Robert Paxton

• Professor
• Professor at Martin Luther University Halle-Wittenberg

Wild fauna and flora are facing variable and challenging environmental disturbances. One of the animal groups that is most impacted by this, concerns pollinators. Pollinators face multiple threats, but the spread of anthropogenic chemicals (i.e. pesticides) form a major potential driver of these threats. WildPosh is a multi-actor, transdisciplinary...

Organisms respond to infectious agents through diverse immune strategies, and may need to cater a specific response to distinct pathogen challenges, such as various strains of a virus, to maximize fitness. Deformed wing virus (DWV) is one of the most damaging viruses of honey bees (Apis mellifera) across the globe, with variant DWV-B currently expa...

Though many wild bee species nest in the ground, little is known of their potential exposure to pesticide residues in soil, or the effects of such exposure. Here, we introduce Anthophora plumipes as a potential model ground-nesting solitary bee species for controlled exposure to pesticides through soil. Bees from a naturally occurring population we...

Many invertebrates exhibit parental care, posited as a precursor to sociality. For example, solitary foundresses of the facultative social orchid bee Euglossa viridissima guard their brood for 6+ weeks before offspring emerge, when the nest may become social. Guarding comes at the fitness cost of foregoing the production of additional offspring. Ye...

Emerging infectious diseases pose a threat to pollinators. Virus transmission among pollinators via flowers may be reinforced by anthropogenic land-use change and concomitant alteration of plant–pollinator interactions. Here, we examine how species’ traits and roles in flower-visitation networks and landscape-scale factors drive key honeybee viruse...

Natural enemies impose a selective pressure on solitary insects that may favour the evolution of sociality. In the socially polymorphic orchid bee Euglossa viridissima , females found nests solitarily and provision a first batch of brood. After brood maturity, a nest can remain solitary (all offspring disperse) or become social, when one or more su...

Despite the major role that insect pollinators play in crop production, agricultural intensification drives them into decline. Various conservation measures have been developed to mitigate the negative effects of agriculture on insect pollinators. In a novel comparison of the efficacy of three conservation measures on honeybee colony growth, we mon...

Floral nectar sugar composition is assumed to reflect the nutritional demands and foraging behaviour of pollinators, but the relative contributions of evolutionary and abiotic factors to nectar sugar composition remain largely unknown across the angiosperms. We compiled a comprehensive dataset on nectar sugar composition for 414 insect-pollinated p...

Simple Summary Increasing honey bee resilience against the parasitic mite Varroa destructor, while respecting sustainability, may be achieved by enriching natural mite resistance traits in the breeding population. Some of these traits are linked to specific variants in the honey bee genome, which can be pinpointed and characterized with high-throug...

Aim Global change, especially landscape simplification, is a main driver of species loss that can alter ecological interaction networks, with potentially severe consequences to ecosystem functions. Therefore, understanding how landscape simplification affects the rate of loss of plant–pollinator interaction diversity (i.e., number of unique interac...

Wild bees are crucial pollinators of flowering plants and concerns are rising about their decline associated with pesticide use. Interspecific variation in wild bee response to pesticide exposure is expected to be related to variation in their morphology, physiology, and ecology, though there are still important knowledge gaps in its understanding....

The transmission of pathogens from reservoir to recipient host species, termed pathogen spillover, can profoundly impact plant, animal, and public health. However, why some pathogens lead to disease emergence in a novel species while others fail to establish or do not elicit disease is often poorly understood. There is strong evidence that deformed...

Bees are the most important group of insect pollinators, but their populations are declining. To gain a better understanding of wild bee responses to different stressors (e.g. land-use change) and conservation measures, regional and national monitoring schemes are currently being established in Germany, which is used here as a model region, and in...

Land use change is a major pressure on pollinator abundance, diversity and plant–pollinator interactions. Far less is known about how land‐use alters the structure of plant–pollinator networks and their robustness to plant–pollinator coextinctions. We analysed the structure of plant–pollinator networks sampled in 12 landscapes along an urbanisation...

