Microbes, molecules, and mates: Unraveling nestmate recognition in Pheidole megacephala

by Myrmecological News Blog · Published 18 February 2026 · Updated 18 February 2026

Reading Time: 2 minutes

How do ants identify who is a nest mate vs. who is not? Cuticular hydrocarbons (CHCs) have been demonstrated to drive such recognition. In the invasive African big-headed ant, Pheidole megacephala, colony the authors show that environment, genetics, and bacterial symbionts may impact CHC profiles and affect nest mate recognition. In their latest article, ‘Genetics, cuticular hydrocarbon profiles, and bacterial endosymbionts are associated with nestmate recognition in the invasive African big-headed ant Pheidole megacephala in Taiwan‘, the authors reveal how the environment and Wolbachia may mediate aggression among workers from different colonies by examining genetic relatedness, CHC profiles, and bacterial endosymbionts — specifically infection by Wolbachia. Their findings from urban and forest populations in Taiwan highlight an under appreciated link between Wolbachia, colony-level trait, and social behavior.

Edited by Rohini Singh and Salvatore Brunetti

Fig. 1 Ant samples were collected using aspirator, small brooms, shovels, and plastic containers in forest and urban areas for aggression tests. The sampling area shown in Fig. 2 corresponds to urban site U6.

Fig.3 In urban environments, *Pheidole megacephala* is commonly found inhabiting cracks and crevices in man-made structures. Colonies were sampled from dead tree logs along paths in urban areas such as a campus (U4) and near farmland (U2).

The sampling areas shown in Fig. 3 correspond to forest sites F7 and F8, respectively.

Aggression tests were conducted at the Agricultural and Environmental Science Building, National Chung Hsing University, Taichung, Taiwan. Colonies collected from 14 sites (6 forest and 8 urban) were each placed in separate plastic containers and transported to the laboratory for pairwise aggression assays. As shown in Fig. 12, the observed aggression corresponded to a score of 3, characterized by biting and death-feigning behavior.

Ant colony investigation, collection, and identification in Taiwan (April–August 2022), chemical analyses conducted at the Department of Entomology, National and Ant and microbiota DNA analyses conducted at the Department of Entomology, National