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Safeguarding pollinators and their values to human well-being

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Abstract

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.

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... representing about 35% of the volume of crops produced annually (Potts et al. 2016). It is thus essential to characterise how pollinators react to changing environments so as to hope to mitigate those effects. ...
... estimated to participate in the reproduction of more than 87% of all Angiosperms(Potts et al. 2016). Consequently, 35% of the volume of annual crops worldwide are positively affected by their pollination service(Potts et al. 2016).For the past few years, researchers working on pollinators have focused more and more on the networks they form with plants. ...
... estimated to participate in the reproduction of more than 87% of all Angiosperms(Potts et al. 2016). Consequently, 35% of the volume of annual crops worldwide are positively affected by their pollination service(Potts et al. 2016).For the past few years, researchers working on pollinators have focused more and more on the networks they form with plants. They have discovered that those networks have one particular property, called nestedness. ...
Thesis
Depuis plusieurs années, on assiste à un déclin important des populations de pollinisateurs sauvages et domestiques qui pose la question du maintien du service de pollinisation, et donc des espèces de plantes à fleur qui en dépendent pour leur reproduction. Ce déclin est multifactoriel mais sa cause principale est la diminution des milieux naturels ou semi-naturels au profit de deux types d’espaces anthropisés principaux ayant des propriétés très différentes : les espaces urbanisés et ceux utilisés pour l’agriculture intensive. Les zones d’agriculture intensive sont souvent des zones de grande utilisation de pesticides, et subissent une forte homogénéisation de la ressource en nectar, ainsi qu’une diminution des zones d’habitat potentielles des pollinisateurs, avec l’arrachage des haies et l’omniprésence du labour. Les espaces urbanisés sont, eux, des zones importantes d’import d’espèces de plantes exotiques, et de changement phénologique de la floraison qui peuvent nuire aux pollinisateurs.De plus, les plantes à fleurs et les pollinisateurs sont reliés par des réseaux d’interaction structurés autour d’un petit groupe d’espèces généralistes qui joue un rôle d’espèce clé. Des études simulant des communautés de plantes et de pollinisateurs ont montré que lorsque l’environnement devient plus anthropisé et donc moins favorable, les pollinisateurs généralistes qui persistent suffisent au départ à maintenir la pollinisation de l’ensemble des espèces de plantes. Cependant, lorsque les facteurs de déclin des pollinisateurs dépassent un certain seuil et que les espèces de pollinisateurs généralistes commencent à disparaitre, un point de basculement va être atteint. Les simulations prédisent alors une disparition simultanée de toutes les espèces encore présentes de pollinisateurs, et donc la disparition du service de pollinisation.L’objectif de la thèse était d’utiliser des observations sur le terrain pour étudier comment les deux types principaux d’anthropisation, urbanisation et agriculture intensive, interagissent et influencent les communautés de plantes et de pollinisateurs et les réseaux qu’ils forment.J’ai commencé par montrer que les réseaux déterminés jusqu’au niveau de l’espèce ont des propriétés comparables à ces mêmes réseaux déterminés au niveau du genre et même de la famille, ce qui m’a permis d’utiliser pour le reste de la thèse le protocole photographique Spipoll pour recenser les interactions plantes-pollinisateurs. Puis, par une étude observationnelle sur 38 sites sélectionnés sur plateau de Saclay le long d’un double gradient urbanisation-agriculture intensive-espaces semi-naturels, j’ai montré que la majorité des pollinisateurs est négativement impactée par l’urbanisation, avec une perte des taxons spécialistes mais aussi de taxons généralistes, et une perte générale de diversité. Cette perte amène à des réseaux moins emboîtés, qui sont ainsi moins résilients face à une perturbation. Cependant, le taxon des Hyménoptères en général apparaît plus résistant à cet effet, et permet d’assurer un service de pollinisation urbain. Mes résultats permettent également de souligner que tous les types d’urbanisation n’ont pas la même influence sur la biodiversité, et l’importance de prendre en compte ces effets pour repenser l’anthropisation des paysages d’une façon raisonnée pour le futur.
... Insects, in general, offer a wide range of essential and irreplaceable ecosystem services for humanity (Noriega et al., 2018). Pollination, for example, favors agricultural production, ensures food security, and contributes to preserving biodiversity and ecosystem stability (Potts et al., 2016;Klein et al., 2006). ...
... There are many groups of pollinating flying insects (Kevan, 1999). Bees and wasps are among the most widely distributed and economically important pollinators (Ross and Matthews, 2018;Potts et al., 2016;Williams et al., 2010;Klein et al., 2006). However, they have faced numerous threats, including environmental pollution, climate change, invasive species, habitat loss, pathogens, and pesticides (Potts et al., 2016;Senapathi et al., 2015;Jevanandam et al., 2013). ...
... Bees and wasps are among the most widely distributed and economically important pollinators (Ross and Matthews, 2018;Potts et al., 2016;Williams et al., 2010;Klein et al., 2006). However, they have faced numerous threats, including environmental pollution, climate change, invasive species, habitat loss, pathogens, and pesticides (Potts et al., 2016;Senapathi et al., 2015;Jevanandam et al., 2013). The increase in the number of studies reporting significant declines of these insects in different regions of the world warns of a timely extinction of flying Hymenoptera (Sánchez-Bayo and Wyckhuys, 2019;Potts et al., 2010). ...
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Automatic monitoring of flying insects enables quick and efficient observations and management of ecologically and economically important targets such as pollinators, disease vectors, and agricultural pests. Studies on this topic mainly cover the tasks of detection and identification or classification, the latter often guided by the flight sounds of insects. This paper uses domain knowledge and taxonomy information to classify bee and wasp species based on abiotic variables and wing-beat data that change depending on climatic-environmental conditions. We survey the state-of-the-art in hierarchical classification and evaluate the most popular local and global methods for this task on flight data from nine hymenopteran species. We collected the data in Brazilian fields employing an inexpensive optical sensor. Our results show that it is possible to hierarchically classify groups of specimens per species, species, and groups of species according to their wing-beat data at different temperature and relative humidity levels with at least 91% accuracy. Besides benefiting research aimed at building insect classifiers adaptable to natural variations in the environment, this study is a vital step in a series of efforts to design non-invasive species monitoring techniques.
... Intensive agriculture also generally creates conditions more suited to less rewarding annual species than the much preferred perennial species (Pywell et al., 2005;. Potts et al. (2016) argued that as with many aspects of biodiversity conservation, it is not easy to generalize what farmers and other people can do to enhance pollinators and derive benefits. However, the compelling evidence is that in any landscape, the greater the diversity and richness of flowering plants and flower abundance, the greater the abundance, diversity and persistence of pollinators year after year. ...
... Those returns will far outweigh the food benefits they take from both crops and non-crop plants. Given below is a summary of some of the recent critical findings in several reports (Altieri et al., 2015;Goulsen et al., 2015;Bretagnolle and Gaba, 2015;Potts et al., 2016;Hicks et al., 2016;Dicks et al., 2016). ...
... Setting aside unmanaged areas to be colonized by non-crop, flowery species are also proven methods to facilitate on-farm pollination of particular crops. The same approach should benefit pollinators inhabiting urban areas (Altieri et al., 2015;Potts et al., 2016) and, eventually, us. ...
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In addition to the benefits weeds provide to natural enemies of pest insects, weedy taxa are emerging as a critical component that can support pollinators, which are crucial for world crops. Understanding the vital interactions between pollinators, weeds, and crops will enable both the scientific community and the public to appreciate the ecological values of colonizing taxa even more. The species richness of wild bees and other pollinators has declined over the past 50 years, with some species undergoing significant declines and a few going extinct. The causal factors include the excessive use of neonicotinoid pesticides, which directly affect pollinator insects and indirect effects, which include fragmentation of habitat and losses of floral resources due to land clearing and intensive agriculture. Agriculture is recognized as the main driver causing pollinator declines through land-use change, declines in traditional farming practices, intensive farming practices, such as monoculture, tillage and agrochemical use, especially neonicotinoid insecticides, and the excessive use of herbicides for weed control. Agriculture also provides opportunities to support pollinators, through ecologically-friendly farming (Diversified and Conservation Farming Systems) in which habitat can be retained and floral resources for pollinators enhanced. Many countries, especially in Western Europe, the U.K. and the U.S.A., now have programmes dedicated to reintroducing 'green' infrastructure and setting aside field margins and unmanaged areas in agricultural landscapes as Nature-Based Solutions (NSBs) to support pollinators with food resources. The overwhelming evidence from research in the last two decades indicates that colonizing taxa can help bees with rich and diverse food and nectar resources over extended periods. The Convention on Biological Diversity (2018) acknowledges the need to improve knowledge of pollinators and pollination and their role in maintaining ecosystem health and integrity beyond agriculture and food production. Ecological restoration of damaged or modified urban ecosystems can increase the connectivity of pollinator-friendly habitats and support species dispersal and gene flow. These measures can also contribute to climate change mitigation and disaster risk reduction. Weedy taxa, with their abundant flowery resources, have a critical role to play in all of the above.
... Eighty-five to ninety percent of the major food crops and 35% of global food production benefit from animal pollination and in particular on bees (Klein et al., 2007). There is great concern regarding the global decline of bees with a negative upshot for pollination services (Dainese et al., 2019;Potts et al., 2016). Land-use intensification, particularly agriculture expansion, is assumed to be a major driver (Potts et al., 2010). ...
... Global agriculture expansion has been associated with the loss of natural habitats and intensified agricultural practices, resulting in the loss of bee diversity and its associated ecosystem services (Goulson et al., 2015;Potts et al., 2016;Steffan-Dewenter & Westphal, 2008). ...
... On the other hand, these practices are increasingly becoming one of the cardinal pressures that directly and indirectly affect bee survival (Sanchez-Bayo & Goka, 2014). Some direct effects of agricultural intensification on bees are evidenced through the use of pesticides that cause direct intoxication (Potts et al., 2016), ploughing and compaction that destroys nests of ground-nesting bees (Kim et al., 2006), or impairing nests in branches or twigs of non-crop plants (Sutter et al., 2017). Conversely, agricultural intensification could indirectly affect bees through decreasing floral resource availability via reduced weed cover and loss of non-crop habitats (Langlois et al., 2020;Tommasi et al., 2021). ...
