Snežana Radenković

Systematics and taxonomy of the ruficornis group of genus Merodon Meigen (Diptera: Syrphidae)

We revise the ruficornis group of species of Merodon Meigen (Diptera, Syrphidae) providing an illustrated key, a discussion of taxonomic characters and a morphological diagnosis. A total of 18 species from the ruficornis group are treated including distributional data. Descriptions are provided for seven new species: M. gallicus Vujić & Radenkovićsp.n., M. hoplitis Hurkmans sp.n., M. lamellatus Vujić & Radenkovićsp.n., M. nigripodus Vujić & Hayat sp.n., M. ovaloides Vujić & Radenkovićsp.n., M. ponticus Vujić & Radenkovićsp.n., and M. turcicus Vujić & Hayat sp.n. The taxon M. auripes Sack, is redefined and a neotype designated. Lectotypes are designated for M. graecus Loew; M. planiceps Loew and M. crymensis Paramonov. The monophyly and systematic position of this species group was assessed based on parsimony and maximum likelihood analyses of mitochondrial COI and nuclear 28S rDNA sequences. A very high level of endemism was observed in the ruficornis species group. Among 18 taxa, 12 are limited‐range endemics, present in few mountain areas or in a small part of the total range of the group. These endemics clearly show the importance of geographic isolation in the process of speciation.

Molecular and Morphological Inference of Three Cryptic Species within the Merodon aureus Species Group (Diptera: Syrphidae).

The Merodon aureus species group (Diptera: Syrphidae: Eristalinae) comprises a number of different sub-groups and species complexes. In this study we focus on resolving the taxonomic status of the entity previously identified as M. cinereus B, here identified as M. atratus species complex. We used an integrative approach based on morphological descriptions, combined with supporting characters that were obtained from molecular analyses of the mitochondrial cytochrome c oxidase I gene as well as from geometric morphometry of wing and surstylus shapes and environmental niche comparisons. All applied data and methods distinguished and supported three morphologically cryptic species: M. atratus stat. nov., M. virgatus sp. nov. and M. balkanicus sp. nov., which constitute the M. atratus species complex. We present an identification key for the sub-groups and species complexes of the M. aureus species group occurring in Europe, describe the taxa and discuss the utility of the applied methods for species delimitation. The estimated divergence times for the species splits of these taxa coincide with the Pleistocene Günz-Mindel interglaciation and the Great interglaciation (between the Ris and Mindel glacial periods).

Biogeographical patterns of the genus Merodon Meigen, 1803 (Diptera: Syrphidae) in islands of the eastern Mediterranean and adjacent mainland

The objective of this study was to obtain a biogeographical perspective on the hoverfly genus Merodon (Diptera, Syrphidae) based on data from 32 islands in the Aegean and Ionian archipelagoes vis‐à‐vis the adjacent mainland. In this part of the world, the genus comprises 57 species, out of more than 160 species described worldwide. The importance of eco‐geographical variables (area, elevation, distance to the nearest island and distance to the nearest mainland) and the species–area relationship (SAR) were studied in order to explain patterns of species richness. All tests supported the dynamic equilibrium concept. The area and distance to closest island were found to be the most important drivers of species richness on the Aegean and Ionian archipelagoes. Out of three SAR models evaluated in this study, the exponential function fitted our data best. It was found that a power model with no intercept value (C = 1) performed even better by using symbolic regression for non‐linear equation optimisation. The cluster and null‐model analyses performed to detect inter‐island similarities and origins of the insular Merodon fauna indicated a clear influence of colonisation history of the species on different islands. The results imply that the current distributions of Merodon species in the study area exhibit the combined effects of historical and present‐day processes.

Revision of the species of the Merodon nanus group (Diptera: Syrphidae) including three new species

The nanus group of the genus Merodon Meigen (Diptera, Syrphidae) is revised, yielding an illustrated key, a discussion of taxonomic characters and morphological diagnosis for the five species of this group. Three new cryptic species are described, Merodon kopensis Vujić et Hayat sp. n., M. neonanus Vujić et Taylor sp. n. and M. rasicus Vujić et Radenković sp. n. New diagnostic characters are given for M. nanus Sack and M. telmateia Hurkmans. In addition, environmental profiles for each investigated species have been defined and compared, and maps of distribution and richness created. Niche dissimilarity was found for each species. Eastern Anatolia and the southern Aegean region of Turkey are reported as the most species rich regions for the nanus group.

The saproxylic hoverflies (Diptera: Syrphidae) of Serbia

The revision of the saproxylic hoverflies collected in Serbia from 1950 to 2010 has revealed a total of 56 species, of which Sphiximorpha subsessilis (Illiger in Rossi) is new to the Balkan Peninsula and Arctophila superbiens (Muller), Blera fallax (Linnaeus), Brachyopa panzeri Goffe, Brachyopa testacea (Fallen), Brachyopa vittata Zetterstedt and Chalcosyrphus piger (Fabricius) are new to Serbia. According to “Syrph the Net, the database of European Syrphidae”, 16 of the 56 species are threatened with extinction in Europe, while 6 species are “strictly protected” and 13 are “protected” under Serbian legislation. Distribution maps for each species, as well as new data on adult habitats, are provided. The conservation status of the saproxylic hoverflies of Serbia is discussed. The present study attempts to provide a basis for the conservation of the saproxylic hoverflies of this Balkan country.

