Polyrhachis flavicornis

In Thailand, carton nests of P. flavicornis were found on the underside of plant leaves or between leaves in lowland evergreen forest and dry evergreen forest (Jaitrong et al., 2023).

Identification
Kohout (2008) - Polyrhachis fruhstorferi bears a close resemblance to Polyrhachis flavicornis, a species that is widely distributed throughout South East Asia, including Borneo. In contrast, P. fruhstorferi appears to be endemic to Sulawesi. The outline and sculpturation of the head and mesosoma is very similar in both species and they have an almost identical configuration of the petiolar spines. I believe that P. fruhstorferi could prove to be just a population of P. flavicornis, but a more detailed study of the geographic variation of the latter species will be necessary to ascertain their true relationship.

Jaitrong et al. (2023) - In Thailand, Polyrhachis flavicornis is most similar to Polyrhachis varicolor. For the worker caste, the head and mesosoma are clearly black in P. flavicornis, but reddish brown in P. varicolor. For body size, P. flavicornis (HW 0.95–1.00 mm in worker, 1.15–1.20 mm in queen, 0.60 mm in male) is on average smaller than P. varicolor (HW 1.00–1.25 mm in worker, 1.25 mm in queen, 0.65 mm in male).

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia, Singapore. Oriental Region: Laos, Thailand.

Nomenclature

 *  flavicornis. Polyrhachis flavicornis Smith, F. 1857a: 63 (w.q.) SINGAPORE. Combination in P. (Myrmatopa): Donisthorpe, 1932c: 446.

Type Material
Jaitrong et al. (2023) examined one syntype worker and one syntype alate queen of Polyrhachis flavicornis from Singapore (A. R. Wallace), deposited in OXUM.

One worker syntype and one alate queen syntype in. Labelled “SING. 16” (= Singapore) and with a Donisthorpe type-label.

References based on Global Ant Biodiversity Informatics

 * Jaitrong W., B. Guenard, E. P. Economo, N. Buddhakala, and S. Yamane. 2016. A checklist of known ant species of Laos (Hymenoptera: Formicidae). Asian Myrmecology 8: 1-32. DOI: 10.20362/am.008019
 * Noon-anant N., S. Watanasit, S. Yamane, and D. Wiwatwitaya. 2008. Nesting habits of Polyrhachis (Myrmatopa) flavicornis (Formicidae: Formicinae) in the lowland tropical rain forest of Peninsulat Thailand. Sociobiology 51(1): 73-86.
 * Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58
 * Robson Simon Database Polyrhachis -05 Sept 2014