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The exponential increase of the human population in tandem with increased food demand has caused agriculture to be the global‐dominant form of land use. Afrotropical drylands are currently facing the loss of natural savannah habitats and agricultural intensification with largely unknown consequences for bees. Here we investigate the effects of agricultural intensification on bee assemblages in the Afrotropical drylands of northern Tanzania. We disentangled the direct effects of agricultural intensification and temperature on bee richness from indirect effects mediated by changes in floral resources. We collected data from 24 study sites representing three levels of management intensity (natural savannah, moderate intensive, and highly intensive agriculture) spanning an extensive gradient of mean annual temperature in northern Tanzania. We used ordinary linear models and path analysis to test the effects of agricultural intensity and mean annual temperature on bee species richness, bee species composition, and body‐size variation of bee communities. We found that bee species richness increased with agricultural intensity and with increasing temperature. The effects of agricultural intensity and temperature on bee species richness were mediated by the positive effects of agriculture and temperature on the richness of floral resources used by bees. During the off‐growing season, agricultural land was characterized by an extensive period of fallow land holding a very high density of flowering plants with unique bee species composition. The increase of bee diversity in agricultural habitats paralleled an increasing variation of bee body sizes with agricultural intensification that, however, diminished in environments with higher temperatures. Synthesis and applications. Our study reveals that bee assemblages in Afrotropical drylands benefit from agricultural intensification in the way it is currently practiced. However, further land use intensification, including year‐round irrigated crop monocultures and excessive use of agrochemicals is likely to exert a negative impact on bee diversity and pollination services, as reported in temperate regions. Moreover, several bee species were restricted to natural savannah habitats. To conserve bee communities and guarantee pollination services in the region, a mixture of savannah and agriculture, with long periods of fallow land should be maintained.
... We need an understanding of how animal pollination can be managed alongside other agronomic inputs to improve crop yield and crop yield stability in different cropping systems and contexts. While empirical studies are typically able to conclude whether there are statistically significant mean effects of animal pollination on crop yield (Aizen et al., 2009;Breeze et al., 2016;Potts et al., 2016), stability (as the opposite of variability) is a summary statistic derived from multiple values and far larger sample sizes are therefore required to identify differences (Mills et al., 2021). Consequently, only a small number of publications have measured the effects of animal pollination on yield stability and they have mostly been correlative (but see Hünicken et al., 2021), either testing associations between the stability of pollinator activity and stability of fruit set (Garibaldi, Steffan-Dewenter, et al., 2011;Lázaro & Alomar, 2019) or comparing yield stability between pollinator-dependent and -independent crops (Garibaldi, Aizen, et al., 2011;Oguro et al., 2019). ...
... Our results provide clear evidence that animal pollination consistently increases crop yield stability across a range of spatial scales in three globally important and representative crop species. Many studies have demonstrated that animal pollination is beneficial to crop yield production (Aizen et al., 2009;Breeze et al., 2016;Klein et al., 2007;Potts et al., 2016). We have used an approach akin to these pollination dependence assessments (see Breeze et al., 2016) to show that the yield of plants receiving animal pollination is on average 32% more stable across space than control plants relying on wind pollination or autogamy. ...
... The monetary value of animal pollination services ($235-577 billion globally each year in 2016; Potts et al., 2016) has been used to promote agronomic management for animal pollinators and to prioritise their conservation (Dicks et al., 2016). The additional benefits that animal pollination provides for crop yield stability that we demonstrate here have not yet been accounted for in economic or natural capital assessments . ...
Article
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The benefits of animal pollination to crop yield are well known. In contrast, the effects of animal pollination on the spatial or temporal stability (the opposite of variability) of crop yield remain poorly understood. We use meta‐analysis to combine variability information from 215 experimental comparisons between animal‐pollinated and wind‐ or self‐pollinated control plants in apple, oilseed rape and faba bean. Animal pollination increased yield stability (by an average of 32% per unit of yield) at between‐flower, ‐plant, ‐plot and ‐field scales. Evidence suggests this occurs because yield benefits of animal pollination become progressively constrained closer to the maximum potential yield in a given context, causing clustering. The increase in yield stability with animal pollination is greatest when yield benefits of animal pollination are greatest, indicating that managing crop pollination to increase yield also increases yield stability. These additional pollination benefits have not yet been included in economic assessments but provide further justification for policies to protect pollinators.
... The value of pollinators to society is immense, but challenging to quantify as so many ecosystem services depend ultimately on the pollination of flowering plants Potts et al., 2016). For example, pollinating animals may indirectly contribute towards carbon storage, flood prevention and ecotourism by facilitating sexual reproduction among rainforest trees. ...
... The major threats facing pollinators and driving their declines are habitat loss, pesticide use, climate change and the spread of parasites and pathogens Goulson et al., 2015;Potts et al., 2016;Soroye et al., 2020). The principal cause underlying most habitat loss and pesticide use is intensive agriculture, which is particularly damaging to pollinators and wider biodiversity (Díaz et al., 2019;Goulson et al., 2015;Tilman et al., 2017). ...
... The increasing evidence for pollinator declines, coupled with a greater appreciation of their widespread importance, has led to a focus on safeguarding pollinators (Gill et al., 2016;Potts et al., 2016). Pollinator populations are regulated by the availability in time and space of particular resources (especially nectar, pollen, nest sites and larval food), along with the timing and severity of incidental risks (such as parasites and pathogens, pesticides, predators and extreme weather events) (Roulston and Goodell, 2011). ...
... With nearly 90% of flowering plant species benefiting from the services of pollinators to set seed and produce fruit, pollinators are an essential component of healthy and diverse ecosystems and contribute significantly to food production [1][2][3][4] . However, populations of both wild and managed pollinators are facing serious challenges 5 . Population declines have been documented in several bee and butterfly species [6][7][8] , including the Eastern population of the monarch butterfly (Danaus plexippus), as indicated by strong reductions in overwintering colony size since the mid-1990s 9 . ...
... U.S. beekeepers lose around a third of their managed honey bee colonies each year 10 . The causes of pollinator declines are multifaceted and somewhat distinct for different taxa, but current evidence suggests that wild bees, honey bees, and butterflies share at least two key stressors: habitat loss and pesticide exposure 5,11,12 . Habitat loss limits the food and nesting resources available to support pollinator populations, while exposure to pesticides can kill pollinators outright or lead to sublethal effects on behavior, immunity, and reproduction 5,[11][12][13][14] . ...
... The causes of pollinator declines are multifaceted and somewhat distinct for different taxa, but current evidence suggests that wild bees, honey bees, and butterflies share at least two key stressors: habitat loss and pesticide exposure 5,11,12 . Habitat loss limits the food and nesting resources available to support pollinator populations, while exposure to pesticides can kill pollinators outright or lead to sublethal effects on behavior, immunity, and reproduction 5,[11][12][13][14] . Furthermore, use of herbicides may influence pollinators indirectly by reducing the availability of their food plants 15 . ...
Article
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Wild and managed pollinators are essential to food production and the function of natural ecosystems; however, their populations are threatened by multiple stressors including pesticide use. Because pollinator species can travel hundreds to thousands of meters to forage, recent research has stressed the importance of evaluating pollinator decline at the landscape scale. However, scientists’ and conservationists’ ability to do this has been limited by a lack of accessible data on pesticide use at relevant spatial scales and in toxicological units meaningful to pollinators. Here, we synthesize information from several large, publicly available datasets on pesticide use patterns, land use, and toxicity to generate novel datasets describing pesticide use by active ingredient (kg, 1997–2017) and aggregate insecticide load (kg and honey bee lethal doses, 1997–2014) for state-crop combinations in the contiguous U.S. Furthermore, by linking pesticide datasets with land-use data, we describe a method to map pesticide indicators at spatial scales relevant to pollinator research and conservation.
... Pollination by insects is a valuable ecosystem service predominantly provided by bees (Potts et al., 2016). Among the 20,000 bee species reported (Michener, 2007), approximately 244 stingless bees species are found in Brazil (Pedro, 2014). ...
... In the last few decades, there have been reports of significant decline in bees diversity (Potts et al., 2016;Zattara and Aizen, 2021). Consequently, plant species diversity may decline, compromising food security (Biesmeijer et al., 2006;Potts et al., 2016). ...
... In the last few decades, there have been reports of significant decline in bees diversity (Potts et al., 2016;Zattara and Aizen, 2021). Consequently, plant species diversity may decline, compromising food security (Biesmeijer et al., 2006;Potts et al., 2016). One of the causes of this decrease in bee diversity is related to agricultural landscapes and practices (Kremen et al., 2002;Potts et al., 2010). ...
Article
The concern about pesticide exposure to neotropical bees has been increasing in the last few years, and knowledge gaps have been identified. Although stingless bees, (e.g.: Melipona scutellaris), are more diverse than honeybees and they stand out in the pollination of several valuable economical crops, toxicity assessments with stingless bees are still scarce. Nowadays new approaches in ecotoxicological studies, such as omic analysis, were pointed out as a strategy to reveal mechanisms of how bees deal with these stressors. To date, no molecular techniques have been applied for the evaluation of target and/or non-target organs in stingless bees, such as the Malpighian tubules (Mt). Therefore, in the present study, we evaluated the differentially expressed genes (DEGs) in the Mt of M. scutellaris after one and eight days of exposure to LC50/100 (0.000543 ng a.i./μL) of thiamethoxam (TMX). Through functional annotation analysis of four transcriptome libraries, the time course line approach revealed 237 DEGs (nine clusters) associated with carbon/energy metabolism and cellular processes (lysosomes, autophagy, and glycan degradation). The expression profiles of Mt were altered by TMX in processes, such as detoxification, excretion, tissue regeneration, oxidative stress, apoptosis, and DNA repair. Transcriptome analysis showed that cell metabolism in Mt was mainly affected after 8 days of exposure. Nine genes were selected from different clusters and validated by RT-qPCR. According to our findings, TMX promotes several types of damage in Mt cells at the molecular level. Therefore, interference of different cellular processes directly affects the health of M. scutellaris by compromising the function of Mt.
... Human societies derive great benefit from a range of natural ecological functions, referred to as ecosystem services (Costanza et al., 1997). Pollination is known as a crucial step in the reproduction of many wild and crop plants Ollerton et al., 2011;Potts et al., 2016;Rodger et al., 2021), and pollinators thereby provide important benefits to humans through the ecosystem service of pollination by securing a reliable and diverse seed, nut and fruit set (e.g., Frimpong et al., 2011;Klein et al., 2012;Potts et al., 2016;Zou et al., 2017), with more than 75% of the world's most important crops dependent on insect pollination . Pollinatordependent crops are also important for balanced human diets by providing many micronutrients such as vitamins A and C (Eilers et al., 2011;Smith et al., 2015). ...
