Data from: Bumblebee queens are better at olfactory learning and more sensitive to scents than workers

Intra-specific variation in cognition can reflect ecological demands, yet
cognitive performance can be driven by non-cognitive processes. Bumblebees
have been a long-standing model in the study of cognition for their
aptitude at learning associations, but nearly all research has been
limited to one life stage: foraging workers. Queen bumblebees also forage,
and previous work shows that they learn visual associations with fewer
errors than workers, offering a useful comparison of the drivers of
variation in cognition. Here we tested whether queens’ better learning
performance holds across another modality: olfaction, and whether
performance could be driven by non-cognitive variables related to their
larger size, including peripheral sensitivity. We first assessed olfactory
learning in wild Bombus vosnesenskii and found that queens learned with
fewer errors than workers. Following additional training and sensitivity
tests, queens and workers did not differ, ruling out non-cognitive
variables as drivers of learning differences. In a second experiment, we
tested scent sensitivity under more controlled conditions in B. impatiens
and found that queens were more sensitive. Our findings confirm learning
differences between bumblebee castes and show that queens also have
greater peripheral sensitivity, hinting at adaptive drivers of these
intra-specific differences.