Despite widespread concern about declines in pollination services, little is known about the patterns of change in most pollinator assemblages. By studying bee and hoverfly assemblages in Britain and the Netherlands, we found evidence of declines (pre-versus post-1980) in local bee diversity in both countries; however, divergent trends were observed in hoverflies. Depending on the assemblage and location, pollinator declines were most frequent in habitat and flower specialists, in univoltine species, and/or in nonmigrants. In conjunction with this evidence, outcrossing plant species that are reliant on the declining pollinators have themselves declined relative to other plant species. Taken together, these findings strongly suggest a causal connection between local extinctions of functionally linked plant and pollinator species.

1There is mounting evidence of pollinator decline all over the world and consequences in many 2 agricultural areas could be significant. We assessed these consequences by measuring 1) the 3 contribution of insect pollination to the world agricultural output economic value, and 2) the 4 vulnerability of world agriculture in the face of pollinator decline. We used a bioeconomic 5 approach, which integrated the production dependence ratio on pollinators, for the 100 crops 6 used directly for human food worldwide as listed by FAO. The total economic value of 7 pollination worldwide amounted to €153 billion, which represented 9.5% of the value of the 8 world agricultural production used for human food in 2005. In terms of welfare, the consumer 9 surplus loss was estimated between €190 and €310 billion based upon average price 10 elasticities of -1.5 to -0.8, respectively. Vegetables and fruits were the leading crop 11 categories in value of insect pollination with about €50 billion each, followed by edible oil 12 crops, stimulants, nuts and spices. The production value of a ton of the crop categories that do 13 not depend on insect pollination averaged €151 while that of those that are pollinator-14 dependent averaged €761. The vulnerability ratio was calculated for each crop category at the 15 regional and world scales as the ratio between the economic value of pollination and the 16 current total crop value. This ratio varied considerably among crop categories and there was a 17 positive correlation between the rate of vulnerability to pollinators decline of a crop category 18 and its value per production unit. Looking at the capacity to nourish the world population 19 after pollinator loss, the production of 3 crop categories -namely fruits, vegetables, and 20 stimulants-will clearly be below the current consumption level at the world scale and even 21 more so for certain regions like Europe. Yet, although our valuation clearly demonstrates the 22 economic importance of insect pollinators, it cannot be considered as a scenario since it does 23 not take into account the strategic responses of the markets. 24

The human impact on life on Earth has increased sharply since the 1970s, driven by the demands of a growing population with rising average per capita income. Nature is currently supplying more materials than ever before, but this has come at the high cost of unprecedented global declines in the extent and integrity of ecosystems, distinctness of local ecological communities, abundance and number of wild species, and the number of local domesticated varieties. Such changes reduce vital benefits that people receive from nature and threaten the quality of life of future generations. Both the benefits of an expanding economy and the costs of reducing nature’s benefits are unequally distributed. The fabric of life on which we all depend—nature and its contributions to people—is unravelling rapidly. Despite the severity of the threats and lack of enough progress in tackling them to date, opportunities exist to change future trajectories through transformative action. Such action must begin immediately, however, and address the root economic, social, and technological causes of nature’s deterioration.

Wild and managed pollinators provide a wide range of benefits to society in terms of contributions to food security, farmer and beekeeper livelihoods, social and cultural values, as well as the maintenance of wider biodiversity and ecosystem stability. Pollinators face numerous threats, including changes in land-use and management intensity, climate change, pesticides and genetically modified crops, pollinator management and pathogens, and invasive alien species. There are well-documented declines in some wild and managed pollinators in several regions of the world. However, many effective policy and management responses can be implemented to safeguard pollinators and sustain pollination services.

Since their discovery in the late 1980s, neonicotinoid pesticides have become the most widely used class of insecticides worldwide, with large-scale applications ranging from plant protection (crops, vegetables, fruits), veterinary products, and biocides to invertebrate pest control in fish farming. In this review, we address the phenyl-pyrazole fipronil together with neonicotinoids because of similarities in their toxicity, physicochemical profiles, and presence in the environment. Neonicotinoids and fipronil currently account for approximately one third of the world insecticide market; the annual world production of the archetype neonicotinoid, imidacloprid, was estimated to be ca. 20,000 tonnes active substance in 2010. There were several reasons for the initial success of neonicotinoids and fipronil: (1) there was no known pesticide resistance in target pests, mainly because of their recent development, (2) their physicochemical properties included many advantages over previous generations of insecticides (i.e., organophosphates, carbamates, pyrethroids, etc.), and (3) they shared an assumed reduced operator and consumer risk. Due to their systemic nature, they are taken up by the roots or leaves and translocated to all parts of the plant, which, in turn, makes them effectively toxic to herbivorous insects. The toxicity persists for a variable period of time—depending on the plant, its growth stage, and the amount of pesticide applied. A wide variety of applications are available, including the most common prophylactic non-Good Agricultural Practices (GAP) application by seed coating. As a result of their extensive use and physicochemical properties, these substances can be found in all environmental compartments including soil, water, and air. Neonicotinoids and fipronil operate by disrupting neural transmission in the central nervous system of invertebrates. Neonicotinoids mimic the action of neurotransmitters, while fipronil inhibits neuronal receptors. In doing so, they continuously stimulate neurons leading ultimately to death of target invertebrates. Like virtually all insecticides, they can also have lethal and sublethal impacts on non-target organisms, including insect predators and vertebrates. Furthermore, a range of synergistic effects with other stressors have been documented. Here, we review extensively their metabolic pathways, showing how they form both compound-specific and common metabolites which can themselves be toxic. These may result in prolonged toxicity. Considering their wide commercial expansion, mode of action, the systemic properties in plants, persistence and environmental fate, coupled with limited information about the toxicity profiles of these compounds and their metabolites, neonicotinoids and fipronil may entail significant risks to the environment. A global evaluation of the potential collateral effects of their use is therefore timely. The present paper and subsequent chapters in this review of the global literature explore these risks and show a growing body of evidence t...

