Data from: The influence of social structure on brood survival and development in a socially polymorphic ant: insights from a cross-fostering experiment

Animal societies vary in the number of breeders per group, which affects many socially and ecologically relevant traits. In several social insect species, including our study species Formica selysi, the presence of either one or multiple reproducing females per colony is generally associated with differences in a suite of traits such as the body size of individuals. However, the proximate mechanisms and ontogenetic processes generating such differences between social structures are poorly known. Here, we cross-fostered eggs originating from single-queen (=monogynous) or multiple-queen (=polygynous) colonies into experimental groups of workers from each social structure to investigate whether differences in offspring survival, development time and body size are shaped by the genotype and/or pre-foster maternal effects present in the eggs, or by the social origin of the rearing workers. Eggs produced by polygynous queens were more likely to survive to adulthood than eggs from monogynous queens, regardless of the social origin of the rearing workers. However, brood from monogynous queens grew faster than brood from polygynous queens. The social origin of the rearing workers influenced the probability of brood survival, with workers from monogynous colonies rearing more brood to adulthood than workers from polygynous colonies. The social origin of eggs or rearing workers had no significant effect on the head size of the resulting workers in our standardized laboratory conditions. Overall, the social backgrounds of the parents and of the rearing workers appear to shape distinct survival and developmental traits of ant brood.

动物社群的群体内繁殖者数量存在差异，这一特征会影响诸多社会与生态相关的性状。在包括本研究所用物种塞氏林蚁（Formica selysi）在内的多种社会性昆虫中，每蚁群仅存在1只或多只繁殖性雌性的社会结构，通常与个体体型等一系列性状的差异相关联。然而，驱动不同社会结构产生此类性状差异的近因机制与个体发育过程，目前仍知之甚少。本研究中，我们将源自单后制（monogynous）或多后制（polygynous）蚁群的卵，交叉寄养至对应两种社会结构的工蜂实验群中，旨在探究子代存活率、发育时长与体型的差异，究竟由卵内携带的基因型及/或寄养前母体效应所决定，抑或是由抚育工蜂的社会背景所塑造。无论抚育工蜂的社会背景如何，多后制蚁后所产的卵发育至成虫阶段的概率，均高于单后制蚁后所产的卵。但单后制蚁后所产的子代幼体，其发育速度快于多后制蚁后的子代幼体。抚育工蜂的社会背景同样会影响子代幼体的存活概率：单后制蚁群的工蜂，相较多后制蚁群的工蜂，可将更多子代幼体抚育至成虫阶段。在本研究的标准化实验室条件下，卵的社会背景或抚育工蜂的社会背景，对最终发育为工蜂的个体的头部大小无显著影响。总体而言，亲本与抚育工蜂的社会背景，似乎会分别塑造蚁类子代幼体的存活与发育性状。