Nigel Raine

University of Guelph | UOGuelph · School of Environmental Sciences

Recent concern over global pollinator declines has led to considerable research on the effects of pesticides on bees. Although pesticides are typically not encountered at lethal levels in the field, there is growing evidence indicating that exposure to field-realistic levels can have sublethal effects on bees, affecting their foraging behaviour, ho...

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 (Go...

Two studies provide evidence that bees cannot taste or avoid neonicotinoid pesticides, and that exposure to treated crops affects reproduction in solitary bees as well as bumblebee colony growth and reproduction. http://www.readcube.com/articles/10.1038%2Fnature14391

Current bee population declines and colony failures are well documented yet poorly understood and no single factor has been identified as a leading cause. The evidence is equivocal and puzzling: for instance, many pathogens and parasites can be found in both failing and surviving colonies and field pesticide exposure is typically sublethal. Here, w...

Reported widespread declines of wild and managed insect pollinators have serious consequences for global ecosystem services and agricultural production. Bees contribute approximately 80% of insect pollination, so it is important to understand and mitigate the causes of current declines in bee populations . Recent studies have implicated the role of...

Seven bee species (Hymenoptera: Apiformes) are documented from Canada for the first time, and their known natural history, distributional range and floral associations are discussed. The new species records for Canada are Andrena (Callandrena) krigiana Robertson, 1901 (Andrenidae); Andrena (Trachandrena) nuda Robertson, 1891; Andrena (Iomelissa) vi...

Essential ecosystem services are provided by many interactions, including plant-pollinator, predator-prey, and host-parasitoid. These services support food and natural systems through pollination and pest control, however they are challenging to qualify, and previous observational studies may underestimate their complexity. The cavity nesting Hymen...

Agricultural intensification has been identified as one of the key causes of global insect biodiversity losses. These losses have been further linked to the widespread use of agrochemicals associated with modern agricultural practices. Many of these chemicals are known to have negative sublethal effects on commercial pollinators, such as managed ho...

In a previous study, an experimental oversight led to the accumulation of water filling a container housing diapausing bumblebee queens. Surprisingly, after draining the water, queens were found to be alive. This observation raises a compelling question: can bumblebee queens endure periods of inundation while overwintering underground? To address t...

Pollinator diversity is critical for optimal ecosystem service and function. While bees are frequently the most efficient pollinators, they represent only a small fraction of pollinator diversity. Non-bee pollinators have received little recognition for their role in commercial agricultural pollination despite representing 95% of flower visitor div...

Mounting evidence supporting the negative impacts of exposure to neonicotinoids on bees has prompted the registration of novel ‘bee-friendly’ insecticides for agricultural use. Flupyradifurone (FPF) is a butenolide insecticide that shares the same mode of action as neonicotinoids and has been assessed to be ‘practically non-toxic to adult honeybees...

Cucurbita pepo crops (pumpkin, squash) are entirely dependent upon insect pollinators for reproduction. In Ontario, Canada, their most important pollinator is the hoary squash bee (Eucera pruinosa), a wild ground-nesting, solitary bee whose only source of pollen in the region is Cucurbita crops. As such, in this context, we have a unique opportunit...

Bees are essential pollinators of many crops and wild plants, and pesticide exposure is one of the key environmental stressors affecting their health in anthropogenically modified landscapes. Until recently, almost all information on routes and impacts of pesticide exposure came from honey bees, at least partially because they were the only model s...

Highbush blueberry production has expanded worldwide in recent decades. To safeguard future yields, it is essential to understand if insect pollination is limiting current blueberry production and which insects contribute to pollination in different production regions. We present a systematic review including a set of meta‐analyses on insect‐mediat...

Ecological intensification has been embraced with great interest by the academic sector but is still rarely taken up by farmers because monitoring the state of different ecological functions is not straightforward. Modelling tools can represent a more accessible alternative of measuring ecological functions, which could help promote their use among...

Habitat loss and fragmentation are major drivers of global pollinator declines, yet even after recent unprecedented periods of anthropogenic land-use intensification the amount of habitat needed to support insect pollinators remains unknown. Here we use comprehensive pan trap bee survey datasets from Ontario, Canada, to determine which habitat type...

