Pollinator diversity (Hymenoptera and Diptera) in semi-natural habitats in Serbia during summer

The aim of this study was to assess species diversity and population abundance of the two main orders of pollinating insects, Hymenoptera and Diptera. The survey was conducted in 16 grassland fragments within agro-ecosystems in Vojvodina, as well as in surrounding fields with mass-flowering crops. Pollinators were identified and the Shannon-Wiener Diversity Index was used to measure their diversity. Five families, 7 subfamilies, 26 genera and 63 species of insects were recorded. All four big pollinator groups investigated were recorded; hoverflies were the most abundant with 32% of the total number of individuals, followed by wild bees - 29%, honeybees - 23% and bumblebees with 16%

Hidden European diversity : a new monotypic hoverfly genus (Diptera: Syrphidae: Eristalinae: Rhingiini)

For the first time in more than 30 years, a new European hoverfly genus has been discovered, Katara gen. nov. Its type species Katara connexa sp. nov. (Diptera: Syrphidae) is described from the Pindos Mountains (Greece), and the systematic position of the monotypic taxon within the tribe Rhingiini is analysed using morphological and molecular data. Phylogenetic analyses resolved Katara connexa gen. et sp. nov. as sister taxon to Pelecocera latifrons. We assert based on the molecular phylogenetic results and the morphological distinctness of Pelecocera latifrons that this taxon merits a generic rank, thus we erect the genus Pseudopelecocera gen. nov. and also place Pelecocera persiana in this new genus based on shared characteristics. Based on our results, we place Chamaesyrphus in subgeneric rank and as a sister group to the nominal subgenus Pelecocera. We provide an identification key to the Rhingiini genera. Our phylogenetic analyses recovered all speciose Rhingiini genera as monophyletic and support existence of three main lineages within the tribe: (1) genus Rhingia with two groups, Palaearctic+Neotropical and Afrotropical taxa, (2) genus Cheilosia with its subgenera, and (3) lineage with remaining genera (Pseudopelecocera gen. nov., Katara gen. nov., Ferdinandea, Psarochilosia, Psarus, Portevinia and Pelecocera).Peer reviewe

Effects of climate change on the distribution of hoverfly species (Diptera : Syrphidae) in Southeast Europe

Climate change presents a serious threat to global biodiversity. Loss of pollinators in particular has major implications, with extirpation of these species potentially leading to severe losses in agriculture and, thus, economic losses. In this study, we forecast the effects of climate change on the distribution of hoverflies in Southeast Europe using species distribution modelling and climate change scenarios for two time-periods. For 2041-2060, 19 analysed species were predicted to increase their areas of occupancy, with the other 25 losing some of their ranges. For 2061-2080, 55% of species were predicted to increase their area of occupancy, while 45% were predicted to experience range decline. In general, range size changes for most species were below 20%, indicating a relatively high resilience of hoverflies to climate change when only environmental variables are considered. Additionally, range-restricted species are not predicted to lose more area proportionally to widespread species. Based on our results, two distributional trends can be established: the predicted gain of species in alpine regions, and future loss of species from lowland areas. Considering that the loss of pollinators from present lowland agricultural areas is predicted and that habitat degradation presents a threat to possible range expansion of hoverflies in the future, developing conservation management strategy for the preservation of these species is crucial. This study represents an important step towards the assessment of the effects of climate changes on hoverflies and can be a valuable asset in creating future conservation plan, thus helping in mitigating potential consequences.Peer reviewe

Resolving the taxonomy of the Merodon dobrogensis species subgroup (Diptera: Syrphidae), with the description of a new species

The taxonomy of Merodon dobrogensis Bradescu, 1982 (Diptera: Syrphidae) species subgroup was reviewed. Multiple data sources (morphology, geometric morphometry of wings and surstylus, molecular data, and distributional data) were used to investigate the species subgroup in the manner of integrative taxonomy. Merodon dobrogensis Bradescu, 1982 and M. puniceus Vujic, Radenkovic, and Perez-Banon, 2011 are supported as distinct species belonging to the M. dobrogensis species complex within the M. dobrogensis species subgroup. Additionally, evidence is presented for the description of a new species, M. rojoi Radenkovic and Vujic new species, with a distribution in mainland Greece, the Greek island Euboea, and the Peloponnese. A short diagnosis is provided for the M. aureus species group, the M. dobrogensis species subgroup, and the newly defined M. dobrogensis species complex, in addition to a description of the new species, with drawings and photographs of adult morphology.Peer reviewe

Merodon chalybeus Subgroup: An Additional Piece of the M. aureus Group (Diptera, Syrphidae) Puzzle

