Honeybees fail to discriminate floral scents in a complex learning task after consuming a neonicotinoid pesticide

Authors

Julie A. Mustard, The University of Texas Rio Grande Valley
Annie Gott, Newcastle University
Jennifer Scott
Nancy L. Chavarria, The University of Texas Rio Grande Valley
Geraldine A. Wright, University of Oxford

Document Type

Article

Publication Date

3-2020

Abstract

Neonicotinoids are pesticides used to protect crops but with known secondary influences at sublethal doses on bees. Honeybees use their sense of smell to identify the queen and nestmates, to signal danger and to distinguish flowers during foraging. Few behavioural studies to date have examined how neonicotinoid pesticides affect the ability of bees to distinguish odours. Here, we use a differential learning task to test how neonicotinoid exposure affects learning, memory, and olfactory perception in foraging-age honeybees. Bees fed with thiamethoxam could not perform differential learning and could not distinguish odours during short and long-term memory tests. Our data indicate that thiamethoxam directly impacts the cognitive processes involved in working memory required during differential olfactory learning. Using a combination of behavioural assays, we also identified that thiamethoxam has a direct impact on the olfactory perception of similar odours. Honeybees fed with other neonicotinoids (clothianidin, imidacloprid, dinotefuran) performed the differential learning task, but at a slower rate than the control. These bees could also distinguish the odours. Our data are the first to show that neonicotinoids have compound specific effects on the ability of bees to perform a complex olfactory learning task. Deficits in decision-making caused by thiamethoxam exposure could be more harmful than other neonicotinoids, leading to inefficient foraging and a reduced ability to identify nest mates.

Comments

© 2020, Published by The Company of Biologists Ltd. Original published version available at https://doi.org/10.1242/jeb.217174

Recommended Citation

Mustard, J. A., Gott, A., Scott, J., Chavarria, N. L., & Wright, G. A. (2020). Honeybees fail to discriminate floral scents in a complex learning task after consuming a neonicotinoid pesticide. Journal of Experimental Biology, 223(5). https://doi.org/10.1242/jeb.217174

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Title

Journal of Experimental Biology

DOI

10.1242/jeb.217174