increased pathogen infestation. The influence of the altitude level inside the river basins and taking into account the slope exposures is noted. Based on the results of one-way variance and regression analyses, the influence of the linear contribution of the altitude gradient to the overall variance has been proved. The coefficient of determination confirmed the significant contribution of the altitude level to the incidence of shot -hole disease in fruit (r² =25,8%) and weak for leaves (r²= 1,7%). The linear correlation coefficient r_xy for fruit was 0,51, for leaves 0,13. Modeling shot-hole disease of fruit and leaf damage taking into account multicollinearity showed a high relative contribution of precipitation during the warm period (bio18) to fruit injury, and a negative contribution for leaves with the minimum temperature of the coldest month (bio6). It is assumed that the cost effectiveness of apricot cultivation in Intramountainous Dagestan is limited to 1200 m above sea level, taking into account micro-conditions, above which the natural infectability of fruit increases significantly.

NEW AND RARE ALIEN SPECIES OF EPHEMEROPHYTES IN THE FLORA OF KHABAROVSK TERRITORY AND THE JEWISH AUTONOMOUS REGION - Antonova L.A., Vernoslova M.I. - Information on 28 new and rare alien ephemerophyte species is provided, 18 of which are new for the flora of Khabarovsk Territory and the Jewish Autonomous Region, including 8 species of which have not previously been reported for the flora of the Russian Far East. Based on their potential for further spread and naturalization, the species are classified into three categories – N0, N1, N2. Five species show a high potential for further expansion (Cota tinctoria, Hypericum perforatum, Lysimachia nummularia, Padus virginiana, Asparagus officinalis) and may eventually pose a risk of biological invasion.

ALIEN SPECIES IN THE ZOOPERIPHYTON OF SEVASTOPOL BAY (BLACK SEA, CRIMEA) - Boltachova N.A., Revkov N.K., Podzorova D.V., Grintsov V.A. - In the period of 2023-2025, the formation of a periphyton community was observed on the surfaces of hydraulic structures in the Inkerman Port area of Sevastopol Bay. A total of 81 macrofaunal species were identified, 10 of which (12%) are alien to the Black Sea. Six of the 18 dominant species in the community (33%) are alien. During the three-year observation period, the density and biomass of both native and invasive species were increasing. By 2025, invasive species accounted for 32% of the total density and 64% of the total biomass. Particularly high quantitative values were recorded for Magallana gigas (Thunberg, 1793), Ficopomatus enigmaticus (Fauvel, 1923), Hydroides dianthus (Verrill, 1873) and Polydora cornuta (Bosc, 1802). A fully established natural aggregation of M. gigas was recorded in the Black Sea for the first time, resulting in a new biocenosis dominated by the giant oyster in terms of biomass. Its maximum biomass value reached 7,387 g/m². In terms of density, F. enigmaticus was the second species in this biocenosis after the native Mytilaster lineatus, with a maximum density of 117,150 individuals per square meter. Taking the mass of the worm tubes into account, this species was also subdominant in terms of biomass (1,176 g/m²). The invasive bivalve Arcuatula senhousia was discovered for the first time near the coast of the Black Sea in Crimea (Sevastopol Bay). The maximum density of this species (875 individuals per square meter) in the established by them colony goes beyond previously documented values in the Black Sea.

VARIABILITY IN GROWTH RATES OF THE MARSH FROG, PELOPHYLAX RIDIBUNDUS (PALLAS, 1771) (AMPHIBIA, RANIDAE), INTRODUCED TO KAMCHATKA IN THE FIRST YEARS AFTER METAMORPHOSIS - Bryakova M.A., Lyapkov S.M. - Using skeletochronology, long-term samples of mature Pelophylax ridibundus from several populations in the invasive part of the species' range in Kamchatka were studied. It is generally accepted that growth rates for this species are maximal immediately after metamorphosis, with a more or less pronounced slowdown occurring before sexual maturity. The change in postmetamorphic growth rate (hereinafter, R) was measured as the increment between the first and second winterings, divided by the increment between the second and third winterings. The proportion of individuals with R < 1 (i.e., with initially slow growth and its acceleration only in the period between the 2nd and 3rd wintering) varies in different populations from 1.4% to 13%. The proportion of individuals with 1 < R < 1.6 (i.e., with a slight slowdown in growth) varies from 1.4% to 9.1%, which indicates the absence of a discrete group of individuals with R < 1. The population mean R value, corresponding to typical growth, varies from 2.3 to 9.7 and does not differ significantly between all the populations studied, with the exception of one case. Males in most populations exhibited faster growth before the second wintering and a more pronounced growth slowdown between the second and third winterings, compared to females. Similar cases of atypical growth were found in marsh frog population from their native range, which has a relatively short active season. The most likely cause of these cases is the relatively large growth increment between the second and third winterings and the associated reaching sexual maturity no earlier than after the third wintering The similar ratio of growth increments in other species of amphibians and in reptiles, known from the literature, indicates the existence of different reasons for the formation of the observed pattern of delayed growth acceleration.

