National records of 3000 European bee and hoverfly species: A contribution to pollinator conservation

Pollinators play a crucial role in ecosystems globally, ensuring the seed production of most flowering plants. They are threatened by global changes and knowledge of their distribution at the national and continental levels is needed to implement efficient conservation actions, but this knowledge is still fragmented and/or difficult to access. As a step forward, we provide an updated list of around 3000 European bee and hoverfly species, reflecting their current distributional status at the national level (in the form of present, absent, regionally extinct, possibly extinct or non-native). This work was attainable by incorporating both published and unpublished data, as well as knowledge from a large set of taxonomists and ecologists in both groups. After providing the first National species lists for bees and hoverflies for many countries, we examine the current distributional patterns of these species and designate the countries with highest levels of species richness. We also show that many species are recorded in a single European country, highlighting the importance of articulating European and national conservation strategies. Finally, we discuss how the data provided here can be combined with future trait and Red List data to implement research that will further advance pollinator conservation

Anchored enrichment dataset for true flies (order Diptera) reveals insights into the phylogeny of flower flies (family Syrphidae)

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.Peer reviewe

Conservation of pollinators in traditional agricultural landscapes – New challenges in Transylvania (Romania) posed by EU accession and recommendations for future research

Farmland biodiversity is strongly declining in most of Western Europe, but still survives in traditional low intensity agricultural landscapes in Central and Eastern Europe. Accession to the EU however intensifies agriculture, which leads to the vanishing of traditional farming. Our aim was to describe the pollinator assemblages of the last remnants of these landscapes, thus set the baseline of sustainable farming for pollination, and to highlight potential measures of conservation. In these traditional farmlands in the Transylvanian Basin, Romania (EU accession in 2007), we studied the major pollinator groups-wild bees, hoverflies and butterflies. Landscape scale effects of semi-natural habitats, land cover diversity, the effects of heterogeneity and woody vegetation cover and on-site flower resources were tested on pollinator communities in traditionally managed arable fields and grasslands. Our results showed: (i) semi-natural habitats at the landscape scale have a positive effect on most pollinators, especially in the case of low heterogeneity of the direct vicinity of the studied sites; (ii) both arable fields and grasslands hold abundant flower resources, thus both land use types are important in sustaining pollinator communities; (iii) thus, pollinator conservation can rely even on arable fields under traditional management regime. This has an indirect message that the tiny flower margins around large intensive fields in west Europe can be insufficient conservation measures to restore pollinator communities at the landscape scale, as this is still far the baseline of necessary flower resources. This hypothesis needs further study, which includes more traditional landscapes providing baseline, and exploration of other factors behind the lower than baseline level biodiversity values of fields under agri-environmental schemes (AES)

ASSESSING THE CONSERVATION STATUS OF EUROPEAN UNION HABITATS – RESULTS OF THE COMMUNITY REPORT WITH A CASE STUDY OF THE GERMAN NATIONAL REPORT

The EU Habitats Directive requires all member states to report every 6 years on the implementation of the Directive. The report covering the period 2000 – 2006 included for the first time an assessment of the conservation status of the habitats and species listed on annexes I, II, IV & V of the Habitats Directive following an agreed format. Based on national reports submitted from member States the European Topic Centre on Biological Diversity has prepared assessments for each biogeographical region at EU-level. The majority of the habitats of Annex I are not at favourable status although there is much variation both between countries and regions and between habitats. The results will be discussed at European level and at member state level with a case study of the German national report. At the same time a number of methodical problems became apparent both in Germany and at EU-level. Work is already under way to improve the next report for the period 2007 – 2012. The dimension of management needs, threats and pressures and the time scale for improvements of the conservation status are discussed. Habitats linked to agriculture appear to be particularly unfavourable

Data and code from : Insect biomass decline scaled to species diversity: General patterns derived from a hoverfly community

