Evolution of ageing, costs of reproduction and the fecundity–longevity trade-off in eusocial insects

Eusocial insects provide special opportunities to elucidate the evolution of ageing as queens have apparently evaded costs of reproduction and reversed the fecundity-longevity trade-off generally observed in non-social organisms. But how reproduction affects longevity in eusocial insects has rarely been tested experimentally. In this study, we took advantage of the reproductive plasticity of workers to test the causal role of reproduction in determining longevity in eusocial insects. Using the eusocial bumblebee Bombus terrestris, we found that, in whole colonies, in which workers could freely 'choose' whether to become reproductive, workers' level of ovarian activation was significantly positively associated with longevity and ovary-active workers significantly outlived ovary-inactive workers. By contrast, when reproductivity was experimentally induced in randomly-selected workers, thereby decoupling it from other traits, workers' level of ovarian activation was significantly negativel...真社会性昆虫（eusocial insects）为阐明衰老演化提供了独特契机，因为蜂后似乎规避了繁殖代价，并逆转了非社会性生物中普遍存在的繁殖力-寿命权衡（fecundity-longevity trade-off）。但迄今为止，学界鲜少通过实验验证繁殖如何影响真社会性昆虫的寿命。本研究借助工蜂的繁殖可塑性，探究了繁殖在决定真社会性昆虫寿命中的因果作用。本研究以真社会性昆虫地熊蜂（Bombus terrestris）为实验对象，结果显示：在工蜂可自由"选择"是否启动繁殖程序的完整蜂群中，工蜂的卵巢激活水平与寿命呈显著正相关，且卵巢激活的工蜂寿命显著长于未激活个体。与之相反，当通过实验手段在随机选取的工蜂中诱导繁殖能力，从而将繁殖能力与其他性状解耦后，工蜂的卵巢激活水平则呈显著负相关……