Nylanderia aurantia, sp. nov. (urn: lsid: zoobank.org: pub: 95A6FAD2-2669-4C01-BE23-CD0B68365AD1)

(Figs 12, 14, and 15)

Holotype worker, MEXICO: Oaxaca, Cafetal Carlota, 3km NW Ayautla, 18.04878508, −96.69065, ± 20 m, elev. 1040m, secondary liquidambar forest, ex sifted leaf litter (miniWinkler), 13.vi.2016, coll. J. T. Longino et al. ADMAC #Wa-F-04-1-25 (USNM: USNMENT01131157) (Figs 12, 14, and 15). Seven paratype workers with same locality information as holotype (USNM: USNMENT01131294, USNMENT01131306, USNMENT01131307; MNCR: USNMENT01131302, USNMENT01131303, USNMENT01131304, USNMENT01131305).

Worker diagnosis: Relatively large and distinctly bicolored with orange to orange-brown head, mesosoma, and metasoma and darker brown femora, tibiae, antennae, and abdominal tergites VI-VII. Most of body with light blue cuticular iridescence resulting from fine cuticular microsculpture. Mesopleuron bearing 1 to 4 small, dark setae and dorsal face of propodeum bearing 1 to 2 pairs of small, dark setae.

Compare with: N. collaborans, N. goeldii

WORKER. Measurements (n = 3): EL: 0.17-0.20; EW: 0.11- 0.12; HE: 0.00-0.01; HL: 0.76-0.82; HLA: 0.29-0.31; HLP: 0.29-0.30; HW: 0.61-0.69; IOD: 0.41-0.43; LHT: 0.87-0.94; MW: 0.24-0.29; PDH: 0.26-0.33; PrW: 0.36-0.40; PTH: 0.12- 0.14; PTL: 0.19-0.22; PTW: 0.14-0.19; PW: 0.48-0.52; SL: 0.99-1.05; TL: 2.80-3.10; WL: 1.04-1.20; MMC: 4; PMC: 9-16; PrMC: 1-2; SMC: 21-24; CI: 81-85; EPI: 97-112; REL: 22-25; SI: 152-162.

Color: uniformly yellow orange to orange-brown, often with darker brown patches on abdominal tergites VI-VII; darker brown on most of antennae, especially the scapes and proximal funicular segments, with distal tip of funiculus yellow to yellow-brown; femora and tibiae darker brown, with tarsi strongly contrasting as yellow to yellow-brown. Sculpturing: overall cuticle with fine cuticular microsculpture, often resulting in a light blue cuticular iridescence. Pilosity: dense pubescence found on all surfaces of the head, mesosoma, metasoma, legs, and antennae; abundant dark, erect macrosetae on scapes, head, pronotum, mesonotum, and metasoma; 1-4 small, dark setae on mesopleuron; 1 to 2 pairs of small, dark setae on dorsal face of propodeum. Head: in full-face view, head longer than broad and quadrate with rounded posterolateral corners, and mostly straight posterior margin; compound eyes large, with approximately 12 to 14 ommatidia along the longest distance across; eyes do not surpass lateral margins of head. Mesosoma: in profile view, anterior margin of mesonotum rises slightly above pronotum; propodeum domed and rounded with no distinct inflection point between dorsal and posterior face.

QUEEN. Unknown.

MALE. Unknown.

Other material examined: MEXICO: Oaxaca, Cafetal Carlota, 18.04756, −96.69252, ± 30 m, elev. 1011m, liquidambar/ cloud forest, ex sifted leaf litter (Winkler), 12.vi.2016, coll. R. S. Anderson, RSA 2016-138 (w, q); Oaxaca, Cafetal Carlota, 3km NW Ayautla, 18.04878508, −96.69065, ± 20 m, elev. 1040m, secondary liquidambar forest, ex sifted leaf litter (miniWinkler), 13.vi.2016, coll. J. T. Longino et al. ADMAC #Wa-F-04-1-25 (w, m); Oaxaca, Cafetal Carlota, 3km NW Ayautla, 18.0486, −96.6914706, ± 20 m, elev. 1040 m, secondary liquidambar forest, ex sifted leaf litter (miniWinkler), 13.vi.2016, coll. J. T.Longinoetal. ADMAC #Wa-F-04-1-47 (w, q, m); Oaxaca, Uluapan, 4 km NE San Bartolomé Ayautla, 18.06188, −96.64635, ± 20 m, elev. 640 m, lowland rainforest, ex sifted leaf litter (maxiWinkler), 11.vi.2016, coll. J. T. Longino et al. ADMAC #Wm-F-03-1-05 (w, q, m); Oaxaca, Cafetal Carlota, 3 km NW Ayautla, 18.04878508, −96.69065, ± 125 m, elev. 1040 m, secondary liquidambar forest, ex sifted leaf litter (maxiWinkler), 13.vi.2016, coll. J. T. Longino et al. ADMAC #Wm-F-04-1-05 (w, q).

Etymology: The species epithet is an adjective derived from the Latin word “aurantius,” which means “orange” or “golden-yellow.” This name refers to the yellow orange to orange-brown color of the species.

Distribution and habitat: The known distribution of this leaf litter species is restricted to moderate elevation (640 to 1040 m) secondary Liquidambar /cloud forest around Cafetal Carlota, Oaxaca, Mexico (Fig. 8).

Notes: Unlike N. goeldii, N. aurantia and N. collaborans workers have dense pubescence on the head and metasoma. Nylanderia aurantia and N. collaborans can also be distinguished from all other known species in the region by the presence of 1 to 4 small, dark setae located on the mesopleuron. Nylanderia aurantia is relatively large compared to N. collaborans, additionally has 1 to 2 pairs of small, dark setae on the dorsal face of the propodeum, and is distinctly bicolored, with an orange to orange-brown body and darker brown color patches on femora, tibiae, antennae, and abdominal tergites VI-VII. Nylanderia aurantia also bears fine cuticular microsculpture across most of its body, resulting in a light blue cuticular iridescence not seen in N. collaborans.