... Human societies derive great benefit from a range of natural ecological functions, referred to as ecosystem services (Costanza et al., 1997). Pollination is known as a crucial step in the reproduction of many wild and crop plants Ollerton et al., 2011;Potts et al., 2016;Rodger et al., 2021), and pollinators thereby provide important benefits to humans through the ecosystem service of pollination by securing a reliable and diverse seed, nut and fruit set (e.g., Frimpong et al., 2011;Klein et al., 2012;Potts et al., 2016;Zou et al., 2017), with more than 75% of the world's most important crops dependent on insect pollination . Pollinatordependent crops are also important for balanced human diets by providing many micronutrients such as vitamins A and C (Eilers et al., 2011;Smith et al., 2015). ...
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Bee species are thought to vary in their pollination efficiency, but they are rarely compared, particularly in the tropics. Here we determined the role in the pollination of 13 native bee species (Apis mellifera and 12 other wild bee species) when visiting pigeon pea (Cajanus cajan) flowers across two growing seasons in Cameroon. Using observations of floral visits coupled with a field experiment to quantify single-visit pollination efficiency, we found that Chalicodoma rufipes was the most efficient pollinator and most abundant flower visitor of pigeon pea. Most other flower visitors, including Apis mellifera, detracted from pigeon pea seed set. Our study highlights the importance of quantifying pollination to reveal functionally important bee species.
... Pollinating insects, particularly bees, have attracted great interest over the years thanks to increasing awareness of their critical role in pollination in both natural and agricultural areas (Potts et al. 2010, Klein et al. 2017 and to their bioactive compounds (Costa-Lotufo et al. 2022 (in press)). In addition to being interesting biologically, the value of symbiosis between plants and pollinators for humanity cannot be overstated (Potts et al. 2016). Wild and managed bees contribute to one-third of the total production of food for humans (Klein et al. 2007(Klein et al. , 2017. ...
... Wild and managed bees contribute to one-third of the total production of food for humans (Klein et al. 2007(Klein et al. , 2017. Globally, insects are estimated to contribute more than US$ 235-575 B yearly to the global economy through their role as crop pollinators (Breeze et al. 2016), but actual contributions may be considerably higher. Given their importance to food security and wildland preservation, improving the understanding of pollinators is critical. ...
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speciesLink is a large-scale biodiversity information portal that exists thanks to a broad collaborative network of people and institutions. CRIA's involvement with the scientific community of Brazil and other countries is responsible for the significant results achieved, currently reaching more than 15 million primary biodiversity data records, 95% of which are associated with preserved specimens and about 25% with high-quality digital images. The network provides data on over 200,000 species, of which over 110,000 occur in Brazil. This article describes thematic networks within speciesLink, as well as some of the most useful tools developed. The importance and contributions of speciesLink are outlined, as are concerns about securing stable budgetary support for such biodiversity data e-infrastructures. Here we review the value of speciesLink as a major source of biodiversity information for research, education, informed decision-making, policy development, and bioeconomy. speciesLink: dados valiosos e ferramentas inovadoras para avaliações digitais da biodiversidade Resumo: speciesLink é um portal de informações em larga escala sobre biodiversidade, que existe graças a uma ampla rede colaborativa de pessoas e instituições. O envolvimento do CRIA com a comunidade científica do Brasil e de outros países é responsável pelos resultados expressivos alcançados, atingindo atualmente mais de 15 milhões de registros de dados primários de biodiversidade, sendo 95% associados a espécimes preservados e cerca de 25% a imagens digitais de alta qualidade. A rede fornece dados sobre mais de 200.000 espécies, das quais mais de 110.000 ocorrem no Brasil. Este artigo descreve as redes temáticas do speciesLink, bem como algumas das ferramentas mais úteis desenvolvidas. A importância e as contribuições do speciesLink são destacadas, assim
... In Nicaragua, beekeeping was linked to a high dietary diversity score. This provides further evidence of the positive contributions of beekeeping to food security and rural livelihoods in the global south (Potts et al., 2016;Kassa Degu and Regasa Megerssa, 2020). ...
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The challenges that coffee smallholder livelihoods face suggest the need to move beyond incremental changes in production. Transformative agroecology offers a potential approach to guide systemic change to achieve food sovereignty among coffee smallholders and cooperatives. This work aims to understand the extent to which diversification practices among coffee smallholders can contribute to a transformative agroecology, and to what extent, participatory action research (PAR) projects may support related transformative processes. The PAR projects described in this paper took place over 3 years with participants associated with two smallholder cooperatives in Mexico, and Nicaragua. After establishing long-term partnerships among cooperatives and universities, we used a PAR approach to guide a mixed methods study that included 338 household surveys, 96 interviews, 44 focus group discussions, and participant observation during farmer-to-farmers exchanges. We found that, although coffee-producing households in both study sites report several diversification activities, more than 50% still face some period of food scarcity each year. In our reflections with farmers and staff from the participating cooperatives, that are also included as co-authors in this study, we conclude that coffee smallholders and cooperatives in both locations are in the early stages of developing a transformative agroecology, as a path toward food sovereignty. Several leverage points to achieve this include land access, native seed conservation, cultural attachment to certain diversification practices, and traditional diets. Some of the more significant challenges to advancing a more transformative agroecology are the prioritization of coffee as a crop (i.e., coffee specialization), and dependency on coffee income. Our PAR project also aimed to contribute to achieving change in the prevailing system through 1) capacity building with community facilitators/promoters, 2) co-creation of questions and knowledge relevant to the strategic planning by coffee cooperatives, 3) sharing farmer-to-farmer pedagogies across territories, and 4) the co-production of popular education material. We conclude that diversification remains an important agroecological strategy for smallholder commodity producers, as a way of achieving food sovereignty. Most of all, we find that achieving diversification is not a linear process, as there are many trade-offs, feedback loops, obstacles and opportunities that should be considered through long-term and collective approaches.
... Loss of important functional groups, such as insect pollinators, has significant implications for wildflower health (Brosi & Briggs, 2013;Ollerton et al., 2014), crop pollination and subsequent food security (Eilers et al., 2011;Gill et al., 2016;Potts et al., 2016). ...
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Insect declines are a global issue with significant ecological and economic ramifications. Yet, we have a poor understanding of the genomic impact these losses can have. Genome‐wide data from historical specimens have the potential to provide baselines of population genetic measures to study population change, with natural history collections representing large repositories of such specimens. However, an initial challenge in conducting historical DNA data analyses is to understand how molecular preservation varies between specimens. Here, we highlight how Next‐Generation Sequencing methods developed for studying archaeological samples can be applied to determine DNA preservation from only a single leg taken from entomological museum specimens, some of which are more than a century old. An analysis of genome‐wide data from a set of 113 red‐tailed bumblebee Bombus lapidarius specimens, from five British museum collections, was used to quantify DNA preservation over time. Additionally, to improve our analysis and further enable future research, we generated a novel assembly of the red‐tailed bumblebee genome. Our approach shows that museum entomological specimens are comprised of short DNA fragments with mean lengths below 100 base pairs (BP), suggesting a rapid and large‐scale post‐mortem reduction in DNA fragment size. After this initial decline, however, we find a relatively consistent rate of DNA decay in our dataset, and estimate a mean reduction in fragment length of 1.9 bp per decade. The proportion of quality filtered reads mapping to our assembled reference genome was around 50%, and decreased by 1.1% per decade. We demonstrate that historical insects have significant potential to act as sources of DNA to create valuable genetic baselines. The relatively consistent rate of DNA degradation, both across collections and through time, mean that population‐level analyses—for example for conservation or evolutionary studies—are entirely feasible, as long as the degraded nature of DNA is accounted for.
... Invertebrates are poorly represented in conservation research (Donaldson et al., 2016), on national and international lists of threatened and endangered species, including the IUCN Red List (Cardoso et al., 2011(Cardoso et al., , 2012, and receive less conservation funding than do vertebrates (Mammola et al., 2020). Invertebrates play key roles in many ecosystem processes, including decomposition and nutrient cycling in soil (Bardgett, 2005;Bardgett & Wardle, 2010), pollination (Potts et al., 2016) and structuring ecosystems (Risch et al., 2018). ...
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Aim Soil arthropods are important decomposers and nutrient cyclers, but are poorly represented on national and international conservation Red Lists. Opportunistic biological records for soil invertebrates are sparse, and contain few observations of rare species but a relatively large number of non‐detection observations (a problem known as class imbalance). Robinson et al. (Diversity and Distributions, 24, 460) proposed a method for under‐sampling non‐detection data using a spatial grid to improve class balance and spatial bias in bird data. For taxa that are less intensively sampled, datasets are smaller, which poses a challenge because under‐sampling data removes information. We tested whether spatially stratified under‐sampling improved prediction performance of species distribution models for millipedes, for which large datasets are not available. We also tested whether using environmental predictor variables provided additional information beyond what is captured by spatial position for predicting species distributions. Location Island of Ireland. Methods We tested the spatially stratified under‐sampling method of Robinson et al. (Diversity and Distributions, 24, 460) by using biological records to train species distribution models of rare millipedes. Results Using spatially stratified under‐sampled data improved species distribution model sensitivity (true positive rate) but decreased model specificity (true negative rate). The spatial pattern of under‐sampling affected model performance. Training data that was under‐sampled in a spatially stratified way sometimes produced worse models than did data that was under‐sampled in an unstratified way. Geographic coordinates were as good as or better than environmental variables for predicting distributions of one out of six species. Main Conclusions Spatially stratified under‐sampling improved prediction performance of species distribution models for rare millipedes. Spatially stratified under‐sampling was most effective for rarer species, although unstratified under‐sampling was sometimes more effective. The good prediction performance of models using geographic coordinates is promising for modelling distributions of poorly studied species for which little is known about ecological or physiological determinants of occurrence.
... Thus, distinguishing which factors are contributing to insect-pollinator losses remains a research priority, and will help inform safeguarding strategies and predict future pollination services. Several global factors are associated with insect-pollinator losses, including climate change, agricultural intensification and spread of invasive species (Ollerton, 2021;Potts et al., 2016). However, we are still limited in our ability to quantify the degree to which such factors have contributed to stress being placed on wild populations (Gill et al., 2016;Ollerton et al., 2014); defined here as a reduction in an individual's energy allocation towards development and reproduction (Beasley et al., 2013). ...
