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Journal Article

Potential routes of exposure as a foundation for a risk assessment scheme: a Conceptual Model

09 Oct 2015-Julius-Kühn-Archiv-Iss: 450, pp 22-22

TL;DR: The quantitative pollinator conceptual model (QPCM) describes the flow pathways and potential exposure routes for honeybees and other bee pollinators in sufficient detail to support quantitative exposure modelling and risk assessment and shows the importance of measuring the distribution of pesticide residues in the areas that lead to exposure and in the hive.

AbstractBackground: The global interest in improving the regulatory risk assessment of pesticides in honeybees and other pollinator insects has led to new test requirements and a conceptual model has been published in the US. It is of interest for modellers and risk assessors to have a more detailed conceptual model that describes the movement of deleterious substances from the point of initial exposure to the point of impact on the protection goals, such as colony health, or honey production. Results: The flow of pesticide residues from application to distribution in the hive is described in an integrated conceptual model. The significance of this model for assessing the relative contribution of various potential routes of exposure, guiding test requirements and describing the quantitative distribution of residues among the castes and task groups of honeybees in the colony was described using data from studies with chlorpyrifos and several neonicotinoids. Conclusion: The quantitative pollinator conceptual model (QPCM) describes the flow pathways and potential exposure routes for honeybees and other bee pollinators in sufficient detail to support quantitative exposure modelling and risk assessment and shows the importance of measuring the distribution of pesticide residues in the areas that lead to exposure and in the hive.

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Journal ArticleDOI
TL;DR: It is submitted that 2 key processes underlie honey bee pesticide exposure: 1) the acquisition of pesticide by foraging bees, and 2) the in‐hive distribution of pesticide returned by foragers.
Abstract: The role of pesticides in recent honey bee losses is controversial, partly because field studies often fail to detect effects predicted by laboratory studies. This dissonance highlights a critical gap in the field of honey bee toxicology: there exists little mechanistic understanding of the patterns and processes of exposure that link honey bees to pesticides in their environment. The authors submit that 2 key processes underlie honey bee pesticide exposure: 1) the acquisition of pesticide by foraging bees, and 2) the in-hive distribution of pesticide returned by foragers. The acquisition of pesticide by foraging bees must be understood as the spatiotemporal intersection between environmental contamination and honey bee foraging activity. This implies that exposure is distributional, not discrete, and that a subset of foragers may acquire harmful doses of pesticide while the mean colony exposure would appear safe. The in-hive distribution of pesticide is a complex process driven principally by food transfer interactions between colony members, and this process differs importantly between pollen and nectar. High priority should be placed on applying the extensive literature on honey bee biology to the development of more rigorously mechanistic models of honey bee pesticide exposure. In combination with mechanistic effects modeling, mechanistic exposure modeling has the potential to integrate the field of honey bee toxicology, advancing both risk assessment and basic research. Environ Toxicol Chem 2017;36:871-881. © 2016 SETAC.

44 citations


Journal ArticleDOI
TL;DR: How certain pesticide risks are particularly important under circumstances related to the cavity nesters is highlighted, incorporating the relative importance of environmental contamination due to pesticide chemical behaviors.
Abstract: Abstract Declines of pollinator health and their populations continue to be commercial and ecological concerns. Agricultural practices, such as the use of agrochemicals, are among factors attributed to honey bee (Apis mellifera L. (Hymenoptera: Apidae)) population losses and are also known to have negative effects on populations of managed non-Apis pollinators. Although pesticide registration routinely requires evaluation of impacts on honey bees, studies of this social species may not reveal important pesticide exposure routes where managed, solitary bees are commonly used. Studies of solitary bees offer additional bee models that are practical from the aspect of availability, known rearing protocols, and the ability to assess effects at the individual level without confounding factors associated with colony living. In addition to understanding bees, it is further important to understand how pesticide characteristics determine their environmental whereabouts and persistence. Considering our research expertise in advancing the management of solitary bees for crop pollination, this forum focuses on routes of pesticide exposure experienced by cavity-nesting bees, incorporating the relative importance of environmental contamination due to pesticide chemical behaviors. Exposure routes described are larval ingestion, adult ingestion, contact, and transovarial transmission. Published research reports of effects of several pesticides on solitary bees are reviewed to exemplify each exposure route. We highlight how certain pesticide risks are particularly important under circumstances related to the cavity nesters.

31 citations


Cites background from "Potential routes of exposure as a f..."

  • ...2014, Purdy 2014, USEPA, PMRA, and CDPR 2014, Heard et al....