Simple Summary Honey bees are very important for nature and food production. However, beekeepers’ work is continuously challenged by pests, pathogens, pesticides, and other impacts of the environment on their honey bee colonies, and, therefore, they would greatly benefit from up-to-date insights on the health condition of their bees. To disturb tho...

Invasive vectors can induce dramatic changes in disease epidemiology. While viral emergence following geographical range expansion of a vector is well known, the influence a vector can have at the level of the host's pathobiome is less well understood. Taking advantage of the formerly heterogeneous spatial distribution of the ectoparasitic mite Var...

Managed bees and other pollinators are exposed to a wide variety of stressors and these often act in combination. Historically, most risk assessments and research have focused on the impacts of individual stressors on honey bees. However, there is broad scientific consensus that there is a need for a systems-based risk assessment approach and a pos...

Introducción: Muchos estudios investigan cómo la diversidad de visitantes florales y los cambios en sus comunidades afectan la producción de café. Sin embargo, muy pocos estudios se han centrado en comprender cómo el comportamiento de los insectos que visitan las flores y la presencia de los virus de abejas melíferas afectan la producción de café,...

Policies and management practices for managed bees and other pollinators are increasingly reliant on the availability of high quality data in order to inform them. This in turn requires the widespread adoption of state-of-the-art standardised methods and approaches so that new data and knowledge are both robust and trustworthy. The PoshBee project...

Global warming may have a significant negative impact on insects in the tropics due to an increase in the frequency and intensity of heat waves. Heat waves may have a particularly harsh impact on the relatively sessile juvenile stages of holometabolous insects, such as larvae and pupae. The honey bee (Apis mellifera L.) is an important tropical hol...

Pathogen spillover is a major threat to biodiversity. Insect pollinators, important providers of the ecosystem service of pollination that are in global decline, are no exception to this threat, with mounting evidence of pathogen spillover from managed into wild bee species in temperate regions. The phenomenon is likely global in scope, though poor...

An essential prerequisite to safeguard pollinator species is characterisation of the multifaceted diversity of crop pollinators and identification of the drivers of pollinator community changes across biogeographical gradients. The extent to which intensive agriculture is associated with the homogenisation of biological communities at large spatial...

Mason bees (Osmia spp.) are efficient fruit tree pollinators that can be encouraged to occupy and breed in artificial nesting material. In sweet cherry orchards, they are occasionally used as an alternative managed pollinator as a replacement for or in addition to honey bees (Apis mellifera). Yet, the lack of practical guidelines on management prac...

Widespread native honey bee species in South and East Asia (Apis cerana, Apis dorsata and Apis florea) and the imported western honey bee (Apis mellifera) share habitats and potentially also share pathogens. Chief among the threats facing A. mellifera in Europe and North America is deformed wing virus (DWV), including its two principal genotypes: A...

Background: Over the last two decades, honey bees (Apis mellifera) have suffered high rates of colony losses that have been attributed to a variety of factors, chief among which are viral pathogens, such as deformed wing virus (DWV), whose virulence has increased because of vector-based transmission by the invasive, ectoparasitic varroa mite (Varr...

Sweat bees have repeatedly gained and lost eusociality, a transition from individual to group reproduction. Here we generate chromosome-length genome assemblies for 17 species and identify genomic signatures of evolutionary trade-offs associated with transitions between social and solitary living. Both young genes and regulatory regions show enrich...

While wild pollinators play a key role in global food production, their assessment is currently missing from the most commonly used environmental impact assessment method, Life Cycle Assessment (LCA). This is mainly due to constraints in data availability and compatibility with LCA inventories. To target this gap, relative pollinator abundance esti...

Simple Summary Diseases, particularly those caused by viruses, are a major cause of bee colony losses. However, little is known about the prevalence of the pathogens, particularly virus prevalence, of the honey bee in Egypt, one of the most important countries for beekeeping and agricultural production in Africa. To address this shortfall, we deter...

Bees are under threat from agricultural intensification, and species which are pollen specialists (oligolectic) are thought to have declined disproportionately compared to pollen generalists (polylectic). When assessing the risks of dietary pesticide (plant protection products) exposure to non-target beneficial insects such as wild bees, effects on...

