Caffeinated Forage Tricks Honeybees into Increasing Foraging and Recruitment Behaviors
Authored by Roger Schuerch, Margaret J Couvillon, Toufailia Hasan Al, Thomas M Butterfield, Felix Schrell, Francis L W Ratnieks
Date Published: 2015
DOI: 10.1016/j.cub.2015.08.052
Sponsors:
Natural Environment Research Council (NERC)
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Model Code URLs:
Model code not found
Abstract
In pollination, plants provide food reward to pollinators who in turn
enhance plant reproduction by transferring pollen, making the
relationship largely cooperative; however, because the interests of
plants and pollinators do not always align, there exists the potential
for conflict, where it may benefit both to cheat the other {[}1, 2].
Plants may even resort to chemistry: caffeine, a naturally occurring, bitter-tasting, pharmacologically active secondary compound whose main
purpose is to detract herbivores {[}3-6], is also found in lower
concentrations in the nectar of some plants, even though nectar, unlike
leaves, is made to be consumed by pollinators {[}5, 7, 8]. A recent
laboratory study showed that caffeine may lead to efficient and
effective foraging by aiding honeybee memory of a learned olfactory
association {[}4], suggesting that caffeine may enhance bee reward
perception. However, without field data, the wider ecological
significance of caffeinated nectar remains difficult to interpret. Here
we demonstrate in the field that caffeine generates significant
individual- and colony-level effects in free-flying worker honeybees.
Compared to a control, a sucrose solution with field-realistic doses of
caffeine caused honeybees to significantly increase their foraging
frequency, waggle dancing probability and frequency, and persistency and
specificity to the forage location, resulting in a quadrupling of
colony-level recruitment. An agent-based model also demonstrates how
caffeine-enhanced foraging may reduce honey storage. Overall, caffeine
causes bees to overestimate forage quality, tempting the colony into
sub-optimal foraging strategies, which makes the relationship between
pollinator and plant less mutualistic and more exploitative.
Tags
exaptation
Pollination
Science
Colonies
Nectar