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Determining when animal populations have experienced stress in the past is fundamental to understanding how risk factors drive contemporary and future species' responses to environmental change. For insects, quantifying stress and associating it with environmental factors has been challenging due to a paucity of time‐series data and because detectable population‐level responses can show varying lag effects. One solution is to leverage historic entomological specimens to detect morphological proxies of stress experienced at the time stressors emerged, allowing us to more accurately determine population responses. Here we studied specimens of four bumblebee species, an invaluable group of insect pollinators, from five museums collected across Britain over the 20th century. We calculated the degree of fluctuating asymmetry (FA; random deviations from bilateral symmetry) between the right and left forewings as a potential proxy of developmental stress. We: (a) investigated whether baseline FA levels vary between species, and how this compares between the first and second half of the century; (b) determined the extent of FA change over the century in the four bumblebee species, and whether this followed a linear or nonlinear trend; (c) tested which annual climatic conditions correlated with increased FA in bumblebees. Species differed in their baseline FA, with FA being higher in the two species that have recently expanded their ranges in Britain. Overall, FA significantly increased over the century but followed a nonlinear trend, with the increase starting c. 1925. We found relatively warm and wet years were associated with higher FA. Collectively our findings show that FA in bumblebees increased over the 20th century and under weather conditions that will likely increase in frequency with climate change. By plotting FA trends and quantifying the contribution of annual climate conditions on past populations, we provide an important step towards improving our understanding of how environmental factors could impact future populations of wild beneficial insects. Determining stress events improves our understanding of the drivers of population declines, but a lack of baseline data makes this challenging. Leveraging museum specimens, the authors measured the change in bumblebee wing‐shape fluctuating asymmetry (FA; proxy of stress) between 1900 and 2000. FA increased over the century, with warmer, wetter conditions predicting higher FA.
... (Button & Elle, 2014;Courcelles et al., 2013;Eeraerts, 2022;Estravis-Barcala et al., 2021;Rodriguez-Saona et al., 2011). Bees capable of buzz-pollination, for example, can adjust their foraging behaviour (within its inherent range) and adopt different strategies to maximize resource extraction from certain plants (Arroyo-Correa et al., 2019;Burkart et al., 2014;Corbet & Huang, 2014;Mesquita-Neto et al., 2018;Switzer et al., 2016;Vallejo-Marín, 2019 (Eeraerts et al., 2021;Potts et al., 2016;Rodríguez et al., 2021;Sutter et al., 2018;Williams et al., 2015;Windsor et al., 2021;Wood et al., 2015). Such efforts would provide nesting habitats and floral resources for native bee communities within farmed landscapes because they not only visit agricultural crops but also depended on native habitats to nest, feed, and reproduce ( Nicholson et al., 2017;Rodríguez et al., 2021). ...
Article
Blueberry is one of the most relevant buzz‐pollinated crops worldwide and Chile is the most important global producer of fresh blueberries during wintertime in the Northern Hemisphere. Thousands of exotic Bombus terrestris are imported from Europe to pollinate blueberries. However, no study has investigated the performance of the native Chilean fauna to pollinate blueberry or other crops. Therefore, we aimed to compare the performance of native Chilean floral visitors with managed visitors to pollinate highbush blueberry. Per‐visit pollination performance (stigmatic pollen deposition) and floral visitation were measured and the presence of sonication behaviour of flower visitors was evaluated for five cultivars in two blueberry orchards located in southern Chile. Floral visitors showed a preference for one or more blueberry cultivars, instead of visiting all cultivars equally. Floral visits with sonication deposited more conspecific pollen on stigmas than visits without sonication. Some native sonicating bees (Cadeguala and Bombus), especially Cadeguala occidentalis, were efficient pollen vectors of blueberry and better pollinators than honeybees (5.8 times more pollen transferred) similar to that of the managed bee B. terrestris. The results indicate that some Chilean native bee species, especially those with sonication behaviour, can provide pollination service to highbush blueberry crops.
... Thus, anticipating effects of warming necessitates study of pest species individually, a substantial challenge. Similar complexities come into play with effects of changing climate on beneficial arthropods such as pollinators, their abundance, diversity, and phenological alignment with the crops they pollinate (Bartomeus et al. 2011, Donnelly et al. 2011, Scaven and Rafferty 2013, Potts et al. 2016, Gonzalez et al. 2021. ...
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Climate change is expected to alter pressure from insect pests and the abundance and effectiveness of insect pollinators across diverse agriculture and forestry systems. In response to warming, insects are undergoing or are projected to undergo shifts in their geographic ranges, voltinism, abundance, and phenology. Drivers include direct effects on the focal insects and indirect effects mediated by their interactions with species at higher or lower trophic levels. These climate-driven effects are complex and variable, sometimes increasing pest pressure or reducing pollination and sometimes with opposite effects depending on climatic baseline conditions and the interplay of these drivers. This special collection includes several papers illustrative of these biological effects on pests and pollinators. In addition, in response to or anticipating climate change, producers are modifying production systems by introducing more or different crops into rotations or as cover crops or intercrops or changing crop varieties, with potentially substantial effects on associated insect communities, an aspect of climate change that is relatively understudied. This collection includes several papers illustrating these indirect production system-level effects. Together, biological and management-related effects on insects comprise the necessary scope for anticipating and responding to the effects of climate change on insects in agriculture and forest systems.
... Gallai et al. 6 reported annual value of pollination service to €153 billion in 2005, contributing 9.5% of agricultural food production crops. Further, the annual market value of additional crop production directly linked with pollination services is estimated at $235bn-$577bn worldwide 7 In the absence of animal pollination, a potential annual net loss of economic welfare of $160 billion-$191 billion incurred globally 2 . In the last few years, there has been substantial increase in the value of this service due to decreasing numbers of insect pollinators, mainly honeybees because of lack awareness of their role in pollination among farming community and adverse impact of indiscriminate use of more toxic pesticides and changing climate scenario in the country. ...
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Dill seeds (Anethumgraveolens L.) is the most valuable medicinal seed spice crop of Apiaceae. It bears small yellow flowers in the form of umbels. Being a cross-pollinated crop, floral visitors play vital role in pollination and seed sets. Hence, the present study was conducted at the ICAR-National Research Centre on Seed Spices, Ajmer (Rajasthan), India to discover the pollinator’s community, foraging behaviour and abundance of most frequent pollinators and different modes of pollination on seed yield and quality of this seed spice crop. The insect visitors community of dill seeds was composed of 28 insect species belonging to 14 families of 6 orders. Most of floral visitors started their foraging activity at 8.00 h, reached peak activity between 12.00 and 14.00 h and their activity ceased at 18.00 h. Apisflorea,A.dorsata,A.mellifera, solitary bee, Halictus sp. and two unidentified species of Hymenoptera; Episyrphusbalteatus (DeGeer), Episyrphus sp., Eristalis sp and two other Musca species of Diptera were identified as potential and regular floral visitors of dill seeds. The highest seed yield of 1505.63 kg/ha was recorded in the treated plots provided with only 10% jaggery solution and was at par with the open pollination. A lower seed yield of 1432.5 kg/ha was recorded in plots pollinated only with A.mellifera inside insect cages. Open pollination with 10% jaggery solution spray increased the seed yield of dill seed crop by 57%, one-thousand seed test weight by 96% and the essential oil content by 27% over control plots. These results show that managed pollination is a much better way to enhance yields and quality of dill seed crop than other treatments including only honeybee-based pollination.
... Honey bees are important pollinators of crops and wild plants (Al Naggar et al., 2018;Khalifa et al., 2021;Potts et al., 2016), but they have been experiencing significant overwinter colony losses since 2006, particularly in Europe and the United States (Lee et al., 2015;Osterman et al., 2021;van der Zee et al., 2012;vanEngelsdorp et al., 2010). Parasites, pathogens, inadequate nutrition, and exposure to pesticides have all been linked to these declines (Neov et al., 2019). ...
Article
The gut microbiome plays an important role in bee health and disease. But it can be disrupted by pesticides and in-hive chemicals, putting honey bee health in danger. We used a controlled and fully crossed laboratory experimental design to test the effects of a 10-day period of chronic exposure to field-realistic sublethal concentrations of two nicotinic acetylcholine receptor agonist insecticides (nACHRs), namely flupyradifurone (FPF) and sulfoxaflor (Sulf), and a fungicide, azoxystrobin (Azoxy), individually and in combination, on the survival of individual honey bee workers and the composition of their gut microbiota (fungal and bacterial diversity). Metabarcoding was used to examine the gut microbiota on days 0, 5, and 10 of pesticide exposure to determine how the microbial response varies over time; to do so, the fungal ITS2 fragment and the V4 region of the bacterial 16S rRNA were targeted. We found that FPF has a negative impact on honey bee survival, but interactive (additive or synergistic) effects between either insecticide and the fungicide on honey bee survival were not statistically significant. Pesticide treatments significantly impacted the microbial community composition. The fungicide Azoxy substantially reduced the Shannon diversity of fungi after chronic exposure for 10 days. The relative abundance of the top 10 genera of the bee gut microbiota was also differentially affected by the fungicide, insecticides, and fungicide-insecticide combinations. Gut microbiota dysbiosis was associated with an increase in the relative abundance of opportunistic pathogens such as Serratia spp. (e.g. S. marcescens), which can have devastating consequences for host health such as increased susceptibility to infection and reduced lifespan. Our findings raise concerns about the long-term impact of novel nACHR insecticides, particularly FPF, on pollinator health and recommend a novel methodology for a refined risk assessment that includes the potential effects of agrochemicals on the gut microbiome of bees.
... Nevertheless, with reference to the emergency of the reduction in pollinators, different studies have shown that Sedum roofs attract a limited number of pollinator species during their almost short flowering period, compared to GRs planted with multiple forms of vegetation (herbaceous roofs) [10]. Thus, to safeguard the rich Mediterranean biodiversity of pollinators [23] through GRs, the inclusion of native plant species from arid environments [24] and with shallow roots [25] should be encouraged. To achieve this aim, interdisciplinary research is needed to assess and foresee how different environmental pressures affect pollinators and to provide evidence-based solutions as the establishment of effective habitat networks, optimizing the UESs that GRs may provide. ...
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Green roofs (GRs) are proposed to offset against numerous environmental and socio- economic concerns associated with climate change and urban sprawl. In Mediterranean urban areas, to protect and conserve biodiversity through GRs, the use of native plant species from arid environments and with shallow roots is generally recommended. In north Europe, Echium vulgare L. is widely used on GRs for its tolerance to abiotic stresses and its attractiveness for bees; unfortunately, since this species requires cold winters to induce flowering and warm wet summers for vegetative growths, its adaptability to Mediterranean GRs has been questioned. The current study is based on the hypothesis that Echium plantagineum L. can adapt better to the Mediterranean environment than E. vulgare and offer blooms to pollinators, thus providing the important urban ecosystem service (UES) of protecting entomofauna biodiversity. To compare the adaptability of E. plantagineum vs. E. vulgare, both Echium species were grown and studied on the extensive GR installed at ENEA Casaccia Research Center, in the north of Rome, Lazio, Italy. The comparative analysis of the GR performance of the two species was based on several plant-related traits, including seed morphology, rosette stage, inflorescence, flower and root-related traits, and their biological life cycle, most of them showing significant differences (for example, rosette area was 1.42-fold major in E. plantagineum than in E. vulgare). The information provided in this manuscript will be useful to update the herbarium records for conservation biology. A dramatic water stress was purposely applied in the GR before the end of the hot summer season, and while E. plantagineum faced with success the imposed dehydration (88.4% vegetation cover), E. vulgare did not (7.5% vegetation cover), presumably because of its biennial life cycle which did not allow it to complete seed maturation (only 46.9% percentage mature seeds in E. vulgare respect to 89.5% in E. plantagineum). In summary, as the main result, this work shows that in Mediterranean areas, the inclusion of E. plantagineum in seed mixes for flower meadow GRs could represent a valuable alternative to E. vulgare in temperate areas, providing a safeguard for pollinators and allowing water and energy saving.
