Neonicotinoid-induced mortality risk for bees foraging on oilseed rape nectar persists despite EU moratorium.

The implication of neonicotinoids in bee declines led in 2013 to an EU moratorium on three neonicotinoids in bee-attractive crops. However, neonicotinoids are frequently detected in wild flowers or untreated crops suggesting that neonicotinoids applied to cereals can spread into the environment and harm bees. Therefore, we quantified neonicotinoid residues in nectar from winter-sown oilseed rape in western France collected within the five years under the EU moratorium. We detected all three restricted neonicotinoids. Imidacloprid was detected in all years with no clear declining trend but a strong inter- and intra-annual variation and maximum concentrations exceeding reported concentrations in treated crops. No relation to non-organic winter-sown cereals was identified even though these were the only crops treated with imidacloprid, but residue levels depended on soil type and increased with rainfall. Simulating acute and chronic mortality suggests a considerable risk for nectar foraging bees. We conclude that persistent imidacloprid soil residues diffuse on a large scale in the environment and substantially contaminate a major mass-flowering crop. Despite the limitations of case-studies and risk simulations, our findings provide additional support to the recent extension of the moratorium to a permanent ban in all outdoor crops.

Description of long-term monitoring of farmland biodiversity in a LTSER.

Understanding the response of biodiversity to management, land use and climate change is a major challenge in farmland to halt the decline of biodiversity. Farmlands shelter a wide variety of taxa, which vary in their life cycle and habitat niches. Consequently, monitoring biodiversity from sessile annual plants to migratory birds requires dedicated protocols. In this article, we describe the protocols applied in a long-term research platform, the LTSER Zone Atelier "Plaine & Val de Sèvre" (for a full description see Bretagnolle et al. (2018) [1]). We present the data in the form of the description of monitoring protocols, which has evolved through time for arable weeds, grassland plants, ground beetles, spiders, grasshoppers, wild bees, hoverflies, butterflies, small mammals, and farmland birds (passerines, owls and various flagship species).

Towards sustainable and multifunctional agriculture in farmland landscapes: Lessons from the integrative approach of a French LTSER platform.

Agriculture is currently facing unprecedented challenges: ensuring food, fiber and energy production in the face of global change, maintaining the economic performance of farmers and preserving natural resources such as biodiversity and associated key ecosystem services for sustainable agriculture. Addressing these challenges requires innovative landscape scale farming systems that account for changing economic and environmental targets. These novel agricultural systems need to be recognized, accepted and promoted by all stakeholders, including local residents, and supported by public policies. Agroecosystems should be considered as socio-ecological systems and alternative farming systems should be based on ecological principles while taking societal needs into account. This requires an in-depth knowledge of the multiple interactions between sociological and ecological dynamics. Long Term Socio-Ecological Research platforms (LTSER) are ideal for acquiring this knowledge as they (i) are not constrained by traditional disciplinary boundaries, (ii) operate at a large spatial scale involving all stakeholders, and (iii) use systemic approaches to investigate biodiversity and ecosystem services. This study presents the socio-ecological research strategy from the LTSER "Zone Atelier Plaine & Val de Sèvre" (ZA PVS), a large study area where data has been sampled since 1994. Its global aim is to identify effective solutions for agricultural development and the conservation of biodiversity in farmlands. Three main objectives are targeted by the ZAPVS. The first objective is intensive monitoring of landscape features, the main taxa present and agricultural practices. The second objective is the experimental investigation, in real fields with local farmers, of important ecosystem functions and services, in relation to pesticide use, crop production and farming socio-economic value. The third aim is to involve stakeholders through participatory research, citizen science and the dissemination of scientific results. This paper underlines the relevance of LTSERs for addressing agricultural challenges, while acknowledging that there are some yet unsolved key challenges.

A 'Landscape physiology' approach for assessing bee health highlights the benefits of floral landscape enrichment and semi-natural habitats.

Understanding how anthropogenic landscape alteration affects populations of ecologically- and economically-important insect pollinators has never been more pressing. In this context, the assessment of landscape quality typically relies on spatial distribution studies, but, whether habitat-restoration techniques actually improve the health of targeted pollinator populations remains obscure. This gap could be filled by a comprehensive understanding of how gradients of landscape quality influence pollinator physiology. We therefore used this approach for honey bees (Apis mellifera) to test whether landscape patterns can shape bee health. We focused on the pre-wintering period since abnormally high winter colony losses have often been observed. By exposing colonies to different landscapes, enriched in melliferous catch crops and surrounded by semi-natural habitats, we found that bee physiology (i.e. fat body mass and level of vitellogenin) was significantly improved by the presence of flowering catch crops. Catch crop presence was associated with a significant increase in pollen diet diversity. The influence of semi-natural habitats on bee health was even stronger. Vitellogenin level was in turn significantly linked to higher overwintering survival. Therefore, our experimental study, combining landscape ecology and bee physiology, offers an exciting proof-of-concept for directly identifying stressful or suitable landscapes and promoting efficient pollinator conservation.