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Mounting evidence suggests that climate change, agricultural intensification and disease are impacting bumblebee health and contributing to species’ declines. Identifying how these factors impact insect communities at large spatial and temporal scales is difficult, partly because species may respond in different ways. Further, the necessary data must span large spatial and temporal scales, which usually means they comprise aggregated, presence-only records collected using numerous methods (e.g. diversity surveys, educational collections, citizen-science projects, standardized ecological surveys). Here, we use occupancy models, which explicitly correct for biases in the species observation process, to quantify the effect of changes in temperature, precipitation and floral resources on bumblebee site occupancy over the past 12 decades in North America. We find no evidence of genus-wide declines in site occupancy, but do find that occupancy is strongly related to temperature, and is only weakly related to precipitation or floral resources. We also find that more species are likely to be climate change ‘losers’ than ‘winners’ and that this effect is primarily associated with changing temperature. Importantly, all trends were highly species-specific, highlighting that genus or community-wide measures may not reflect diverse species-specific patterns that are critical in guiding allocation of conservation resources.

A challenge in conservation is the gap between knowledge generated by researchers and the information being used to inform conservation practice. This gap, widely known as the research-implementation gap, can limit the effectiveness of conservation practice. One way to address this is to design conservation tools that are easy for practitioners to use. Here, we implement data science methods to develop a tool to aid in conservation of pollinators in British Columbia. Specifically, in collaboration with Pollinator Partnership Canada, we jointly develop an interactive web app, the goal of which is two-fold: (i) to allow end users to easily find and interact with the data collected by researchers on pollinators in British Columbia (prior to development of this app, data were buried in supplements from individual research publications) and (ii) employ up to date statistical tools in order to analyse phenological coverage of a set of plants. Previously, these tools required high programming competency in order to access. Our app provides an example of one way that we can make the products of academic research more accessible to conservation practitioners. We also provide the source code to allow other developers to develop similar apps suitable for their data.

Hydrocarbon discharges into the ocean, both regulated and accidental, occur from offshore drilling and production operations, and can result in oil sheen (≤3 μm thick) and slick (>3 μm thick) formation, potentially harming marine birds. Sheens may commonly occur around offshore oil and gas platforms in Atlantic Canada, however, there is little information on regularity of occurrence. Further, there are few direct studies on potential impacts of sheens, associated with offshore oil and gas operations, on marine birds. We reviewed potential sources and frequency of hydrocarbon accumulation on sea surfaces from offshore oil and gas operations in Atlantic Canada, and the likelihood of overlap with marine birds. We conducted a literature review on lethal and sub-lethal effects of low levels of oil contact and ingestion on marine birds, focusing on studies that describe measured dosages of oil. We extrapolated from these data on low-dose oil exposure to link possible effects to marine birds resulting from exposure to sheens. We found that sheens occur around production operations in Atlantic Canada at allowable levels of oil concentrations in produced water. Frequency and extent of occurrence cannot be estimated from current monitoring practices. While immediate lethal effects to seabirds likely are not common from external oiling of feathers from sheens, added stressors, such as cold weather, can result in external oiling from sheens having significant impact on seabird metabolic rate and can be ultimately lethal. Ingestion of small amounts of oil, doses that realistically could be expected from exposure to sheens, in some cases resulted in sub-lethal effects to adult seabirds, primarily affecting metabolic rate, sub-lethal health impacts, and reproductive output. Nestlings and eggs do not come in direct contact with sheens, yet these life stages are highly sensitive to oil, and transfer of oil from adults exposed to sheens likely is above tolerance levels at times. Negative effects to reproductive output from small doses of ingested oil could be causing undetected impacts on marine birds and marine bird populations. Lack of standardized monitoring of marine bird contact with sheens and potential harm makes assessments of magnitude and extent of impact problematic.

North America has more than 4000 bee species, yet we have little information on the health, distribution, and population trends of most of these species. In the United States, what information is available is distributed across multiple institutions, and efforts to track bee populations are largely uncoordinated on a national scale. An overarching framework for monitoring U.S. native bees could provide a system that is responsive to national needs, resources, and capacities. Five major action areas and priorities for structuring a coordinated effort include: (1) Defining the scope, aims, and cost of a national native bee monitoring program; (2) Improving the national capacity in bee taxonomy and systematics; (3) Gathering and cataloging data that are standardized, accessible, and sustainable; (4) Identifying survey methods and prioritizing taxa to monitor; and (5) Prioritizing geographic areas to be monitored. Here, we detail the needs, challenges, and opportunities associated with developing a multi-layered U.S. national plan for native bee monitoring.