THE ROLE OF HYBRIDIZATION IN THE INVASIVE SUCCESS OF THE REYNOUTRIA HOOK. SPP. (POLYGONACEAE) IN EUROPE: INTEGRATION OF GENETIC AND MORPHOLOGICAL DATA - Vinogradova Yu.K., Shelepova O.V., Galkina M.A., Mayorov S.R. - The role of hybridization in the successful invasion of Reynoutria complex in Europe was studied. Samples of Reynoutria species from their native and secondary distribution ranges were examined: R.Sachalinensis (3 samples), R.japonica (3 samples), and their cultigenic hybrid R. × bohemica, which originated in the secondary range of the parent species (12 samples). These taxa are alien naturalized species. R. × bohemica is capable of backcrossing, which triggered a process of intense introgression and the formation of a hybrid complex with high genetic and phenotypic diversity. Molecular genetic analysis (ISSR markers) confirmed that the majority of spontaneous populations in Europe and Russia are represented by second-generation hybrids (F2) or backcrosses, rather than by the «pure» species of R. japonica. Morphometric analysis of leaves revealed high variability in diagnostic traits, particularly in leaf base shape, complicating field identification of the taxa. Geographic variability in micro-traits (the presence of conical trichomes on the midvein) was discovered. The invasive success of the complex is explained by the synergy of hybridization, which provided genetic diversity and restored sexual reproduction, and high phenotypic plasticity, facilitating rapid adaptation to various conditions. The results underscore the importance of an integrative approach combining genetic and morphological methods for effective monitoring and control of invasive populations.

CLIMATE CHANGE AS A DRIVER OF RANGE EXPANSION OF NEMORAL PAPILIONOIDEA (LEPIDOPTERA) INTO EASTERN SIBERIA - Gordeev S.Yu., Gordeeva T.V., Zaitseva S.V. - Based on long-term transect counts conducted in three altitudinal belts (steppe, forest-steppe, and taiga) and meteorological station data from 2002 to 2014, we applied principal component analysis (PCA) to identify the key climatic factors driving the population dynamics of Papilionoidea (butterflies) in the Selenginskoe mid-mountains (Western Transbaikalia). The community dynamics were most closely linked to variations in temperature and humidity. We revealed clear ecological differentiation: forest-dwelling species were more strongly influenced by moisture-related variables (air humidity, precipitation, and snow depth), whereas species of open habitats were more sensitive to thermal conditions. Our results further demonstrate that successful overwintering and range expansion of nemoral species, particularly those of the genus Apatura, are facilitated by a specific combination of cold-season conditions—warm and wet autumns, stable snow cover, and early springs. These findings confirm that regional climate changes, manifested in moderated temperature and moisture regimes, are a key mechanism driving the eastward expansion of nemoral Lepidoptera into Eastern Siberia. The climatic predictors identified in this study may serve as valuable tools for forecasting further range shifts of these species.

PHENOLOGICAL ADAPTATIONS OF AMBROSIA ARTEMISIIFOLIA L. (ASTERACEAE) IN THE CENTRAL CAUCASUS - Zherukova S.Z., Shkhagapsoev S.Kh., Chadaeva V.A. - Phenological variability is an important component of plant adaptation during dispersal to new territories. A key feature of the seasonal development of Ambrosia artemisiifolia in the foothills of the Central Caucasus is the formation of up to four generations (cohorts) of seedlings during a growing season – in April-May, June, August, and September. Summer cohorts of plants serve as a population reserve in the case of spring seedlings death. They had the shortened periods of vegetative growth (by 25-41 days), flowering (by 8-10 days), and seed dispersal (by 15-25 days). This allowed to plants to synchronize the flowering phase with the optimal photoperiod and to form seeds before frost damage. The exception was the fourth plant generation with the shortest life cycle (93 days), insufficient to complete the fruiting phase, interrupted by frosts in the second decade of December. Several generations of A. artemisiifolia necessitate repeated measures for their eradication (from April to September) and adjusted timing of seasonal pollinosis, as the pollen release period extends from July-August to early December. The primary target for eradication of A. artemisiifolia plants is the first cohort with long periods of vegetative growth (88 days), flowering (37 days), and seeding (45 days). These plants maximize the species reproductive potential and contribute most to the replenishment of the soil seed bank. The phenological plasticity of common ragweed largely determines the successful restoration of populations in highlands. With the late emergence of a single seedling cohort (July) and a short life cycle (120 days versus 200 days for the foothill first cohort), plants still managed to form viable seeds. The main phenological adaptations of highland populations included expression of the vegetative growth phase (42 days) while maintaining the duration of critical reproductive phases, such as flowering (33 days), fruiting (39 days), and seed dispersal (32 days). The results reflect the biological potential for the seasonal development of A. artemisiifolia in the Central Caucasus, as they were obtained in 2025, a year with an unusually warm autumn and early winter. At the same time, given current climate trends, it is possible to predict the repeated realization of this potential, considering the long-term storage of ragweed seeds in the soil.

