Social organisation of the Tree Bumblebee (Bombus hypnorum)
Ryan Edward Brock, Ryan E. Brock , Andrew F. G. Bourke
School of Biological Sciences, University of East Anglia, Norwich, Norfolk, UK; School of Biological Sciences, University of East Anglia, Norwich, Norfolk, UK ; School of Biological Sciences, University of East Anglia, Norwich, Norfolk, UK
Worldwide declines of bumblebee populations are a major concern because of their importance as pollinators. In this respect, the Tree Bumblebee (Bombus hypnorum) represents an enlightening case study, having rapidly spread across the UK since first being recorded in southern England in 2001 to become one of the most abundant UK bumblebee species. Thus, in contrast to the majority of other bumblebees, whose populations are either stable, declining or at future risk, B. hypnorum represents a species increasing in both range and abundance. Although a few studies have investigated the ecology of B. hypnorum in the UK, little is known regarding its colony demography, social organisation, and genetic structure, or whether any of these have contributed to its ecological success. B. hypnorum queens exhibit facultative polyandry, which creates within-population, between-colony kin structure variation, so allowing tests of predictions from inclusive fitness theory regarding relationships between kinship, colony productivity, and worker reproductive behaviour. Hence the aims of this recently-started project are threefold: i) to characterise the demography of B. hypnorum colonies in the UK population; ii) to investigate their social organisation in light of inclusive fitness theory; and iii) to investigate their genetic structure (including levels of diploid male production). Overall, the results should both help elucidate the ecological success of B. hypnorum in the UK and further test the role of kin selection in social evolution in the eusocial Hymenoptera.