Eusocial insects are characterised by a reproductive caste differentiation such that egg-laying is restricted to a small number of queens. The majority of the colony members function as non-reproducing workers and gain indirect fitness by rearing the offspring of the reproductives. In primitively eusocial species, some workers can also get direct fitness by sneaking in some eggs in the presence of the queens, replacing the queens and becoming new queens, or initiating new nests. Here we aimed to understand the factors that permit some workers to gain direct fitness and alter the number of workers doing so, using the primitively eusocial wasp Ropalidia marginata. We transplanted 12 naturally occurring colonies into large laboratory cages where there was adequate space for the workers to leave their natal nests and initiate new colonies. We compared six control colonies that we provided with ad libitum food placed near the nest to six test colonies in which we hand-fed the wasps in addition to the ad libitum food. Wasps in test colonies consumed more food, showed more aggression, replaced their queens, and initiated new nests significantly more often than those in control colonies. When considering all 12 colonies, the rates of queen replacement and nest foundation were significantly positively correlated with food consumption rates. The additional nutrition gained by hand-fed wasps appears to help workers in test colonies to develop their ovaries and lay eggs, implying that they are nutritionally castrated in control colonies.

真社会性昆虫的特征是生殖种姓分化，因此产卵仅限于少数蜂后。大多数殖民地成员作为非繁殖工人运作，并通过抚养繁殖后代获得间接适应性。在原始真社会性物种中，一些工蚁也可以通过在蚁后的情况下偷偷产卵、替换蚁后成为新的蚁后，或发起新的巢穴来获得直接适应度。在这里，我们旨在了解允许一些工人获得直接健康并改变这样做的工人数量的因素，使用原始的真社会黄蜂Ropalidia marginata. 我们将 12 个自然产生的菌落移植到大型实验室笼子中，那里有足够的空间让工人离开他们的出生巢并开始新的菌落。我们比较了我们在巢附近提供随意食物的六个对照菌落与六个测试菌落，其中除了随意食物外，我们还用手喂养黄蜂。与对照群体中的黄蜂相比，测试群体中的黄蜂消耗了更多的食物，表现出更多的攻击性，更换了蜂后，并且开始建造新巢的频率明显更高。在考虑所有 12 个蜂群时，蜂王更换率和巢基基础与食物消耗率显着正相关。人工喂养的黄蜂获得的额外营养似乎有助于测试蜂群中的工作人员发育卵巢和产卵，