Assured fitness returns in a social wasp with no worker caste

作者：Lucas Eric R^*; Field Jeremy

来源：Proceedings of the Royal Society B, 2011, 278(1720): 2991-2995.

DOI：10.1098/rspb.2011.0128

• assured fitness returns
• insurance-based advantages
• cooperative brood care
• origin of sociality
• Microstigmus

The theory of assured fitness returns proposes that individuals nesting in groups gain fitness benefits from effort expended in brood-rearing, even if they die before the young that they have raised reach independence. These benefits, however, require that surviving nest-mates take up the task of rearing these young. It has been suggested that assured fitness returns could have favoured group nesting even at the origin of sociality (that is, in species without a dedicated worker caste). We show that experimentally orphaned brood of the apoid wasp Microstigmus nigrophthalmus continue to be provisioned by surviving adults for at least two weeks after the orphaning. This was the case for brood of both sexes. There was no evidence that naturally orphaned offspring received less food than those that still had mothers in the nest. Assured fitness returns can therefore represent a real benefit to nesting in groups, even in species without a dedicated worker caste.

• 出版日期2011-10-7