SummaryThe bumblebee, Bombus terrestris, is an important pollinator commercially used on a global scale. The exported subspecies B. t. terrestris has colonised diverse environments, in some cases displacing wild pollinators to the verge of local extinction. In this sense, the native Iberian subspecies B. t. lusitanicus may be threatened by the subspecies B. t. terrestris, naturally distributed from the Pyrenees to Central Europe but also observed in southern Spain due to escapes from commercial nests. Mitochondrial genomes have a low recombination rate and a small effective population size owing to their maternal inheritance, thus providing an accurate approach to study hybridisation events between populations. Therefore, we present the sequences of the mitogenomes of both subspecies as a molecular framework to select suitable markers to detect possible introgression events between them. We used metagenomics to obtain approximately 17 kbp of the mitogenome from both subspecies. Their mitogenomes differed in 358 bp (excluding the AT‐rich region). Four mitogenomic fragments were selected to be tested as subspecific diagnostic markers. A RFLP detected in the gene nad2 (NADH dehydrogenase subunit 2) has proven to be an efficient, quick and cost‐effective tool to assess the dispersion of the non‐endemic subspecies into Iberian native populations. Subspecific haplotypes were observed in both morphological subspecies, suggesting introgression events in the northern natural contact area and in the new human‐mediated contact area in the south of the Iberian Peninsula.

Bumblebees (genus Bombus Latreille) are pollinator insects of great ecological and economic importance, which commercial use for pollination has increased since the 80s. However, the introduction of foreign Bombus terrestris (Linnaeus) has resulted in a decline of native bumblebee populations in Japan, Chile or Argentina among others. To study the potential introgression of commercial B. terrestris into the Iberian endemic subspecies Bombus terrestris lusitanicus Krüger, it is necessary to find a precise molecular marker that differentiates both subspecies. For this purpose, comparative analyses were carried out between B. t. lusitanicus and B. t. terrestris (Linnaeus) from Spain and from Belgium by sequencing the nuclear genes elongation factor 1-α and arginine kinase and the mitochondrial gene 16S ribosomal RNA, and genotyping with eleven microsatellite loci. No differentiation was observed at the nuclear level, but haplotypes found within the 16S sequence correlated with the morphological characterization of the subspecies. In a case study including individuals sampled before the establishment of bumblebee rearing companies and others from recent samplings, we detected hybrid individuals (those with non-matching morphological subspecies and 16S haplotype) more frequently in the south supporting the naturalization of commercial B. t. terrestris and introgression events between both subspecies. This marker should be used in Iberian populations with the aim to support management and conservation actions in endemic populations of B. t. lusitanicus.

Commercial apple production relies on managed honey bees (Apis mellifera) for pollination, and on intensive management for pest control. Previous studies have highlighted the potentially detrimental effects of intensive crop management on wild bee diversity in agroecosystems, potentially jeopardizing the pollination services they provide. However, the extent to which honey bee dominance and crop management interact under field-realistic conditions and drive the structure of wild bee assemblages has not been investigated so far. In this study, we measured species richness, as well as the functional and phylogenetic diversity of wild bee assemblages in 36 paired organic and non-organic apple orchards during their flowering season and along a geographic gradient across western Europe. Our results show a strong significant and negative association between honey bee dominance and all wild bee diversity metrics, regardless of local management. Semi-natural habitats had a significant and positive effect on functional diversity, while urbanization and crop cover around the orchards showed no effect on all measured diversity metrics. A greater number of species exhibited less common, or frequent, combinations of functional traits at sites with high honey bee dominance, especially larger bee species with longer tongues. Collectively, we show that wild bee diversity decreases with increasing honey bee dominance, and that this negative association is not buffered by alternative (i.e., organic) management practices in commercial apple orchards. Although organic farming can bring about biodiversity benefits, our study demonstrates that, in the context of commercial apple production, other measures are needed to enhance and harness biodiversity for sustainable and profitable crop production. In particular, a lowered reliance on honey bees and a redesign of orchards through configurational crop heterogeneity and/or the restoration of in-field semi-natural elements are required beyond agricultural input substitution.

