A failed invasion? Commercially introduced pollinators in Southern France

The natural diversity of Bombus terrestris subspecies could be under threat from the commercialisation of bumblebees. Therefore, to determine whether commercially imported bumblebees are able to establish and spread, we carried out long-term observations of bumblebees in southern France. Our surveys occurred before, during, and after the importation (between 1989 and 1996) of thousands of colonies of the Sardinian subspecies B. t. sassaricus. Queens and males of B. t. sassaricus were observed foraging outside commercial greenhouses in 1991, 1993, and 1994 and feral workers were observed foraging on native vegetation nearly two years after the importation of B. t. sassaricus ceased. However, no B. t. sassaricus, or F1 hybrids were observed after 1998. We conclude that B. t. sassaricus remains inconspicuous in France and competition from the three native subspecies may have prevented it from becoming invasive. However, genetic interference through introgression cannot be ruled out

Première estimation de la dérive faunique chez les Bourdons de la Belgique (Hymenoptera, Apidae)

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Extreme Food-Plant Specialisation in Megabombus Bumblebees as a Product of Long Tongues Combined with Short Nesting Seasons

© 2015 Huang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. http://creativecommons.org/licenses/by/4.0/ The attached file is the published version of the article

Developing European conservation and mitigation tools for pollination services: approaches of the STEP (Status and Trends of European Pollinators) project

Pollinating insects form a key component of European biodiversity, and provide a vital ecosystem service to crops and wild plants. There is growing evidence of declines in both wild and domesticated pollinators, and parallel declines in plants relying upon them. The STEP project (Status and Trends of European Pollinators, 2010-2015, www.stepproject.net) is documenting critical elements in the nature and extent of these declines, examining key functional traits associated with pollination deficits, and developing a Red List for some European pollinator groups. Together these activities are laying the groundwork for future pollinator monitoring programmes. STEP is also assessing the relative importance of potential drivers of pollinator declines, including climate change, habitat loss and fragmentation, agrochemicals, pathogens, alien species, light pollution, and their interactions. We are measuring the ecological and economic impacts of declining pollinator services and floral resources, including effects on wild plant populations, crop production and human nutrition. STEP is reviewing existing and potential mitigation options, and providing novel tests of their effectiveness across Europe. Our work is building upon existing and newly developed datasets and models, complemented by spatially-replicated campaigns of field research to fill gaps in current knowledge. Findings are being integrated into a policy-relevant framework to create evidence-based decision support tools. STEP is establishing communication links to a wide range of stakeholders across Europe and beyond, including policy makers, beekeepers, farmers, academics and the general public. Taken together, the STEP research programme aims to improve our understanding of the nature, causes, consequences and potential mitigation of declines in pollination services at local, national, continental and global scales

Genes Suggest Ancestral Colour Polymorphisms Are Shared across Morphologically Cryptic Species in Arctic Bumblebees

email Suzanne orcd idCopyright: © 2015 Williams et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Species richness declines and biotic homogenization have slowed down for NW-European pollinators and plants

Concern about biodiversity loss has led to increased public investment in conservation. Whereas there is a widespread perception that such initiatives have been unsuccessful, there are few quantitative tests of this perception. Here, we evaluate whether rates of biodiversity change have altered in recent decades in three European countries (Great Britain, Netherlands and Belgium) for plants and flower visiting insects. We compared four 20-year periods, comparing periods of rapid land-use intensification and natural habitat loss (1930–1990) with a period of increased conservation investment (post-1990). We found that extensive species richness loss and biotic homogenisation occurred before 1990, whereas these negative trends became substantially less accentuated during recent decades, being partially reversed for certain taxa (e.g. bees in Great Britain and Netherlands). These results highlight the potential to maintain or even restore current species assemblages (which despite past extinctions are still of great conservation value), at least in regions where large-scale land-use intensification and natural habitat loss has ceased

The decline and conservation of bumblebees

Declines in bumblebee species in the last 60 years are well documented in Europe, where they are primarily driven by habitat loss and declines in floral abundance and diversity resulting from agricultural intensification. Impacts of habitat degradation and fragmentation are likely to be compounded by the social nature of bumblebees and their largely monogamous breeding system which renders their effective population size low. Hence populations are susceptible to stochastic extinction events and inbreeding. In North America, catastrophic declines of some bumblebee species since the 1990s are probably attributable to the accidental introduction of a non-native parasite from Europe, a result of global trade in domesticated bumblebee colonies used for pollination of greenhouse crops. Given the importance of bumblebees as pollinators of crops and wildflowers, it is vital that steps be taken to prevent further declines. Suggested measures include tight regulation of commercial bumblebee use and targeted use of agri-environment schemes to enhance floristic diversity in agricultural landscapes

Spatial distribution modelling reveals climatically suitable areas for bumblebees in undersampled parts of the Iberian Peninsula

The Iberian Peninsula supports a high diversity of bumblebees, with 38 species all of which are at or near the south-western edge of their range. We might expect them to be threatened by climate change, but their distributions within Iberia are poorly documented. In this study, we examine the climatic conditions that explain the distribution of Iberian bumblebees. Species distribution models (SDMs) were built using a presence-only technique (Maxent), incorporating presence data of Iberian bumblebees (initially 5795 records for 38 species) with seven climatic variables. We observed that: (i) mountain regions were highlighted as rich in species (bumblebee hot spots); (ii) rare species are climatic specialist species that mainly inhabit mountain regions; (iii) common species are more tolerant of a broader range of climates, notably of higher temperatures; (iv) some areas of Iberia are largely undersampled, including areas predicted to support high bumblebee diversity. We identify areas where targeted searches may reveal undiscovered populations of rare bumblebee species. Obtaining a good knowledge of the current distribution of species is a vital first step towards devising approaches for their conservation