Efficient visual learning by bumble bees in virtual‐reality conditions: Size does not matter

Recent developments allowed establishing virtual‐reality (VR) setups to study multiple aspects of visual learning in honey bees under controlled experimental conditions. Here, we adopted a VR environment to investigate the visual learning in the buff‐tailed bumble bee Bombus terrestris. Based on responses to appetitive and aversive reinforcements used for conditioning, we show that bumble bees had the proper appetitive motivation to engage in the VR experiments and that they learned efficiently elemental color discriminations. In doing so, they reduced the latency to make a choice, increased the proportion of direct paths toward the virtual stimuli and walked faster toward them. Performance in a short‐term retention test showed that bumble bees chose and fixated longer on the correct stimulus in the absence of reinforcement. Body size and weight, although variable across individuals, did not affect cognitive performances and had a mild impact on motor performances. Overall, we show that bumble bees are suitable experimental subjects for experiments on visual learning under VR conditions, which opens important perspectives for invasive studies on the neural and molecular bases of such learning given the robustness of these insects and the accessibility of their brain. We studied the visual learning of tethered bumble bees walking stationary on a treadmill and presented with virtual vertical cylinders differing in color and reinforcement type. We show that bumble bees interact with the virtual objects and learn both to choose the rewarded colored cylinder and to avoid the punished one. Size polymorphism did not affect visual learning although it had a mild effect on motor performances. These results thus establish bumble bees as a suitable model for studying visual cognition in controlled virtual‐reality environments.