DISTRIBUTION OF NATIVE LEAF-ROLLING WEEVIL CYCNOTRACHELODES CYANOPTERUS (MOTSCHULSKY, 1861) (COLEOPTERA, ATTELABIDAE) ON THE NORTH AMERICAN BLACK LOCUST ROBINIA PSEUDOACACIA IN THE SOUTH OF THE RUSSIAN FAR EAST - Kolyada N.A., Efremenko A.A., Kirichenko N.I. - This paper presents the results of investigation of the East Asian leaf-rolling weevil Cycnotrachelodes cyanopterus, which has formed a new trophic association with the North American black locust (Robinia pseudoacacia, Fabaceae) in the south of the Russian Far East. The leaf-rolling weevil was found on Robinia pseudoacacia in 15 of 17 surveyed settlements in Primorsky Territory in 2025, indicating its widespread distribution and successful adaptation to the new host plant. A total of 30 weevil adults were collected in these settlements: 10 adults were captured feeding on the black locust leaves in the field, and 20 were reared in the laboratory from leaf rolls of the black locust. The largest number of the beetles (12 adults from 7 model trees) was documented in the settlement of Slavyanka. Further observations of the native beetle populations on alien plant are needed to study the insect harmfulness and invasive potential.

ALIEN AND NATIVE SPECIES OF HIGHER CRUSTACEANS IN THE RIVER MOUTHS - TRIBUTARIES OF RESERVOIRS OF THE MIDDLE AND LOWER VOLGA - Kurina E.M. - The study presents an analysis of the current species composition and key quantitative characteristics of higher crustaceans in the river mouth of tributaries of the Middle and Lower Volga reservoirs. The most common and abundant amphipods were Pontogammarus maeoticus (Sowinsky, 1894) in the tributaries of the Middle Volga reservoirs and Dikerogammarus haemobaphes (Eichwald, 1841) in the tributaries of the Lower Volga reservoirs. The only representatives of freshwater fauna, the isopod Asellus aquaticus (L., 1758), were encountered sporadicly in the studied river mouths. The dominant species complex in the rivers is represented by mysids and isopods, and in the river mouths and reservoirs by amphipods. Despite the relatively rare occurrence of mysids and cumaceans, they form the maximal number of statistically significant cenotic relationships with other crustacean species in the river mouths. It is shown that the biomass of amphipods associated with mollusks of the genus Dreissena decreases in the tributaries of the Middle Volga reservoirs.

CHARACTERISTICS OF THE POPULATION GENETIC STRUCTURE OF BROWN RATS (RATTUS NORVEGICUS, RODENTIA, MURINAE) IN MOSCOW - Maltsev A.N., Korablev M.P., Kotenkova E.V., Komarov V.Y. - An assessment of the population genetic structure of the Moscow brown rat was conducted. The study puts forward key hypotheses regarding factors influencing changes in the population size and genetic structure of Rattus norvegicus. This theme of work was conducted in Russia for the first time in the study of an invasive commensal species in the largest metropolis in Europe. In the study, 13 microsatellite loci were used as autosomal markers of genetic polymorphism. The rat material was divided into local samples based on the administrative districts of Moscow: Zelenograd, North-West, West, South-West, South-East, Central, East, and North. Rats from Zelenograd (ZelAO) demonstrated the highest genetic diversity, and the lowest inbreeding coefficient. Moderate variability was observed in the North-West and West Administrative Districts. The lowest genetic diversity was recorded in the Central Administrative District, although the highest inbreeding coefficient was observed there. According to the distribution of genetic differences, rats captured in the center (Central Administrative District) and southwest (South-West) of Moscow were the most distinct. Rats from Zelenograd (ZelAO), northwest (North-West), west (West), and southeast (South-East) Moscow demonstrated similarities. It is assumed that the heterogeneity of the population genetic structure of the brown rat in Moscow is due to the isolation and territorial conservatism of rats in some settlements (Central, Eastern, and Southwestern Administrative Districts) and high migratory activity in others (ZelAO, SZAO, ZAO, and YuVAO). Moreover, according to our hypothesis, brown rat migration in Moscow occurs along a branched network of rivers and canals, starting from the Skhodnya River in Zelenograd outside the Moscow Ring Road and continuing along the Moskva River within the Moscow Ring Road to southeastern Moscow and beyond, according to our collected data. Adaptations associated with resistance to anticoagulants allow brown rat colonies in the Southwestern Administrative District to maintain their numbers and subsequently recover.

THE FIRST RECORD OF FRESHWATER HYDROMEDUSA CRASPEDACUSTA SOWERBII LANKESTER, 1880 (CNIDARIA) IN THE KALININGRAD REGION - Polunina Ju.Ju., Gerb M.A., Chernaya E.R. - The freshwater hydromedusa Craspedacusta sowerbii Lankester, 1880 was first recorded in the Kaliningrad Region in former gravel-sand quarry with semi-aquatic and aquatic vegetation in August 2025. The jellyfish were swimming above thickets of Myriophyllum spicatum L. at a depth of 0,5-2,0 m. The water temperature during sampling constituted +22 °C, salinity - 0,15 PSU, and water transparency - 2 m. The jellyfish density in the habitat was 1-3 specimens/m³. The umbrella diameter of the jellyfish varied from 3 to 26 mm, with a predominance of individuals of 17-18 mm in size. Small-sized organisms were prevalent among the zooplankton in the jellyfish habitat. Great crested grebes (Podiceps cristatus Linneus, 1758) inhabited the water area. Meteorological summer in the Kaliningrad region in 2025 lasted for 115 days, of which 24 days were characterized by air temperatures above 25°C. This facilitated to the development of the medusoid stage of the C. sowerbii. The transit corridors and invasion vectors of C. sowerbii in local water ecosystems have not been established. The distribution of these jellyfish in temperate waters is facilitated by the increase in water temperatures in various regions due to climate change and the transfer of the polyp stage by waterfowl.

