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Description of the subject. Understanding the current situation and evolution of forests is essential for a sustainable management plan that maintains forests' ecological and socio-economic functions. Remote sensing is a helpful tool in developing this knowledge. Objectives. This paper investigates the new opportunities offered by using Sentinel-2 (S2) imagery for forest mapping in Belgian Ardenne ecoregion. The first classification objective was to create a forest map at the regional scale. The second objective was the discrimination of 11 forest classes (Fagus sylvatica L., Betula sp., Quercus sp., other broad-leaved stands, Pseudotsuga menziesii (Mirb.) Franco, Larix sp., Pinus sylvestris L., Picea abies (L.) H.Karst., young needle-leaved stands, other needle-leaved stands, and recent clear-cuts). Method. Two S2 scenes were used and a series of spectral indices were computed for each. We applied supervised pixel-based classifications with a Random Forest classifier. The classification models were processed with a pure S2 dataset and with additional 3D data to compare obtained precisions. Results. 3D data slightly improved the precision of each objective, but the overall improvement in accuracy was only significant for objective 1. The produced forest map had an overall accuracy of 93.3%. However, the model testing tree species discrimination was also encouraging, with an overall accuracy of 88.9%. Conclusions. Because of the simple analyses done in this study, results need to be interpreted with caution. However, this paper confirms the great potential of S2 imagery, particularly SWIR and red-edge bands, which are the most important S2 bands in our study.

In the context of worldwide biodiversity and wild bee decline, it is increasingly important to better understand the effect of land-use changes on wild bee communities at a global scale. To do so, we studied the effect of city area and urban green spaces layout on wild bee species richness and community composition, as well as on wild bee species with an unfavorable UICN conservation status. This study was based on a large European dataset encompassing 20 cities from France, Belgium and Switzerland. We found a mean wild bee species richness in cities of 96 ± 48 (SD), showing that this species richness was highly variable among cities. The main factor positively influencing wild bee species richness in cities was the area of the city. Conversely, species richness was not significantly related to the total area of urban green spaces in a given city, measured as the spatial extent of urban parks, wastelands and other semi-natural habitats, excluding urban private gardens. Species with conservation status were quite scarce in urban environments, especially when compared to the European Red List of Bees, and we could not link their presence to either city or urban green space area. Dissimilarities in wild bee species community compositions were not associated with any of the studied characteristics of cities. We found that the dissimilarity of wild bee community composition among cities was mainly driven by the rarest species, as the most common ones were found in a majority of the cities sampled. Overall, these results emphasize that larger cities host more wild bee species, but are no refuge for the ones with concerning conservation status. Thus, stakeholders are encouraged to design their cities in favor of biodiversity to better support wild bee communities, and perhaps mitigate the established effect of the urban ecological filter.

Morocco is considered to be one of the main diversity hotspots of bees in the Mediterranean basin. However, this fauna remains largely understudied in both urban and natural eco-systems. Bee monitoring primarily conducted during 2023 in an urban area (i.e. Safi) has unveiled three new bee species for Morocco: Lithurgus tibialis, Tetralonia aff. lanzarotensis and Coelioxys ruficauda as well as records of 28 new bee species for the region Marrakech Safi. This work provides descriptions of the spatial distribution, the diagnostic characters, and host plants of these three species. We also take the opportunity to highlight the quality of urban areas as habitats for bees and the importance of implementating bee-friendly management practices to preserve bee species.

Abstract Phases with spontaneous time-reversal ( $${{{{{{{\mathcal{T}}}}}}}}$$ T ) symmetry breaking are sought after for their anomalous physical properties, low-dissipation electronic and spin responses, and information-technology applications. Recently predicted altermagnetic phase features an unconventional and attractive combination of a strong $${{{{{{{\mathcal{T}}}}}}}}$$ T -symmetry breaking in the electronic structure and a zero or only weak-relativistic magnetization. In this work, we experimentally observe the anomalous Hall effect, a prominent representative of the $${{{{{{{\mathcal{T}}}}}}}}$$ T -symmetry breaking responses, in the absence of an external magnetic field in epitaxial thin-film Mn5Si3 with a vanishingly small net magnetic moment. By symmetry analysis and first-principles calculations we demonstrate that the unconventional d-wave altermagnetic phase is consistent with the experimental structural and magnetic characterization of the Mn5Si3 epilayers, and that the theoretical anomalous Hall conductivity generated by the phase is sizable, in agreement with experiment. An analogy with unconventional d-wave superconductivity suggests that our identification of a candidate of unconventional d-wave altermagnetism points towards a new chapter of research and applications of magnetic phases.