Key for European species of the Cheilosia proxima group (Diptera, Syrphidae) with a description of a new species.

Abstract A new hoverfly species, Cheilosia barbafacies Vujić & Radenković sp. n. (Diptera, Syrphidae), is described and distinguished from the closely related species Cheilosia pascuorum Becker, 1894, based on material collected from the mountains of the Balkan Peninsula. Diagnostic characteristics and an identification key for the members of the proxima group of Cheilosia s. str., including the new taxon, are provided.

Diversity of the genus Eumerus Meigen (Diptera, Syrphidae) on the eastern Mediterranean islands with description of three new species

Summary A list of 25 species of the genus Eumerus Meigen (Diptera: Syrphidae) from the eastern Mediterranean islands is presented. Descriptions are given for three new species: Eumerus aurofinis Grković, Vujić & Radenković n. sp. from Lesvos, Samos, Rhodes islands (Greece) and Bozdağ mountain (Turkey), E. torsicus Grković & Vujić n. sp. from Chios Island (Greece) and Cyprus; E. crassus Grković, Vujić & Radenković n. sp. from Lesvos Island (Greece). In addition to classical morphological characters, mitochondrial COI barcode sequences were generated for several specimens of two available taxa. The status of Eumerus alpinus Rondani, 1857 is revised, and the taxon is resurrected from synonymy of E. olivaceus Loew, 1848. The zoogeographical significance of the described endemic taxa to the biodiversity of the Aegean islands is discussed.

Bee (Hymenoptera: Apoidea) and hoverfly (Diptera: Syrphidae) pollinators in Pannonian habitats of Serbia, with a description of a new Eumerus Meigen species (Syrphidae)

The diversity of bee (Hymenoptera: Apoidea) and hoverfly (Diptera: Syrphidae) pollinators from ten localities in Vojvodina, Serbia was surveyed. Among different types of Pannonian habitat (grasslands, heathland and scrub, woodland and forest habitats) all localities were categorised as forest and steppe. They were in protected areas, mostly undisturbed by human activity. Censuses of pollinators took place from 30 March to 10 October, 2014. We recorded 218 pollinator species; 135 bee species (42 Halictidae; 32 Apidae; 29 Andrenidae; 24 Megachilidae; 7 Colletidae; 1 Melittidae) and 83 species of hoverflies. We describe a new species of hoverfly, Eumerus pannonicus sp. nov., and compare it to other similar species. Based on our study, the Special Nature Reserve of Pašnjaci Velike Droplje is critical for the conservation of this new Eumerus-being only found at this locality-and other species such as Chrysotoxum lineare (Zetterstedt), which is rare in Europe and protected under Serbian legislation. The highest numbers of bee species were recorded in the Deliblato and Subotica sand areas (40 and 32, respectively), while Fruška Gora Mountain and the Vršac Mountains harboured the highest number of hoverfly species.

Revision of the Palaearctic species of the Merodon desuturinus group (Diptera, Syrphidae)

Abstract This revision of material belonging to the Merodon desuturinus group from the Palaearctic Region resulted in the delimitation of four species: Merodon cabanerensis Marcos-García, Vujić & Mengual, 2007; Merodon desuturinus Vujić, Šimić & Radenković, 1995; Merodon neolydicus Vujić, nom. n.; and Merodon murorum Fabricius, 1794. Merodon murorum is redescribed. A neotype for Merodon auripilus Meigen, 1830 is designated, which is a new junior synonym of Merodon murorum. The related Afrotropical species Merodon cuthbertsoni Curran, 1939 is re-evaluated and compared to its sibling Palaearctic taxon Merodon desuturinus. An identification key for the Merodon desuturinus group is provided.

Three new Eastern-Mediterranean endemic species of the Merodon aureus group (Diptera: Syrphidae)

The Merodon aureus group (Diptera: Syrphidae: Eristalinae) comprises a number of different subgroups and species complexes, including the M. bessarabicus subgroup, which is revised here. In this study, we present an identification key to species complexes and species within the M. bessarabicus subgroup and focus on clarifying the taxonomic status of previously described species within this subgroup, based on a study of the type material. Merodon flavicornis Macquart, a species with an unknown type locality, is re-evaluated and recognized as a valid Western Mediterranean species from France. We describe a new species, M. adriaticus sp. n., from M. bessarabicus subgroup, as well as another two species with a clearly separate position within the M. aureus group due to their distinct morphological features: M. nisi sp. n. and M. robustus sp. n.. Results of the present study indicate the high diversity and endemism levels of the genus Merodon in Europe.