Discovery of a New Crematogaster Species with 10-Segmented Antennae from the Indochina Region, with Description of the Species and Its Phylogenetic Position (Hymenoptera: Formicidae)

Here we report, for the first time, the occurrence of a Crematogaster species with 10-segmented antennae in the Indochina region. Specifically, the new species, Crematogaster indosinensis sp. nov., exhibits size polymorphism in the worker caste and was collected in Cambodia. However, it is not currently known whether C. indosinensis has an association with ant-plants. The interspecific cytochrome c oxidase subunit I divergence for C. indosinensis versus C. borneensis was 20%, suggesting that the taxa diverged relatively long ago. Molecular phylogenetic analysis using nuclear genes revealed that C. indosinensis is sister to the remainders of the C. borneensis-group.