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Phylogenetic relationships of theSphaerophorialineage (SphaerophoriaLe Peletier & Audinet-Serville and related genera) were inferred based on molecular characters, with the specific aim to infer the phylogenetic placement of the AfrotropicalSphaerophoriaspecies andLoveridgeana beattieivan Doesburg & van Doesburg. Three molecular markers were used, i.e., the mitochondrial protein-coding gene cytochrome c oxidase subunit I (COI) and the nuclear 28S and 18S ribosomal RNA genes. TheSphaerophorialineage generaExallandraVockeroth andLoveridgeanawere resolved within the genusSphaerophoria, and the IndomalayanEosphaerophoriaFrey was placed sister toCitrogrammaVockeroth, both related to a large species radiation from the New World.FaziaShannon andAllograptaOsten Sacken were recovered as non-monophyletic. Our results recovered two differentFaziaclades with dissimilar natural history resulted from our analyses, andAllograptaspecies were resolved into two clades, one with Nearctic and Neotropical species and a second clade with species from Oceanian, Indomalayan and Afrotropical Regions.Exallandrais considered a subgenus ofSphaerophoria,S. (Exallandra)stat. rev.,andSphaerophoria cinctifacies(Speiser)n. comb.a member of this subgenus together withS. loewiiZetterstedt. A newSphaerophoriasubgenus is designatedS.(Loveridgeana)stat. rev.to includeS. beattiein. comb.and the South African species, i.e.,S. quadrituberculataBezzi,S. retrocurvaHull, andS. aff.retrocurva. Based on their phylogenetic distinctiveness, functional traits, and ecological relevance we do recommend further ecological study and protection efforts for this Afrotropical group of pollinators.

Pre-imaginal morphology of the flower fly species Graptomyza signata (Walker) is described and figured in detail based on specimens collected on a decomposed Aloe-like plant in KwaZulu-Natal province, South Africa. Third-instar larva is described for the first time and the puparium morphology is re-described using both light (optical) and electron microscopy. The present work represents the second larval description for a species of the genus Graptomyza, after the description of the larva of G. alabeta Séguy. The immatures of these two Graptomyza species were examined and compared to the pre-imaginal stages of the other members of the tribe Volucellini, pointing out the possible diagnostic characters of the genus Graptomyza. Moreover, new DNA barcodes are provided for G. signata and deposited in the NCBI GenBank. The study was funded by the project of the European Union: Horizon 2020, Marie Skłodowska-Curie action, Research and Innovation Staff Exchange (RISE) Programme: FlyHigh – “Insect-plant relationships: insights into biodiversity and new applications”.

Background: The black soldier fly (Hermetia illucens) is the most promising insect candidate for nutrient-recycling through bioconversion of organic waste into biomass, thereby improving sustainability of protein supplies for animal feed and facilitating transition to a circular economy. Contrary to conventional livestock, genetic resources of farmed insects remain poorly characterised. We present the first comprehensive population genetic characterisation of H. illucens. Based on 15 novel microsatellite markers, we genotyped and analysed 2862 individuals from 150 wild and captive populations originating from 57 countries on seven subcontinents. Results: We identified 16 well-distinguished genetic clusters indicating substantial global population structure. The data revealed genetic hotspots in central South America and successive northwards range expansions within the indigenous ranges of the Americas. Colonisations and naturalisations of largely unique genetic profiles occurred on all non-native continents, either preceded by demographically independent founder events from various single sources or involving admixture scenarios. A decisive primarily admixed Polynesian bridgehead population serially colonised the entire Australasian region and its secondarily admixed descendants successively mediated invasions into Africa and Europe. Conversely, captive populations from several continents traced back to a single North American origin and exhibit considerably reduced genetic diversity, although some farmed strains carry distinct genetic signatures. We highlight genetic footprints characteristic of progressing domestication due to increasing socio-economic importance of H. illucens, and ongoing introgression between domesticated strains globally traded for large-scale farming and wild populations in some regions. Conclusions: We document the dynamic population genetic history of a cosmopolitan dipteran of South American origin shaped by striking geographic patterns. These reflect both ancient dispersal routes, and stochastic and heterogeneous anthropogenic introductions during the last century leading to pronounced diversification of worldwide structure of H. illucens. Upon the recent advent of its agronomic commercialisation, however, current human-mediated translocations of the black soldier fly largely involve genetically highly uniform domesticated strains, which meanwhile threaten the genetic integrity of differentiated unique local resources through introgression. Our in-depth reconstruction of the contemporary and historical demographic trajectories of H. illucens emphasises benchmarking potential for applied future research on this emerging model of the prospering insect-livestock sector. This work was primarily supported by the Swiss Federal Office for Agriculture (grant no. 627000824 to CS), as well as by the R4D programme of the Swiss Agency for Development and Cooperation and the Swiss National Science Foundation (grant no. IZ01Z0_147278 to CS, and grant no. 400540_152154 to MKen), the Austrian Science Foundation (grant no. FWF P32275 to MKap), the Canadian International Development Research Centre (IDRC) and the Australian Centre for International Agricultural Research (ACIAR) (grant no. 108866-001 to CMT), and the National Research Foundation, South Africa (reference no. CSRP170506229933 to CR).

