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Caffeine in Floral Nectar Enhances a Pollinator's Memory of Reward

Lookup NU author(s): Professor Geraldine Wright, Daniel Stabler, Dr Eileen Power, Emerita Professor Anne Borland



Plant defense compounds occur in floral nectar, but their ecological role is not well understood. We provide evidence that plant compounds pharmacologically alter pollinator behavior by enhancing their memory of reward. Honeybees rewarded with caffeine, which occurs naturally in nectar of Coffea and Citrus species, were three times as likely to remember a learned floral scent as were honeybees rewarded with sucrose alone. Caffeine potentiated responses of mushroom body neurons involved in olfactory learning and memory by acting as an adenosine receptor antagonist. Caffeine concentrations in nectar did not exceed the bees' bitter taste threshold, implying that pollinators impose selection for nectar that is pharmacologically active but not repellent. By using a drug to enhance memories of reward, plants secure pollinator fidelity and improve reproductive success.

Publication metadata

Author(s): Wright GA, Baker DD, Palmer MJ, Stabler D, Mustard JA, Power EF, Borland AM, Stevenson PC

Publication type: Article

Publication status: Published

Journal: Science

Year: 2013

Volume: 339

Issue: 6124

Pages: 1202-1204

Print publication date: 08/03/2013

Acceptance date: 21/02/2012

Date deposited: 19/01/2015

ISSN (print): 0036-8075

ISSN (electronic): 1095-9203

Publisher: American Association for the Advancement of Science


DOI: 10.1126/science.1228806


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Funder referenceFunder name
Linnean Society of London
BB/I000968/1UK government Insect Pollinators Initiative