... However, the decline in the abundance and diversity of pollinators raises concern about inadequate pollination services for food production (Cameron et al., 2011;Potts et al., 2016). ...
Article
Apple is one of the most widely cultivated fruit crops worldwide, and apple yield benefits from pollination by insects. The global decline in wild pollinator populations raises concern about the adequacy of pollination services in apple production. Here, we present a global meta‐analysis of pollination in apple. We assembled from the literature a dataset comprising results of 48 studies across five continents on fruit set and seed set in apple with insect pollination, artificial pollination and pollinator exclusion, and analysed the effects of explanatory factors such as variety and continent. Fruit set was on average 41% lower with open pollination than with artificial pollination, while seed set was 20% lower. These pollination deficits varied across continents and cultivars. Pollination deficits for fruit set were greatest in Asia (63%) followed by Europe (30%), whereas pollination deficits for seed set were greatest in Asia (47%) and South America (40%). Important differences in pollination deficit were also identified between cultivars but these differences were confounded with continent effects. Fruit set and seed set were 71% and 62% higher, respectively, when insects had open access to flowers than when they were artificially excluded, while results varied among cultivars. Synthesis and Applications. Globally, there are substantial contributions of pollinators to fruit set and seed set in apple, as well as considerable limitations in apple pollination services, particularly in Asia, Europe and South America. Several management strategies could be applied to reduce the pollination deficits in apple production: (1) conserving wild bees and enhancing their abundance and diversity, (2) using managed bees for pollination, (3) using varieties with low pollinator dependency, and/or (4) artificial pollination. These strategies should be tailored to the regional situation, considering the potential of landscapes for restoring wild pollinators, the acceptability of cultivated varieties for available pollinators, the acceptance in the market of self‐compatible varieties, and the costs of management, such as artificial pollination, pollinator conservation, beekeeping and planting self‐compatible varieties. Conservation of wild pollinators is preferred in regions with sufficient potential for wild pollinators as it contributes to biodiversity conservation and improves pollination in both crops and wild plants.
... Wild bees provide essential pollination services to crops and wild plants (Potts et al., 2016;Wei et al., 2021), but are jeopardized by habitat loss and intensive agriculture (Goulson et al., 2015). To counteract declines in agricultural landscapes, management measures to conserve these semi-natural habitats (SNH) would ensure essential floral and nesting resources for wild bees throughout the season. ...
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Semi‐natural habitats provide important resources for wild bees in agricultural landscapes. Landscapes under management are dynamic and floral resources fluctuate in space and time. Thus, promoting different semi‐natural habitat types within landscapes could be key to support diverse bee meta‐communities throughout the season. Here, we integrate analyses of α‐diversity (species richness) and β‐diversity and species‐habitat networks to examine the relative contribution of all major semi‐natural habitats to wild bee meta‐communities in agricultural landscapes. We sampled extensively and conventionally managed meadows, flower strips, hedgerows and forest edges in spring, early and late summer in 25 landscapes in Switzerland. Habitat types varied in their importance for wild bees throughout the season: While extensively managed meadows supported more rare species, habitat specialists and bee species overall than the other habitat types, flower strips were most important later in the season. Each of the five investigated habitat types harboured relatively unique sets of species with different habitats generally acting as distinct modules in the overall bee‐habitat network. Not only flower richness in a habitat per se, but also flower‐habitat network properties (habitat strength and functional complementarity) were good predictors of wild bee richness. In addition to local floral richness, landscape composition and configuration interactively influenced β‐diversity patterns across habitats. Synthesis and applications. Our study highlights the value of pollinator‐habitat network analysis to inform pollinator conservation management at the landscape scale, especially when combined with information on floral resources and flower‐habitat networks. Maintaining different types of semi‐natural habitats offers diverse and complementary resources throughout the season, which are crucial to sustain diverse wild bee meta‐communities in agricultural landscapes. Particularly meadow extensification schemes can play a key role in safeguarding rare and specialist species in these landscapes. While locally a high flower richness promoted bee abundance and richness in general, our results indicate that increasing connectivity between habitat patches in landscapes dominated by arable crops appears to improve species exchange between local bee communities of different habitats, thereby possibly increasing their resilience to disturbances.
... The recent increase in research on competition between managed/introduced and native bees has likely been driven by concerns for native bee declines and their importance to agricultural production ( Dicks et al., 2021 ;Potts et al., 2016Potts et al., , 2010. While similar concerns may be involved in the recent increases in research on pathogen transmission between bee species, it is also possible that Varroa-related spread of viruses and colony collapse disorder among honey bees have contributed ( Fürst et al., 2014 ;McMahon et al., 2015 ;Pirk et al., 2017 ). ...
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Worldwide, the use of managed bees for crop pollination and honey production has increased dramatically. Concerns about the pressures of these increases on native ecosystems has resulted in a recent expansion in the literature on this subject. To collate and update current knowledge, we performed a systematic review of the literature on the effects of managed and introduced bees on native ecosystems, focusing on the effects on wild bees. To enable comparison over time, we used the same search terms and focused on the same impacts as earlier reviews. This review covers: (a) interference and resource competition between introduced or managed bees and native bees; (b) effects of introduced or managed bees on pollination of native plants and weeds; and (c) transmission and infectivity of pathogens; and classifies effects into positive, negative, or neutral. Compared to a 2017 review, we found that the number of papers on this issue has increased by 47%. The highest increase was seen in papers on pathogen spill-over, but in the last five years considerable additional information about competition between managed and wild bees has also become available. Records of negative effects have increased from 53% of papers reporting negative effects in 2017 to 66% at present. The majority of these studies investigated effects on visitation and foraging behaviour. While only a few studies experimentally assessed impacts on wild bee reproductive output, 78% of these demonstrated negative effects. Plant composition and pollination was negatively affected in 7% of studies, and 79% of studies on pathogens reported potential negative effects of managed or introduced bees on wild bees. Taken together, the evidence increasingly suggests that managed and introduced bees negatively affect wild bees, and this knowledge should inform actions to prevent further harm to native ecosystems.
... More than 80% of described eukaryotic species on Earth are invertebrates (2), with the majority being insects (3). They affect many ecosystem functions and services (4) and provide extensive benefits to human societies (5,6). Knowledge on the taxonomic diversity and functional roles of insects remains nonetheless very limited, with estimates suggesting that around 80% of species remain to be described (3). ...
Article
Knowledge on the distribution and abundance of organisms is fundamental to understanding their roles within ecosystems and their ecological importance for other taxa. Such knowledge is currently lacking for insects, which have long been regarded as the “little things that run the world”. Even for ubiquitous insects, such as ants, which are of tremendous ecological significance, there is currently neither a reliable estimate of their total number on Earth nor of their abundance in particular biomes or habitats. We compile data on ground-dwelling and arboreal ants to obtain an empirical estimate of global ant abundance. Our analysis is based on 489 studies, spanning all continents, major biomes, and habitats. We conservatively estimate total abundance of ground-dwelling ants at over 3 × 10 ¹⁵ and estimate the number of all ants on Earth to be almost 20 × 10 ¹⁵ individuals. The latter corresponds to a biomass of ∼12 megatons of dry carbon. This exceeds the combined biomass of wild birds and mammals and is equivalent to ∼20% of human biomass. Abundances of ground-dwelling ants are strongly concentrated in tropical and subtropical regions but vary substantially across habitats. The density of leaf-litter ants is highest in forests, while the numbers of actively ground-foraging ants are highest in arid regions. This study highlights the central role ants play in terrestrial ecosystems but also major ecological and geographic gaps in our current knowledge. Our results provide a crucial baseline for exploring environmental drivers of ant-abundance patterns and for tracking the responses of insects to environmental change.
... Although pollinators play an integral role in human well-being, their continued global decline reflects the need to provide and evaluate general pollinator knowledge to promote their conservation Potts et al., 2016;Schönfelder & Bogner, 2018;Westerhold et al., 2018). Many studies and organizations have implemented interventions, such as citizen science projects (BumbleBeeWatch.org; ...
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Background Although pollinators play an integral role in human well-being, their continued global decline reflects the need to provide and evaluate general pollinator knowledge to promote their conservation. Enhancing learners’ understanding of the complexity inherent in pollination systems within the science classroom may help them make more informed decisions regarding pollinator conservation actions. By measuring conceptual understanding of pollination systems, science educators can identify learners’ knowledge needs and inform their teaching in science classrooms. Based on previously developed theoretical frameworks describing pollination systems knowledge, we created and evaluated a new instrument to assess pollination systems and conservation actions knowledge. The Pollination Systems Knowledge Assessment (PSKA) is a multiple-true–false instrument containing 18 question stems and 70 accompanying T–F items encompassing three organizational components of pollination knowledge regarding (1) plant structures, (2) pollinator structures and behaviors, and (3) pollination systems function and pollinator conservation. Results We refined the PSKA based on expert discussions, think-aloud interviews, and pilot testing before and after presenting a wild pollinator conservation unit within a postsecondary science literacy course. The PSKA elucidated learners’ misconceptions and revealed discriminating items from the three organizational components of pollination systems knowledge. Conclusions The PSKA may aid educators in exploring learners’ conceptual understanding, identifying areas of misconceptions, and refining educational programming aimed at improving learners’ pollination systems knowledge.
... Stingless bees (Hymenoptera: Apidae: Meliponini) are the group of eusocial bees with ecological, economic, and cultural importance Heard, 1999). They are widely distributed in the tropical and subtropical regions of the world and are considered the primary pollinators of both native and cultivated plants (Layek et al., 2022;Michener, 2007;Potts et al., 2016). They primarily nest inside the forest cover (Brown et al., 2016), but they have been relevant in human culture since ancient times as they provide resources for local ethnic community (Layek et al., 2021(Layek et al., , 2022Reyes-Gonzalez et al., 2014). ...
