Appetitive reversal learning differences of two honey bee subspecies with different foraging behaviors
- Published
- Accepted
- Subject Areas
- Animal Behavior, Ecology, Entomology, Evolutionary Studies
- Keywords
- associative learning, behavioral ecology, social insect, hymenoptera, learning plasticity, specialist, extinction, memory
- Copyright
- © 2018 Pérez Claudio et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2018. Appetitive reversal learning differences of two honey bee subspecies with different foraging behaviors. PeerJ Preprints 6:e27274v1 https://doi.org/10.7287/peerj.preprints.27274v1
Abstract
We aimed to examine mechanistically the observed foraging differences across two honey bee, Apis mellifera, subspecies using the Proboscis Extension Response (PER) assay. Specifically, we compared differences in appetitive reversal learning ability between honey bee subspecies:Apis mellifera caucasica(Pollman), andApis mellifera syriaca(Skorikov) in a “common garden” apiary. It was hypothesized that specific learning differences could explain previously observed foraging behavior differences of these subspecies: A.m. caucasica switches between different flower color morphs in response to reward variability, and A.m. syriaca does not switch. We suggest that flower constancy allows reduced exposure by minimizing search and handling time, whereas plasticity is important when maximizing harvest in preparation for long winter is at a premium. In the initial or Acquisition phase of the test we examined specifically discrimination learning, where bees were trained to respond to a paired conditioned stimulus with an unconditioned stimulus and not to respond to a second conditioned stimulus that is not followed by an unconditioned stimulus. We found no significant differences among the subspecies in the Acquisition phase in appetitive learning. During the second, Reversal phase of the experiment, where flexibility in association was tested, the paired and unpaired conditioned stimuli were reversed. During the Reversal phaseA. mellifera syriacashowed a reduced ability to learn the reverse association in the appetitive learning task. This observation is consistent with the hypothesis that A.m. syriaca foragers cannot change the foraging choice because of lack of flexibility in appetitive associations under changing contingencies. Interestingly, both subspecies continued responding to the previously rewarded conditioned stimulus in the reversal phase. We discuss potential ecological correlates and molecular underpinnings of these differences in learning across the two subspecies. In addition, in a supplemental experiment we demonstrated that these differences in appetitive reversal learning do not occur in other learning contexts.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Proboscis Extension Response of honeybees from two different subspecies during a Reversal Learning test
Electric Shock Avoidance data for two honeybee subspecies during a Reversal Learning test
In this data-set 1 means the individual was at the shock side in that particular second, 0 means the individual was not in the shock side.
Proboscis Extension Response data for A. mellifera of different ages during a Reversal Learning test
Reversal learning plot in Proboscis Extension Response Conditioning of bees from typicalApis melliferacolonies. (Ben-Shahar et al., 2000).
Electric Shock Avoidance data for honeybee subspecies A.m caucasica and A.m. syriaca during a Reversal Learning test
Comparison of spatial-avoidance learning rate between honey bee subspecies during an ESA assay. Each data point shows the percentage of time (± standard error) bees spent on the shock side during the trial. Both in Acquisition and Reversal phase bees reduce the time spent on shock side over the duration of the training (Repeated measures ANOVA: Acquisition P-value<0.0001, F(4,436)=10.25 and Reversal P-value<0.0001, F(4,436)=6.143. A two-way ANOVA test shows there are no differences between subspecies during Acquisition (F (1, 109) = 2.315, P-value > 0.13) or during Reversal (F (1, 109) = 0.0065, P-value > 0.93).