Global pollinator declines threaten food production and natural ecosystems. The drivers of declines are complicated and driven by numerous factors such as pesticide use, loss of habitat, rising pathogens due to commercial bee keeping and climate change. Halting and reversing pollinator declines will require a multidisciplinary approach and internat...

Neonicotinoid insecticides are among the most widely used agrochemicals globally. Given the critical importance of bees for biodiversity, crop productivity, and human health, recent decades have seen substantial interest in the impacts of neonicotinoids on bees and the pollination services they provide, both among researchers and the public. Social...

Groups of cooperative organisms, including humans, benefit from the contributions of both specialist and generalist individuals. Group responses to resource or task demand emerge from the specific actions of individuals within the group. Bumble bee colonies need to respond to resource demands for both pollen and nectar for colony growth and reprodu...

Gynandromorphs exhibit both male and female morphological features simultaneously and are rare amongst most genera of wild bees. This is the first description of a gynandromorph individual of Hylaeus modestus Say (Hymenoptera: Colletidae) and the first record from the subgenus Prosopis as currently defined. The specimen was passively trapped at a m...

Exposure to pesticides is a major threat to bumblebee (Bombus spp.) health. In temperate regions, queens of many bumblebee species hibernate underground for several months, putting them at potentially high risk of exposure to soil contaminants. The extent to which bumblebees are exposed to residues in agricultural soils during hibernation is curren...

Exposure to pesticides is a major threat to bumblebee ( Bombus spp.) health. In temperate regions, queens of many bumblebee species hibernate underground for several months, putting them at potentially high risk of exposure to soil contaminants. The extent to which bumblebees are exposed to residues in agricultural soils during hibernation is curre...

Fungicides account for more than 35% of the global pesticide market and their use is predicted to increase in the future. While fungicides are commonly applied during bloom when bees are likely foraging on crops, whether real-world exposure to these chemicals – alone or in combination with other stressors – constitutes a threat to the health of bee...

Seventy five percent of the world's food crops benefit from insect pollination. Hence, there has been increased interest in how global change drivers impact this critical ecosystem service. Because standardized data on crop pollination are rarely available, we are limited in our capacity to understand the variation in pollination benefits to crop y...

The Common Eastern Bumblebee (Bombus impatiens) is native to North America with an expanding range across Eastern Canada and the USA. This species is commercially produced primarily for greenhouse crop pollination and is a common and abundant component of the wild bumblebee fauna in agricultural, suburban and urban landscapes. However, there is a d...

The phenology of crop flowering and pollinator reproduction can become asynchronous at the edge of their respective ranges. At a northern site in Peterborough County, Ontario, we evaluated offspring emergence of Cucurbita pollen specialist hoary squash bees (Eucera pruinosa) from nests in enclosures to determine their phenological synchrony with a...

Individual animals allowed the opportunity to learn generally outperform those prevented from learning, yet, within a species the capacity for learning varies markedly. The evolutionary processes that maintain this variation in learning ability are not yet well understood. Several studies demonstrate links between fitness traits and visual learning...

The increasing demand for insect-pollinated crops highlights the need for crop pollination paradigms that include all available pollinators. In North America, Cucurbita crops (pumpkin, squash) depend on both wild (solitary and Bombus spp.: Hymenoptera: Apidae) and managed honey bees (Apis mellifera L. 1758: Hymenoptera: Apidae) for pollination. Tem...

Eastern North American migratory monarch butterflies (Danaus plexippus) have faced sharp declines over the past two decades. Captive rearing of monarch butterflies is a popular and widely used approach for both public education and conservation. However, recent evidence suggests that captive-reared monarchs may lose their capacity to orient southwa...

Insect pollinators are threatened by multiple environmental stressors, including pesticide exposure. Despite being important pollinators, solitary ground-nesting bees are inadequately represented by pesticide risk assessments reliant almost exclusively on honeybee ecotoxicology. Here we evaluate the effects of realistic exposure via squash crops tr...

Migratory insects use a variety of innate mechanisms to determine their orientation and maintain correct bearing. For long-distance migrants, like the monarch butterfly (Danaus plexippus), these journeys could be affected by exposure to environmental contaminants. Neonicotinoids are synthetic insecticides that work by affecting the nervous system o...

Habitat loss and fragmentation are major drivers of global pollinator declines, yet even after recent unprecedented periods of anthropogenic land-use intensification the amount of habitat needed to support pollinators remains unknown. Here we use comprehensive datasets to determine the extent and amount of habitat needed. Safeguarding wild bee comm...