Microplastics (MPs), in the form of fragments and fibers, were recently found in honey samples collected in Ecuador as well as in honey bees collected from Denmark and China. However, little is known about how MPs impact bee health. To fill this knowledge gap, we investigated the potential toxicity of irregularly shaped polystyrene (PS)-MP fragment...

Nosema ceranae is a microsporidian that infects Apis species. Recently, natural compounds have been proposed to control nosemosis and reduce its transmission among honey bees. We investigated how ethanolic extract of Tetrigona apicalis’s propolis and chito-oligosaccharide (COS) impact the health of N. ceranae-infected Apis dorsata workers. Nosema c...

Pests and pathogens are a major factor in the health and wellbeing of pollinators. We provide a brief review of the major pests and pathogens of three important insect pollinator taxa of crop plants: honey bees (Apis spp.), bumble bees (Bombus spp.) and other wild bees. For honey bees, the varroa mite (Varroa destructor)-Deformed wing virus (ectopa...

The bee genus Andrena is both species-rich and taxonomically challenging due to inter- and intra-specific variation, particularly for bivoltine taxa. One such case involves the subgenus Hoplandrena. Two species within this subgenus are widespread across the West Palaearctic, one of which is bivoltine and the other usually univoltine. The two specie...

To accommodate an ever-increasing human population, agriculture is rapidly intensifying at the expense of natural habitat, with negative and widely reported effects on biodiversity in general and on wild bee abundance and diversity in particular. Cities are similarly increasing in area, though the impact of urbanisation on wild bees is more equivoc...

Deformed wing virus (DWV), notorious for its virulence in the western honey bee ( Apis mellifera) when vectored by the ectoparasitic mite Varroa destructor , is also widespread among wild bumble bee species, presumably through spillover from honey bees. Experimental studies on the virulence of DWV in Bombus spp. have provided equivocal results and...

Simple Summary Stingless bees are the most diverse group of highly social bees, and they are ecologically and economically important species in the tropics and subtropics. Stingless bees provide important ecological services, such as the pollination of native plants and crops. However, agrochemical treatment is a common practice in the management o...

Understanding how niche‐based and neutral processes contribute to the spatial variation in plant–pollinator interactions is central to designing effective pollination conservation schemes. Such schemes are needed to reverse declines of wild bees and other pollinating insects, and to promote pollination services to wild and cultivated plants. We use...

There is growing evidence that pesticides may be among the causes of worldwide bee declines, which has resulted in repeated calls for their increased scrutiny in regulatory assessments. One recurring concern is that the current frameworks may be biased towards assessing risks to the honey bee. This paradigm requires extrapolating toxicity informati...

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...

Urbanization is a global phenomenon that can affect fitness and could challenge the persistence of most species, including wild bee pollinators. Yet, how and which environmental features affect bee health and fitness within the urban ecosystem remain unclear. Here, we placed experimental Bombus terrestris colonies in sites spanning from the edge in...

To provide a complete portrayal of the multiple factors negatively impacting insects in agricultural landscapes it is necessary to assess the concurrent incidence, magnitude, and interactions among multiple stressors over substantial biogeographical scales. Trans-national ecological field investigations with wide-ranging stakeholders typically enco...

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 nic...

The cleptoparasitic bee attacking the Bilberry Mining Bee Andrena lapponica Zetterstedt, which has traditionally been regarded as a form of Nomada panzeri Lepeletier, is confirmed as a distinct species based on both morphology and the mitochondrial CO1 gene sequence (DNA barcode). It is here referred to as Nomada glabella sensu Stöckhert nec Thomso...

The western honey bee (Apis mellifera) is of major economic and ecological importance, with elevated rates of colony losses in temperate regions over the last two decades thought to be largely caused by the exotic ectoparasitic mite Varroa destructor and deformed wing virus (DWV), which the mite transmits. DWV currently exists as two main genotypes...

Beekeeping with the western honey bee (Apis mellifera) is important in tropical regions but scant information is available on the possible consequences of global warming for tropical beekeeping. We evaluated the effect of heat stress on developmental stability, the age at onset of foraging (AOF) and longevity in Africanized honey bees (AHBs) in the...