Article
Literature records indicate that ethnic people from different areas of the Western Ghats practice meliponiculture. However, ethnobiological knowledge and beekeeping practices remain poorly documented. We conducted ethnographic surveys in 6 districts of Karnataka and recorded traditional uses and current practices of meliponiculture from the region. We also offer a quantitative analysis to explore the relative cultural importance of stingless bees among these ethnic groups. Bees and bee products are primarily used for food, medicines, crafts, and cultural beliefs. Bamboo poles, clay pots, and traditional log hives are used to keep stingless bees in the front and backyards. Among the five ethnic communities, the Brahmins are practicing the most sustainable meliponiculture using some innovative hives built from locally available materials. Moreover, they explore safe honey extraction techniques for minimal damage to the colonies. The Kunbis tribe, who lives primarily inside the Kali Tiger Forest Reserve, utilizes the bees and bee products maximally compared to the other four ethnic communities. However, the Kunbis people largely exploit bees through destructive extractive practices and pose threats to the colony’s survival. Herein, we report traditional knowledge and current status of meliponiculture practices among five ethnic communities (the Brahmins, the Gowdas, the Naiks, the Marathas and the Kunbis) of the Western Ghats region in the state of Karnataka. We also gather biological information such as nesting substrates, nesting characteristics, and behavior of bees from the area, which will be crucial for the local conservation and sustainable meliponiculture in the Western Ghats region of India.
... Bees are integral to many ecosystems due to their roles as pollinators (Ollerton et al. 2011;Garibaldi et al. 2013;Aizen and Feinsinger 2003;Ollerton 2021); however, there are concerns about their conservation (Potts et al. 2016). Pollinators appear to be particularly susceptible to habitat loss (Taki and Kevan 2007), suggesting that anthropogenic processes such as urban development (Güneralp et al. 2013) can lead to a reduction in flower-visitor network integrity (Aizen and Feinsinger 2003). ...
Article
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Bipartite networks of flowering plants and their visitors (potential pollinators) are increasingly being used in studies of the structure and function of these ecological interactions. Whilst they hold much promise in understanding the ecology of plant–pollinator networks and how this may be altered by environmental perturbations, like land-use change and invasive species, there is no consensus about the scale at which such networks should be constructed and analysed. Ecologists, however, have emphasised that many processes are scale dependent. Here, we compare network- and species-level properties of ecological networks analysed at the level of a site, pooling across sites within a given habitat for each month of surveys, and pooling across all sites and months to create a single network per habitat type. We additionally considered how these three scales of resolution influenced conclusions regarding differences between networks according to two contrasting habitat types (urban bushland remnants and residential gardens) and the influence of honey bee abundance on network properties. We found that most network properties varied markedly depending on the scale of analysis, as did the significance, or lack thereof, of habitat type and honey bee abundance on network properties. We caution against pooling across sites and months as this can create unrealistic links, invalidating conclusions on network structure. In conclusion, consideration of scale of analysis is also important when conducting and interpreting plant–pollinator networks.
... Among the primary crop pollinators, bees have a prominent role. Of more than 20,000 described species worldwide, a small fraction of them is managed for crop pollination, such as the Western honey bee, some bumble bees, and stingless bee species [21,22]. Given the pivotal role of these social bees in agroecosystems [23] and the increasing use of EF for pest control, risk assessment of EF's impact on bees is crucial for ensuring more sustainable agricultural practices. ...
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The use of fungal-based biopesticides to reduce pest damage and protect crop quality is often considered a low-risk control strategy. Nevertheless, risk assessment of mycopesticides is still needed since pests and beneficial insects, such as pollinators, co-exist in the same agroecosystem where mass use of this strategy occurs. In this context, we evaluated the effect of five concentrations of three commercial entomopathogenic fungi, Beauveria bassiana, Metarhizium anisopliae, and Cordyceps fumosorosea, by direct contact and ingestion, on the tropical stingless bees Scaptotrigona depilis and Tetragonisca angustula, temperate bee species, the honey bee Apis mellifera, and the bumble bee Bombus terrestris, at the individual level. Furthermore, we studied the potential of two infection routes, either by direct contact or ingestion. In general, all three fungi caused considerable mortalities in the four bee species, which differed in their response to the different fungal species. Scaptotrigona depilis and B. terrestris were more susceptible to B. bassiana than the other fungi when exposed topically, and B. terrestris and A. mellifera were more susceptible to M. anisopliae when exposed orally. Interestingly, increased positive concentration responses were not observed for all fungal species and application methods. For example, B. terrestris mortalities were similar at the lowest and highest fungal concentrations for both exposure methods. This study demonstrates that under laboratory conditions, the three fungal species can potentially reduce the survival of social bees at the individual level. However, further colony and field studies are needed to elucidate the susceptibility of these fungi towards social bees to fully assess the ecological risks.
... Stingless bees (Hymenoptera: Apidae: Meliponini) are the group of eusocial bees with ecological, economic, and cultural importance Heard, 1999). They are widely distributed in the tropical and subtropical regions of the world and are considered the primary pollinators of both native and cultivated plants (Layek et al., 2022;Michener, 2007;Potts et al., 2016). They primarily nest inside the forest cover (Brown et al., 2016), but they have been relevant in human culture since ancient times as they provide resources for local ethnic community (Layek et al., 2021(Layek et al., , 2022Reyes-Gonzalez et al., 2014). ...
... Wild and managed bees are important providers of pollination services and benefit the production of various insect-pollinated crops [1,2]. Recent bee declines are thought to be driven by several interacting factors, many related to agricultural intensification [3]. The use of insecticides, which is an integral part of contemporary agriculture, is expected to be one of them [4]. ...
Article
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Neonicotinoid insecticides applied to flowering crops can have negative impacts on bees, with implications for crop pollination. To assess if exposure to the neonicotinoid clothianidin via a treated crop (rapeseed) affected bee behaviour, pollination performance (to strawberry), and bee reproduction, we provided each of 12 outdoor cages with rapeseed (autumn-sown plants complemented with a few spring-sown plants to extend the flowering period) grown from either clothianidin-treated or untreated (control) seeds, together with strawberry plants and a small population of red mason bees ( Osmia bicornis ). We expected clothianidin to reduce bee foraging activity, resulting in impaired strawberry pollination and bee reproduction. During the early stage of the experiment, we observed no difference between treatments in the length of entire foraging trips, or the combined number of rapeseed and strawberry flowers that the bees visited during these trips. During the later stage of the experiment, we instead determined the time a female took to visit 10 rapeseed flowers, as a proxy for foraging performance. We found that they were 10% slower in clothianidin cages. Strawberries weighed less in clothianidin cages, suggesting reduced pollination performance, but we were unable to relate this to reduced foraging activity, because the strawberry flowers received equally many visits in the two treatments. Clothianidin-exposed females sealed their nests less often, but offspring number, sex ratio and weight were similar between treatments. Observed effects on bee behaviour appeared by the end of the experiment, possibly because of accumulated effects of exposure, reduced bee longevity, or higher sensitivity of the protocols we used during the later phase of the experiment. Although the lack of a mechanistic explanation calls for interpreting the results with cautiousness, the lower strawberry weight in clothianidin cages highlights the importance of understanding complex effects of plant protection products, which could have wider consequences than those on directly exposed organisms.
... Thus, it should be our priority to investigate the mechanisms shaping species structure in various types of urban habitats [8]. This is particularly relevant with reference to bees (as the most common pollinators), which perform significant ecosystem services in both natural and anthropogenically transformed habitats [3,9]. ...
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... Apis mellifera is an important source of compounds with a variety of biological properties, especially propolis and melittin. The last is the main compound present in apitoxin (about 50% of the dry weight) that has antibacterial activity [7,[13][14][15]. ...
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... Documented global declines of insect pollinators (e.g. Zattara and Aizen 2021) have led to concerns about the consequences for ecosystem functioning and pollination services to wild and crop plant species (Potts et al. 2016). The main drivers behind global pollinator losses are thought to include agricultural intensification, the loss of natural and semi-natural habitats that reduces flower and nesting resources, and an increased use of pesticides with both direct and indirect negative effects on pollinators (Pott et al. 2010, Goulson et al. 2015. ...
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... An urban nesting device, also called "bee hotel"Fig. 7.5 Urban beekeeping in Turin F. Larcher et al.2010;Nieto et al. 2014;Potts et al. 2016; Roy et al. 2016; Underwood et al. 2017;Bonelli et al. 2018;.A variety of sampling methods is available for arthropod census, even if some methods can be biased, and their performance varies widely(Rega et al. 2018). Direct counts of individuals, sweep-netting and trapping methods (pan traps, malaise traps and sticky traps) are commonly used (McCravy 2018). ...
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Urban prairie gardens/plots are gaining popularity for providing similar ecological services as remnant and restored prairies, which are predominantly found in rural areas. However, it is not known to what extent small urban prairies can sustain the plant-pollinator interactions that are vital to both the insects and the plants. The goal of our research was to examine plant/pollinator interactions in three urban prairies in southwest Missouri and compare them to rural managed/restored prairies using a visit-based approach. Urban prairies were all in Springfield, Mo. and shared similar habitat matrices (within an area of 8 km2); rural prairies were located within 68 km of urban prairies, shared similar habitat matrices to each other, and shared soil edaphic characteristics with an urban prairie. From May through August 2018 in all six prairies, we observed the five most abundant forbs in bloom, the number of pollinator visits by bees, butterflies/moths, wasps, beetles, and flies; and, pollinator fidelity from dawn to dusk. The areas observed within a prairie, hereafter plot(s), were determined randomly by where at least two plants of the same species, out of the five most abundant forbs, were located. Using these criteria of observations on the five most abundant species across six prairies and four months, a total of 66 forb species were identified, with 58 of the species native to tallgrass prairies. However, only eight of the 58 native forb species were shared across urban and rural prairies. Jaccard similarity indices indicate lower similarity of the five abundant forbs within urban plots (9%) when compared to rural plots (24%), and low similarity between urban and rural plots (9%). Insect visitation varied by prairie type (rural/urban), month, and insect group; however, urban plots received 61% of the total visits compared to 39% in rural plots. Bees accounted for 5913 visits out of 10,113 visits recorded; high bee visits were similar in urban and rural plots. Insect fidelity was over 97% and did not significantly differ between rural and urban prairies. Therefore, the lack of similarity among and across urban and rural prairies in dominant species did not affect insect visitation rates or fidelity in our study. Our results suggest that establishment and management of urban prairie gardens and plots of various size may sustain the same or greater levels of pollinator services as rural prairies.