A battery-less 5.8-GHz transmitter (TX), compact and lightweight enough to enable flight of $\sim 90$ mg honeybees and free roaming of bumblebees within their nest, was developed. The TX was coupled to a compact phased-array antenna receiver to achieve angle of arrival (AOA) estimation and bee localization through a received signal strength indic...

Despite their indispensable role in food production , insect pollinators are threatened by multiple environmental stressors, including pesticide exposure. Although honeybees are important, most pollinating insect species are wild, solitary, ground-nesting bees that are inadequately represented by honeybee-centric regulatory pesticide risk assessmen...

The Common Eastern Bumblebee ( Bombus impatiens ) is native to North America with an expanding range across Eastern Canada and the USA. This species is commercially produced primarily for greenhouse crop pollination and is a common and abundant component of the wild bumblebee fauna in agricultural, suburban and urban landscapes. However, there is a...

Eastern North American migratory monarch butterflies (Danaus plexippus) have faced sharp declines over the last two decades. Although captive rearing has been used as an important tool for engaging the public and supplementing conservation efforts, a recent study that tested monarchs in a flight simulator suggested that captive-reared monarchs lose...

Currently honeybees are the sole model insect pollinator for regulatory pesticide risk assessments globally. Here we question whether this surrogacy approach provides adequate protection against potential non-target impacts of pesticide exposure for the wide diversity of insect pollinators on which agricultural production and wild plant ecosystems...

Using the hoary squash bee (Peponapis pruinosa) as a model, we provide the first probabilistic risk assessment of exposure to systemic insecticides in soil for ground-nesting bees. To assess risk in acute and chronic exposure scenarios in Cucurbita and field crops, concentrations of clothianidin, thiamethoxam and imidacloprid (neonicotinoids) and c...

Background Individual bees exhibit complex movement patterns to efficiently exploit small areas within larger plant populations. How such individual spatial behaviours scale up to the collective level, when several foragers visit a common area, has remained challenging to investigate, both because of the low resolution of field movement data and th...

Acute toxicity testing (lethal dose and lethal concentration for 50% of the population; LD 50 and LC 50 ) is a required component of the first level of pesticide risk assessment. A review of peer-reviewed and ECOTOX database toxicity values was conducted to assess methodology and toxicity value consistency. Bumble bee LD 50 and LC 50 tests varied i...

Acute toxicity testing (lethal dose and lethal concentration for 50% of the population; LD 50 and LC 50 ) is a required component of the first level of pesticide risk assessment. A review of peer-reviewed and ECOTOX database toxicity values was conducted to assess methodology and toxicity value consistency. Bumble bee LD 50 and LC 50 tests varied i...

Current pesticide risk assessment for bees relies on a single (social) species, the western honey bee, Apis mellifera L. (Hymenoptera: Apidae). However, most of the >20,000 bee species worldwide are solitary. Differences in life history traits between solitary bees (SB) and honey bees (HB) are likely to determine differences in routes and levels of...

Current pesticide risk assessment practices use the honey bee, Apis mellifera L., as a surrogate to characterize the likelihood of chemical exposure of a candidate pesticide for all bee species. Bees make up a diverse insect group that provides critical pollination services to both managed and wild ecosystems. Accordingly, they display a diversity...

To date, regulatory pesticide risk assessments have relied on the honey bee (Apis mellifera L.) (Hymenoptera: Apidae) as a surrogate test species for estimating the risk of pesticide exposure to all bee species. However, honey bees and non-Apis bees may differ in their susceptibility and exposure to pesticides. In 2017, a workshop ('Pesticide Expos...

Neonicotinoid exposure impairs the social dynamics of bumblebees inside the nest

Using the hoary squash bee ( Peponapis pruinosa ) as a model, we provide the first probabilistic risk assessment of exposure to systemic insecticides in soil for ground-nesting bees. To assess risk in acute and chronic exposure scenarios in Cucurbita and field crops, concentrations of clothianidin, thiamethoxam and imidacloprid (neonicotinoids) and...

Sustainably feeding the next generation is often described as one of the most pressing “grand challenges” facing the 21st century. Generally, scholars propose addressing this problem by increasing agricultural production, investing in technology to boost yields, changing diets, or reducing food waste. In this paper, we explore whether global food p...