Item does not contain fulltextTo study changes in flying insect communities, and hoverflies in particular, malaise trap samples from a German site were compared between two years (Hallmann et al. 2020). The data files deposited here contain data obtained from six malaise traps in the Wahnbachtal (North Rhine-Westphalia, Germany, 50.851944N, 7.320833E) that were deployed in 1989 and again in 2014, at the exact same locations. Traps were situated in wet meadows as well as tall perennial meadows, in close proximity to shrub corridors, to forest–grassland borders, and to the Wahnbach River and surrounded by agricultural land, essentially a rather heterogeneous habitat. The Wahnbach River and the greater part of the valley are protected for watershed purposes and are subject to nature conservation management by the Wahnbach Talperrenverband. Hence, several restrictions apply to safeguard against water contamination. Total insect biomass collected with these traps was already included in Hallmann et al. (2017), but here we focus on additional information: the abundance and richness of hoverflies (Syrphidae) in each of the collected samples (pots). Methodologies of collection are described in Sorg (1990), Schwan et al. (1993), Sorg et al. (2013), Hallmann et al. (2017), and Ssymank et al. (2018). In brief, malaise traps were deployed throughout the growing season and operated continuously (day and night). Malaise trap construction (e.g., size, material, colouring, and ground sealing) and placing (e.g., positioning, orientation, and slope of the locations) were standardised in all aspects. Insect samples were preserved in 80% ethanol solution. Catches of the six traps investigated in the present study were emptied regularly: On average exposure intervals were 7.0 d (SD = 0.5) in 1989 and 16.7 d (SD = 5.6) in 2014. Across the six traps in 2014 the total exposure time (in number of days) was 42% higher compared to 1989. All collected samples (n = 196) were used in the present analysis with in total 19,604 individual hoverflies counted, distributed over 162 species and 59 genera. To assess how environmental conditions have changed over the 25 year, several additional datasets were assembled. Climatic data were obtained from 169 climatic stations and were used to interpolate daily weather variables to each trap location, using spatiotemporal kriging. These steps are described in detail in Hallmann et al. (2017). Our analysis (see R code) consists of three components. First, we considered total abundance, species richness, and species diversity, at two temporal scales: pooled per year, i.e., across the sampling season, and seasonally (i.e., per day), and we compared these metrics between 1989 and 2014. Second, we examined how total flying biomass (i.e., the weight of all trapped insects, of which hoverflies are only a small proportion) related to total abundance as well as species richness of hoverflies. Third, we derived persistence probabilities and population growth rate trends per species, to examine interspecific variation in these parameters. Descriptions of the deposited files: Groups.csv MF_NR = identifier of each of the six malaise trap locations yrf = year of sampling pot = sample identifier dt = number of sampling days from.dnr = day-of-the-year on which a pot was attached to a malaise trap to.dnr = day-of-the-year on which a pot was collected from a malaise trap mean.daynr = mean day-of-the-year of the sampling period Nspec = number of different hoverfly species found in a pot Nind = number of hoverfly individuals found in a pot Counts.csv A matrix of counts of individual hoverflies per pot per species. The 196 rows represent the pots in the same order as in the file 'Groups.csv'. The columns represent the 162 different hoverfly species found. The scientific species names are indicated in the column headers. PairedData.csv pot = sample identifier JAHR = year of sampling MF_NR = identifier of each of the six malaise trap locations dt = number of sampling days from.dnr = day-of-the-year on which a pot was attached to a malaise trap to.dnr = day-of-the-year on which a pot was collected from a malaise trap NI = number of hoverfly individuals found in a potbiomass.daily NSP = number of different hoverfly species found in a pot biomass.daily = daily fresh weight [gram] of flying insects: total fresh weight in a pot divided by the number of sampling days. ModelFrame.csv MF_NR = identifier of each of the six malaise trap locations yrf = year of sampling pot = sample identifier dt = number of sampling days from.dnr = day-of-the-year on which a pot was attached to a malaise trap to.dnr = day-of-the-year on which a pot was collected from a malaise trap mean.daynr = mean day-of-the-year of the sampling period plot = identifier of each of the six malaise trap locations date = date for which the weather variables are interpolated daynr = day-of-the-year for which the weather variables are interpolated altitude = altitude [m] of the malaise trap locations year = year of sampling temperature = interpolated temperature [degrees Celsius] precipitation = interpolated precipitation [mm per day] wind.speed = interpolated wind speed [m/s] Data_Rcode.pdf This pdf provides the R-code behind the analysis of the Hoverfly data. Three datasets are provided along with this R-code document, namely "Counts.csv", "Groups.csv", "PairedData.csv" and "ModelFrame.csv". Additionally, the BUGS-code ""syrphidModel.jag" is required for running the daily-activity model in JAGS. syrphidModel.jag This BUGS-code is required for running the daily-activity model in JAGS. We greatly acknowledge members of the Entomological Society Krefeld and cooperating botanists and entomologists that were involved in the investigations: K. Coelln, B. Franzen, M. Grigo, M. Hellenthal, J. Hembach, A. Hemmersbach, T. Hoerren, J. Illmer, N. Mohr, S. Risch, O. and W. Schmitz, H. Schwan, R. Seliger, W. Stenmans, H. Sumser, and H. Wolf. For funding, C.A.H. and E.J. were supported by NWO Grants 840.11.001 and 841.11.007. The investigations of the Entomological Society Krefeld and its members are spread over numerous individual projects at different locations and in different years. Grants and permits that have made this work possible are as follows: F + E Biodiversitaetsverluste in FFH-LRT des Offenlandes, gefoerdert durch das Bundesamt fuer Naturschutz mit Mitteln des Bundesministerium fuer Umwelt, Naturschutz und nukleare Sicherheit (BMU), Bezirksregierung Koeln, Bergischer Naturschutzverein, Rhein-Sieg Kreis, and Land Nordrhein-Westfalen–Europaeische Gemeinschaft ELER. References Hallmann CA, Sorg M, Jongejans E, Siepel H, Hofland N, Schwan H, Stenmans W, Müller A, Sumser H, Hörren T, Goulson D, de Kroon H (2017) More than 75 percent decline over 27 years in total flying insect biomass in protected areas. PLoS ONE 12:e0185809 Hallmann CA, Ssymank A, Sorg M, de Kroon H, Jongejans E (2020) Insect biomass decline scaled to species diversity: general patterns derived from a hoverfly community. Proceedings of the National Academy of Sciences of the USA. doi: 10.1073/pnas.2002554117 Schwan H, Sorg M, Stenmans W (1993) Naturkundliche Untersuchungen zum Naturschutzgebiet 'Die Spey' (Stadt Krefeld, Kreis Neuss) - I. Untersuchungsstandorte und Methoden. Natur. Am. Niederrh. 8, 1–13 Sorg M (1990) Entomophage Insekten des Versuchsgutes Höfchen (BRD, Burscheid).- Teil 1. Aphidiinae (Hymenoptera, Braconidae). Pflanzenschutz-Nachrichten Bayer 43, 29–45 Sorg M, Schwan H, Stenmans W, Müller A (2013) Ermittlung der Biomassen flugaktiver Insekten im Orbroicher Bruch mit Malaise Fallen in den Jahren 1989 und 2013. Mitteilungen Entomologischen Verein Krefeld 2013, 1–5 Ssymank A, Sorg M, Doczkal D, Ruhig B, Merkel-Wallner G, Vischer-Leopold M (2018) Praktische Hinweise und Empfehlungen zur Anwendung von Malaisefallen für Insekten in der Biodiversitätserfassung und im Monitoring. Series Naturalis 1, 1–12nul