Due to the paucity of suitable habitat, hippos are very rare in the Congo Bassin. Compared to East-African populations, Central African populations of hippos have been less studied. Information found in the literature regarding the animal's basic ecology is limited. This study focuses on the description of the diet of an isolated hippo population in Loango National Park (Gabon), comparing faecal analysis with a reference collection of herbaceous species from the savannas. The effectiveness of using faecal analysis versus using the floristic description of hippos' pastures was demonstrated. The most frequent herbaceous species identified in faeces samples were Paspalum vaginatum, Axonopus compressus, Stenotaphrum secundatum (Poaceae) and Desmodium triflorum (Fabaceae). The voluntary consumption of a dicotyledonous species (Desmodium triflorum) is novel for this species.

Bees are important actors in terrestrial ecosystems and are recognised for their prominent role as pollinators. In the Iberian Peninsula, approximately 1,100 bee species are known, with nearly 100 of these species being endemic to the Peninsula. A reference collection of DNA barcodes, based on morphologically identified bee specimens, representing 514 Iberian species, was constructed. The "InBIO Barcoding Initiative Database: DNA Barcodes of Iberian bees" dataset contains records of 1,059 sequenced specimens. The species of this dataset correspond to about 47% of Iberian bee species diversity and 21% of endemic species diversity. For peninsular Portugal only, the corresponding coverage is 71% and 50%. Specimens were collected between 2014 and 2022 and are deposited in the research collection of Thomas Wood (Naturalis Biodiversity Center, The Netherlands), in the FLOWer Lab collection at the University of Coimbra (Portugal), in the Andreia Penado collection at the Natural History and Science Museum of the University of Porto (MHNC-UP) (Portugal) and in the InBIO Barcoding Initiative (IBI) reference collection (Vairão, Portugal).Of the 514 species sequenced, 75 species from five different families are new additions to the Barcode of Life Data System (BOLD) and 112 new BINs were added. Whilst the majority of species were assigned to a single BIN (94.9%), 27 nominal species were assigned to multiple BINs. Although the placement into multiple BINs may simply reflect genetic diversity and variation, it likely also represents currently unrecognised species-level diversity across diverse taxa, such as Amegilla albigena Lepeletier, 1841, Andrena russula Lepeletier, 1841, Lasioglossum leucozonium (Schrank, 1781), Nomada femoralis Morawitz, 1869 and Sphecodes alternatus Smith, 1853. Further species pairs of Colletes, Hylaeus and Nomada were placed into the same BINs, emphasising the need for integrative taxonomy within Iberia and across the Mediterranean Basin more broadly. These data substantially contribute to our understanding of bee genetic diversity and DNA barcodes in Iberia and provide an important baseline for ongoing taxonomic revisions in the West Palaearctic biogeographical region.

This work explains that the Coulomb elastic process on the nucleus is a major source of single-event effects (SEE) for protons within the energy range of 1–10 MeV. The infinite range of Coulomb interactions implies an exceptionally high recoil probability. This research seeks to extend the investigations under which the elastic process becomes significant in the energy deposition process by providing a simplified methodology to evaluate the elastic contribution impact on the reliability of electronics. The goal is to derive a method to provide a simple way to calculate and predict the SEE cross-section. At very low energy, we observe a significant increase in the proton differential cross-section. The use of a direct Monte Carlo approach would mainly trigger low energy recoiling ions, and a very long calculation time would be necessary to observe the tail of the spectrum. In this sense, this work provides a simple methodology to calculate the SEE cross-section. The single-event upset (SEU) cross-section results demonstrate a good agreement with the experimental data in terms of shape and order of magnitude for different technological nodes.

