Contribution to the knowledge of the bee fauna (Hymenoptera, Apoidea, Anthophila) in Serbia.

The current work represents summarised data on the bee fauna in Serbia from previous publications, collections, and field data in the period from 1890 to 2020. A total of 706 species from all six of the globally widespread bee families is recorded; of the total number of recorded species, 314 have been confirmed by determination, while 392 species are from published data. Fourteen species, collected in the last three years, are the first published records of these taxa from Serbia: Andrenabarbareae (Panzer, 1805), A.clarkella (Kirby, 1802), A.fulvicornis (Schenck, 1853), A.intermedia (Thomson, 1870), A.lapponica (Zetterstedt, 1838), A.pandellei (Pérez, 1895), A.paucisquama (Noskiewicz, 1924), A.simillima (Smith, 1851), Panurginusherzi (Morawitz, 1892), Epeoloidescoecutiens (Fabricius, 1775), Nomadaleucophthalma (Kirby, 1802), Chelostomanasutum (Pérez, 1895), Hoplitisclaviventris (Thomson, 1872), and Dasypodapyrotrichia (Förster, 1855). Almost all the species recorded so far in Serbia belong to the West-Palaearctic biogeographical region, except Megachilesculpturalis (Smith, 1853), which is an alien invasive species native to East Asia. According to the European Red List of bees, 221 species listed in this paper were assessed as Data Deficient; threatened species mostly belong to the families Apidae with 13 species, Colletidae with eight species, and Halictidae with five species. This study contributes to the knowledge of the distribution of bee species in Europe. The present work provides a baseline for future research of wild bee diversity in Serbia and neighbouring regions at the local and regional levels, and a basis for their conservation.

Revision of the Merodon serrulatus group (Diptera, Syrphidae).

The phytophagous hoverfly genus Merodon Meigen, 1803 (Diptera, Syrphidae), which comprises more than 160 species distributed in Palaearctic and Afrotropical regions, can be differentiated into multiple groups of species that harbor high levels of hidden diversity. In this work, the serrulatus species group of Merodon is revised, providing an illustrated key to species, a detailed discussion on the taxonomic characters and a morphological diagnosis, including also the first data about the preimaginal morphology of this species group. The study includes characteristics of the 13 species of the M. serrulatus group, along with the available distributional data. Moreover, descriptions are provided for seven new species, namely M. defectus Vujic, Likov & Radenkovic sp. nov., M. disjunctus Vujic, Likov & Radenkovic sp. nov., M. medium Vujic, Likov & Radenkovic sp. nov., M. nigrocapillatus Vujic, Likov & Radenkovic sp. nov., M. nigropunctum Vujic, Likov & Radenkovic sp. nov., M. opacus Vujic, Likov & Radenkovic sp. nov., and M. trianguloculus Vujic, Likov & Radenkovic sp. nov. In addition, the taxa M. serrulatus (Wiedemann in Meigen, 1822), M. bequaerti Hurkmans, 1993, M. hirsutus Sack, 1913, M. kawamurae Matsumura, 1916, M. sacki (Paramonov, 1936) and M. sophron Hurkmans, 1993 are redefined and redescribed. Following a detailed study of the type material sourced from different entomological collections, the status of all available taxa related to M. serrulatus is revised and a new synonymy is proposed: M. tener Sack, 1913 syn. nov. (junior synonym of M. serrulatus). The identity of M. trizonus (Szilády, 1940) could not be assessed as the type specimens are lost. Thus, the name M. trizonus is considered as nomen dubium. The monophyly and composition of this species group are assessed through Maximum Parsimony and Maximum Likelihood analyses of the mitochondrial COI and nuclear 28S rRNA gene sequences.

Stability and changes in the distribution of Pipiza hoverflies (Diptera, Syrphidae) in Europe under projected future climate conditions.