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Climate changes have profound effects on the distribution of numerous plant and animal species 1-3 . However, whether and how different taxonomic groups are able to track climate changes at large spatial scales is still unclear. Here, we measure and compare the climatic debt accumulated by bird and butterfly communities at a European scale over two decades (1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008). We quantified the yearly change in community composition in response to climate change for 9,490 bird and 2,130 butterfly communities distributed across Europe 4 . We show that changes in community composition are rapid but different between birds and butterflies and equivalent to a 37 and 114 km northward shift in bird and butterfly communities, respectively. We further found that, during the same period, the northward shift in temperature in Europe was even faster, so that the climatic debts of birds and butterflies correspond to a 212 and 135 km lag behind climate. Our results indicate both that birds and butterflies do not keep up with temperature increase and the accumulation of different climatic debts for these groups at national and continental scales.Species are not equally at risk when facing climate change. Several species-specific attributes have been identified as increasing species' vulnerability to climate change, including diets, migratory strategy, main habitat types and ecological specialization [5][6][7] . Moreover, although phenotypic plasticity may enable some species to respond rapidly and effectively to climate change 8,9 , others may suffer from the induced spatial mismatch and temporal mistiming with their resources 10,11 . For instance, species such as great tits and flycatchers have been shown to become desynchronized with their main food supply during the nesting season 12 .However, beyond individual species' fates, climate change should also affect species interactions and the structure of species assemblages within and across different taxonomic groups over large spatial scales [13][14][15] . For instance, ectotherms should be more directly affected by climate warming and taxonomic groups with short generation time should favour faster evolutionary responses to selective pressures induced by climate changes 13 . Yet, whether different taxonomic groups are tracking climate change at the same rate over large areas is still unclear, and methods to routinely assess the mismatch between temperature increases and biodiversity responses at different spatial scales are still missing 16 .Here, we used extensive monitoring data of birds and butterflies distributed across Europe to assess whether, regardless of their species-specific characteristics, organisms belonging to a given group are responding more quickly or more slowly than organisms belonging to another group over large areas. We characterized bird and butterfly communities in 9,490 and 2,130 sample sites respectively by their community temperature index (CTI) for ea...

Bee pollinators are currently recorded with many different sampling methods. However, the relative performances of these methods have not been systematically evaluated and compared. In response to the strong need to record ongoing shifts in pollinator diversity and abundance, global and regional pollinator initiatives must adopt standardized sampling protocols when developing large‐scale and long‐term monitoring schemes. We systematically evaluated the performance of six sampling methods (observation plots, pan traps, standardized and variable transect walks, trap nests with reed internodes or paper tubes) that are commonly used across a wide range of geographical regions in Europe and in two habitat types (agricultural and seminatural). We focused on bees since they represent the most important pollinator group worldwide. Several characteristics of the methods were considered in order to evaluate their performance in assessing bee diversity: sample coverage, observed species richness, species richness estimators, collector biases (identified by subunit‐based rarefaction curves), species composition of the samples, and the indication of overall bee species richness (estimated from combined total samples). The most efficient method in all geographical regions, in both the agricultural and seminatural habitats, was the pan trap method. It had the highest sample coverage, collected the highest number of species, showed negligible collector bias, detected similar species as the transect methods, and was the best indicator of overall bee species richness. The transect methods were also relatively efficient, but they had a significant collector bias. The observation plots showed poor performance. As trap nests are restricted to cavity‐nesting bee species, they had a naturally low sample coverage. However, both trap nest types detected additional species that were not recorded by any of the other methods. For large‐scale and long‐term monitoring schemes with surveyors with different experience levels, we recommend pan traps as the most efficient, unbiased, and cost‐effective method for sampling bee diversity. Trap nests with reed internodes could be used as a complementary sampling method to maximize the numbers of collected species. Transect walks are the principal method for detailed studies focusing on plant–pollinator associations. Moreover, they can be used in monitoring schemes after training the surveyors to standardize their collection skills.