Defense castes are know from highly eusocial insects yet have rarely been described in social species with a small colony size. In nests of Euglossa viridissima, an orchid bee exhibiting primitively eusocial behavior, we recorded one subordinate female per nest to specialize in guarding in the presence of a dominant and a second subordinate who spe...

Pollinator declines have prompted efforts to assess how land‐use change affects insect pollinators and pollination services in agricultural landscapes. Yet many tools to measure insect pollination services require substantial landscape‐scale data and technical expertise. In expert workshops, 3 straightforward methods (desk‐based method, field surve...

Stingless bees are the largest group of eusocial pollinators with diverse natural histories, including obligate cleptobionts (genus Lestrimelitta) that completely abandoned flower visitation to rely on other stingless bees for food and nest materials. Species of Lestrimeliita are thought to specialize upon different host species, and deception thro...

Cross-species transmission of a pathogen from a reservoir to a recipient host species, spillover, can have major impacts on biodiversity, domestic species and human health. Deformed wing virus (DWV) is a panzootic RNA virus in honeybees that is causal in their elevated colony losses, and several correlative field studies have suggested spillover of...

Viruses are omnipresent, yet the knowledge on drivers of viral prevalence in wild host populations is often limited. Biotic factors, such as sympatric managed host species, as well as abiotic factors, such as climatic variables, are likely to impact viral prevalence. Managed and wild bees, which harbor several multi-host viruses with a mostly fecal...

Mitigating pollinator declines in agriculturally dominated landscapes to safeguard pollination services requires the involvement of farmers and their willingness to adopt pollinator-friendly management. However, farmer knowledge, perceptions, and actions to support on-farm pollinators and their alignment with science-based knowledge and recommendat...

Oceanic islands have long been considered engines of differentiation and speciation for terrestrial organisms. Here we investigated colonisation and radiation processes in the Madeira Archipelago and the Canary Islands of the Andrena wollastoni group of bees (subgenus Micrandrena ), which comprises six endemic species and five endemic subspecies on...

A plain langauge 2 page overview of the paper "Opportunities to reduce pollination deficits and address production shortfalls in an important insect-pollinated crop" designed for non-acedemic audiences (or very busy acedemics). Please feel free to pass this along.

Pollinators face multiple pressures and there is evidence of populations in decline. As demand for insect‐pollinated crops increases, crop production is threatened by shortfalls in pollination services. Understanding the extent of current yield deficits due to pollination and identifying opportunities to protect or improve crop yield and quality th...

Cultivation of pollinator-dependent crops has expanded globally, increasing our reliance on insect pollination. This essential ecosystem service is provided by a wide range of managed and wild pollinators whose abundance and diversity are thought to be in decline, threatening sustainable food production. The Western honey bee (Apis mellifera) is am...

Over the past two decades, the cultivated area of oilseed rape (Brassica napus L. or OSR), a mass-flowering crop, has markedly increased in Europe in response to bioenergy demands. As well as representing a major shift in floral composition across the landscape, mass-flowering OSR may alter pollination services to other simultaneously blooming crop...

PoshBee is a 5-year funded project (2018-2023) that aims to support healthy bee populations, sustainable beekeeping, and consequently pollination for crops and wildflowers across Europe. To do this we take a range of approaches, from the laboratory to the field, from molecules to ecosystems, and from fundamental science to risk assessment. This doc...

In temperate regions of the world dominated by intensive agriculture, cities harbor a rich diversity and abundance of bee species, often exceeding those of the rural environment. In less industrialized tropical countries, in contrast, stressful conditions may exist in cities for bees with perennial colonies such as stingless bees because of the lac...

This protocol was developed for the COST-Action “Super-B”, whose purpose was to coordinate research, outreach and policy towards sustainable pollination1-3. The protocol addresses the detection of parasites and pathogens across bee species, as one of several possible drivers of bee decline4,5. It consists of four major components: 1. A sample colle...

In eusocial insects, chemical communication is crucial for mediating many aspects of social activities, especially the regulation of reproduction. Though queen signals are known to decrease ovarian activation of workers in highly eusocial species, little is known about their evolution. In contrast, some primitively eusocial species are thought to c...