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 of behaviors and vary greatly in their lifestyles and phenologies, such as their timing of emergence, degree of sociality and foraging and nesting behaviors. Some of these factors may lead to disparate or variable routes of exposure when compared to honey bees. For those that possess life histories that are distinct from A. mellifera, further risk assessments may be warranted. In January 2017, forty bee researchers, representative of regulatory agencies, academia and agrochemical industries, gathered to discuss the current state of science on pesticide exposure to non-Apis bees and to determine how well honey bee exposure estimates, implemented by different regulatory agencies, may be protective for non-Apis bees. Workshop participants determined that although current risk assessment procedures for honey bees are largely conservative, several routes of exposure are unique to non-Apis bees and warranted further investigation. In this forum article, we discuss these key routes of exposure relevant to non-Apis bees and identify important research gaps that can help inform future bee risk assessment decisions.

Supporting managed honey bees by pasturing in natural landscapes has come under review due to concerns that honey bees could negatively impact the survival of wild bees through competition for floral resources. Critique and assessment of the existing body of published literature against our criteria focussing on studies that can support best management resulted in 19 experimental papers. Indirect measures of competition examining foraging patterns and behavior yielded equivocal results. Direct measures of reproduction and growth were investigated in only seven studies, with six indicating negative impacts to wild bees from the presence of managed honey bees. Three of these studies examined fitness impacts to BombusLatreille and all three indicated reduced growth or reduced reproductive output. Because there is a severe lack of literature, yet potential that honey bee presence could negatively impact wild bees, exemplified with bumble bee studies, we advocate for further research into the fitness impacts of competition between managed and wild pollinators. Conservative approaches should be taken with respect to pasturing honey bees on natural lands with sensitive bumble bee populations. Correspondingly, forage opportunities for honey bees in managed, agricultural landscapes, should be increased in an effort to reduce potential pressure and infringement on wild bee populations in natural areas.

Seabirds and other aquatic avifauna are highly sensitive to exposure to petroleum oils. A small amount of oil is sufficient to break down the feather barrier that is necessary to prevent water penetration and hypothermia. Far less attention has been paid to potential effects on aquatic birds of so called ‘edible oils’, non-petroleum oils such as vegetable and fish oils. In response to a sardine oil discharge by a vessel off the coast of British Columbia, we conducted an experiment to assess if feather exposure to sheens of sardine oil (ranging from 0.04 to 3 μm in thickness) resulted in measurable oil and water uptake and significant feather microstructure disruption. We designed the experiment based on a previous experiment on effects of petroleum oils on seabird feathers. Feathers exposed to the thinnest fish oil sheens (0.04 μm) resulted in measurable feather weight gain (from oil and water uptake) and significant feather microstructure disruption. Both feather weight gain and microstructure disruption increased with increasing fish oil thickness. Because of the absence of primary research on effects of edible oils on sea birds, we conducted interviews with wildlife rehabilitation professionals with experience rehabilitating sea birds after edible oil exposure. The consensus from interviews and our experiment indicated that physical contact with fish and other ‘edible oils’ in the marine environment is at least as harmful to seabirds as petroleum oils.

In intensive agricultural landscapes, restoration within farms could enhance biodiversity and ecosystem services such as pollination by native pollinators. Although governments and conservation groups are promoting small-scale restoration on working farms, there are few studies that assess whether these practices enhance pollinator communities in restored areas. Further, there is no information on whether floral enhancements will deplete pollinators in adjacent fields by concentrating ambient populations or whether they result in a net increase in abundance in adjacent farm fields. We investigated whether field edges restored with native perennial plants in California's Central Valley agricultural region increased floral abundance and potential bee nesting sites, and native bee and syrphid fly abundance and diversity, in comparison to relatively unmanaged edges. Native bees and syrphid flies collected from flowers were more abundant, species-rich, and diverse at hedgerow sites than in weedy, unmanaged edges. Abundance of bees collected passively in pan traps was negatively correlated with floral abundance, was significantly different from communities captured by net sampling from flowers, and did not distinguish between site types; we therefore focused on the results of net samples and visual observations. Uncommon species of native bees were sevenfold more abundant on hedgerow flowers than on flowers at weedy, unmanaged edges. Of the species on flowers at hedgerows, 40% were exclusive to hedgerow sites, but there were no species exclusively found on flowers at control sites. Hedgerows were especially important for supporting less-common species of native bees in our intensive agricultural landscape. Hedgerows did not concentrate ambient native bee, honey bee, or syphid fly populations, and they acted as net exporters of native bees into adjacent fields. Within-farm habitat restoration such as hedgerow creation may be essential for enhancing native pollinator abundance and diversity, and for pollination services to adjacent crops. © 2013 by the Ecological Society of America.