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The decline of pollinators is a widespread problem in today's agriculture, affecting the yield of many crops. Improved pollination management is therefore essential, and honey bee colonies are often used to improve pollination levels. In this work, we applied a spatially explicit agent-based model for the simulation of crop pollination by honey bees under different management scenarios and landscape configurations. The model includes 1) a representation of honey bee social dynamics; 2) an explicit representation of resource dynamics; 3) a probabilistic approach to the foraging site search process; and 4) a mechanism of competition for limited resources. We selected 60 sample units from the rural landscape of the Chilean region with the largest apple-growing area and evaluated the effectiveness of different pollination strategies in terms of number of visits and number of pollinated flowers per hectare of apple crops. Finally, we analyzed how the effects of these practices depended on the structure of adjacent landscapes. Higher colony density per hectare in the focal crop increased the number of honey bee visits to apple inflorescences; however, the effects were nonlinear for rates of pollinated flowers, suggesting that there is an optimum beyond which a greater number of honey bees does not signify increased levels of crop pollination. Furthermore, high relative proportions of mass flowering crops and natural habitats in the landscape led to a decrease in honey bee densities in apple fields in landscapes with high relative cover of apple orchards (dilution effect). Our results indicate that for optimal crop pollination, strategies for management of pollinator species should consider the modulating effects of the surrounding landscape on pollination effectiveness. This model could thus be a useful tool to help farmers, beekeepers, and policy-makers plan the provision of pollination services, while also promoting the biodiversity and sustainability of agroecosystems.
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In tropical environments, and especially tropical rainforests, a major part of pollination services is provided by diverse insect lineages. Unbeknownst to most, beetles, and more specifically hyperdiverse weevils (Coleoptera: Curculionoidea), play a substantial role there as specialist mutualist brood pollinators. The latter contrasts with a common view where they are only regarded as plant antagonists. This study aims at giving a comprehensive understanding of what is known on plant-weevil mutualist interactions, through a review of the known reciprocal behavioral, morphological and physiological adaptations found in plant-weevil systems, and the identification of potential knowledge gaps to fill. To date, plant-weevil associations have been described or indicated in no less than 600 instances. Representatives of all major plant lineages (gymnosperms, angiosperms monocots and dicots) are involved in these interactions, which have emerged independently at least a dozen times. Strikingly, these mutualistic interactions have led to a range of multiple convergent adaptations in plants and weevils. Plants engaged in weevil-mediated pollination are generally of typical cantharophilous type and they also show specific structures to host the larval stages of their specialist pollinators. Another characteristic feature is that flowers often perform thermogenesis and exhibit a range of strategies to separate sexual phases, either physically or chronologically. Conversely, lineages of brood-site weevil pollinators present numerous behavioral and physiological adaptations, and often form multispecific assemblages of closely related species on a single host; recent studies also revealed that they generally display a high degree of phylogenetic niche conservatism. This pollination mutualism occurs in all tropical regions, and the contrasts between the known and expected diversity of these systems suggests that a wide range of interactions remain to be described globally. Our early estimates of the species richness of the corresponding weevil clades and the marked pattern of phylogenetic niche conservatism of host use further suggest that weevil-based pollination far exceeds the diversity of other brood-site mutualistic systems, which are generally restricted to one or a few groups of plants. As such, weevil pollinators constitute a relevant model to explore the emergence and evolution of specialized brood-site pollination systems in the tropics.
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Bumblebees (Apidae: Bombus spp.) are a major group of wild and domesticated bees that provide crucial ecosystem services through wildflower and crop pollination. However, most of bee populations, including bumblebees, are declining worldwide, partly because of parasite spill-over and spill-back between bumblebee commercial colonies and wild populations. Breeders have to cope with invasions by a vast array of bumblebees’ parasites, and techniques need to be developed to prevent such invasions to support breeders and wild bee populations. Our 10-year study is based on 327 nests of seven bumblebee species (B. humilis, B. hypnorum, B. lapidarius, B. lucorum, B. pascuorum, B. sylvarum, B. terrestris) reared in outdoor boxes. Some boxes were equipped with parasite-preventing techniques, namely (i) an airlock (n = 2) or (ii) an additional chamber with natural fragrances (n = 74). We recorded the invasion of the nests by the wax moth Aphomia sociella, the eulophid Melittobia acasta and the cuckoo bumblebees Bombus subgenus Psithyrus spp. Overall, 8.26 %, 1.53 % and 3.67 % of the colonies were invaded by A. sociella, M. acasta and Psithyrus spp., respectively, without coinfection. Neither the airlock nor the additional chamber with natural fragrances prevented A. sociella infestation. Despite that no nest equipped with an airlock or an additional chamber with natural fragrances was invaded by M. acasta or Psithyrus spp., we lacked replicates to properly demonstrate the efficiency of these techniques. Nest inspection remains a time-consuming but powerful technique to reduce artificial nest spoilage by parasites, yet it is inefficient against tiny invaders (< 1 mm) that are left unnoticed. We therefore encourage further studies to actively seek for parasite-preventing techniques to reduce artificial nest spoilage and to mitigate spill-over towards wild populations.
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Alpine plant‐pollinator communities play an important role in the functioning of alpine ecosystems, which are highly threatened by climate change. However, we still have a poor understanding of how environmental factors and spatio‐temporal variability shape these communities. Here, we investigate what drives structure and beta diversity in a plant‐pollinator metacommunity from the Australian alpine region using two approaches: pollen DNA metabarcoding (MB) and observations. Individual pollinators often carry pollen from multiple plant species, therefore we expected MB to reveal a more diverse and complex network structure. We used two gene regions (ITS2 and trnL) to identify plant species present in the pollen loads of 154 insect pollinator specimens from three alpine habitats and construct MB networks, and compared them to networks based on observations alone. We compared species and interaction turnover across space for both types of networks, and evaluated their differences for plant phylogenetic diversity and beta diversity. We found significant structural differences between the two types of networks; notably, MB networks were much less specialised but more diverse than observation networks, with MB detecting many cryptic plant species. Both approaches revealed that alpine pollination networks are very generalised, however, we estimated a high spatial turnover of plant species (0.79) and interaction rewiring (0.6) as well as high plant phylogenetic diversity (0.68) driven by habitat differences based on the larger diversity of plant species and species interactions detected with MB. Overall, our findings show that habitat and microclimatic heterogeneity drives diversity and fine‐scale spatial turnover of alpine plant‐pollinator networks.
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The productivity of approximately 75% of crops worldwide depends to some extent on insect pollination. However, while global agriculture is becoming more dependent on pollinators, wild populations of pollinators are declining. For this reason, hives of Apis mellifera (honeybees), the most widely used pollinator, are commonly placed in the fields; in recent years, alternative managed pollinators (AMPs) such as Bombus spp. or Osmia spp. have also been used. Thus, for evidence-based pollination management, we need to know whether the pollination service provided by AMPs can replace, complement or synergistically interact with that provided by honeybees. We asked: Does crop productivity differ between fields with honeybees and those with AMPs? Does productivity increase by incorporating AMPs in addition to managed honeybees? Do the effects of managed honeybees and AMPs interact? We performed a meta-analysis based on 28 studies on 20 crops. We estimated effect sizes (ln(R)) for crop productivity (fruit/seed set, fruit/seed quality and yield) from 73 comparisons between honeybees and an AMP, and 21 comparisons between honeybees alone and honeybees plus an AMP. Overall, we found no evidence of difference in crop productivity between honeybees and AMPs when managed separately. However, the productivity of crops pollinated by honeybees together with AMPs was 22% ± 6 (SE) higher than that of crops pollinated only by honeybees. Moreover, we found a weak evidence of a positive effect of beehive density on crop productivity when an AMP was added, suggesting a synergistic interaction between honeybees and AMPs. We conclude that, on average, honeybee performance is similar to that of AMPs, and that increasing the number of managed pollinator species can improve crop productivity in the short-term, particularly in systems with impoverished pollinator faunas. More generally, this review confirms the positive effect of pollinator diversity on pollination service, suggesting this can be partly recreated using a suite of managed pollinators.
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There is increasing evidence that farmers in many areas are achieving below maximum yields due to insufficient pollination. Practical and effective approaches are needed to maintain wild pollinator populations within agroecosystems so they can deliver critical pollination services which underpin crop production. We established nesting and wildflower habitat interventions in 24 UK apple orchards and measured effects on flower‐visiting insects and the pollination they provide, exploring how this was affected by landscape context. We quantified the extent of pollination deficits and assessed whether the management of wild pollinators can reduce deficits and deliver improved outcomes for growers over three years. Wildflower interventions increased solitary bee numbers visiting apple flowers by over 20% but there was no effect of nesting interventions. Other pollinator groups were influenced by both local and landscape‐scale factors, with bumblebees and hoverflies responding to the relative proportion of semi‐natural habitat at larger spatial scales (1000 m) while honeybees and other flies responded at 500 m or less. By improving fruit number and quality, pollinators contributed more than £15k per hectare. However, deficits (where maximum potential was not being reached due to a lack of pollination) were recorded and the extent of these varied across orchards, and from year to year, with a 22% deficit in the worst (~£11k/ha) compared to less than 3% (~£1k/ha) in the best year. Although no direct effect of our habitat interventions on deficits in gross output was observed, initial fruit set and seed set deficits were reduced by abundant bumblebees, and orchards with a greater abundance of solitary bees saw lower deficits in fruit size. The abundance of pollinators in apple orchards is influenced by different local and landscape factors which interact and vary between years. Consequently, pollination, and the extent of economic output deficits, also vary between orchards and years. We highlight how approaches, including establishing wildflower areas and optimising the ratio of cropped and non‐cropped habitats can increase the abundance of key apple pollinators and improve outcomes for growers. This article is protected by copyright. All rights reserved.
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Although most of the wild bee species are ground-nesting, little is known about their nesting requirements and the conservation measures to promote ground-nesting bees. Calcareous grasslands are one of the most species-rich habitats in Central Europe and therefore essential for protecting bee diversity. The management practices of calcareous grasslands are so far often focused on plant populations, but in order to support declining insect populations, additional measures have to be considered for nature conservation. As wild bees depend on the availability of nesting sites, we studied the effects of locally increased bare ground availability on ground-nesting bees on four large and four small calcareous grasslands in Central Germany. Vegetation cover of 24 experimental plots (1 m²) was removed. The number of bee nests as well as the presence of bees on these plots (here: nesting activity) were compared to 24 control plots during six sampling runs. Results showed that the number of bee nests on experimental plots was fourteen times higher compared to control plots, positively related to the surrounding flower cover and higher on steeper slopes, independent of grassland area. Moreover, the observed nesting activity on experimental plots was 2.5 times higher compared to the control and positively related to the currently prevailing soil surface temperature. Bee abundance quantified during transect walks increased on grasslands with a generally higher bare ground availability and a higher flower cover. In conclusion, our study emphasizes the need to consider the availability of nesting resources to promote the vast majority of wild bees, which are ground-nesting. They benefited from bare ground availability as well as adjacent floral resources, and experimental removal of the vegetation cover appeared to be a major, so far underestimated conservation practice.