This study provides the first record of Lasioglossum subfasciatum (Imhoff, 1832) (Hymenoptera, Apoidea, Halictidae) in the Sila National Park (Calabria, Italy), a Biosphere Reserve included in the UNESCO program. The species has been classified as endangered (EN) on the IUCN Red List, throughout Europe. Three specimens were found during a monitoring activity, in May 2022. Here, we provide a description of the species, the environmental characteristics of the site where it was found and a chronological map of its European distribution.

The long-horn bee genus Tetralonia consists of 35 Western Palaearctic species that are associated mostly with the family Asteraceae as host plants. A minority of the species are, however, exclusively associated with other host plants that have particularly large pollen grains, such as those in the plant families Caprifoliaceae, Malvaceae, and Onagraceae. This work presents a taxonomic account and morphological description of the assemblages of Tetralonia species with atypical (non-Asteraceae) host plants. It includes a key to the pollinosa-group, which contains most of the species, a description of three regionally restricted new species, namely T. eoacinctella Dorchin sp. nov., T. epilobii Dorchin sp. nov., and T. stellipilis Dorchin sp. nov., a lectotype designation for Eucera cinctella Saunders, 1908 [=Tetralonia cinctella (Saunders, 1908)], and a neotype designation for Apis malvae Rossi, 1790 [=Tetralonia malvae (Rossi, 1790)]. In addition, the name Eucera macroglossa Illiger, 1806 is confirmed as a synonym of Apis malvae Rossi, 1790; Tetralonia macroglossa ssp. xanthopyga Alfken, 1936 is officially placed in synonymy with Apis malvae Rossi, 1790; and Macrocera confusa Pérez, 1902 is listed as a doubtful synonym of Tetralonia scabiosae Mocsàry, 1879 (syn. nov.).

Abstract Background Within the Hymenoptera, bees are notable for their relationship with flowering plants, being almost entirely dependent on plant pollen and nectar. Though functionally herbivorous, as a result of their role as pollinators, bees have received comparatively little attention as models for insect herbivory. Bees often display dietary specialization, but quantitative comparison against other herbivorous insects has not previously been conducted. Results In the most comprehensive analysis to date for 860 bee species, dietary specialization amounted to 50.1% of studied species collecting pollen from between 1 and 2 botanical families with a relatively long tail of dietary generalists, with 11.1% of species collecting from more than 10 botanical families. This distribution deviated from the truncated Pareto distribution of dietary breadth seen in other herbivorous insect lineages. However, this deviation was predominantly due to eusocial bee lineages, which show a range of dietary breadths that conformed to a normal distribution, while solitary bees show a typical truncated distribution not strongly different from other herbivorous insects. We hypothesize that the relatively low level of dietary specialization in bees as a whole reflects the relaxation of the constraints typically observed in herbivorous insects with a comparatively reduced importance of plant chemistry and comparatively increased importance of phenology and foraging efficiency. The long flight periods of eusocial bees that are necessary to allow overlapping generations both allows and necessitates the use of multiple flowering resources, whereas solitary bees with short flight periods have more limited access to varied resources within a constrained activity period. Conclusions Collectively, solitary bees show slightly lower specialization compared to other herbivorous insects, possibly due to their balanced relationship with plants, rather than direct antagonism such as seen in the direct consumption of plant tissues. An additional factor may be the mediocre diversity of bees at low latitudes combined with low levels of dietary specialization, whereas these areas typically display a high rate of specialization by herbivorous insects in general. Though the most important factors structuring dietary specialization in bees appear to differ from many other herbivorous insects, solitary bees show a surprisingly similar overall pattern of dietary specialization.

