Nylanderia birmana

Nylanderia birmana (Forel, 1902)

(Figure 13; Figure 25.B)

Prenolepis birmana Forel, 1902: 291. Myanmar.

In Paratrechina (Nylanderia): Emery, 1925: 219; in Nylanderia: LaPolla et al., 2010: 127; diagnosis: Wachkoo & Bharti, 2015: 107.

Diagnosis. Nylanderia birmana can be distinguished from other species of Nylanderia from Southeast China by the combination of dorsal margin of the propodeum almost as long as posterior margin, head and dorsum of mesosoma completely reticulate, pronotum with 4 to 8 erect macrosetae (PMC 2–4), and mesonotum with 4 to 8 erect macrosetae (MMC 2–4).

Measurements (n = 1 worker). MdL 0.393; ClL 0.199; ClW 0.480; HL 0.712; HW 0.593; EL 0.189; MaD 0.142; IoD 0.373; SL 0.811; ML 1.027; PrL 0.353; PrW 0.439; PrFL 0.727; MeL 0.247; MeW 0.250; PrpL 0.213; PrpH 0.396; PrpW 0.327; PL 0.230; Ab3L 0.505; TL 2.474; PMC 4; MMC 4; CI 83.3; DNI 56.9; IoI 62.9; OI 31.9; SI 136.7; REL 26.5; MaI 75.1.

Compare with: N. emmae, N. flaviabdominis, N. IBBL-01, N. yaeyamensis.

Morphology. This species is promptly recognized by its sculpturing pattern on the body. Interestingly, the diagnosis provided by Wachkoo & Bharti (2015) does not match the observed images of the type specimens for the species (specimen CASENT0911000); it does, however, match with the characters observed in the type specimen of one of its subspecies, Nylanderia birmana hodgsoni (Forel, 1902), described also from Myanmar (specimen CASENT0911001). It is possible that what researchers have been calling N. birmana may be composed of two different species, with N. birmana hodgsoni being one of them. Nonetheless, only with an inclusive revisionary study for the genus—including direct examination of the type specimens for each taxon—will it be possible to support this claim.

Ecology. The species has been recorded mostly in subtropical forests, both semi-evergreen and evergreen (Wachkoo & Bharti 2015; Wheeler 1927). According to Wachkoo & Bharti (2015), the only specimen sampled was found underneath a stone along a roadside at Palampur, Himachal Pradesh, in a subtropical, semi-evergreen forest of Uttarakhand with honey baiting. In this study, the sole worker sampled was found in a well-preserved area, hinting at very specific habitat requirements for this species.

Distribution. Although it has a widespread distribution (from Northwestern India to Southeastern China), it is not commonly recorded, with several distribution gaps in-between.

Examined material. Image of a syntype worker from Mawlamyine, Myanmar (CASENT0911000) deposited in MHNG, Geneva, Switzerland. Image of a syntype worker of Nylanderia birmana hodgsoni from Mawlamyine, Myanmar (CASENT0911001) deposited in MHNG, Geneva, Switzerland. Hong Kong: (1 worker) Tai Po, Tai Po Kau, 22.43245 114.18593 ±500 m, elevation 77 m, 17.v.2016, Y. Luo col., #ISP0057. [IBBL].