Agricultural intensification is a leading cause of global biodiversity loss, which can reduce the provisioning of ecosystem services in managed ecosystems. Organic farming and plant diversification are farm management schemes that may mitigate potential ecological harm by increasing species richness and boosting related ecosystem services to agroecosystems. What remains unclear is the extent to which farm management schemes affect biodiversity components other than species richness, and whether impacts differ across spatial scales and landscape contexts. Using a global metadataset, we quantified the effects of organic farming and plant diversification on abundance, local diversity (communities within fields), and regional diversity (communities across fields) of arthropod pollinators, predators, herbivores, and detritivores. Both organic farming and higher in‐field plant diversity enhanced arthropod abundance, particularly for rare taxa. This resulted in increased richness but decreased evenness. While these responses were stronger at local relative to regional scales, richness and abundance increased at both scales, and richness on farms embedded in complex relative to simple landscapes. Overall, both organic farming and in‐field plant diversification exerted the strongest effects on pollinators and predators, suggesting these management schemes can facilitate ecosystem service providers without augmenting herbivore (pest) populations. Our results suggest that organic farming and plant diversification promote diverse arthropod metacommunities that may provide temporal and spatial stability of ecosystem service provisioning. Conserving diverse plant and arthropod communities in farming systems therefore requires sustainable practices that operate both within fields and across landscapes., EML and DC were supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2014‐51106‐22096. BMF was supported by the National Council for Scientific and Technological Development‐CNPq, Brasília, Brazil #305062/2007‐7. SGP and MO were supported by the Felix Trust and STEP Project (EC FP7 244090).

© 2016, Oxford University Press. All rights reserved. Field edge habitat in homogeneous agricultural landscapes can serve multiple purposes including enhanced biodiversity, water quality protection, and habitat for beneficial insects, such as native bees and natural enemies. Despite this ecosystem service value, adoption of field border plantings, such as hedgerows, on large-scale mono-cropped farms is minimal. With profits primarily driving agricultural production, a major challenge affecting hedgerow plantings is linked to establishment costs and the lack of clear economic benefits on the restoration investment. Our study documented that hedgerows are economically viable to growers by enhancing beneficial insects and natural pest control and pollination on farms. With pest control alone, our model shows that it would take 16 yr to break even from insecticide savings on the US$4,000 cost of a typical 300-m hedgerow field edge planting. By adding in pollination benefits by native bees, where honey bees (Apis mellifera L.) may be limiting, the return time is reduced to 7 yr. USDA cost share programs allow for a quicker return on a hedgerow investment. Our study shows that over time, small-scale restoration can be profitable, helping to overcome the barrier of cost associated with field edge habitat restoration on farms.

Hedgerows of native California shrubs and perennial grasses bordering field crops were examined for the abundance of beneficial and pest insects compared with adjacent weedy areas. During 2 years of sampling in the Sacramento Valley, hedgerows attracted more beneficial than pest insects, while weedy areas showed the opposite trend, attracting significantly more pest than beneficial insects. We conclude that replacing weedy areas at field crop edges with managed hedgerow plantings will sustain or increase beneficial rather than pest insects on farms.