Intensive landscape modifications have led to the loss of floral resources, partly in early spring when bumble bee queens need suitable pollen to establish their brood. Adequate floral resources are also crucial to mitigate parasite infection, a stress compromising reproductive success. Among early blooming trees, willows represent an important and highly suitable pollen resource. Alas, riparian areas and their associated willows have been declining. In this study, we found that hedgerow and orchard pollen were at least as suitable as willow pollen for bumble bee survival and microcolony development. Moreover, orchard pollen seemed an interesting candidate to help reduce parasite infection, but unlikely due to its flavonoids. Such non-willow trees could then be favoured in agri-environmental schemes implemented in bee conservation strategies, but pollen chemicals underlying beneficial effects remain to be determined.

Abstract Background To understand mechanisms of adaptation and plasticity of pollinators and other insects a better understanding of diversity and function of their key symbionts is required. Commensalibacter is a genus of acetic acid bacterial symbionts in the gut of honey bees and other insect species, yet little information is available on the diversity and function of Commensalibacter bacteria. In the present study, whole-genome sequences of 12 Commensalibacter isolates from bumble bees, butterflies, Asian hornets and rowan berries were determined, and publicly available genome assemblies of 14 Commensalibacter strains were used in a phylogenomic and comparative genomic analysis. Results The phylogenomic analysis revealed that the 26 Commensalibacter isolates represented four species, i.e. Commensalibacter intestini and three novel species for which we propose the names Commensalibacter melissae sp. nov., Commensalibacter communis sp. nov. and Commensalibacter papalotli sp. nov. Comparative genomic analysis revealed that the four Commensalibacter species had similar genetic pathways for central metabolism characterized by a complete tricarboxylic acid cycle and pentose phosphate pathway, but their genomes differed in size, G + C content, amino acid metabolism and carbohydrate-utilizing enzymes. The reduced genome size, the large number of species-specific gene clusters, and the small number of gene clusters shared between C. melissae and other Commensalibacter species suggested a unique evolutionary process in C. melissae, the Western honey bee symbiont. Conclusion The genus Commensalibacter is a widely distributed insect symbiont that consists of multiple species, each contributing in a species specific manner to the physiology of the holobiont host.

DNA barcoding technologies have provided a powerful tool for the fields of ecology and systematics. Here, we present a part of the InBIO Barcoding Initiative Database: contribution to the knowledge on DNA barcodes of cuckoo wasps (Hymenoptera, Chrysididae) dataset representing 144 specimens and 103 species, covering approximately 44% of the Iberian and 21% of the European fauna. The InBIO Barcoding Initiative (IBI – DNA Barcoding Portuguese terrestrial invertebrate biodiversity) aims to fill the barcoding gap for the terrestrial invertebrate taxa. All DNA extractions are deposited in the IBI collection at CIBIO, Research Center in Biodiversity and Genetic Resources and specimens are deposited in the University of Mons collection (Belgium) and in the Natur-Museum in Lucerne (Switzerland).This dataset increases the knowledge on the DNA barcodes and distribution of 102 species of cuckoo wasps. A total of 52 species, from 11 different genera, were new additions to the Barcode of Life Data System (BOLD), with DNA barcodes for another 44 species added from under-represented taxa in BOLD. All specimens have their DNA barcodes publicly accessible through the BOLD online database. Nine cuckoo wasp species are newly recorded for Portugal. Additionally, two new species for science are described: Chrysis crossi Rosa, sp. nov. from southern Portugal and Hedychridium calcarium Rosa, sp. nov. from eastern Spain. Several taxonomic changes are proposed and Hedychrum rutilans Dahlbom, 1845 is found to consist of two different taxa that can be found in sympatry, Hedychrum rutilans s. str. and Hedychrum viridaureum Tournier, 1877 stat. nov. Stilbum westermanni Dahlbom, 1845 stat. nov. is confirmed as distinct from Stilbum calens (Fabricius, 1781), with the latter species not confirmed as present in Iberia; barcoded Stilbum material from Australia is distinct and represents Stilbum amethystium (Fabricius, 1775) sp. resurr.; Portuguese material identified as Hedychridium chloropygum Buysson, 1888 actually belongs to Hedychridium caputaureum Trautmann & Trautmann, 1919, the first confirmed record of this species from Iberia. Philoctetes parvulus (Dahlbom, 1845) is confirmed to be a synonym of Philoctetes punctulatus (Dahlbom, 1845). Chrysis lusitanica Bischoff, 1910 is confirmed as a valid species. Chrysis hebraeica Linsenmaier, 1959 stat. nov. is raised to species status.