Available Kilocalories and their equivalent servings from the FAO’s Food balance sheets for agricultural year 2011. Serving calculations were based on Canada’s Food Guide serving sizes and USDA guidelines. (PDF)

The amount of food produced, their uses for human food and livestock feed and arable land area under each food group based on FAO 2011 data. (PDF)

Breakdown of greenhouse gas emissions by food category. (PDF)

First Place Award in Grad Student Virtual Poster Competition

Exposure to a sulfoximine-based pesticide has substantial adverse effects on bumblebee colonies. This finding suggests that concerns over the risks of exposing bees to insecticides should not be limited to neonicotinoids.

Neonicotinoid pesticides are used in agriculture to reduce damage from crop pests. However, beneficial insects such as bees can come into contact with these pesticides when foraging in treated areas, with potential consequences for bee declines and pollination service delivery. Honeybees are typically used as a model organism to investigate insecti...

Pollinators are in global decline and agricultural pesticides are a potential driver of this. Recent studies have suggested that pesticides may significantly impact bumblebee colonies—an important and declining group of pollinators. Here, we show that colony-founding queens, a critical yet vulnerable stage of the bumblebee lifecycle, are less likel...

m studies of a single species. There is an urgent need to understand whether such results can be generalized across a range of species. Here, we present results of a laboratory experiment testing the impacts of field-relevant doses (1.87–5.32 ppb) of the neonicotinoid thiamethoxam on spring-caught wild queens of four bumblebee species: Bombus terre...

Despite widespread interest in the potential adaptive value of individual differences in cognition, few studies have attempted to address the question of how variation in learning and memory impacts their performance in natural environments. Using a novel split-colony experimental design we evaluated visual learning performance of foraging naïve bu...

Despite a presumed fitness advantage for individuals with well-developed cognitive abilities, learning performance is usually found to be highly variable within a population. Although little is currently known about the mechanisms responsible for maintaining such variation, there is correlative evidence to suggest that learning performance may be l...

Most of the world’s wild flowering plants (87.5%) are pollinated by insects and other animals (established but incomplete), more than three quarters of the leading types of global food crops can benefit, at least in part, from animal pollination (well established) and it is estimated that about one-third of global food volume produced similarly ben...

Fig. S1. Aerial image of study location. Appendix S1. Rationale for choosing thiamethoxam exposure levels. Appendix S2. RFID data manipulation. Appendix S3. Homing data filtering. Appendix S4. Effect sizes and confidence intervals of colony growth & homing data. Appendix S5. Acute homing experiment data and results.

Lay Summary

Table S1. Sequences and flower handling times (in seconds) of the first 30 floral choices for all foragers exposed to control (a) or pesticide (10 ppb thiamethoxam) (b) treatments; n = the total number of flowers visited in the foraging bout. Light grey represents visits to Lotus corniculatus, and dark grey represents visits to Trifolium repens.

The ability to forage and return home is essential to the success of bees as both foragers and pollinators. Pesticide exposure may cause behavioural changes that interfere with these processes, with consequences for colony persistence and delivery of pollination services. We investigated the impact of chronic exposure (5–43 days) to field‐realistic...

The capacity to explore soft tissue structures in detail is important in understanding animal physiology and how this determines features such as movement, behaviour and the impact of trauma on regular function. Here we use advances in micro-computed tomography (micro-CT) technology to explore the brain of an important insect pollinator and model o...

Pollinators, such as bees, often develop multi-location routes (traplines) to exploit subsets of flower patches within larger plant populations. How individuals establish such foraging areas in the presence of other foragers is poorly explored. Here we investigated the foraging patterns of pairs of bumble bees (Bombus terrestris) released sequentia...

Following event. A bee (bee 1, tag: white 32) lands on a flower 2 s after a previous bee (bee 8, tag: white 24) has left. Bee 8 probes the empty feeding cup and leaves. Labels (bee 1 and 8) refer to the same individuals throughout the study. (M4V)

Joining event followed by a pushing event and an eviction. A bee (bee 6, tag: white 32) lands on a flower already occupied by another bee (bee 13, tag: white 24). Bee 6 pushes bee 13 in the back and evicts it from the landing platform. Bee 6 probes the empty feeding cup, then leaves. Labels (bee 6 and 13) refer to the same individuals throughout th...