ECOLOGICAL NICHE MODELS OF ALLIUM PARADOXUM (M. BIEB.) G. DON (ALLIACEAE): FROM A RARE SPECIES IN THE CAUCASUS TO AN AGGRESSIVE INVADER IN EUROPE - Pshegusov R.H., Chadaeva V.A. - The article examined the issue of ecological niche conservatism of Allium paradoxum, a rare species in the native range (Caucasus, Northern Iran, Turkmenistan), but an aggressive invader in Western and Central Europe. The ecological niches of the Subcaucasian and European population groups differed significantly: the overlap in the space of integrated environmental factors did not exceed 20% (Schoener's D). The weakest overlap was for moisture-related parameters, such as winter precipitations (Schoener's D = 0.17) and soil water balance (Schoener's D = 0.24). The native climatic niche was almost fully realized in Europe (Unfilling = 4%), while invasive populations had occupied 40% of novel climatic conditions (Expansion = 40%), primarily habitats with high winter precipitation (Expansion = 43%). A niche contraction in the invasive range was revealed for soil water balance (Unfilling = 57%). The predicted range of Subcaucasian populations (1,352,000 km²) covered the Caucasus and included additional cores in Central and Eastern Europe. The potential range of European populations (1,028,000 km²) was limited to Western Europe. The geographic overlap of the ranges was only 4.6%. The successful invasion of A. paradoxum in Europe was facilitated by the expansion of its climatic niche (particularly for winter precipitation), vivipary, and active dispersal by gardeners. The rarity of the species in its native range is associated with climatic limitations (Western Caucasus and Western Transcaucasia) and, probably, fragmentation of forest habitats (Central Caucasus).

NEW DATA ON ALIEN PLANTS OF SAKHALIN - Seregin A.P., Lozhnikova O.O. - We report data on 61 alien vascular plant species recorded by the authors in 2025. These include 41 species new to the flora of Sakhalin, 16 species first recorded between 2015 and 2024, and 4 species for which earlier undocumented records were accounted for. Nine species are reported for the first time in the flora of the Russian Far East: Geum ×spurium, Prunus cerasifera, Rubus allegheniensis, Amelanchier alnifolia, Circaea ×intermedia, Cirsium incanum, Salix cinerea, Salix triandra, and Viola ×wittrockiana. Three species recorded on Sakhalin for the first time were previously included in the Black Data Book of the Flora of the Russian Far East (Bidens frondosa, Pimpinella saxifraga, and Parthenocissus inserta). All known localities for the species new to the island are cited, alongside information regarding their occurrences in adjacent territories is given. The majority of the new species escaped from cultivation (18 species), while eight are considered accidental introductions by humans (on clothing, footwear, or vehicles). Five species each were accidentally introduced via commercial seed mixtures and construction machinery. Most new records were found in various habitats on the outskirts of summer settlements and within urban areas. Data on the dispersal of 16 alien species that appeared on Sakhalin over the last decade are summarised. These include both rapidly spreading species (e.g., Medicago lupulina, Veronica filiformis) and those that remain restricted to rare, occasional occurrences. All known records for each of these species are provided. A potential dispersal scenario for Silene dioica on Sakhalin is discussed in detail. Furthermore, the dispersal histories of Telekia speciosa, Fragaria ×ananassa, Hesperis matronalis, and Stellaria aquatica are presented, accounting for earlier records that had previously been neglected. The alien flora of Sakhalin Island currently comprises 370 species.