Abstract Body size is a trait that can affect plant–pollinator interaction efficiency and plant reproductive success. We explored the impact of intraspecific size shifts on the interactions between pollinators and flowering plants under controlled conditions. We considered two development conditions leading to the production of large and small individual flowers of Borago officinalis and Echium plantagineum. We also used the natural variability of worker size within bumblebee colonies to isolate small and large workers. We performed a fully crossed experiment with the two flower sizes of each plant species and the two sizes of bumblebee workers. Our results show that the size of both partners did not affect bee foraging behavior in most of the evaluated parameters and both bee sizes were equally efficient in depositing pollen. Significant differences were found only in pollen deposition across the life of a flower in small flowers of B. officinalis, with the greatest quantity of pollen deposited by small bees. We did not find a relationship between pollinator size and plant fitness. Our results suggest that generalist plant–pollinator interactions may be resilient to future potential mismatches in the size of the partners but remain to be tested if they are still resilient under the new environmental conditions resulting from global changes.

Abstract Wild bees are declining, mainly due to the expansion of urban habitats that have led to land-use changes. Effects of urbanization on wild bee communities are still unclear, as shown by contrasting reports on their species and functional diversities in urban habitats. To address this current controversy, we built a large dataset, merging 16 surveys carried out in 3 countries of Western Europe during the past decades, and tested whether urbanization influences local wild bee taxonomic and functional community composition. These surveys encompassed a range of urbanization levels, that were quantified using two complementary metrics: the proportion of impervious surfaces and the human population density. Urban expansion, when measured as a proportion of impervious surfaces, but not as human population density, was significantly and negatively correlated with wild bee community species richness. Taxonomic dissimilarity of the bee community was independent of both urbanization metrics. However, occurrence rates of functional traits revealed significant differences between lightly and highly urbanized communities, for both urbanization metrics. With higher human population density, probabilities of occurrence of above-ground nesters, generalist and small species increased. With higher soil sealing, probabilities of occurrence of above-ground nesters, generalists and social bees increased as well. Overall, these results, based on a large European dataset, suggest that urbanization can have negative impacts on wild bee diversity. They further identify some traits favored in urban environments, showing that several wild bee species can thrive in cities.

Background Pollinating insects provide economically and ecologically valuable services, but are threatened by a variety of anthropogenic changes. The availability and quality of floral resources may be affected by anthropogenic land use. For example, flower-visiting insects in agroecosystems rely on weeds on field edges for foraging resources, but these weeds are often exposed to agrochemicals that may compromise the quality of their floral resources. Methods We conducted complementary field and greenhouse experiments to evaluate the: (1) effect of low concentrations of agrochemical exposure on nectar and pollen quality and (2) relationship between floral resource quality and insect visitation. We applied the same agrochemcial treatments (low concentrations of fertilizer, low concentrations of herbicide, a combination of both, and a control of just water) to seven plant species in the field and greenhouse. We collected data on floral visitation by insects in the field experiment for two field seasons and collected pollen and nectar from focal plants in the greenhouse to avoid interfering with insect visitation in the field. Results We found pollen amino acid concentrations were lower in plants exposed to low concentrations of herbicide, and pollen fatty acid concentrations were lower in plants exposed to low concentrations of fertilizer, while nectar amino acids were higher in plants exposed to low concentrations of either fertilizer or herbicide. Exposure to low fertilizer concentrations also increased the quantity of pollen and nectar produced per flower. The responses of plants exposed to the experimental treatments in the greenhouse helped explain insect visitation in the field study. The insect visitation rate correlated with nectar amino acids, pollen amino acids, and pollen fatty acids. An interaction between pollen protein and floral display suggested pollen amino acid concentrations drove insect preference among plant species when floral display sizes were large. We show that floral resource quality is sensitive to agrochemical exposure and that flower-visiting insects are sensitive to variation in floral resource quality.