Climate change is now considered a significant threat to terrestrial biodiversity. Species distribution models (SDMs) are among the modern tools currently used to assess the potential impacts of climate change on species. Pipiza Fallén, 1810 is a well known aphidophagous hoverfly genus (Diptera, Syrphidae) at the European level, for which sampling has been conducted across the region, and long-term databases and geo-referenced datasets have been established. Therefore, in this work, we investigated the potential current distributions of the European species of this genus and their response to future climate change scenarios, as well as evaluated stability in their ranges and potential changes in species-richness patterns. We applied three climate models (BCC_CSM1.1, CCSM4, HadGEM2-ES) to four representative concentration pathways (RCP 2.6, RCP 4.5, RCP 6.0, RCP 8.5) for two time frames (2050 and 2070). Our results show that the distribution of most Pipiza species may slightly differ under different climate models. Most Pipiza species were predicted not to be greatly affected by climate change, maintaining their current extent. Percentages of stable areas will remain high (above 50%) for the majority of studied species. According to the predicted turnover of species, northern Europe, could become the richest in terms of species diversity, thus replacing Central Europe as the current hot spot.

Two new enigmatic species of the genus Merodon Meigen (Diptera: Syrphidae) from the north-eastern Middle East.

Two new remarkable species of the genus Merodon Meigen (Diptera: Syrphidae) are described from biodiversity hotspots in the Middle East: Merodon eumerusi Vujic, Radenkovic et Likov sp. n. and Merodon mixtum Vujic, Radenkovic et Likov sp. n. Although M. eumerusi, from the Mountains of Central Asia, belongs clearly to the lineage of M. avidus-nigritarsis, it possesses some unique features within the genus that are also present in other Merodontini genera. M. mixtum, from the Irano-Anatolian mountains, has typical characters of different species groups within the M. albifrons lineage. Here, we discuss the unusual apomorphic characters of these newly discovered taxa and highlight the need for further analyses to ascertain the phylogenetic relationships within the tribe Merodontini and the genus Merodon.

Pupal stages of three species of the phytophagous genus Merodon Meigen (Diptera: Syrphidae).

plants, are mostly unknown. All known immature stages of Merodon feed on underground storage organs (bulbs, rhizomes and corms) of geophytes of the families Asparagaceae, Iridaceae and Amaryllidaceae. Of 160 known Merodon species, to date, the pupal stages have been described for only four: M. equestris (Fabricius), M. bombiformis Hull, M. luteihumerus Marcos-García, Vujic Mengual, and M. geniculatus Strobl. During field investigations in Derdap National Park, Serbia, Merodon puparia were found in the ground near the bulbs of Ornithogalum umbellatum L. (Asparagaceae). DNA barcoding revealed that they belonged to the species M. aureus Fabricius and M. avidus (Rossi). Analysis of museum material from the Bavarian State Collection of Zoology in Germany revealed the puparium of an additional species, M. rufus Meigen. In our study we provide for the first time descriptions of the puparia of these three Merodon species. The main diagnostic morphological characters of the pupal spiracles and posterior respiratory processes are described using scanning electron microscopy, and cephalopharyngeal skeletons using binocular microscopy. In addition, puparium morphology of M. aureus, M. avidus and M. rufus is compared with known puparia of four other Merodon species and with the third larval stage of M. hurkmansi Marcos-García, Vujic Mengual.

The Phenolics of the Ornithogalum umbellatum L. (Hyacinthaceae): Phytochemical and Ecological Characterization.

Ornithogalum umbellatum L. is a widely distributed species in Europe, that exhibits considerable variability at ecological, morphological, anatomical, and karyological level. Previous reports of the chemical investigations among Ornithogalum species indicate significant diversity of the secondary metabolites, as well. Knowing that environment affects the phenolic composition in plants to a large extent, the main objective of the research was to define relationship between phytochemical and ecological characters. To estimate an environmental influence on these results, plant material was collected at four habitats that differ in ecological factors and belong to two biogeographical regions: the Balkan Peninsula and the Pannonian Plane. Measured phytochemical characters are yield of dry extract, total phenolic and flavonoid contents, the presence of selected phenolic compounds as well as free-radical scavenging activity (neutralization of DPPH and OH radicals). Results revealed that all analyzed phytochemical parameters differ between investigated O. umbellatum samples. The moisture level of habitat has the highest correlation, either positive or negative, with most of phytochemical characters, and is followed by temperature and soil reaction. Light intensity and nitrogen level have mostly moderate correlation coefficient with phytochemical characters. More complex correlation is revealed between ecological factors and nine phenolic compounds, with three observed patterns of relationship.