Biting behaviour as a tactic of escape in two bumblebee species with different nesting habits, Bombus terrestris L. and B. pascuorum Scopoli (Hymenoptera: Apidae)

Abstract

Workers of two bumblebee species, Bombus terrestris L. and B. pascuorum Scopoli, had to find the way of escape out of a test tube closed with a paper membrane stretched against its open end. Nearly all of the tested individuals solved successfully that task by tearing a hole in the membrane closing the tube. However, their escape behaviour showed significant interspecific differences. B. terrestris started biting the membrane sooner than B. pascuorum, and they were biting it more persistently. These behavioural differences matched well the differences in the nesting ecology of these two species. Whereas B. pascuorum is a surface-nesting species, B. terrestris nest in underground cavities connected with the outside world by long tunnels. B. terrestris are thus more likely to be well adapted to deal with obstacles obstructing their way, and/or to have more experience in removing them. Neither the efficiency of biting behaviour as a tactic of escape, nor the total test time differed significantly between the tested species.