Chu, H.-Y., Fang, Y.-T., Lin, T.-H., Chen, J.T.-C. & Tseng, S.-P.

Insights into social organization and population genetics of introduced Odontomachus troglodytes (Hymenoptera: Formicidae) in Taiwan

Supercoloniality and unique reproductive strategies are critical factors driving the ecological dominance of invasive ant species. However, their role in the post-introduction success of species belonging to the Ponerinae subfamily remains largely unexplored. Odontomachus troglodytes, a ponerine ant native to sub-Saharan Africa, has been recently reported to have established populations in southern Taiwan. In the present study, we conducted behavioral assays and developed 11 novel polymorphic microsatellite markers to investigate the social organization, breeding system, and population structure of O. troglodytes in its introduced range. Genotypic analyses indicated sexual reproduction with no evidence of clonal propagation. Both field observations and genetic data revealed high levels of polygyny and polyandry, accompanied by a notable frequency of diploid males, likely resulting from inbreeding. Our findings suggest that the Kaohsiung population exhibits some supercolonial traits, including polygyny, polydomy, and the absence of inter-nest aggression across distances of several kilometers. This marks the first reported case of such a social structure in the Odontomachini tribe. While workers from different nests displayed tolerance, genetic data suggest incomplete homogenization across nests. The present study offers new insights into the colony structure and reproductive biology of O. troglodytes in an introduced context and highlights the potential role of social structure in supporting population persistence and spread.

Open access, licensed under CC BY 4.0. © 2025 The Author(s).

Invasive species, microsatellite, Ponerinae, supercolony