Floral sonication is an innate behaviour in bumblebees that can be fine-tuned with experience in manipulating flowers

Citation

Morgan T, Whitehorn PR, Lye G & Vallejo-Marín M (2016) Floral sonication is an innate behaviour in bumblebees that can be fine-tuned with experience in manipulating flowers. Journal of Insect Behavior, 29 (2), pp. 233-241. https://doi.org/10.1007/s10905-016-9553-5

Abstract
Bumblebees demonstrate an extensive capacity for learning complex motor skills to maximise exploitation of floral rewards. This ability is well studied in nectar collection but its role in pollen foraging is less well understood. Floral sonication is used by bees to extract pollen from some plant species with anthers which must be vibrated (buzzed) to release pollen. Pollen removal is determined by sonication characteristics including frequency and amplitude, and thus the ability to optimise sonication should allow bees to maximise the pollen collection. We investigated the ability of the buff-tailed bumblebee (Bombus terrestris) to modify the frequency and amplitude of their buzzes with increasing experience manipulating flowers of the buzz-pollinated plantSolanum rostratum. We analysed flight and feeding vibrations generated by naïve workers across feeding bouts. Feeding buzzes were of a higher frequency and a lower amplitude than flight buzzes. Both flight and feeding buzzes had reduced amplitudes with increasing number of foraging trips. However, the frequency of their feeding buzzes was reduced significantly more than their flight buzzes as bumblebee workers gained experience manipulating flowers. These results suggest that bumblebees are able to modify the characteristics of their buzzes with experience manipulating buzz-pollinated flowers. We discuss our findings in the context of bumblebee learning, and the current understanding of the optimal sonication characteristics for releasing pollen in buzz-pollinated species. Our results present a tantalising insight into the potential role of learning in floral sonication, paving the way for future research in this area.

Keywords
Bombus terrestris; bumblebee; buzz pollination; learning; pollen foraging; sonication

Journal
Journal of Insect Behavior: Volume 29, Issue 2

• Morgan et al_J Insect Behav_2016.pdf