GENETIC STRUCTURE OF POPULATIONS OF THE ALIEN SPECIES HELIX POMATIA LINNAEUS, 1758 (HELICIDAE) IN THE SOUTH OF THE CENTRAL RUSSIAN UPLAND BASED ON MICROSATELLITE LOCI ANALYSIS - Snegin E.A., Sychev A.A., Artemchuk O.Yu., Snegina E.A. - The genetic structure of alien Helix pomatia L. populations in the southern Central Russian Upland (Belgorod Region) and adjacent territories was studied using microsatellite DNA loci (SSR, STR). A total of the 156 individuals from seven populations were analyzed. One adventive group of Helix thessalica (Boettger, 1886) (20 individuals) inhabiting the study area was used for comparison. A total of the 20 alleles were identified in the five STR loci studied, of which six (30%) were private. Private alleles were found in four of the studied populations, constituting 50 % of their total number. On average, all groups showed low levels of genetic variability (Ho=0.204±0.039, He=0.193±0.035) and high rates of genetic originality (Fst=0.467, Фst=0.439, Nm=0.736). With the help of two nonparametric methods: the Chao1-bc method and the first-order jackknife one, the potential genetic diversity was assessed, which was expected under increasing the amount of sampling ad infinitum (Nmax). Three of the eight groups turned out to have very low both real and potential genetic diversity. The cluster analysis revealed two groups of H. pomatia populations that likely have different origins. The H. thessalica group (near the village of Yablonovo, Belgorod region), known since the end of the 19th century, is characterized by stable naturalization in the natural environment, has significantly distanced itself from the H. pomatia populations, confirming its species status. Calculation of effective population size using the LD method, the HetEx method, and the MS method revealed that, across all three calculation methods, significant results were obtained for only two populations (Ne varied from 0.6 to 4.8). Due to low genetic variability, Ne could not be calculated for the other groups. Deficiency in allelic polymorphism together with expressed genetic differentiation of samples under study is determined by effect of founder and genetic heterogeneity of initial lines. The reduction of effective size of populations Ne and parameters of genetic diversity points to a low adaptive potential and increased vulnerability of these groups to stochastic factors.

PARASITES OF TWO INVASIVE FISH SPECIES, ROTAN PERCCOTTUS GLENII (ACTINOPTERYGII: ODONTOBUTIDAE) AND THE SILVER CRUCIAN CARP CARASSIUS AURATUS COMPLEX (ACTINOPTERYGII: CYPRINIDAE), IN THE PONDS OF MOSCOW - Sokolov S.G., Voropaeva E.L., Pikel K.V., Khasanov F.K., Petrovskiy A.B., Reshetnikov A.N. - Various alien fish species are actively spreading in freshwater bodies across the planet, leading to the transformation of established parasitic systems. We focused on the parasite fauna of two alien invasive fish species (rotan Perccottus glenii and the silver crucian carp Carassius auratus complex), which are widespread in the ponds of Moscow City, since assessing parasite diversity contributes to understanding the ecological role of the aforementioned fishes in the water bodies of a large metropolis. In three urban ponds, 10 parasite taxa were detected in rotan and 28 taxa in the silver crucian carp. Notably, no parasite species common to both these species were found. These differences are partly related to the host specificity of certain parasitic species; however, the reasons for the absence of shared non-specific parasite species in rotan and silver crucian carp remain unclear. The analysis confirmed that rotan facilitates the colonization by parasites in planktonic invertebrates, and possibly benthos, while the silver crucian carp does so mainly in benthos in the studied Moscow ponds. The life cycles of almost all detected parasites are completed within the specific aquatic ecosystem and are not associated with terrestrial animals. None of the parasite species found in rotan and silver crucian carp pose a threat to the health of domestic animals or humans.

ASSESSMENT OF VARIABILITY IN THE SPECIES COMPOSITION AND DIVERSITY OF GROUND BEETLE ASSEMBLAGES (COLEOPTERA, CARABIDAE) IN DERIVATIVE GRAY ALDER FORESTS (ALNETUM INCANAE AEGOPODIOSUM) WITH VARIOUS COVER OF SOLIDAGO CANADENSIS - Sushko G.G., Lakotko A.A., Tkachenko A.S., Litvenkova I.A. - The article presents the results of a comparative analysis of the alpha and beta diversity of ground beetle assemblages in derivatives of alder forests, in habitats with varying degrees of Solidago canadensis distribution (absolute dominance, about 50% of the cover and minimal ( < 5% in cover) presence). The studies were carried out in 2025 in the northern part of the Republic of Belarus. Low species diversity (H’ = 0.73 – 1.86) of ground beetles was recorded, which varied significantly (F = 145.8; p  <  0.01) in sites with different cover of Solidago canadensis. The assemblages were dominated by characteristic forest ground beetle species: Pterostichus niger, P. oblongopunctatus, P. melanarius, and Carabus nemoralis. Their relative abundance varied in habitats with different Solidago canadensis cover. Sites with absolute and moderate dominance of Solidago canadensis were characterized by distinct differences in ground beetle species composition compared to the sites with minimal presence of the invader. The main drivers of ground beetle alpha diversity in habitats with different Solidago canadensis coverage were the height and species richness of herbaceous plants, which shape microclimatic parameters on the soil surface and the width of trophic webs, as well as soil moisture.

EXPANSION OF THE AMERICAN SIGNAL CRAYFISH PACIFASTACUS LENIUSCULUS (DANA, 1852) (DECAPODA: ASTACIDAE) INTO THE LAKE-RIVER SYSTEM OF THE VUOKSA RIVER WITHIN RUSSIA - Tamulyonis A.Yu., Besaeva E.A., Zuyev Yu.A. - In 2024-2025, the American signal crayfish Pacifastacus leniusculus was recorded in the sections of the lake-river system of the Vuoksa River bordering Finland – the Svetogorskoe reservoir and the section of the Vuoksa River below the Lesogorsky bridge for the first time. Fifty three and sixty five individuals of this crayfish species were caught in the Svetogorskoe reservoir in 2024 and 2025, respectively. At the Vuoksa River section below the Lesogorsky bridge, the material was collected in 2025, and only 4 specimens were found. Most of the individuals in the studied areas were represented by males. Among the signal crayfish caught in the Svetogorskoe reservoir, signs of the eroded swimmeret syndrome (ESS) were noticed. Previously, this crayfish disease had not been registered in Russia. For the Svetogorske reservoir, the captured part of the signal crayfish population in 2024 amounted to 5,3 thousand individuals, in 2025 – 6,3 thousand individuals. The calculation of the primary crayfish stock in the reservoir based on the results of scientific fishing has shown that, so far, the crayfish productivity of this waterbody remains at a low level. In general, at the bottom the crayfish kept to natural shelters: depressions between rocks, vegetation thickets and logs. The obtained research results indicate the successful expansion of signal crayfish into the lake-river system of the Vuoksa River and its eastward movement towards Lake Ladoga.