In this study, we examined the morphology, genetics and distribution of the members of the Merodon chalybeus subgroup (M. aureus species group): M. chalybeus Wiedemann in Meigen, 1822, M. minutus Strobl, 1893 and M. robustus Veselić, Vujić & Radenković, 2017. Two of the species, M. chalybeus and M. minutus, are morphologically very similar and often misidentified in the literature. Here, by employing an integrative taxonomic approach we provide strong evidence for the separation of M. chalybeus and M. minutus. Our results show their clear allopatric distribution: M. minutus on the Balkan Peninsula, Sicily, Sardinia and Corsica, while M. chalybeus is a western Mediterranean species distributed on the Iberian Peninsula and northwest Africa. Data on the distribution of M. robustus were updated, with new records from Cyprus, Israel and Turkey, besides its type locality (Samos in Greece). We provide evidence for M. chalybeus and M. minutus representing a species complex, named the M. chalybeus complex, which together with M. robustus constitute the M. chalybeus subgroup.Peer reviewe

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 Gunz-Mindel interglaciation and the Great interglaciation (between the Ris and Mindel glacial periods).Peer reviewe

Close relatives of Mediterranean endemorelict hoverflies (Diptera, Syrphidae) in South Africa : Morphological and molecular evidence in the Merodon melanocerus subgroup

An ongoing study of the genus Merodon Meigen, 1803 in the Republic of South Africa (RSA) has revealed the existence of new species related to M. melanocerus Bezzi, 1915. The M. melanocerus subgroup belongs to the Afrotropical lineage of the M. desuturinus group. Revision of all available material from museums and detailed analyses of newly -collected specimens from our own expeditions to RSA resulted in delimitation of five species: M. capensis Hurkmans sp. n., M. commutabilis Radenkovic et Vujic sp. n., M. drakonis Vujic et Radenkovic sp. n., M. flavocerus Hurkmans sp. n. and M. melanocerus. In addition to classical morphological characters, sequences of the mitochondrial COI gene are provided for four related taxa. Results of molecular phylogenetic analyses supports monophyly of the M. desuturinus group and confirmed delimitation between species. Links between Palaearctic and Afrotropical faunas of this group, as well as possible evolutionary paths, are discussed. Based on phylogenetic analyses, four lineages (putative subgenera) have been recognized within the genus Merodon; besides the three previously established ones, albifrons+desuturinus, aureus (sensu lato) and avidus-nigritarsis, one new lineage named natans is distinguished.Peer reviewe

The Merodon planifacies subgroup (Diptera, Syrphidae) : Congruence of molecular and morphometric evidences reveal new taxa in Drakensberg mountains valleys (Republic of South Africa)

Hoverflies (Syrphidae) represent an insect group of great importance in ecosystems and indicators of ecosystem change. The genus Merodon Meigen, 1803 (tribe Merodontini) is one of the most species-rich hoverfly genera, distributed across the Palaearctic and Afrotropical regions. The genus Merodon Meigen, 1803 is less diverse in the Afrotropical Region than in the Palaearctic (11 versus 160 known species). An ongoing study of the genus Merodon in Africa has revealed the existence of two new species into the taxon previously known as Merodon planifacies Bezzi, 1915. The M. planifacies subgroup belongs to the Afrotropical lineage of the Merodon desuturinus group. Morphological analysis of male genitalia has classified the available specimens of the M. planifacies taxon into two sets: the first one corresponds to M. planifacies with folded theca, while the other with smooth theca, later named Merodon capi complex was found exclusively at the Drakensberg mountains in the Republic of South Africa, specifically in the Cathedral Peak National Park and the Royal Natal National Park. Further, molecular and morphometric evidences revealed two cryptic taxa within this complex: M. capi sp. nov. Vujic et Radenkovic and Merodon roni sp. nov. Radenkovic et Vujic. (c) 2020 Elsevier GmbH. All rights reserved.Peer reviewe

Defining species boundaries in the Merodon avidus complex (Diptera, Syrphidae) using integrative taxonomy, with the description of a new species

Several recent studies have detected and described complexes of cryptic and sibling species in the genus Merodon (Diptera, Syrphidae). One representative of these complexes is the Merodon avidus complex that contains four sibling species, which have proven difficult to distinguish using traditional morphological characters. In the present study, we use two geometric morphometric approaches, as well as molecular characters of the 5' -end of the mtDNA COI gene, to delimit sibling taxa. Analyses based on these data were used to strengthen species boundaries within the complex, and to validate the status of a previously-recognized cryptic taxon from Lesvos Island (Greece), here described as Merodon megavidus Vujic & Radenkovic sp. nov. Geometric morphometric results of both wing and surstylus shape confirm the present classification for three sibling species-M. avidus (Rossi, 1790), M. moenium Wiedemann in Meigen, 1822 and M. ibericus Vujic, 2015-and, importantly, clearly discriminate the newly-described taxon Merodon megavidus sp. nov. In addition to our geometric morphometric results, supporting characters were obtained from molecular analyses of mtDNA COI sequences, which clearly differentiated M. megavidus sp. nov. from the other members of the M. avidus complex. Molecular analyses revealed that the earliest divergence of M. ibericus occurred around 800 ky BP, while the most recent separation happened between M. avidus and M. moenium around 87 ky BP.Peer reviewe