Why do workers of the primitively eusocial wasp Polistes chinensis antennalis remain at their natal nest?

In social insects, workers stay in their natal nests and help to rear their siblings, rather than founding independent nests. In three field experiments, we investigated the factors influencing the decision of workers of the paper wasp Polistes chinensis antennalis to stay in their natal nest. We divided nests of P. chinensis antennalis in half and placed each half separately in the field. Workers were then allowed to choose one of the halves, one of which had a queen and the other did not. Workers initially visited both halves, but later visited only one. When both half-nests contained brood, they were maintained by a group of wasps as two independent colonies, even though one had no queen. In addition, the initial presence of workers in the nests did not affect which nests were maintained. When one half-nest contained brood and the other did not, only the half with brood was maintained. This result is consistent with the 'life insurance advantage' hypothesis for the evolution of eusociality.