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. Vujić et Radenković and Merodon roni sp. nov. Radenković et Vujić. This work was funded by a project of the European Union: Horizon 2020, Marie Skłodowska-Curie action, Research and Innovation Staff Exchange (RISE) Programme: FlyHigh - Insect-plant relationships: insights into biodiversity and new applications (project number 645636, 2015e2018); and partially by the RSA SAEON network, a member of International Long-Term Ecological Research Network (ILTER) and Ministry of Education, Science and Technological Development of the Republic of Serbia (OI173002, III43002, III44006, 451-03-68/2020-14/200358 and 451-03-68/2020-14/200125).

Background: The black soldier fly (Diptera: Stratiomyidae, Hermetia illucens) is renowned for its bioconversion ability of organic matter, and is the worldwide most widely used source of insect protein. Despite varying extensively in morphology, it is widely assumed that all black soldier flies belong to the same species, Hermetia illucens. We here screened about 600 field-collected and cultured flies from 39 countries and six biogeographic regions to test this assumption based on data for three genes (mitochondrial COI, nuclear ITS2 & 28S rDNA) and in order to gain insights into the phylogeography of the species. Results: Our study reveals a surprisingly high level of intraspecific genetic diversity for the mitochondrial barcoding gene COI (divergences up to 4.9%). This level of variability is often associated with the presence of multiple species, but tested nuclear markers (ITS2 and 28S rDNA) were invariant and fly strain hybridization experiments under laboratory conditions revealed reproductive compatibility. COI haplotype diversity is not only very high in all biogeographic regions (56 distinct haplotypes in total), but also in breeding facilities and research centers from six continents (10 haplotypes: divergences up to 4.3%). The high genetic diversity in fly-breeding facilities is mostly likely due to many independent acquisitions of cultures via sharing and/or establishing new colonies from field-collected flies. However, explaining some of the observed diversity in several biogeographic regions is difficult given that the origin of the species is considered to be New World (32 distinct haplotypes) and one would expect severely reduced genetic diversity in the putatively non-native populations in the remaining biogeographic regions. However, distinct, private haplotypes are known from the Australasian (N = 1), Oriental (N = 4), and the Eastern Palearctic (N = 4) populations. We reviewed museum specimen records and conclude that the evidence for introductions is strong for the Western Palearctic and Afrotropical regions which lack distinct, private haplotypes. Conclusions: Based on the results of this paper, we urge the black soldier fly community to apply molecular characterization (genotyping) of the fly strains used in artificial fly-breeding and share these data in research publications as well as when sharing cultures. In addition, fast-evolving nuclear markers should be used to reconstruct the recent invasion history of the species. This work was funded by the H2020 Research and Innovation Staff Exchange Programme of the European Commission (RISE), project 645636: ‘Insect-plant relationships: insights into biodiversity and new applications’ (FlyHigh), and the grants R-154-000-B46–114 and R-154-000-A94–592 to RM, as well as a grant of the Swiss Federal Office for Agriculture to CS (‘Efficiency and sustainability of the production and feeding of insect based feedstuff to fish and poultry’).

© 2018 The Linnean Society of London. 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).