INTRODUCTION OF THE AMERICAN ROTIFER KELLICOTTIA BOSTONIENSIS (ROUSSELET, 1908) (ROTIFERA: BRACHIONIDAE) INTO THE BELOKHOLUNITSKOYE RESERVOIR (KIROV REGION) - Tselishcheva E.M. - In 2025, for the first time the rotifer Kellicottia bostoniensis (Rousselet, 1908) was recordered in the Belokholunitskoye Reservoir (Belaya Kholunitsa River, Volga basin) and registered for the Kirov Region. The species occurred in over 70% of samples, reaching a maximum abundance of 31.02 thous. ind./m³. The invader coexists with the related native species K. longispina (Kellicott, 1879).

PHYLOGEOGRAPHY AND ORIGIN OF THE ASIAN TIGER MOSQUITO AEDES ALBOPICTUS (DIPTERA: CULICIDAE) POPULATION IN DAGESTAN - Shaikevich E.V., Patraman I.V. - In 2025, Aedes albopictus (Diptera: Culicidae) mosquitoes were detected on the Caspian Sea coast, specifically in Makhachkala and Derbent for the first time. The range expansion of the invasive mosquito Ae. albopictus occurs continuously worldwide, typically facilitated by transport networks. The introduction of Ae. albopictus into Dagestan may originate from the regions with established populations: from the Krasnodar Territory to the north, and from Iran along the Caspian coast to the south. The aim of this study was to determine the phylogenetic relationships between the newly emerged Dagestan population of Ae. albopictus and mosquitoes from neighboring regions to trace the origin of this new invasive population. An analysis of a 1400-bp fragment of the mitochondrial DNA cytochrome c oxidase subunit I gene was performed. Identical sequences were identified among individuals collected from the three sampling sites in Dagestan. Restriction fragment length polymorphism analysis confirmed that the mtDNA of all 57 specimens belonged to the H1 haplotype. Screening for the endosymbiotic bacterium Wolbachia in the 57 examined Ae. albopictus specimens revealed the presence of two strains, wAlbA and wAlbB. While both bacterial strains occur in the Russian Federation, only one is found in Iran. Genetic analysis confirms that the Dagestan population is closely related to the Ae. albopictus population from the Krasnodar Territory.

MORPHOLOGY AND DISTRIBUTION OF A NEW PLANKTONIC DIATOM SPECIES FOR THE BLACK SEA AND THE SEA OF AZOV, CERATAULINA CF. DENTATA HASLE IN HASLE & SYVERTSEN, 1980 (BACILLARIOPHYCEAE, HEMIAULACEAE) - Yasakova O.N., Teyubova V.F. - The article presents the data on discovery and distribution of a new species of diatoms for the Black Sea and the Sea of Azov, Cerataulina cf. dentata Hasle, previously known for the tropical and subtropical waters of South and North America, Asia, and Japan. A marine species inhabiting coastal areas with warm water, in the seas of Russia it was found only in the waters of the Sea of Japan in the temperature range of 9.8-22°C. In the Sea of Azov, Cerataulina cf. dentata with a population of 66-5,30 thous. cells/l and a biomass of 0.3-46.8 mg/m³ was noted in plankton samples of Temryuk Bay in the autumn-winter period 2020 - 2022. In the Black Sea, the species was found in the Novorossiysk area from August to October 2021 (0,225-23,90 thous.cells/l; and 1.15-84.4 mg/m³, respectively). In general, the species formed no more than 1.5 % of the total abundance and 15 % of the phytoplankton biomass in the Temryuk Bay of the Sea of Azov and less than 3 % and 6 % of the total abundance and biomass of phytoplankton, respectively, in the northeastern part of the Black Sea. The presence of Cerataulina cf. dentata in the port waters of two inland seas of Russia indicates the probable penetration of this species with the ballast waters of commercial ships; most likely, the species was brought from the coastal regions of Asia or the Far East, where it has long been known.