Sustainable agricultural landscapes by definition provide high magnitude and stability of ecosystem services, biodiversity and crop productivity. However, few studies have considered landscape effects on the stability of ecosystem services. We tested whether isolation from florally diverse natural and semi-natural areas reduces the spatial and temporal stability of flower-visitor richness and pollination services in crop fields. We synthesised data from 29 studies with contrasting biomes, crop species and pollinator communities. Stability of flower-visitor richness, visitation rate (all insects except honey bees) and fruit set all decreased with distance from natural areas. At 1 km from adjacent natural areas, spatial stability decreased by 25, 16 and 9% for richness, visitation and fruit set, respectively, while temporal stability decreased by 39% for richness and 13% for visitation. Mean richness, visitation and fruit set also decreased with isolation, by 34, 27 and 16% at 1 km respectively. In contrast, honey bee visitation did not change with isolation and represented > 25% of crop visits in 21 studies. Therefore, wild pollinators are relevant for crop productivity and stability even when honey bees are abundant. Policies to preserve and restore natural areas in agricultural landscapes should enhance levels and reliability of pollination services.

Onion thrips, previously considered of minor importance to hybrid onion seed production in California, vector the newly introduced iris yellow spot virus, a serious pathogen of onions that can cause significant yield losses. Insecticide use to control onion thrips has increased in onion seed fields, coincident with a steep decrease in yields, especially in Colusa County. We examined a number of possible contributing factors and found a strong positive correlation between honey bee activity and onion seed set, indicating that a lack of pollination may be contributing to the reduced yields. In addition, honey bee visits to onion flowers were negatively correlated with the number of insecticides applied per field and field size. Reduced onion seed yields in recent years could be associated with the increase in insecticide use, which may be repelling or killing honey bees, important pollinators of this crop.

Operational discharges of hydrocarbons from maritime activities can have major cumulative impacts on marine ecosystems. Small quantities of oil (i.e., 10 ml) results in often lethally reduced thermoregulation in seabirds. Thin sheens of oil and drilling fluids form around offshore petroleum production structures from currently permissible operational discharges of hydrocarbons. Methodology was developed to measure feather microstructure impacts (amalgamation index or AI) associated with sheen exposure. We collected feather samples from two common North Atlantic species of seabirds; Common Murres (Uria aalge) and Dovekies (Alle alle). Impacts were compared after feather exposure to crude oil and synthetic lubricant sheens of varying thicknesses. Feather weight and microstructure changed significantly for both species after exposure to thin sheens of crude oil and synthetic drilling fluids. Thus, seabirds may be impacted by thin sheens forming around offshore petroleum production facilities from discharged produced water containing currently admissible concentrations of hydrocarbons.

Summary Agricultural intensification and expansion are major present and future causes of global ecosystem disruption. Natural and semi-natural reserve areas in agroecosystems are thought to be important for preservation of essential ecosystem services such as pollination, but data about land use patterns and pollinator abundance are lacking. We assessed wild bee populations in canola fields in an agriculturally intense area where virtually all land was either tilled agricultural fields or semi-natural grazed pasturelands, with the expectation that mosaics of land use types may better support ecosystem services than homogenous crop areas. Fields were chosen in two categories, five with little or no pastureland (

Natural habitats are considered inherently indispensable to the global economy by conservationists, but few natural ecosystems afford direct and quantifiable economic benefits. Quantification of natural land value can provide compelling evidence favoring preservation over development. Wild bees are important pollinators of many crop plants, and natural patches in agroecosystems enhance pollinator services and crop yield. Bee abundance was greatest in canola fields that had more uncultivated land within 750 m of field edges and seed set was greater in fields with higher bee abundance. A cost–benefit model that estimates profit in canola agroecosystems with different proportions of uncultivated land is presented. Yield and profit could be maximized with 30% of land uncultivated within 750 m of field edges.

The ecological impacts of agriculture are of concern, especially with genetically modified and other intensive, modern cropping systems, yet little is known about effects on wild bee populations and subsequent implications for pollination. Pollination deficit (the difference between potential and actual pollination) and bee abundance were measured in organic, conventional, and herbicide-resistant, genetically modified (GM) canola fields (Brassica napus and B. rapa) in northern Alberta, Canada, in the summer of 2002. Bee abundance data were collected using pan traps and standardized sweep netting, and pollination deficit was assessed by comparing the number of seeds per fruit from open-pollinated and supplementally pollinated flowers. There was no pollination deficit in organic fields, a moderate pollination deficit in conventional fields, and the greatest pollination deficit in GM fields. Bee abundance was greatest in organic fields, followed by conventional fields, and lowest in GM fields. Overall, there...

