Search

Numerous wild bee (Hymenoptera, Apoidea, Anthophila) species show negative population trends, while the knowledge gaps on their occurrences and distributions prevent adequate conservation actions. The need for continuous updating of species records and reconfirmation of their presence has been recognized, especially in understudied areas. The present study presents the results of bee monitoring at 30 Serbian localities, each surveyed three times during 2023. Two sampling methods were used, the transect walks and the pan traps, resulting in a detection of 232 wild bee species. Among them, 13 species found at 13 localities, represent the first published records from Serbia: Andrena ferox Smith, 1847, A. nana (Kirby, 1802), A. praecox (Scopoli, 1763), A. pusilla Pérez, 1903, A. susterai Alfken, 1914, A. angustior (Kirby,1802), A. curvungula Thomson,1870, A. falsifica Perkins, 1915, Hoplitis mitis (Nylander, 1852), Hylaeus friesei (Alfken, 1904), Melitta melanura (Nylander, 1852), Nomada trapeziformis Schmiedeknecht, 1882, and Osmia uncinata Gerstaecker, 1869. This study contributes to an update of the list of bee species in Serbia, that now counts 744 species, and also provides additional data on European distributions. The new information on Melitta melanura is especially noteworthy, since this species has been assessed as Endangered by the European Red List of Bees due to its small area of occupancy and a severely fragmented distribution. Other important findings include the confirmation of the presence of some wild bee species in Serbia, i.e., 10 species reported as new records within the previous update, and 19 species that were without previously available records from the 21st century. Additionally, the present study indicates the effectiveness of both conducted monitoring techniques, in terms of different recorded species and numbers of specimens. These results lead to the conclusion that corroborates the application of complementary sampling methods as an adequate way to survey bee diversity and abundance.

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 21st 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.

Grasslands represent a biodiversity hotspot in the European agricultural landscape, their restoration is necessary and offers a great opportunity to mitigate or halt harmful processes. These measures require a comprehensive knowledge of historical landscape changes, but also adequate management strategies. The required data was gathered from the sand grasslands of northern Serbia, as this habitat is of high conservation priority. This area also has a long history of different habitat management approaches (grazing and mowing versus unmanaged), which has been documented over of the last two decades. This dataset enabled us to quantify the effects of different measures across multiple taxa (plants, insect pollinators, and birds). We linked the gathered data on plants, pollinators, and birds with habitat management measures. Our results show that, at the taxon level, the adopted management strategies were beneficial for species richness, abundance, and composition, as the highest diversity of plant, insect pollinator, and bird species was found in managed areas. Thus, an innovative modelling approach was adopted in this work to identify and explain the effects of management practices on changes in habitat communities. The findings yielded can be used in the decision making as well as development of new management programmes. We thus posit that, when restoring and establishing particular communities, priority needs to be given to species with a broad ecological response. We recommend using the decision tree as a suitable machine learning model for this purpose.

Detection of morphologically indistinguishable cryptic species implies using an integrative taxonomic approach with a combination of molecular, contemporary morphological, ecological and other relevant analyses. Within a contemporary morphological analysis, two approaches are commonly used in hoverfly taxonomy: a geometric morphometric analysis of the wing and surstyle shape. Here, the importance of the R4+5 vein shape is tested in cryptic species delimitation within four Merodon species groups using linear and semilandmark geometric morphometric analyses. As expected, geometric morphometrics showed a stronger resolution compared to linear morphometrics. Linear morphometrics failed to detect differences related to sexual dimorphism or differences among the species M. pruni and M. obscurus. However, all cryptic species and sexes were separated with high significance based on the R4+5 vein shape. Moreover, obtained results concurred with the landmark-defined wing shape and molecular results published in previous studies. Additionally, combining two characters, the semilandmark R4+5 vein shape and the landmark-defined wing shape, provided more detailed and precise insights into the shape differences. Our results showed that the R4+5 vein shape stands out as an important character in species delimitation of hoverflies where the sinuation of this vein is present. Therefore, it can be beneficial as a single character or in combination with a landmark-based wing shape analysis.

The phytophagous hoverfly genus Merodon Meigen, 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 the Merodon tarsatus species 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 the M. tarsatus group, together with available distributional data. Moreover, we provide descriptions for five new species, namely Merodon angustitarsis Vujić & Gilasian sp. nov., M. dumosus Vujić, Likov & Radenković sp. nov., M. latiantennatus Vujić, Popov & Prokhorov sp. nov., M. namaghijamii Vujić, Likov & Radenković sp. nov. and M. pakistanicus Vujić, Likov & Radenković sp. nov. Additionally, we describe one more species, Merodon nigroalatus Vujić, Likov & Radenković sp. nov., that belongs to the same lineage and is related to the Merodon tarsatus group 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 the M. tarsatus group. Following detailed analyses of type material, we revise the status of all available taxa related to M. tarsatus and we propose the following new synonyms: M. ankylogaster Hurkmans, 1993 syn. nov. (junior synonym of M. hypochrysos Hurkmans, 1993); M. persicus Hurkmans, 1993 syn. nov. (junior synonym of M. oidipous Hurkmans, 1993); and M. xanthipous Hurkmans, 1993 syn. nov. (junior synonym of M. marginicornis Hurkmans, 1993). We apply Maximum Parsimony and Maximum Likelihood analyses of the 5′ end of the mitochondrial COI gene sequences to genetically characterize species in the M. tarsatus group and the related species, M. nigroalatus Vujić, Likov & Radenković sp. nov.

Abstract Merodon natans group (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) and M. pulveris Vujić & Radenković in Radenković et al. 2011, and reveals the existence of a new species, M. makrisi Vujić, Radenković & Tot sp. nov., which is described. It also highlights the existence of a series of natans group 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 the natans lineage species currently recognised, and preimaginal stages of some natans-group species are described for the first time. Redescriptions for M. calcaratus and M. natans are provided. A neotype is selected for M. natans. Lectotypes are designated for M. annulatus (Fabricius, 1794) and M. melancholicus (Fabricius, 1794). Merodon annulatus is recognised as a synonym of M. natans.

In the present work, the Afrotropical species of the bombiformis species group, part of the aureus lineage, are revised. Six species are recognized, based on a combination of morphological and genetic features. Three of these species are new to science: Merodon lotus Vujić & Radenković sp. nov., M. vittatus Vujić & Likov sp. nov., and M. zebra Vujić & Radenković sp. nov. Redescriptions are provided for the other three species: M. bombiformis Hull, 1944, M. multifasciatus Curran, 1939, and M. nasicus Bezzi, 1915. The female of M. bombiformis is described. The name Merodon edentulus Macquart, 1855 is considered here as a nomen dubium. One new synonymy is proposed: M. apimima Hull, 1944 syn. nov. (junior synonym of M. multifasciatus). The distribution of the bombiformis species group is discussed. The larval host plant of M. multifasciatus is identified as Gladiolus. A key to the identification of both males and females of the bombiformis group is provided.