Geographic patterns in colonial reproductive strategy in Myrmecina nipponica: links between biogeography and a key polymorphism in ants

The ability to express different phenotypes can help define species distributions by allowing access to, and exploitation of, new environments. Social insects employ two markedly different reproductive strategies with contrasting cost/benefit characteristics: independent colony foundation (ICF), which is associated with high dispersal range and high risk, and dependent colony foundation (DCF), characterized by low risk but low dispersal. The ant Myrmecina nipponica employs both of these strategies, with the frequency of each apparently varying between populations. We combine molecular data with data on reproductive strategy from different populations of this species throughout Japan to explore how this polymorphism is linked to environmental factors and if this relationship can help explain the current and historical biogeography of this species. Reproductive strategy exhibited a strong geographic pattern, with ICF predominant in southern populations and DCF more common in northern and ...