Recent developments of new families of pesticides and growing awareness of the importance of wild pollinators for crop pollination have stimulated interest in potential effects of novel pesticides on wild bees. Yet pesticide toxicity studies on wild bees remain rare, and few studies have included long-term monitoring of bumble bee colonies or testing of foraging ability after pesticide exposure. Larval bees feeding on exogenous pollen and exposed to pesticides during development may result in lethal or sub-lethal effects during the adult stage. We tested the effects of a naturally derived biopesticide, spinosad, on bumble bee (Bombus impatiens Cresson) colony health, including adult mortality, brood development, weights of emerging bees and foraging efficiency of adults that underwent larval development during exposure to spinosad. We monitored colonies from an early stage, over a 10-week period, and fed spinosad to colonies in pollen at four levels: control, 0.2, 0.8 and 8.0 mg kg(-1), during weeks 2 through 5 of the experiment. At concentrations that bees would likely encounter in pollen in the wild (0.2-0.8 mg kg(-1)) we detected minimal negative effects to bumble bee colonies. Brood and adult mortality was high at 8.0 mg kg(-1) spinosad, about twice the level that bees would be exposed to in a 'worst case' field scenario, resulting in colony death two to four weeks after initial pesticide exposure. At more realistic concentrations there were potentially important sub-lethal effects. Adult worker bees exposed to spinosad during larval development at 0.8 mg kg(-1) were slower foragers on artificial complex flower arrays than bees from low or no spinosad treated colonies. Inclusion of similar sub-lethal assays to detect effects of pesticides on pollinators would aid in development of environmentally responsible pest management strategies.

Two experiments were conducted testing for lethal and sublethal effects of the transgenic proteins Cry1Ac and chitinase, and the chemical seed and soil treatment imidacloprid on bumble bees (Bombus occidentalis Greene and B. impatiens Cresson, Hymenoptera: Apidae). In the first experiment, B. occidentalis colonies were exposed to realistic residue levels of Cry1Ac, chitinase, and imidacloprid found in pollen. There were no effects on pollen consumption, bumble bee worker weights, colony size, amount of brood, or the number of queens and males produced. In the second experiment, using B. impatiens, we tested the effects of Cry1Ac and two levels of imidacloprid. Similar colony health measures were collected as in the first experiment, but in addition foraging ability of individual bees was tested on complex artificial flowers. There were no differences in colony characteristics among treatments. However, bees in the high-imidacloprid treatment had longer handling times on the complex flowers than b...

Nous avons procede a des experiences en laboratoire pour evaluer la relation entre les toits de polyethylene des serres et l'activite des bourdons, Bombus impatiens Cresson (Hymenoptera: Apidae), de meme que les pertes par le systeme de ventilation. L'activite a ete mesuree dans quatre petites serres recouvertes de differents types de polyethylene. L'activite a ete quantifiee au moyen de tunnels munis de photodiodes montes a l'entree des ruches. Contrairement aux experiences sur des serres commerciales, les divers types de toit utilises ici n'ont pas affecte differemment l'activite des bourdons. II y avait une relation lineaire positive entre la temperature dans les serres experimentales et l'activite des bourdons. La perte potentielle d'insectes par les systemes de ventilation ouverts a ete quantifiee au moyen d'un labyrinthe en Y pour cinq types de toit. Les bourdons etaient plus attires par la lumiere directe que par la lumiere transmise a travers des toits qui bloquent les rayons ultraviolets (UV), alors qu'ils etaient attires autant par les toits qui laissent passer l'UV que par la lumiere directe. Ces experiences permettent de croire que les serres a toits de plastique qui laissent passer l'UV occasionnent probablement moins de pertes par les systemes de ventilation.