No abstract

No abstract

Against the context of global wildlife declines, targeted mitigation strategies have become critical to preserve what remains of biodiversity. However, the effective development of conservation tools in order to counteract these changes relies on unambiguous taxonomic determination and delineation. In this study, we focus on an endemic bumblebee species recorded only from the highest altitudes of the Sierra Nevada (Spain), Bombus reinigiellus (Rasmont, 1983). The species has the smallest range of any European bumblebee, along with a restricted diet and an inability to disperse because of its isolated montane distribution, making it an appropriate conservation target. However, through an integrative taxonomic approach including genetics, morphometrics and semio‐chemistry, we demonstrate the conspecificity of this taxon with one of the most common and widespread bumblebee species of Europe, Bombus hortorum (L. 1761). We assign a subspecies status to this endemic taxon (Bombus hortorum reinigiellus comb. nov.) shown to be different in colour and morphology but also in wing shape and relative wing size compared to the other conspecific subspecies. Following our taxonomic revision, we reassessed the IUCN conservation status of Bombus hortorum both at the continental and Spanish scale. We then propose how historic climatic oscillations of the last Ice age could explain such a phenotypic divergence in a post‐glacial refugium and highlight the critical role of establishing unambiguous taxonomic revision prior to any conservation assessment.

Human-induced environmental impacts on wildlife are widespread, causing major biodiversity losses. One major threat is agricultural intensification, typically characterised by large areas of monoculture, mechanical tillage, and the use of agrochemicals. Intensification leads to the fragmentation and loss of natural habitats, native vegetation, and nesting and breeding sites. Understanding the adaptability of insects to these changing environmental conditions is critical to predicting their survival. Bumblebees, key pollinators of wild and cultivated plants, are used as model species to assess insect adaptation to anthropogenic stressors. We investigated the effects of agricultural pressures on two common European bumblebees, Bombus pascuorum and B. lapidarius. Restriction-site Associated DNA Sequencing was used to identify loci under selective pressure across agricultural-natural gradients over 97 locations in Europe. 191 unique loci in B. pascuorum and 260 in B. lapidarius were identified as under selective pressure, and associated with agricultural stressors. Further investigation suggested several candidate proteins including several neurodevelopment, muscle, and detoxification proteins, but these have yet to be validated. These results provide insights into agriculture as a stressor for bumblebees, and signal for conservation action in light of ongoing anthropogenic changes.

Morocco has a diverse bee fauna, but one that has also been relatively understudied in recent years. Here a revision of the species-rich genus Andrena is presented that reveals eleven new species for science and substantially improves our understanding of North African Andrena. From Morocco, Andrena (Aciandrena) semiadesus Wood, sp. nov., Andrena (Aciandrena) triangulivalvis Wood sp. nov., Andrena (Campylogaster) sparsipunctata Wood sp. nov., Andrena (Carandrena) hebescens Wood sp. nov., Andrena (Cnemidandrena) niveofacies Wood sp. nov., Andrena (incertae sedis) tenebricorpus Wood sp. nov., Andrena (Notandrena) acutidentis Wood sp. nov., Andrena (Poliandrena) breviceps Wood sp. nov., and Andrena (Poliandrena) farinosoides Wood sp. nov. are described and their ecology is discussed. Andrena (Aciandrena) astrella Warncke, 1975 is synonymised with Andrena (Aciandrena) fulica Warncke, 1974 syn. nov. The unknown female of Andrena (Nobandrena) ounifa Warncke, 1974, and the unknown male of Andrena (Poliandrena) guichardi Warncke, 1980 are described. Andrena (incertae sedis) gafsensis Wood sp. nov. from Tunisia is described due to its similarity to Andrena tenebricorpus. Andrena (Poecilandrena) nigriclypeus Wood sp. nov. from Algeria is also described as it was collected within 10 km of the Moroccan border. A further 18 species are recorded in Morocco for the first time. Andrena (Melandrena) nitida (Müller, 1776) and Andrena (Notandrena) nitidiuscula Schenck, 1853 are removed from the Moroccan list due to historic problems in the application of these names to Mediterranean taxa.