Pollinators play a crucial role in ecosystems globally, ensuring the seed production of most flowering plants. They are threatened by global changes and knowledge of their distribution at the national and continental levels is needed to implement efficient conservation actions, but this knowledge is still fragmented and/or difficult to access. As a step forward, we provide an updated list of around 3000 European bee and hoverfly species, reflecting their current distributional status at the national level (in the form of present, absent, regionally extinct, possibly extinct or non‐native). This work was attainable by incorporating both published and unpublished data, as well as knowledge from a large set of taxonomists and ecologists in both groups. After providing the first National species lists for bees and hoverflies for many countries, we examine the current distributional patterns of these species and designate the countries with highest levels of species richness. We also show that many species are recorded in a single European country, highlighting the importance of articulating European and national conservation strategies. Finally, we discuss how the data provided here can be combined with future trait and Red List data to implement research that will further advance pollinator conservation.

We revise the Merodon constans species group of the genus Merodon Meigen, 1803 (Diptera: Syrphidae), provide morphological diagnoses and descriptions, as well as an illustrated key and a discussion on the different taxonomic characters used. In total, 15 species were studied, their geographic distributions are presented on maps, and nine new species are described. Two species are redefined and neotypes are designated, lectotypes are designated for five species, and one species is reinstated as valid. Following a detailed study of type material in different entomological collections, the status of several species is revised and three new synonymies are proposed. The M. constans species group was resolved as being monophyletic within the M. albifrons lineage based on molecular analyses using COI and 28S rRNA gene sequences. Three species morphologically similar to M. constans (Rossi, 1794) but occurring outside its distributional range were supported as being valid and distinct species on the basis of molecular data, but they were not distinguishable based on morphological characters. By contrast, continental populations of M. analis Meigen, 1822 could not be separated from Mediterranean M. constans based on differences in COI or 28S rRNA genes. The same molecular markers could not discriminate between two other species pairs. We conclude that these molecular markers only partially resolve species within the M. constans group. Geometric morphometry of wing shape successfully separated M. analis and M. constans, as well as M. spineus Vujić, Šašić Zorić & Likov, sp. nov. in both species and population analyses.

Merodon natansgroup (Diptera, Syrphidae) taxa are reviewed using an integrative taxonomic approach combining morphological, morphometric and molecular techniques. The approach substantiates recognition of the three species:M. calcaratus(Fabricius, 1794),M. natans(Fabricius, 1794) andM. pulverisVujić & Radenković in Radenković et al. 2011, and reveals the existence of a new species,M. makrisiVujić, Radenković & Totsp. nov., which is described. It also highlights the existence of a series ofnatansgroup populations, especially on some of the Mediterranean islands, in the Levant and in the Afrotropical Region, for which more comprehensive data are required to clarify their status. A key is provided to thenatanslineage species currently recognised, and preimaginal stages of somenatans-group species are described for the first time. Redescriptions forM. calcaratusandM. natansare provided. A neotype is selected forM. natans. Lectotypes are designated forM. annulatus(Fabricius, 1794) andM. melancholicus(Fabricius, 1794).Merodon annulatusis recognised as a synonym ofM. natans.

Numerous scientific projects have been initiated with the aim of tackling the decline in insect pollinators, a crucial group for the functioning of terrestrial ecosystems. One of the first steps is to address information gaps on species spatial distribution, diversity, and abundance that prevent effective conservation actions in Europe. Given that Serbia belongs to the understudied areas, efforts are being made to improve knowledge of its bee diversity and abundance. The present study includes the monitoring of bees at 54 sites, surveyed three times during 2022. The conducted protocol combined two methods, transect walks and pan traps, resulting in the discovery of 312 bee species. The main results present the records of 25 species, not previously mentioned in Serbia, while another important finding is the confirmation of the presence of 26 species, without any available records from the 21^st century. Moreover, 79 here examined species were known only from literature-based data. Six of the recorded species are considered threatened and 67 (10 newly recorded) have been assessed as Data Deficient in the European Red List of Bees. Therefore, the present study not only contributes to an update and confirms the list of bee species in Serbia, that now counts 731 species, but also provides additional information about European distribution, required for new assessment at the European level. In addition, the results indicate that the combination of complementary sampling methods is an effective way to assess bee diversity and abundance.

The phytophagous hoverfly genusMerodonMeigen, 1803 (Diptera, Syrphidae) presently comprises 205 described species distributed in the Palaearctic and Afrotropical regions, and it is differentiated into multiple species groups. In this work, we revise theMerodon tarsatusspecies group, providing an illustrated key to species, a detailed discussion on relevant taxonomic characters, and a morphological diagnosis. We summarize morphological characteristics of the 12 species in theM. tarsatusgroup, together with available distributional data. Moreover, we provide descriptions for five new species, namelyMerodon angustitarsisVujić & Gilasiansp. nov.,M. dumosusVujić, Likov & Radenkovićsp. nov.,M. latiantennatusVujić, Popov & Prokhorovsp. nov.,M. namaghijamiiVujić, Likov & Radenkovićsp. nov.andM. pakistanicusVujić, Likov & Radenkovićsp. nov.Additionally, we describe one more species,Merodon nigroalatusVujić, Likov & Radenkovićsp. nov., that belongs to the same lineage and is related to theMerodon tarsatusgroup based on molecular markers and structure of male genitalia, but lacks modifications of the metatarsus and sternum 4 that are the main diagnostic features of the group. Furthermore, we redefine and redescribe seven taxa of theM. tarsatusgroup. Following detailed analyses of type material, we revise the status of all available taxa related toM. tarsatusand we propose the following new synonyms:M. ankylogasterHurkmans, 1993syn. nov.(junior synonym ofM. hypochrysosHurkmans, 1993);M. persicusHurkmans, 1993syn. nov.(junior synonym ofM. oidipousHurkmans, 1993); andM. xanthipousHurkmans, 1993syn. nov.(junior synonym ofM. marginicornisHurkmans, 1993). We apply Maximum Parsimony and Maximum Likelihood analyses of the 5′ end of the mitochondrialCOIgene sequences to genetically characterize species in theM. tarsatusgroup and the related species,M. nigroalatusVujić, Likov & Radenkovićsp. nov.

Understanding biodiversity dynamics in agricultural landscapes is essential for promoting sustainable land use and conserving wildlife. We examined butterfly communities in a monoculture‐dominated landscape, comparing remnant grassland sites surrounded by agricultural land (AGR), grasslands (GR), and forests (FOR). Data were collected from 30 sites across these three categories. We used non‐metric multidimensional scaling (NMDS) to assess community composition, rank abundance curves for community structure, and Hill numbers for alpha diversity. Generalised additive models (GAMs) identified key drivers of rare species richness and the abundance of the most common species, Coenonympha pamphilus . Results showed a few dominant species, with most having low abundances. Species richness was similar across all site categories, but differences in evenness and species dominance highlighted variations in community structure. GR and FOR sites had higher numbers of both rare and abundant species, indicating a more balanced distribution compared to AGR sites. NMDS revealed significant differences in composition, especially between FOR and AGR. The GAM results showed that the combination of agricultural land and forest cover enhances rare species richness, while agricultural cover alone had a negative impact. Even for the most common species C. pamphilus , high agricultural cover negatively impacts its population but shifts positively when combined with greater vegetation height in adjacent grasslands. These findings highlight the critical role of forest habitats within monoculture‐dominated landscapes in enhancing butterfly community diversity and stability. The adaptability of butterfly species to agricultural landscapes is limited to a small number of species and only up to a certain extent.