A SURPRISING CONCENTRATION OF ALIEN PLANT SPECIES IN A SINGLE LOCALITY IN ARMENIA - Fayvush G., Aleksanyan A., Hovhannisyan H., Khachatryan L., Janjughazyan K. - During planned surveys of the territory of Armenia aimed at studying the distribution of invasive plant species, we encountered an unusual phenomenon in Northern Armenia, near the town of Alaverdi. Seven alien species were found co-occurring within a single habitat: Ailanthus altissima, Robinia pseudoacacia, Amorpha fruticosa, Ambrosia artemisiifolia, Nicandra physalodes, Phytolacca acinosa and Symphyotrichum novi-belgii. This article aims to identify the vectors responsible for the introduction of these species into Armenia and the study area, as well as to present the results of their risk assessment. Four of these species are invasive in Armenia, one is naturalized, and two are casual. It has to be noticed that Risk assessment scores are very high for all these species (from 14 to 24). According to the Australian Weed Risk Assessment (WRA) method, a score exceeding 6 indicates a high risk (suggesting the species is not recommended for cultivation for any purpose and requires close monitoring if found in natural populations). Despite receiving high scores, the last three species have not yet demonstrated invasive traits. In fact, our discovery marks the first time they have been found not in culture but in a semi-natural ecosystem. They require further monitoring in the wild.

SHARED PERCEPTIONS, SHARED SOLUTIONS: INTEGRATING HOUSEHOLD AND SCIENTIFIC INSIGHTS FOR SUSTAINABLE MANAGEMENT OF THE INVASIVE NELTUMA JULIFLORA (SW.) RAF. (FABACEAE: MIMOSOIDEAE) IN ETHIOPIA - Gebrehiwot K., Zeynu A. - This study explores the socio-economic and ecological impacts of Neltuma juliflora (Sw.) Raf., a species that has been widely regarded as invasive and harmful to the environment and people. The study was conducted in three purposively selected districts near Lake Abbe, where 37 households were randomly sampled across invasion-level strata, while 18 scientists with expertise in invasive plant species, particularly N. juliflora, were purposively selected to provide scientific perspectives. Data were collected through semi-structured household and key informant interviews, complemented by focus group discussions, enabling the integration of local community perceptions with expert knowledge for a comprehensive assessment of the species' impacts and management. A chi-square test of independence showed that there was no significant difference between the households and scientists that negative impact outweighs the positive impact (df = 1, Pearson Chi-Square= 1.49, p = .223). We suggest that N. juliflora could be used as charcoal, animal and human food, and for house construction. We argue that utilizing the species could be a viable option for managing it, as eradicating seems impossible in areas where it has already spread. The authors acknowledge that promoting the species through utilization could be controversial, but argue that it is worth considering as a potential solution given that eradication appears impractical in its current state. Our study notes that current management practices have been ineffective and costly. Further research is needed to fully understand the effectiveness of Benzene-rinsed N. juliflora burning, which was not previously reported in Ethiopia or elsewhere in the world.

BIOLOGY AND DEVELOPMENT COMPARISON OF ALTICA HIMENSIS (COLEOPTERA: CHRYSOMELIDAE) ON BOTH INVASIVE ALIEN PLANT RUMEX HASTATUS AND NATIVE IMPATIENS BALSAMINA IN KASHMIR HIMALAYA - Mehraj M., Ahmad T., Rashid I., Ahmad R. - The invasive alien plant species Rumex hastatus and a native plant species Impatiens balsamina are considered as obnoxious weeds present in the Kashmir valley covering major habitat types like orchards, agricultural fields and barren lands. The specialist native insect herbivore Altica himensis collected at field sites has a greater potential to act as bio control agent. Host specificity tests of no choice and dual choice revealed that R. hastatus and I. balsamina are only hosts of A. himensis egg and larvae. The egg oviposition and development of A. himensis larvae was found on these two plant species making them a realized host range. The developmental duration of A. himensis was faster on R. hastatus (57.27±2.03 days) as compared to I. balsamina (61.26±1.72 days) making the invasive alien plant an ideal host for this beetle. The beetle has a much greater potential to completely defoliate the host plant leading to mortality. The reduced number of leaves decreases the process of photosynthesis, slow plant growth, less production of flowers and ultimately lower seeds. This way the use of A. himensis at specific sites where the density of two plants is greater under controlled conditions can lead to eradicate the menace and subsequent seed bank in soil.

USE OF SPARTINA ALTERNIFLORA LOISEL. (GRAMINEAE) SALT MARSHES BY JUVENILE FISHES: EFFECTS OF THE PRESENCE OF MAGALLANA GIGAS (THUNBERG, 1793) ON DISTRIBUTION PATTERNS - Molina L.M., Luppi L., Barrio D. - Salt marshes are ecologically important ecosystems that provide high biodiversity and key ecosystem services but are increasingly threatened by global wetland loss driven by climate change, sea-level rise, and human activities. Invasive species such as the Pacific oyster Magallana gigas can function as autogenic ecosystem engineers, which modify habitat structure and associated biological communities. In the Bahía Blanca Estuary, Argentina, we evaluated the effects of oyster presence on fish assemblages in vegetated Spartina alterniflora marshes and adjacent non-vegetated habitats. Fish were sampled using gillnets during nine tidal cycles, and changes in prey availability and sediment characteristics were also assessed. Vegetated areas showed higher fish abundance, greater species diversity, and larger body sizes than non-vegetated oyster-dominated areas. Oyster invasion was additionally associated with shifts in benthic food resources and sediment properties. These results demonstrate that M. gigas significantly alters fish assemblage structure, underscoring the need to incorporate biological invasions into salt marsh conservation and management strategies.