Eusocial insect queens are remarkable in their ability to maximise both fecundity and longevity, thus escaping the typical trade-off between these two traits. Several mechanisms have been proposed to underlie the remoulding of the trade-off, such as reshaping of the juvenile hormone pathway, or caste-specific susceptibility to oxidative stress. How...

Adult honey bees host a remarkably consistent gut microbial community that is thought to benefit host health and provide protection against parasites and pathogens. Currently, however, we lack experimental evidence for the causal role of the gut microbiota in protecting the Western honey bees (Apis mellifera) against their viral pathogens. Here we...

Life’s most dramatic innovations, from the emergence of self-replicating molecules to highly-integrated societies, often involve increases in biological complexity. Some groups traverse different levels of complexity, providing a framework to identify key factors shaping these evolutionary transitions. Halictid bees span the transition from individ...

Multiple global change pressures, and their interplay, cause plant-pollinator extinctions and modify species assemblages and interactions. This may alter the risks of pathogen host shifts, intra- or interspecific pathogen spread, and emergence of novel population or community epidemics. Flowers are hubs for pathogen transmission. Consequently, the...

The life-prolonging effects of antioxidants have long entered popular culture, but the scientific community still debates whether free radicals and the resulting oxidative stress negatively affect longevity. Social insects are intriguing models for analysing the relationship between oxidative stress and senescence because life histories differ vast...

The exceptional longevity of social insect queens despite their lifelong high fecundity remains poorly understood in ageing biology. To gain insights into the mechanisms that might underlie ageing in social insects, we compared gene expression patterns between young and old castes (both queens and workers) across different lineages of social insect...

Pollinator biodiversity may benefit crop pollination. Yet benefits in agro-ecosystems may be context-dependent and offset by agronomic or other limiting orchard-specific or tree-specific factors that obscure biodiversity-ecosystem service relationships. To test if crop pollination benefitted from pollinator biodiversity, we sampled local wild bee c...

PoshBee is a 5-year funded project (2018-2023) that aims to support healthy bee populations, sustainable beekeeping, and consequently pollination for crops and wildflowers across Europe. To do this we take a range of approaches, from the laboratory to the field, from molecules to ecosystems, and from fundamental science to risk assessment. This doc...

Abstract. For 160 years, Anthrenus pimpinellae isabellinus Küster, 1848 has been considered a subspecies of A. pimpinellae Fabricius, 1775. However, habitus shape differs between the subspecies with A. p. isabellinus being broader than A. p. pimpinellae and resembling more closely A. dorsatus Mulsant & Rey, 1868. Here A. p. pimpinellae and A. p. is...

Bees and flowering plants are two closely interacting groups of organisms. Habitat loss and fragmentation associated with urbanisation are major threats to both partners. Yet how and why bee and floral richness and diversity co-vary within the urban landscape remain unclear. Here, we sampled bees and flowering plants in urban green spaces to invest...

The decline of insect pollinators threatens global food security. A major potential cause of decline is considered to be the interaction between environmental stressors, particularly between exposure to pesticides and pathogens. To explore pesticide–pathogen interactions in an important pollinator insect, the honey bee, we used two new nicotinic ac...

Urbanisation is a global phenomenon with major effects on species, the structure of community functional traits and ecological interactions. Body size is a key species trait linked to metabolism, life‐history and dispersal as well as a major determinant of ecological networks. Here, using a well‐replicated urban‐rural sampling design in Central Eur...

Eusocial insect queens are remarkable in their ability to maximise both fecundity and longevity, thus escaping the typical trade-off between these two traits. In species exhibiting complex eusocial behaviour, several mechanisms have been proposed to underlie the remoulding of the trade-off, such as reshaping of the juvenile hormone pathway, or cast...

Wild and managed bees are essential for global food security and the maintenance of biodiversity. At present, the conservation of wild bees is hampered by a huge shortfall in knowledge about the trends and status of individual species mainly due to their large diversity and variation in life histories. In contrast, the managed Western honey bee Api...