Fil: Garibaldi, Lucas Alejandro. Universidad Nacional de Río Negro. Sede Andina; Argentina. Fil: Garibaldi, Lucas Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Carvalheiro, Luísa G. University of Leeds; Reino Unido. Naturalis Biodiversity Center; Países Bajos Fil: Leonhardt, Sara D. University of Würzburg; Alemania Fil: Aizen, Marcelo A. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina Fil: Aizen, Marcelo A. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Aizen, Marcelo A. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche; Argentina Fil: Blaauw, Brett R. Michigan State University; Estados Unidos Fil: Rufus, Isaacs. Michigan State University; Estados Unidos Fil: Kuhlmann, Michael. Natural History Museum; Reino Unido Fil: Kleijn, David. Wageningen University; Países Bajos Fil: Klein, Alexandra M. University of Freiburg; Alemania Fil: Kremen, Claire. University of California at Berkeley; Estados Unidos Fil: Morandin, Lora. University of California at Berkeley; Estados Unidos Fil: Scheper, Jeroen. Animal Ecology Team, Wageningen; Países Bajos Fil: Winfree, Rachael. Rutgers University; Estados Unidos Recent evidence highlights the value of wild-insect species richness and abundance for crop pollination world-wide. Yet, deliberate physical importation of single species (eg European honey bees) into crop fields for polli-nation remains the mainstream management approach, and implementation of practices to enhance cropyield (production per area) through wild insects is only just beginning. With few exceptions, studies measur-ing the impacts of pollinator-supporting practices on wild-insect richness and pollination service success – par-ticularly in relation to long-term crop yield and economic profit – are rare. Here, we provide a general frame-work and examples of approaches for enhancing pollinator richness and abundance, quantity and quality ofpollen on stigmas, crop yield, and farmers’ profit, including some benefits detected only through long-termmonitoring. We argue for integrating the promotion of wild-insect species richness with single-species man-agement to benefit farmers and society.

Within-farm habitat enhancements such as hedgerows could aid pest control in adjacent crops; however, there is little information on whether small-scale restoration impacts pests and natural enemies, and crop damage, and how far effects may extend into fields. We compared restored, California native perennial hedgerows to unenhanced field edges consisting of commonly occurring semi-managed, non-native weeds. Pest and natural enemy communities were assessed in both edge types and into adjacent processing tomato fields. Using sentinel pest eggs, pest control was quantified, and pest pressure and crop damage was compared between field types. Economically-important pests were fewer and parasitoid wasps were more abundant in hedgerows than weedy crop edges. There was no difference in predatory arthropod abundance between edge types, but there was greater predator richness in hedgerow than weedy edges. Predatory lady beetles were more abundant and aphids were lower in fields with hedgerows, up to 200. m into fields, the maximum extent of observations. Fewer of the fields adjacent to hedgerows reached threshold pest levels requiring insecticide application. Benefits of hedgerows to pest control from parasitism extended to 100. m but not 200. m into fields. Farm-scale hedgerow restoration can provide pest control benefits up to 100 or 200. m into fields and multiple hedgerows around fields could enhance pest control throughout entire fields, reducing the need for chemical pest control. © 2014 Published by Elsevier B.V.

Commercial greenhouse studies were conducted to assess levels of pollination of tomato (Lycopersicon esculentum Mill.) flowers in relation to bumble bee (Bombus impatiens Cresson) colony activity and colony densities. For the assessment of pollination levels of tomato flowers, five categories were defined based on bruising levels caused by bumble bee pollination. Colony activity was measured as bee trips per ha/d using electric powered photodiode monitors inserted into the hive entrance. Levels of pollination were positively correlated with bee activity levels, up to a mean of approximately 400 pollen grains per stigma per day, after which greater activity did not result in further increases in daily pollination levels. Densities of colonies in the commercial greenhouses studied ranged from 7.6 to 19.8 colonies per hectare with a mean of 11.6 +/- 0.9. We found that an average activity of 2,000 bee trips per hectare per day was more than adequate to ensure sufficient pollination, and that this level of activity could be achieved with 7-15 colonies per hectare, depending on greenhouse conditions. Greenhouses requiring >15 colonies per hectare to achieve this level of pollination may be able to increase bee activity through alteration of greenhouse conditions. Across 50-m rows of tomato plants, levels of pollination decreased with increasing distance from bee colonies, suggesting that colonies should be evenly distributed throughout the greenhouses.

