Sociality in the Australian Allodapine Bee Brevineura elongata: Small Colony Sizes Despite Large Benefits to Group Living
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Allodapine bees (family Apidae, subfamily Xylocopinae) provide substantial material for investigating the evolution of sociality because of their wide variation in colony size, life history traits, and caste differentiation. Two recent studies have shown that the Australian allodapine genus Brevineura exhibits a strong increase in per capita brood production (PCBP) in social colonies compared to single-female nests. However both species previously examined, B. xanthoclypeata and B. froggatti, show relatively few multi-female nests, which is puzzling considering the apparently large advantages for group-living in these species. Here we show that in a third species, B. elongata, there are also substantial benefits for group living, involving increased PCBP and a greatly reduced likelihood of nests without brood. As expected from these observations, we also found strongly female biased sex allocation. Nevertheless only a small percentage of nests contained more than one adult female, similar to the other two Brevineura species, raising the question of why multifemale colonies are not more common in this genus. Solving this puzzle will throw light on conditions that constrain sociality when group living apparently provides major advantages.
KEY WORDS:Allodapine Brevineura elongata Per capita brood production Social behaviour
We thank Nick Bull for substantial help and direction during this project. We also thank Nick Bull, Simon Tierney and Zeta Steen for help with field work. We thank Mary Lyons for helpful comments on this manuscript. This project was supported by Australian Research Council grants to M. Schwarz.
- Hogendoorn, K., and Schwarz, M. P. (1998). Guarding specialisation in pre-reproductive colonies of the allodapine bee Exoneura bicolor. Ethol. Ecol. Evol. 10(1): 67–77.Google Scholar
- Houston, T. F. (1977). Nesting biology of three allodapine bee in the subgenus Exoneurella Michener (Hymenoptera: Anthophoridae). T. Roy. Soc. South Aust. 101: 99–113.Google Scholar
- Hurst, P. S. (2002). Social biology of Exoneurella tridentata, an Australian allodapine bee with morphological castes and perennial colonies. Ph.D. Thesis. Flinders University of South Australia, Adelaide.Google Scholar
- Joyce, N. C. (2001). Life cycle and social behaviour in south eastern Queensland populations of allodapine bees, Exoneura nr robusta, Brevineura elongata, and Braunsapis protuberans. Honours Thesis. Flinders University of South Australia, Adelaide.Google Scholar
- Michener, C. D. (1965). The life cycle and social organization of bees of the genus Exoneura and their parasite Inquilina. U. Kansas. S. Bul. 46: 317–358.Google Scholar
- Reeve, H. K. (1991). Polistes. In Ross, K. G. and Matthews, R. W. (eds.), The Social Biology of Wasps, Cornell Univ. Press, Ithaca, pp. 99–148.Google Scholar
- Schwarz, M. P., Fuller, S. Tierney, S. M., & Cooper, S. J. B. (in press) Molecular phylogenetics of the exoneurine allodapine bees reveal an ancient and puzzling dispersal from Africa to Australia. Sys. Biol. Google Scholar
- Steen, Z., and Schwarz, M. P. (1998). Within-nest behaviour in a eusocial Australian allodapine bee Exoneura (Exoneurella) tridentata Houston (Apidae: Xylocopinae). T. R. Soc. South Aust. 122(1–2): 55–63.Google Scholar
- Thompson, S., and Schwarz, M. P. (in press). Sociality and sex allocation in a tropical allodapine bee, Macrogalea candida. Biol. J. Linn. Soc. Google Scholar