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The most used pesticides have neurotoxic action on the neurotransmitter system of target and non-targeted insects, such as honeybees. However, honeybees have foremost importance worldwide, which has encouraged the development of tools to evaluate the action of specific pesticide molecules on their nervous system, providing accurate data on damage to their brain. In this sense, our study aimed to optimize in vitro honeybee nervous tissue culture to assess pesticide risks. To this end, six forager honeybee brains were dissected and transferred to different combinations of Leibovitz-15 (L-15) culture medium supplemented with Fetal Bovine Serum (FBS), Hank's Balanced Salt Solution (HBSS), and Insect Medium Supplement (IMS). Nervous tissues were collected after different incubation times (1, 6, 12, and 24 h) for morphology and Kenyon cell analyses. Our results showed that L-15 medium supplemented with HBSS and with HBSS plus FBS were the best media for culturing honey nervous tissue, as they resulted in less tissue spacing and cell disarrangement. Therefore, they may be assessed in future ecotoxicological tests.
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Overall, 9.2% of bees are considered threatened in all of Europe, while at the EU 27 level, 9.1% are threatened with extinction. A further 5.2% and 5.4% of bees are considered Near Threatened in Europe and the EU 27, respectively (101 species at both levels). However, for 1,101 species (56.7%) in Europe and 1,048 species (55.6%) at the EU 27, there was not enough scientific information to evaluate their risk of extinction and thus, they were classified as Data Deficient. When more data become available, many of these might prove to be threatened as well. Looking at the population trends of European bee species, 7.7% (150 species) of the species have declining populations, 12.6% (244 species) are more or less stable and 0.7% (13 species) are increasing. The population trends for 1,535 species (79%) remains unknown. A high proportion of threatened bee species are endemic to either Europe (20.4%, 400 species) or the EU 27 (14.6%, 277 species), highlighting the responsibility that European countries have to protect the global populations of these species. Almost 30% of all the species threatened (Critically Endangered, Endangered, or Vulnerable) at the European level are endemic to Europe (e.g., found nowhere else in the world). The species richness of bees increases from north to south in Europe, with the highest species richness being found in the Mediterranean climate zone. In particular, the Iberian, Italian and Balkan peninsulas are important areas of species richness. Regarding the distribution of endemic species, southern Europe shows the highest concentration of endemism. The largest numbers of threatened species are located in south-central Europe and the pattern of distribution of Data Deficient species is primarily concentrated in the Mediterranean region. The main threat to European bees is habitat loss as a result of agriculture intensification (e.g., changes in agricultural practices including the use of pesticides and fertilisers), urban development, increased frequency of fires and climate change.
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Wild bee declines have been ascribed in part to neonicotinoid insecticides. While short-term laboratory studies on commercially bred species (principally honeybees and bumblebees) have identified sub-lethal effects, there is no strong evidence linking these insecticides to losses of the majority of wild bee species. We relate 18 years of UK national wild bee distribution data for 62 species to amounts of neonicotinoid use in oilseed rape. Using a multi-species dynamic Bayesian occupancy analysis, we find evidence of increased population extinction rates in response to neonicotinoid seed treatment use on oilseed rape. Species foraging on oilseed rape benefit from the cover of this crop, but were on average three times more negatively affected by exposure to neonicotinoids than non-crop foragers. Our results suggest that sub-lethal effects of neonicotinoids could scale up to cause losses of bee biodiversity. Restrictions on neonicotinoid use may reduce population declines.
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Deformed wing virus (DWV) and its vector, the mite Varroa destructor, are a major threat to the world’s honeybees. Although the impact of Varroa on colony-level DWV epidemiology is evident, we have little understanding of wider DWV epidemiology and the role that Varroa has played in its global spread. A phylogeographic analysis shows that DWV is globally distributed in honeybees, having recently spread from a common source, the European honeybee Apis mellifera. DWV exhibits epidemic growth and transmission that is predominantly mediated by European and North American honeybee populations and driven by trade and movement of honeybee colonies. DWV is now an important reemerging pathogen of honeybees, which are undergoing a worldwide manmade epidemic fueled by the direct transmission route that the Varroa mite provides.
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A summary is provided of recent advances in the natural science evidence base concerning the effects of neonicotinoid insecticides on insect pollinators in a format (a ‘restatement') intended to be accessible to informed but not expert policymakers and stakeholders. Important new studies have been published since our recent review of this field (Godfray et al. 2014 Proc. R. Soc. B 281, 20140558. (doi:10.1098/rspb.2014.0558)) and the subject continues to be an area of very active research and high policy relevance.
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Anthropogenic declines of animal pollinators and the associated effects on human nutrition are of growing concern. We quantified the nutritional and health outcomes associated with decreased intake of pollinator-dependent foods for populations around the world. We assembled a database of supplies of 224 types of food in 156 countries. We quantified nutrient composition and pollinator dependence of foods to estimate the size of possible reductions in micronutrient and food intakes for different national populations, while keeping calorie intake constant with replacement by staple foods. We estimated pollinator-decline-dependent changes in micronutrient-deficient populations using population-weighted estimated average requirements and the cutpoint method. We estimated disease burdens of non-communicable, communicable, and malnutrition-related diseases with the Global Burden of Disease 2010 comparative risk assessment framework. Assuming complete removal of pollinators, 71 million (95% uncertainty interval 41-262) people in low-income countries could become newly deficient in vitamin A, and an additional 2·2 billion (1·2-2·5) already consuming below the average requirement would have further declines in vitamin A supplies. Corresponding estimates for folate were 173 million (134-225) and 1·23 billion (1·12-1·33). A 100% decline in pollinator services could reduce global fruit supplies by 22·9% (19·5-26·1), vegetables by 16·3% (15·1-17·7), and nuts and seeds by 22·1% (17·7-26·4), with significant heterogeneity by country. In sum, these dietary changes could increase global deaths yearly from non-communicable and malnutrition-related diseases by 1·42 million (1·38-1·48) and disability-adjusted life-years (DALYs) by 27·0 million (25·8-29·1), an increase of 2·7% for deaths and 1·1% for DALYs. A 50% loss of pollination services would be associated with 700 000 additional annual deaths and 13·2 million DALYs. Declines in animal pollinators could cause significant global health burdens from both non-communicable diseases and micronutrient deficiencies. Winslow Foundation, Bill & Melinda Gates Foundation. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Wild bee communities provide underappreciated but critical agricultural pollination services. Given predicted global shortages in pollination services, managing agroecosystems to support thriving wild bee communities is, therefore, central to ensuring sustainable food production. Benefits of natural (including semi-natural) habitat for wild bee abundance and diversity on farms are well documented. By contrast, few studies have examined toxicity of pesticides on wild bees, let alone effects of farm-level pesticide exposure on entire bee communities. Whether beneficial natural areas could mediate effects of harmful pesticides on wild bees is also unknown. Here, we assess the effect of conventional pesticide use on the wild bee community visiting apple (Malus domestica) within a gradient of percentage natural area in the landscape. Wild bee community abundance and species richness decreased linearly with increasing pesticide use in orchards one year after application; however, pesticide effects on wild bees were buffered by increasing proportion of natural habitat in the surrounding landscape. A significant contribution of fungicides to observed pesticide effects suggests deleterious properties of a class of pesticides that was, until recently, considered benign to bees. Our results demonstrate extended benefits of natural areas for wild pollinators and highlight the importance of considering the landscape context when weighing up the costs of pest management on crop pollination services. © 2015 The Author(s) Published by the Royal Society. All rights reserved.
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Beekeeping with stingless bees (meliponiculture) in Mexico is an ancient tradition which today is in the process of disappearing as a consequence of changes in cultural, economic and ecological factors. This article reviews the historical background of meliponiculture as well as its potential uses in Mexico. Meliponiculture could be revived, providing an important source of income for peasant farmers in areas where the use of Africanized honey bees is restricted, provided technical and marketing problems are solved. We outline the current weaknesses and the changes needed to exploit these bees to their full potential for honey and wax production and use in other activities such as pollination.
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Change in land cover is thought to be one of the key drivers of pollinator declines, and yet there is a dearth of studies exploring the relationships between historical changes in land cover and shifts in pollinator communities. Here, we explore, for the first time, land cover changes in England over more than 80 years, and relate them to concurrent shifts in bee and wasp species richness and community composition. Using historical data from 14 sites across four counties, we quantify the key land cover changes within and around these sites and estimate the changes in richness and composition of pollinators. Land cover changes within sites, as well as changes within a 1 km radius outside the sites, have significant effects on richness and composition of bee and wasp species, with changes in edge habitats between major land classes also having a key influence. Our results highlight not just the land cover changes that may be detrimental to pollinator communities, but also provide an insight into how increases in habitat diversity may benefit species diversity, and could thus help inform policy and practice for future land management.
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Agriculture today places great strains on biodiversity, soils, water and the atmosphere, and these strains will be exacerbated if current trends in population growth, meat and energy consumption, and food waste continue. Thus, farming systems that are both highly productive and minimize environmental harms are critically needed. How organic agriculture may contribute to world food production has been subject to vigorous debate over the past decade. Here, we revisit this topic comparing organic and conventional yields with a new meta-dataset three times larger than previously used (115 studies containing more than 1000 observations) and a new hierarchical analytical framework that can better account for the heterogeneity and structure in the data. We find organic yields are only 19.2% (±3.7%) lower than conventional yields, a smaller yield gap than previous estimates. More importantly, we find entirely different effects of crop types and management practices on the yield gap compared with previous studies. For example, we found no significant differences in yields for leguminous versus non-leguminous crops, perennials versus annuals or developed versus developing countries. Instead, we found the novel result that two agricultural diversification practices, multi-cropping and crop rotations, substantially reduce the yield gap (to 9 ± 4% and 8 ± 5%, respectively) when the methods were applied in only organic systems. These promising results, based on robust analysis of a larger meta-dataset, suggest that appropriate investment in agroecological research to improve organic management systems could greatly reduce or eliminate the yield gap for some crops or regions.
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We contend that biocultural approaches to conservation can achieve effective and just conservation outcomes while addressing erosion of both cultural and biological diversity. Here, we propose a set of guidelines for the adoption of biocultural approaches to conservation. First, we draw lessons from work on biocultural diversity and heritage, social-ecological systems theory, integrated conservation and development, co-management, and community-based conservation to define biocultural approaches to conservation. Second, we describe eight principles that characterize such approaches. Third, we discuss reasons for adopting biocultural approaches and challenges. If used well, biocultural approaches to conservation can be a powerful tool for reducing the global loss of both biological and cultural diversity.