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Journal ArticleDOI
TL;DR: It is suggested that the analysis of pesticides in bee bread and in bees from the brood comb is a useful addition to dead bee and suspected crop analysis in poisoning incidents to inform the extent of recent in-hive contamination.
Abstract: Honey bees are major pollinators of crops with high economic value. Thus, bees are considered to be the most important nontarget organisms exposed to adverse effects of plant protection product use. The side effects of pesticides are one of the major factors often linked to colony losses. Fewer studies have researched acute poisoning incidents in comparison to the study of the sublethal effects of pesticides. Here, we compared pesticides in dead/dying bees from suspected poisoning incidents and the suspected crop source according to government protocols. Additionally, we analyzed live bees and bee bread collected from the brood comb to determine recent in-hive contamination. We used sites with no reports of poisoning for reference. Our analysis confirmed that not all of the suspected poisonings correlated with the suspected crop. The most important pesticides related to the poisoning incidents were highly toxic chlorpyrifos, deltamethrin, cypermethrin and imidacloprid and slightly toxic prochloraz and thiacloprid. Importantly, poisoning was associated with pesticide cocktail application. Almost all poisoning incidents were investigated in relation to rapeseed. Some sites were found to be heavily contaminated with several pesticides, including a reference site. However, other sites were moderately contaminated despite agricultural use, including rapeseed cultivation sites, which can influence the extent of pesticide use, including tank mixes and other factors. We suggest that the analysis of pesticides in bee bread and in bees from the brood comb is a useful addition to dead bee and suspected crop analysis in poisoning incidents to inform the extent of recent in-hive contamination.

6 citations


References
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Book
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TL;DR: This book describes the life cycle of a honey bee, focusing on the courtship and mating activities of Worker Bees and their role in the evolution of monogamy.
Abstract: 1. Introduction 2. The Origins and Evolutionary History of Bees 3. Form and Function: Honey Bee Anatomy 4. Development and Nutrition 5. Nest Architecture 6. The Age-Related Activities of Worker Bees 7. Other Worker Activities 8. The Chemical World of Honey Bees 9. Communication and Orientation 10. The Collection of Food 11. Reproduction: Swarming and Supersedure 12. Drones, Queens, and Mating 13. The Biology of Temperate and Tropical Honey Bees Reference Author Index Subject Index

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1,253 citations


Journal ArticleDOI
TL;DR: The proposed risk assessment scheme for systemic compounds was shown to be applicable to assess the risk for side-effects of neonicotinoids as it considers the effect on different life stages and different levels of biological organization (organism versus colony).
Abstract: Neonicotinoid insecticides are successfully applied to control pests in a variety of agricultural crops; however, they may not only affect pest insects but also non-target organisms such as pollinators. This review summarizes, for the first time, 15 years of research on the hazards of neonicotinoids to bees including honey bees, bumble bees and solitary bees. The focus of the paper is on three different key aspects determining the risks of neonicotinoid field concentrations for bee populations: (1) the environmental neonicotinoid residue levels in plants, bees and bee products in relation to pesticide application, (2) the reported side-effects with special attention for sublethal effects, and (3) the usefulness for the evaluation of neonicotinoids of an already existing risk assessment scheme for systemic compounds. Although environmental residue levels of neonicotinoids were found to be lower than acute/chronic toxicity levels, there is still a lack of reliable data as most analyses were conducted near the detection limit and for only few crops. Many laboratory studies described lethal and sublethal effects of neonicotinoids on the foraging behavior, and learning and memory abilities of bees, while no effects were observed in field studies at field-realistic dosages. The proposed risk assessment scheme for systemic compounds was shown to be applicable to assess the risk for side-effects of neonicotinoids as it considers the effect on different life stages and different levels of biological organization (organism versus colony). Future research studies should be conducted with field-realistic concentrations, relevant exposure and evaluation durations. Molecular markers may be used to improve risk assessment by a better understanding of the mode of action (interaction with receptors) of neonicotinoids in bees leading to the identification of environmentally safer compounds.

732 citations


Journal ArticleDOI
TL;DR: This article concentrates heavily on virus propagation and methods for detection, with minor excursions into surveying, sampling management and background information on the many viruses found in bees.
Abstract: SummaryHoney bee virus research is an enormously broad area, ranging from subcellular molecular biology through physiology and behaviour, to individual and colony-level symptoms, transmission and epidemiology The research methods used in virology are therefore equally diverse This article covers those methods that are very particular to virological research in bees, with numerous cross-referrals to other BEEBOOK papers on more general methods, used in virology as well as other research At the root of these methods is the realization that viruses at their most primary level inhabit a molecular, subcellular world, which they manipulate and interact with, to produce all higher order phenomena associated with virus infection and disease Secondly, that viruses operate in an exponential world, while the host operates in a linear world and that much of the understanding and management of viruses hinges on reconciling these fundamental mathematical differences between virus and host The article concentrates

216 citations


"Potential routes of exposure as a f..." refers background in this paper

  • ..._ENREF_13 (13)(14) Given that it is not possible to do research on bees in the absence of these factors, bee studies must include or control health, nutrition, beecare and other cofactors....

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Journal ArticleDOI

202 citations


"Potential routes of exposure as a f..." refers background in this paper

  • ...(12) This is of particular significance now, since virus and other disease symptoms are being promoted as neonicotinoid toxicity effects....

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