Colony defence in bumblebees (<em>Bombus terrestris</em>)

Abstract

Bumblebees are key pollinators of both wild plants and agricultural crops; hence, understanding their biology is critical for conservation efforts as well as for managing domesticated colonies. While their foraging and reproductive ecology have received a lot of attention, we know little about another crucial part of their behavioural repertoire: colony defence. The first dataset examines the defensive responses of individuals in whole colonies, maintained at the laboratory, after disturbing them with a mechanical jolt. As a result, we present a detailed ethogram of the defensive behaviour of Bombus terrestris in response to mechanical disturbances, as could be induced by vertebrate attacks or handling. In addition to identifying and describing the different responses elicited by this disturbance, this data contains information about their temporal sequence, their location and the proportion of bees involved. We also determined whether individual bees produce specific associations of behaviours, which revealed that a core set of responses is exhibited by all bees, with other behaviours being randomly associated. The second dataset compares defensive response based on disturbance type (mechanical jolt, intruder breath or foreign object). Overall, we demonstrate that colony defence includes measures preparing members for a response by signalling about the threat, searching for the source of the disturbance, warning intruders to maintain distance, and finally recovering from the disturbance. This comprehensive overview provides a valuable starting point to further understand how defensive behaviour is regulated such that bumblebee colonies can survive predator attacks and thrive.