MNEMIOPSIS LEIDYI (CTENOPHORA: TENTACULATA) COMMUNITY STRUCTURE IN THE SOUTHERN CASPIAN SEA: DECADAL CHANGES - Kheirabadi N., Ghodrati Shojaei M., Abtahi B., Mahmoudi N., Vostokov S., Roohi A. - Mnemiopsis leidyi has markedly altered plankton dynamics and disrupted the food web in the Caspian Sea region. This study compared 10-year changes in the population structure of M. leidyi in the southern Caspian Sea by comparing seasonal samples collected in two years (2011 and 2021), along three transects. Sampling was conducted across three depth layers—surface (0–10 m), middle (10–20 m), and deep (20–30 m) to study vertical distribution patterns. The results showed that Neka had the highest abundance of ctenophores among other sites with the highest abundance of the M. leidyi being observed in the larval stage in both periods. There was a marked decrease in abundance for M. leidyi throughout all stages in 2021, particularly in the middle and deep layers at the Babolsar and Neka sites. Vertical patterns showed that M. leidyi was concentrated in the upper layer (0–10 m), where temperature, oxygen, and food resources were most favorable. However, seasonal peaks shifted from summer dominance in 2011 to autumn in 2021. Seasonally, only the autumn exhibited a significant difference in M. leidyi abundance between these two periods. This suggests potential seasonal variations in the factors influencing the ctenophore population dynamics due to changes in temperature during these seasons. The appearance of ctenophore, Beroe ovata, global warming and environmental degradation has been identified as possible contributors to the decline of M. leidyi population.

PHENOLOGICAL SHIFTS OF INVASIVE ALIEN PLANTS IN THE EASTERN HIMALAYAS: A STUDY RESPONSE TO CLIMATE CHANGE AND FOREST TYPE - Singh H.B. - The shift of phenology played an important role in determining the proliferation of invasive alien plant species. Changes in climatic parameters specifically precipitation, relative humidity, temperature (minimum and maximum) affects the phenophases of invasive alien plants species, resulting in vibrant expansion. In this present study, nine invasive species were selected for annual observation on leaf initiation, flowering, fruiting and leaf fall along with four climatic parameters in five forest types of Pakke Tiger Reserve, Arunachal Pradesh. Weekly monitoring, followed by statistical analysis using coefficient of variation (%), analysis of variance (ANOVA) followed by post hoc Tukey pairwise test (if significant), correlation, regression and canonical correspondence analysis (CCA) were performed to understand their association. The result revealed that Bidens pilosa L. had the longest duration in flowering, Chromolaena odorata (L.) R.M.King & H.Rob. in fruiting and Urena lobata L. in leaf initiation and fall, respectively. Moreover, majority of the species displayed asynchronous phenophases. Repeated measures of ANOVA indicated that Ageratum conyzoides L. in flowering and Chromolaena odorata (L.) R.M.King & H.Rob. in leaf initiation had significant variation in phenophases across the forest types. However, Pearson correlation and linear regression displayed that the climatic parameters had role in the proliferation of these species. Further, CCA revealed that precipitation was the major influenced in flowering and leaf fall while relative humidity and temperature, in combination were more associated in all phenophases. The present study revealed a hidden knowledge that invasive flora were influenced by the climatic parameters in expansion toward tropical semi evergreen forest of eastern Himalayan region.

THE FIRST DOCUMENTED RECORD OF WILD-ESTABLISHED ORNAMENTAL KOI CARP MORPHOLOGICALLY CONSISTENT WITH CYPRINUS RUBROFUSCUS LACEPEDE, 1803 (CYPRINIDAE, ACTINOPTERYGII) FROM MOROCCO AND NORTH AFRICA - El Caidi S., Taybi A.F., Mabrouki Y. - Human activities, particularly the aquarium trade, are increasingly facilitating the introduction of exotic aquatic species beyond their natural biogeographical ranges, posing major threats to freshwater biodiversity worldwide. This study reports, for the first time, the establishment of a feral population of koi carp (Cyprinus rubrofuscus) in Morocco and, more broadly, in North Africa. The population was discovered in the Ain Smen dam, located within the Sebou basin. Seven specimens displaying different colour morphotypes were collected and identified based on diagnostic morphological characters, notably the number of dorsal fin rays and lateral line scales. Field investigations revealed that the introduction was intentional and linked to ornamental fish farming for commercial purposes. This new record increases the number of confirmed exotic freshwater fish species in Morocco to 25 species belonging to eight families, representing approximately 37.3% of the national ichthyofauna. Among these, five species are associated with the aquarium and ornamental fish trade. Our findings highlight the growing role of the ornamental fish trade as an emerging pathway for biological invasions in Moroccan freshwaters and emphasise the urgent need for strengthened monitoring programmes, public awareness initiatives, and stricter regulations governing the importation, breeding, and trade of ornamental species in order to protect Morocco’s endemic aquatic biodiversity.

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