An identification key to the species of the hover fly genus Cheilosia (Diptera, Syrphidae) occurring in Europe is presented. This is the second time, and the first time since 1932, that all known European species of Cheilosia are presented in one key. The number of species included in the key is 126. A short discussion on the not resolved questions in the Cheilosia fauna of Europe is provided.

Wild bees (Hymenoptera: Anthophila) and hoverflies (Diptera: Syrphidae), the two major groups of insect pollinators, are undergoing alarming declines worldwide, including Europe. The lack of accessible and verified spatial and temporal occurrence records currently challenges efforts to understand and mitigate this decline. Here, we compiled datasets from diverse sources, including taxonomists, national experts, public repositories, museum collections, published literature, verified open-access platforms, and aggregated datasets from previous European projects. The collected data were standardised, cleaned and validated by taxonomists and national experts. This collective effort resulted in two databases comprising more than 4.34 million and 1.04 million records for wild bees and hoverflies, respectively. The databases cover 97% of the European bee fauna (2,083 species out of 2,138 recorded in Europe) and 97% of the European hoverfly fauna (886 species out of 913 recorded in Europe). These standardised databases constitute essential resources for future assessments of status and trends, habitat associations, and other research and conservation initiatives to protect and understand wild pollinators on the European continent.

A checklist and an identification key to the species of the hover fly genus Cheilosia (Diptera: Syrphidae: Rhingiini) from the Caucasus Region is presented, based on literature research and new field expeditions. The field expeditions and barcoding analysis resulted in 14 species new to science: Cheilosia (Cheilosia) aurantia sp. nov., C. (C.) borjomi sp. nov., C. (C.) caucasi sp. nov., C. (C.) confusa sp. nov., C. (C.) gemmula sp. nov., C. (C) inarmata sp. nov., C. (C.) megaclama sp. nov., C. (C.) pogonias sp. nov., C. (C.) ushguliensis sp. nov., C. (C.) vansteenisi sp. nov., C. (Montanocheila) contrasta sp. nov., C. (M.) rufa sp. nov., C. (Taeniochilosia) ouwehandae Bot sp. nov. and C. (T.) longifacies sp. nov. Further, Cheilosia circassica Ståhls & Barkalov, 2017 syn. nov. is herewith considered junior synonym of Cheilosia armeniaca Stackelberg, 1960, and we recognize Cheilosia aenigmatosa Barkalov, 1993 stat. rev. as a distinct species and not a junior synonym of Cheilosia pollinifacies Stackelberg, 1968. After our survey, we consider Cheilosia caucasogenita Kuznetzov, 1997 to be a doubtful species. Our extensive genetic analysis based on DNA barcodes including other European Cheilosia taxa clusters all members of the subgenus Taeniochilosia Oldenberg, 1916 in a well-supported group. A short discussion on the Cheilosia fauna of the Caucasus Region is provided, detailing the presence of the different subgenera and the high intraspecific morphological variability within Cheilosia in the Caucasus.

We report the results of a field expedition to the Azores archipelago. A total of 13 species of hover flies were collected, including several species new to certain islands of the archipelago. The records of the expedition are supplemented with new island records found on iNaturalist and observation.org websites. A species new to science, Eristalis (Eoseristalis) azorensis sp. nov., was collected in our survey and is described here in full. DNA barcodes of this species were sequenced and compared to other European species of the genus. The new species was restricted to the mountainous region on the western side of S & atilde;o Miguel Island. Furthermore, we provide identification tools for the new species, as well as for Palaearctic species ofXanthandrus Verrall, 1901, including the endemic Macaronesian taxa. Our findings raise the total number of the Azorean hover fly fauna to 24 species.

During several field expeditions to Greece in the years 2021-2024, a total of 295 species of hoverflies were recorded, of which 31 species are new for the country. Our findings raise the total number of the Greek hoverfly fauna to 457 species. We provide a full annotated account of our records for all the species that are new to Greece and for all the species that are Endangered or Critically Endangered according to the recent European Red List of Syrphidae. One new species, Cheilosia pangeoensis Van de Meutter & Bot sp. nov., is here described in full. The DNA barcode of this species was sequenced and compared to similar species. This species was discovered on Mount Pangeon in northern Greece, an isolated mountain next to the Mediterranean coast, and was later also found to be present in Bulgaria.

The European species of the Cheilosia subgen. Neocheilosia Barkalov, 1983 (Diptera, Syrphidae) are revised. The identities of Cheilosia morio (Zetterstedt, 1838) and of its synonyms are reviewed, and C. scanica Ringdahl, 1937 is established as a junior synonym of C. morio. Cheilosia luteicornis (Zetterstedt, 1838) is re-installed as the name for C. morio of authors pro parte, not Zetterstedt. Cheilosia morio and C. luteicornis are redescribed, and lectotypes are designated for Eristalis lineata Wahlberg, 1843 and for E. luteicornis Zetterstedt, 1838 in order to ensure the consistent future interpretation of the names. The hitherto unknown male of Cheilosia barovskii Stackelberg, 1930 is described, and the female of C. barovskii is redescribed. We also provide updated distributional records and an identification key. Finally, we present a Neighbor-Joining tree for mtDNA COI barcodes of four species of the subgen. Neocheilosia.

The ecological aspects, distribution, and possible conservation of a syrphid hoverfly, Axona chalcopyga (Wiedemann, 1839) is poorly known due to their rare records. Three female individuals of A. chalcopyga were discovered in the Gelam forests of Terengganu state, which is the first record in Peninsular Malaysia. Here, we provided a pictorial description of the female. We also noted the functional role of the hoverfly as a potential pollinator candidate for the Gelam trees by visiting its flowers.