Laboratory studies were conducted to assess tomato, Lycopersicon esculentum Mill. (Solanaceae), quality in relation to the level of buzz-pollination by bumble bees. Studies were conducted in commercial tomato greenhouses in the Leamington, Ontario, area to categorize bruising of tomato anther cones by bumble bees into five levels of bruising. The number of pollen grains per stigma was determined for each bruising level, and the bruising level was found to be a good predictor of stigmatic pollen load. Experimental flowers were pollinated by bumble bees and assigned to bruising levels based on the degree of anther cone discoloration. Fruit set, tomato weight, minimum diameter, the number of days until ripe, roundness, weight, percentage sugars, and number of seeds were assessed and compared among bruising level. Fruit set in flowers receiving no pollination visits was 30.2%, whereas, 83.3, 84.4, 81.2, and 100% of the flowers set fruit in bruising levels 1, 2, 3, and 4, respectively. Minimum diameter, number of seeds, and tomato weight all increased from no bruising to different levels of bruising. There was no increase in weight or diameter above a bruising level of 1, and no increase in the number of seeds per fruit after a bruising level of 2. We found that pollination of tomato flowers greater than a bruising level of 2 (corresponding to approximately one to two bee visits) did not result in a significant increase in quality.

Bees provide essential pollination services that are potentially affected both by local farm management and the surrounding landscape. To better understand these different factors, we modelled the relative effects of landscape composition (nesting and floral resources within foraging distances), landscape configuration (patch shape, interpatch connectivity and habitat aggregation) and farm management (organic vs. conventional and local-scale field diversity), and their interactions, on wild bee abundance and richness for 39 crop systems globally. Bee abundance and richness were higher in diversified and organic fields and in landscapes comprising more high-quality habitats; bee richness on conventional fields with low diversity benefited most from high-quality surrounding land cover. Landscape configuration effects were weak. Bee responses varied slightly by biome. Our synthesis reveals that pollinator persistence will depend on both the maintenance of high-quality habitats around farms and on local management practices that may offset impacts of intensive monoculture agriculture. Bees provide essential pollination services that are potentially affected both by local farm management and the surrounding landscape. To better understand these different factors, we modelled the relative effects of landscape composition (nesting and floral resources within foraging distances), landscape configuration (patch shape, interpatch connectivity and habitat aggregation) and farm management (organic vs. conventional and local-scale field diversity), and their interactions, on wild bee abundance and richness for 39 cropsystems globally. Bee abundance and richness were higher in diversified and organic fields and in landscapes comprising more high-quality habitats; bee richness on conventional fields with low diversity benefited most from high-quality surrounding land cover. Landscape configuration effects were weak. Beeresponses varied slightly by biome. Our synthesis reveals that pollinator persistence will depend on boththe maintenance of high-quality habitats around farms and on local management practices that may offsetimpacts of intensive monoculture agriculture.

Habitat restoration to promote wild pollinator populations is becoming increasingly common in agricultural lands. Yet, little is known about how wild bees, globally the most important wild pollinators, use resources in restored habitats. We compared bee use of native and exotic plants in two types of restored native plant hedgerows: mature hedgerows (>10 years from establishment) designed for natural enemy enhancement and new hedgerows (≤2 years from establishment) designed to enhance bee populations. Bees were collected from flowers using timed aerial netting and flowering plant cover was estimated by species using cover classes. At mature hedgerow sites, wild bee abundance, richness, and diversity were greater on native plants than exotic plants. At new sites, where native plants were small and had limited floral display, abundance of bees was greater on native plants than exotic plants; but, controlling for floral cover, there was no difference in bee diversity and richness between the two plant types. At both mature and new hedgerows, wild bees preferred to forage from native plants than exotic plants. Honey bees, which were from managed colonies, also preferred native plants at mature hedgerow sites but exhibited no preference at new sites. Our study shows that wild bees, and managed bees in some cases, prefer to forage on native plants in hedgerows over co-occurring weedy, exotic plants. Semi-quantitative ranking identified which native plants were most preferred. Hedgerow restoration with native plants may help enhance wild bee abundance and diversity, and maintain honey bee health, in agricultural areas. © 2012 Society for Ecological Restoration.

We conducted laboratory experiments to investigate the lethal and sublethal effects of clothianidin on bumble bee, Bombus impatiens Cresson, colony health and foraging ability. Bumble bee colonies were exposed to 6 ppb clothianidin, representing the highest residue levels found in field studies on pollen, and a higher dose of 36 ppb clothianidin in pollen. Clothianidin did not effect pollen consumption, newly emerged worker weights, amount of brood or the number of workers, males, and queens at either dose. The foraging ability of worker bees tested on an artificial array of complex flowers also did not differ among treatments. These results suggest that clothianidin residues found in seed-treated canola and possibly other crops will not adversely affect the health of bumble bee colonies or the foraging ability of workers.