Pesticide Risk Assessment for Pollinators

David Fischer, Tom Moriarty

• Publisher: Wiley-Blackwell
• Year: 2014
• Print ISBN: 9781118852521
• eBook ISBN: 9781118852699
• Edition: 1
• Topic: Biological Sciences
• Subtopic: Microbiology
• Index: Biological Sciences

Pollinators play a vital role in ecosystem health and are essential to ensuring food security. With declines in both managed and wild pollinator populations in recent years, scientists and regulators have sought answers to this problem and have explored implementing steps to protect pollinator populations now and for the future. Pesticide Risk Assessment for Pollinators focuses on the role pesticides play in impacting bee populations and looks to develop a risk assessment process, along with the data to inform that process, to better assess the potential risks that can accompany the use of pesticide products.

Pesticide Risk Assessment for Pollinators opens with two chapters that provide a biological background of both Apis and non- Apis species of pollinators. Chapters then present an overview of the general regulatory risk assessment process and decision-making processes. The book then discusses the core elements of a risk assessment, including exposure estimation, laboratory testing, and field testing. The book concludes with chapters on statistical and modeling tools, and proposed additional research that may be useful in developing the ability to assess the impacts of pesticide use on pollinator populations.

Summarizing the current state of the science surrounding risk assessment for Apis and non- Apis species, Pesticide Risk Assessment for Pollinators is a timely work that will be of great use to the environmental science and agricultural research communities.

• Assesses pesticide risk to native and managed pollinators
• Summarizes the state of the science in toxicity testing and risk assessment
• Provides valuable biological overviews of both Apis and non- Apis pollinators
• Develops a plausible overall risk assessment framework for regulatory decision making
• Looks towards a globally harmonized approach for pollinator toxicity and risk assessment

1
Introduction

CONTENTS

1. 1.1 Workshop Balance and Composition

Worldwide declines in managed and non-managed pollinators have led to an increased global dialogue and focus concerning the potential factors that may be causing these declines. Although a number of factors have been hypothesized as potential contributors to pollinator declines, at this time, no single factor has been identified as the cause. The available science suggests that pollinator declines are a result of multiple factors which may be acting in various combinations. Research is being directed at identifying the individual and combined stressors that are most strongly associated with pollinator declines. Pesticide use is one of the factors under consideration.

In an effort to further the global dialogue, the Society of Environmental Toxicology and Chemistry (SETAC) held a Pellston Workshop¹ to explore the state of the science on pesticide risk assessment for pollinators. The proposal for this SETAC Workshop was developed by a steering committee (hereafter referred to as the Steering Committee) comprised of members from the government and nongovernmental organizations who were interested in advancing the science to understand the effect of pesticides on nontarget insects. Workshop participants were tasked to advance the current state of the science of pesticide risk assessment by more thoroughly vetting quantitative and qualitative measures of exposure and effects on the individual bee, and where appropriate, on the colony. In doing so, the Workshop aimed to synthesize the global understanding and work that has, thus far, taken place, and to move toward a harmonized process for evaluating and quantitatively characterizing risk to pollinators from exposure to pesticides; and to identify the data needed to inform that process. The Workshop focused on four major topics:

1. design and identify testing protocols to estimate potential exposure of bees to pesticide residues in pollen and nectar, as well as exposure through other routes;
2. design and identify testing protocols to measure the effects of pesticides on developing brood and adult honey bees at both the individual and the colony levels;
3. propose a tiered approach for characterizing the potential risk of pesticides to pollinators; and
4. explore the applicability of testing protocols, used for honey bees (Apis bees), to measure the effects of pesticides and pesticide risk to other non-Apis bee species.

Although the term “pollinators” encompasses a broad number of taxa, for the purposes of this SETAC Workshop and its proceedings, the term “pollinators” refers specifically to subspecies and strains of Apis mellifera that originated in Europe (i.e., the honey bee) and other (non-Apis mellifera) bees, for example, bumble bees, solitary bees, and stingless bees. The Workshop built upon the numerous efforts of different organizations, regulatory authorities, and individuals, both nationally and internationally, aiming to better understand the role and effects of pesticide products on honey bees² and other bee species.

1.1 WORKSHOP BALANCE AND COMPOSITION

Similar to other timely and relevant scientific issues addressed by SETAC Pellston Workshops, the issue of pollinator protection is of high interest to scientists employed by governments, business, academia, and nongovernmental organizations. For this reason, SETAC requires that its workshops be similarly balanced. The Workshop on Pesticide Risk Assessment for Pollinators represented an exceptionally diverse composition by both sector (employer) and geography. The 48 participants (35 panelists and 13 Steering Committee members) included individuals from industry, nongovernmental organizations, federal and state governments, the beekeeping community, and academia and represented five continents (South America, Europe, Australia, North America, and Africa) (see Acknowledgments).

This proceeding of the Workshop on Pesticide Risk Assessment for Pollinators has several sections:

• Chapters 2–6 provide background and overview of key elements such as bee biology, ecological risk assessment, and protection goals.
• Chapters 7–10 capture recommendations by the Workshop on the elements of exposure assessment, effects assessment (laboratory and field testing), and risk assessment.
• Chapters 11–14 capture discussion around statistical analysis, modeling, risk management, and research needs.