Flower flies (Diptera: Syrphidae) are one of the most species‐rich dipteran families and provide important ecosystem services such as pollination, biological control of pests, recycling of organic matter and redistributions of essential nutrients. Flower fly adults generally feed on pollen and nectar, but their larval feeding habits are strikingly diverse. In the present study, high‐throughput sequencing was used to capture and enrich phylogenetically and evolutionary informative exonic regions. With the help of the baitfisher software, we developed a new bait kit (SYRPHIDAE1.0) to target 1945 CDS regions belonging to 1312 orthologous genes. This new bait kit was successfully used to exon capture the targeted loci in 121 flower fly species across the different subfamilies of Syrphidae. We analysed different amino acid and nucleotide data sets (1302 loci and 154 loci) with maximum likelihood and multispecies coalescent models. Our analyses yielded highly supported similar topologies, although the degree of the SRH (global stationarity, reversibility and homogeneity) conditions varied greatly between amino acid and nucleotide data sets. The sisterhood of subfamilies Pipizinae and Syrphinae is supported in all our analyses, confirming a common origin of taxa feeding on soft‐bodied arthropods. Based on our results, we define Syrphini stat.rev. to include the genera Toxomerus and Paragus . Our divergence estimate analyses with beast inferred the origin of the Syrphidae in the Lower Cretaceous (125.5–98.5 Ma) and the diversification of predatory flower flies around the K–Pg boundary (70.61–54.4 Ma), coinciding with the rise and diversification of their prey.

By travelling vast distances, migratory birds take advantage of earth's seasonality. Afro-Palearctic migrants can profit from lush spring conditions in temperate regions for chick rearing, but must also gain sufficient energy reserves to cross the Sahara. Rainfall during the dry season in Africa may influence the food available to birds to accumulate reserves. Conflicts of interests in resource exploitation at locations thousands of kilometres apart may occur if migrants encounter poor food conditions during these migratory preparations. Studying how wild birds adjust their fuelling and migration decisions to dynamic environments allows us to understand how flexible migrants can be, which is particularly important in an era of rapid change. We performed supplemental feeding prior to migration in individual Pied Flycatcher Ficedula hypoleuca wintering territories in Ivory Coast and remotely monitored their body mass change until they started their spring migration flight over the Sahara. We tested how access to extra food causally affects fuelling, departure mass and departure date. Seasonal fluctuations in natural arthropod availability prior to migration were monitored in two years, to explore how natural resource dynamics alters fuel accumulation. Birds that fully accessed extra food in March–April put on weight earlier and faster than birds without extra food supply, and departed 12 days earlier. Birds accumulated fuel loads that were higher than required for the Sahara-crossing, regardless of their access to extra food. Fuelling rates fluctuated in synchrony with natural conditions, as non-supplemented birds achieved the highest body mass gains at the time that natural arthropod availability peaked in the study area. Fuelling rates were lower in 2020, i.e. the year when the first rains after the dry season started late, than in 2019. Our study showed that Pied Flycatchers modulated fuelling rates – but not departure fuel loads – to food dynamics in West Africa, causing flexibility in the timing of departure. This strategy probably enhances a safe Sahara crossing, but may limit the possibilities of migrants to anticipate advancing spring conditions at breeding sites.

We present the first multigene phylogeny focused on Eristalinae (Diptera: Syrphidae) utilizing a dataset containing 120 flower fly species from across all four subfamilies and representing 13 out of 16 tribes. Eight genes were used in the construction of the phylogeny: mitochondrial cytochrome c oxidase subunit I and the nuclear genes 28S ribosomal DNA, Alanylt RNA Synthetase, the carbamoyl phosphate synthase domain of CAD, Period, RNA-binding Protein 15 (RBP–15, 5’), Casein Kinase 1 and TULP for a total of ~6.7 kB of data. Eristalinae is recovered as paraphyletic with strong support for the elevation of Cerioidini, Merodontini and Volucellini to subfamilial status. Deineches, Flukea and Malometasternum render Criorhinina paraphyletic with respect to the type genus Criorhina. A clade with Criorhina, Matsumyia and Sphecomyia is strongly supported. The generic concept of Criorhina is paraphyletic, while Sphecomyia is monophyletic and Matsumyia is monophyletic but requires expansion. Evidence supports the resurrection of Romaleosyrphus and the creation of new genera. Criorhinina (stat. rev.) is restricted to contain Criorhina, Matsumyia, Romaleosyrphus and Sphecomyia. Thirteen changes to the higher classification of Syrphidae are proposed.

Milesia cretica Bot & van Steenis sp. nov. is described from the Island of Crete, Greece. An identification key to all the European species of Milesia Latreille, 1804 is provided, together with DNA barcodes to distinguish the new species.

A checklist of the Syrphidae species of the Republic of Georgia is presented. New hover fly (Diptera: Syrphidae) records from Georgia are provided as a result of field work conducted in 2018. At the same time, published syrphid records for the country are here reviewed and updated. A total of 357 species of hoverflies are now documented from Georgia, 40 of which are reported for the first time. Moreover, DNA barcodes were sequenced for 238 specimens, representing 74 species from this country.

Six new species of the myrmecophilous hoverfly genus Microdon Meigen (Diptera: Syrphidae) are described from Madagascar. Redescriptions are given for the three other Madagascan species of this genus. Keys are presented to the Madagascan genera of the subfamily Microdontinae and to the Madagascan species of Microdon.