Nylanderia emmae (Forel, 1894), comb. nov.

(Figs 124–126)

Prenolepis emmae Forel, 1894: 406 (w.). Lectotype worker (designated here), CHINA : Hong Kong, Victoria Park (MHNG: CASENT0911039) . 2 paralectotype workers (designated here), same locality as lectotype (AMNH: Acc. 35566). Combination in Prenolepis (Nylanderia): Emery, 1906: 133; in Paratrechina (Euprenolepis): Emery, 1925: 224; in Prenolepis: Brown, 1953: 7 (where the name was wrongly rendered as Prenolepis geei; see Wheeler, 1930b: 80).

Morphology. Worker. Measurements (n=9): CMC: 30–34; EL: 0.19–0.24; EW: 0.14–0.17; HL: 0.77–0.92; HLA: 0.33–0.40; HLP: 0.37–0.47; HW: 0.66–0.84; IOD: 0.44–0.48; LF1: 0.18–0.23; LF2: 0.09–0.14; LHT: 1.03–1.24; MMC: 2–3; MTW: 0.39–0.47; MW: 0.23–0.28; PDH: 0.30–0.38; PMC: 3–4; PrCL: 0.51–0.60; PrCW: 0.29–0.36; PrFL: 0.88–1.03; PrFW: 0.19–0.24; PTH: 0.29–0.38; PTL: 0.30–0.33; PTW: 0.17–0.21; PW: 0.48–0.54; SL: 1.09–1.35; TL: 2.64–3.49; WF1: 0.06–0.08; WF2: 0.06–0.07; WL: 1.14–1.41; BLI: 165–188; CI: 85–92; EPI: 82–90; FLI: 158–200; HTI: 142–155; PetHI: 91–100; PetWI: 62–68; PrCI: 56–61; PrFI: 22–25; REL: 24–27; REL2: 27–31; REL3: 40–49; SI: 158–165.

Yellow to light brown; cuticle of head lightly reticulate; cuticle of pronotum smooth and shiny; cuticle of mesonotum, metanotum, mesopleura, and propodeum with deep longitudinal striations; long, erect macrosetae with thick setal bases on head, pronotum, mesonotum, gaster, and legs; erect setae on scapes; macrosetae the same color as the rest of the cuticle; light, decumbent hairs on the dorsal face of the propodeum; head slightly longer than broad and oval in shape with indistinct posterolateral corners and a weakly convex posterior margin; compound eyes are positioned slightly anterior to the midline of the head (EPI <100); compound eyes are moderately sized and convex, but do not surpass the lateral margins of the head in full-face view; mandibles with 6 teeth on the masticatory margin; cuticle of ectal surface of mandibles smooth and shiny; mesosoma is gracile (Fig 30); in profile view the dorsal surface of the mesonotum is flat and elongate; propodeum is highly domed with a rounded dorsal face; dorsal apex of petiole scale is sharply angled and forward-inclined; mesonotal and metanotal sutures are deep and complete.

Notes. Based on both morphological (present study) and molecular data (Blaimer et al. 2015) we are able to move this species to Nylanderia . This species has deep and complete mesonotal and metanotal sutures (Fig 30), anteriorly-placed eyes, and macrosetae with thick setal bases all of which are characteristic of Nylanderia . This species was likely thought to be a Prenolepis because its elongate mesosoma appears to be constricted. However, this species does not have the depression in the dorsal surface of the mesonotum that is seen in Prenolepis species.

Other material examined. CHINA: Hong Kong, N.T., Tai Po Kau (S. Yamane); Hong Kong, N.T.; Hong Kong, Victoria Park, 27.vi.1999 (S. Yamane); Mokanshan (N. Gist Gee). In: AMNH, MCZC, USNM.