The phytophagous hoverfly genusMerodonMeigen, 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, theserrulatusspecies group ofMerodonis 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 theM. serrulatusgroup, along with the available distributional data. Moreover, descriptions are provided for seven new species, namelyM. defectusVujić, Likov & Radenkovićsp. nov.,M. disjunctusVujić, Likov & Radenkovićsp. nov.,M. mediumVujić, Likov & Radenkovićsp. nov.,M. nigrocapillatusVujić, Likov & Radenkovićsp. nov.,M. nigropunctumVujić, Likov & Radenkovićsp. nov.,M. opacusVujić, Likov & Radenkovićsp. nov., andM. trianguloculusVujić, Likov & Radenkovićsp. nov.In addition, the taxaM. serrulatus(Wiedemann in Meigen, 1822),M. bequaertiHurkmans, 1993,M. hirsutusSack, 1913,M. kawamuraeMatsumura, 1916,M. sacki(Paramonov, 1936) andM. sophronHurkmans, 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 toM. serrulatusis revised and a new synonymy is proposed:M. tenerSack, 1913syn. nov.(junior synonym ofM. serrulatus). The identity ofM. trizonus(Szilády, 1940) could not be assessed as the type specimens are lost. Thus, the nameM. trizonusis considered asnomen 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.

The Palaearctic species of the Cheilosia caerulescens group (Diptera: Syrphidae) are revised in this work. The species group belongs to the genus Cheilosia subgenus Taeniocheilosia Oldenberg. One new species is described from north Caucasus, Cheilosia (Taeniocheilosia) circassica sp. n. Cheilosia primulae Hering is established as a junior synonym of Cheilosia laeviventris Loew. Four lectotype designations are made. The species of the Cheilosia caerulescens group are redescribed and illustrated, and a table of diagnostic characters and an identification key to species are provided. MtDNA COI barcodes were generated for several specimens of C. (T.) caerulescens Meigen and other Cheilosia (Taeniocheilosia) and Cheilosia s. str. taxa. Parsimony and maximum likelihood analyses did not place the morphologically similar C. hercyniae Loew in the C. caerulescens group but among other Cheilosia (Taeniocheilosia) taxa. The following eight taxa are included in the Cheilosia (T.) caerulescens group of species: Cheilosia armeniaca Stackelberg, 1960, C. caerulescens caerulescens (Meigen, 1822), C. caerulescens calculosa Skufjin, 1977, C. circassica sp. n., C. herculana Bradescu, 1982, C. kerteszi Szilady, 1938, C. laeviventris Loew, 1857, and C. venosa Loew, 1857.

TheMerodon aureusspecies 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 asM.cinereusB, here identified asM.atratusspecies 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.atratusstat. nov.,M.virgatussp. nov.andM.balkanicussp. nov., which constitute theM.atratusspecies complex. We present an identification key for the sub-groups and species complexes of theM.aureusspecies 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).

Background Anchored hybrid enrichment is a form of next-generation sequencing that uses oligonucleotide probes to target conserved regions of the genome flanked by less conserved regions in order to acquire data useful for phylogenetic inference from a broad range of taxa. Once a probe kit is developed, anchored hybrid enrichment is superior to traditional PCR-based Sanger sequencing in terms of both the amount of genomic data that can be recovered and effective cost. Due to their incredibly diverse nature, importance as pollinators, and historical instability with regard to subfamilial and tribal classification, Syrphidae (flower flies or hoverflies) are an ideal candidate for anchored hybrid enrichment-based phylogenetics, especially since recent molecular phylogenies of the syrphids using only a few markers have resulted in highly unresolved topologies. Over 6200 syrphids are currently known and uncovering their phylogeny will help us to understand how these species have diversified, providing insight into an array of ecological processes, from the development of adult mimicry, the origin of adult migration, to pollination patterns and the evolution of larval resource utilization. Results We present the first use of anchored hybrid enrichment in insect phylogenetics on a dataset containing 30 flower fly species from across all four subfamilies and 11 tribes out of 15. To produce a phylogenetic hypothesis, 559 loci were sampled to produce a final dataset containing 217,702 sites. We recovered a well resolved topology with bootstrap support values that were almost universally >95 %. The subfamily Eristalinae is recovered as paraphyletic, with the strongest support for this hypothesis to date. The ant predators in the Microdontinae are sister to all other syrphids. Syrphinae and Pipizinae are monophyletic and sister to each other. Larval predation on soft-bodied hemipterans evolved only once in this family. Conclusions Anchored hybrid enrichment was successful in producing a robustly supported phylogenetic hypothesis for the syrphids. Subfamilial reconstruction is concordant with recent phylogenetic hypotheses, but with much higher support values. With the newly designed probe kit this analysis could be rapidly expanded with further sampling, opening the door to more comprehensive analyses targeting problem areas in syrphid phylogenetics and ecology. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0714-0) contains supplementary material, which is available to authorized users.