Foraging bumblebees acquire a preference for neonicotinoid treated food with prolonged exposure
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Social bees represent an important group of pollinating insects that can be exposed to potentially harmful pesticides when foraging on treated or contaminated flowering plants. To investigate if such exposure is detrimental to bees, many studies have exclusively fed individuals with pesticide-spiked food, informing us about the hazard but not necessarily the risk of exposure. While such studies are important to establish the physiological and behavioural effects on individuals, they do not consider the possibility that the risk of exposure may change over time. For example, many pesticide assays exclude potential behavioural adaptations to novel toxins, such as rejection of harmful compounds by choosing to feed on an uncontaminated food source, thus behaviourally lowering the risk of exposure. In this paper, we conducted an experiment over 10 days in which bumblebees could forage on an array of sucrose feeders containing 0, 2 and 11 parts per billion of the neonicotinoid pesticide thiamethoxam. This more closely mimics pesticide exposure in the wild by allowing foraging bees to (i) experience a field realistic range of pesticide concentrations across a chronic exposure period, (ii) have repeated interactions with the pesticide in their environment, and (iii) retain the social cues associated with foraging by using whole colonies. We found that the proportion of visits to pesticide-laced feeders increased over time, resulting in greater consumption of pesticide-laced sucrose relative to untreated sucrose. After changing the spatial position of each feeder, foragers continued to preferentially visit the pesticide-laced feeders which indicates that workers can detect thiamethoxam and alter their behaviour to continue feeding on it. The increasing preference for consuming the neonicotinoid-treated food therefore increases the risk of exposure for the colony during prolonged pesticide exposure. Our results highlight the need to incorporate attractiveness of pesticides to foraging bees (and potentially other insect pollinators) in addition to simply considering the proportion of pesticide-contaminated floral resources within the foraging landscape.
Date Issued
2018-08-29
Date Acceptance
2018-08-07
Citation
Proceedings of the Royal Society B: Biological Sciences, 2018, 285 (1885)
ISSN
1471-2954
Publisher
Royal Society, The
Journal / Book Title
Proceedings of the Royal Society B: Biological Sciences
Volume
285
Issue
1885
Copyright Statement
© 2018 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution
License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original
author and source are credited.
License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original
author and source are credited.
Sponsor
Natural Environment Research Council (NERC)
Grant Number
NE/L00755X/1
Subjects
Science & Technology
Life Sciences & Biomedicine
Biology
Ecology
Evolutionary Biology
Life Sciences & Biomedicine - Other Topics
Environmental Sciences & Ecology
aversion
chronic exposure
hazard
insect pollinator
risk
thiamethoxam
PESTICIDE EXPOSURE
ENVIRONMENTAL RISKS
HONEY-BEES
WILD BEES
INSECTICIDES
POLLINATORS
ECOLOGY
BEHAVIOR
THREATS
ROUTE
06 Biological Sciences
11 Medical And Health Sciences
07 Agricultural And Veterinary Sciences
Publication Status
Published