Pollinators, and the honey bee in particular, have been identified as a valued group of organisms because of the services they provide to agriculture and to ecosystem biodiversity. While both managed and unmanaged (Apis and non-Apis) bees contribute to crop pollination, most of the current knowledge of the side effects of agricultural pesticides on pollinators is in relation to the honey bee. Since it is not possible to test all species, regulatory authorities rely on one or several surrogate species to represent a wider range of species within a taxon. Unlike the North American process that uses the honey bee as a surrogate for other terrestrial invertebrates, the European process includes testing requirements for honey bees specifically (representing pollinating insects), and includes other surrogate test species for nontarget arthropods in general. The proposed process discussed herein relies mainly on the honey bee, but includes other species, such as bumble bees, for example, to represent the many different species of bees. Therefore, it is important to understand the ecology and biology of the Apis bee as a test organism, as well as that of non-Apis bees.

NOTES

¹ The first Pellston Workshop was held in 1977 to address the needs and means for assessing the hazards of chemicals to aquatic life. Since then, many workshops have been held to evaluate current and prospective environmental issues. Each has focused on a relevant environmental topic, and the proceedings of each have been published as a peer-reviewed or informal report. These documents have been widely distributed and are valued by environmental scientists, engineers, regulators, and managers because of their technical basis and their comprehensive, state-of-the-science reviews. The first four Pellston workshops were initiated before the Society of Environmental Toxicology and Chemistry (SETAC) was effectively functioning. Beginning with the 1982 workshop, however, SETAC has been the primary organizer and SETAC members (on a volunteer basis) have been instrumental in planning, conducting, and disseminating workshop results. Taken from http://www.setac.org/node/104 ² USDA Technical Working Group Report on Honey Bee Toxicity Testing, July 8 and 9, 2009, http://www.aphis.usda.gov/plant_health/plant_pest_info/honey_bees/downloads/twg_report_july_2010.pdf; International Commission for Plant–Bee Relationships 10th International Symposium, 2009, http://www.uoguelph.ca/icpbr/pubs/2008%20ICPBR%20symposium%20archives%20Pesticides.pdf

2
Overview of the Honey Bee

J. Pettis

CONTENTS

1. 2.1 Overview of Honey Bee Biology

A key goal of regulatory authorities charged with licensing the use of pesticide products is to protect nontarget organisms from the potential adverse effects from those pesticide products. As it is not possible to test all species, the pesticide risk assessment framework relies on surrogate species to represent major taxa, including insect pollinators. The European honey bee (Apis mellifera), among the many different bee species, is a desirable surrogate test species in that it is both commercially valued and is also adaptable to laboratory research. In many countries, such as Canada and the United States, the honey bee is used as a surrogate for insect pollinators and many other nontarget terrestrial insects. While honey bees may be subject to collateral effects from the use of pesticides in crop production, they are also the beneficiaries of pesticide applications, as beekeepers routinely employ registered pesticides to manage pest problems that occur in managed hives. The in-hive use of pesticides by beekeepers and the potential exposure of honey bees to environmental mixtures of pesticides used in agriculture coupled with the complex social organization and biology of honey bees can complicate pesticide risk assessment. While these are major challenges facing risk assessment, their resolution will require additional research efforts and so they are beyond the scope of this document and are not addressed further herein (see Chapter 14).

2.1 OVERVIEW OF HONEY BEE BIOLOGY

From a risk assessment perspective, there are several aspects of honey bee biology which are important to consider as they potentially influence the toxicity studies required as well as the approach for evaluating potential risks. Colony growth and survival are dependent on the collective actions of individuals that perform various critical tasks; therefore, honey bee colonies act collectively as a “superorganism.” The different castes of bees within the hive structure have different functions which can result in differential exposure in terms of route, duration, magnitude, and mode (direct vs. indirect, secondary exposure). The survival of an individual bee may be of little consequence as colonies typically have a 10–30% reserve of workers, which reflects and accommodates the high turnover rate (of the individual) and flexibility of the colony to adapt to its environment. An examination of the roles of various castes within the hive and the implication for risk assessments follows.

A honey bee colony is made up of one queen, several drones, thousands of workers, and many immature bees in various stages of development (eggs,...

Table of contents

• Cover
• Cronology
• Titlepage
• Copyright
• Series
• Dedication
• Acknowledgments
• About the Editors
• Workshop Participants
• Pellston Workshop Series
• 1 Introduction
• 2 Overview of the Honey Bee
• 3 Overview of Non-Apis Bees
• 4 Overview of Protection Goals for Pollinators
• 5 Overview of the Pesticide Risk Assessment and the Regulatory Process
• 6 Problem Formulation for an Assessment of Risk to Honey Bees from Applications of Plant Protection Products to Agricultural Crops
• 7 Assessing Exposure of Pesticides to Bees
• 8 Assessing Effects Through Laboratory Toxicity Testing
• 9 Assessing Effects Through Semi-Field and Field Toxicity Testing
• 10 Overview of a Proposed Ecological Risk Assessment Process for Honey bees (Apis mellifera) and Non-Apis Bees
• 11 Ecological Modeling for Pesticide Risk Assessment for Honey Bees and Other Pollinators
• 12 Data Analysis Issues
• 13 Risk Mitigation and Performance Criteria
• 14 Recommendations for Future Research in Pesticide Risk Assessment for Pollinators
• Appendix 1: Elements for a Chronic Adult Oral Toxicity Study
• Appendix 2: Elements of a Larval Study
• Appendix 3: Elements of Artificial Flower Test
• Appendix 4: Elements of the Visual Learning Test
• Appendix 5: Foraging Behavior with Radio Frequency Identification
• Appendix 6: Detailed Description of the Proposed Overall Risk Assessment Scheme
• Glossary of Terms
• Index
• End User License Agreement