Nylanderia breviscapa, Williams & Williams & Lapolla & Lucky, 2025

Williams, Jason L., Williams, John F., Lapolla, John S. & Lucky, Andrea, 2025, Nylanderia of the World, Part IV: Taxonomic contributions to the American Clade I of New World Nylanderia (Hymenoptera: Formicidae), Zootaxa 5569 (3), pp. 549-593 : 559-561

Nylanderia breviscapa , sp. nov.

Figs. 8–10 (worker); Figs. 11–12 (queen); Figs. 13–16 (male)

Holotype worker, MEXICO: Chiapas, 2km SE Custepec , 15.72197 -92.94163 ± 100m, elev. 1850m, 17.v.2008, ridge oak forest, sifted litter, R.S. Anderson #RSA2008-010 ( USNM: USNMENT01131317 ). 6 paratype workers, 1 paratype queen, and 4 paratype males with same locality data as holotype ( USNM: USNMENT01130960 , USNMENT01131318 , USNMENT01131319 , USNMENT01131868 , USNMENT01131869 , USNMENT01131870 ;MNCR:USNMENT01131320, USNMENT01131321, USNMENT01131322, USNMENT01131962, USNMENT01132155).

Worker diagnosis: Antennae relatively short, scapes surpassing posterior margin by less than a quarter of their length; light brown and sometimes bicolored with medium brown head and gaster; meso- and metacoxae about same color as mesosoma; microsculpture and blue iridescence subtle, most visible on head; dense cephalic pubescence.

Compare with: N. austroccidua

WORKER. Measurements (n=12): TL: 1.71–2.08; EL: 0.10–0.11; EW: 0.07–0.09; IOD: 0.30–0.33; HE: 0.00– 0.01; HL: 0.53–0.58; HW: 0.44–0.48; HLA: 0.18–0.21; HLP: 0.23–0.27; SL: 0.53–0.59; PW: 0.32–0.35; MW: 0.18–0.21; PrW: 0.23–0.29; PDH: 0.17–0.25; PTW: 0.11–0.15; LHT: 0.40–0.50; WL: 0.61–0.66; GL: 0.57–0.91; SMC: 6–8; PMC: 2–4; MMC: 2–3. Indices: BLI: 134–146; CI: 81–85; EPI: 70–84; HTI: 93–113; REL: 18–20; SI: 114–128.

Color: Light brown, sometimes bicolored with medium brown head and gaster; meso- and metacoxae about same color as mesosoma; overall cuticle with some microsculpture resulting in subtle blue iridescence on head and mesosoma. Pilosity: dense cephalic pubescence covering all surfaces of head in full-face view; mesosoma pubescence sparse to absent, at most limited to scattered hairs on pronotum; gaster pubescence sparse to absent; pair of small, erect setae on apex of petiole. Head: longer than broad and quadrate with distinct posterolateral corners and flattened posterior margin, usually with no medial emargination; scapes surpass posterior margin of head by less than a quarter of their length; median ocellus small and not always apparent; lateral ocelli absent or not apparent. Mesosoma: posterior margin of pronotum forming obtuse angle with anterior margin of mesonotum in profile view; propodeum low and evenly rounded, with posterior face about same length as dorsal face.

QUEEN. Measurements (n=1): TL: 2.69; EL: 0.18; HL: 0.60; HW: 0.57; SL: 0.61; WL: 0.92; GL: 1.18. Indices: BLI: 154; CI: 96; REL: 29; SI: 106.

Relatively small (TL <3) Color: Uniformly yellow-brown to light brown; Pilosity: most of body covered in moderate to dense pubescence; lacking pubescence on posterior face of propodeum; 5-6 small, erect setae on anepisternum. Head: As broad as long; scapes surpass posterior margin of head by about a third of their length.

MALE. Measurements (n=2): TL: 1.79–1.92; EL: 0.15–0.16; HL: 0.47–0.48; HW: 0.41–0.43; SL: 0.49–0.51; WL: 0.63–0.66; GL: 0.69–0.78. Indices: BLI: 154–155; CI: 87–90; REL: 32–34; SI: 119–120.

Color: uniformly light to medium brown; meso- and metacoxae concolorous with mesosoma. Pilosity: dense pubescence on head, mesoscutum, and mesoscutellum; pubescence sparse to absent on pronotum, anepisternum, katepisternum, propodeum, and gaster. Head: as broad as long; compound eyes surpass lateral margins of head in full-face view; scapes surpass posterior margin of head by about a third of their length. Mesosoma: In profile view, propodeum gently and evenly rounded, with dorsal face about as long as posterior face. Genitalia: gonopod broad at base, taper strongly to a narrow, digitiform shape, with the apex rounded and slightly turned upward ( Fig. 71); in ventral view, ventromedial edge of basivolsella strongly curved ( Fig. 15); gonossiculus mostly straight, gradually curved medially toward penial sclerite, and nearly three times as long as cuspis.

Other material examined: MEXICO: Chiapas, 2km SE Custepec , 15.72188 -92.93677 ± 100m, elev. 1900m, 19.v.2008, oak-pine forest, sifted litter, R.S. Anderson #RSA2008-016 ; Chiapas, 2km SE Custepec , 15.72216 - 92.94298 ± 100m, elev. 1820m, 20.v.2008, oak forest, sifted litter, R.S. Anderson #RSA2008-020 ; Chiapas, 2km SE Custepec , 15.7214 -92.93909 ± 100m, elev. 1830m, 20.v.2008, hardwood forest, sifted litter, R.S. Anderson #RSA2008-023 ; Chiapas, 3km SE Custepec , 15.71578 -92.93847 ± 50m, elev. 1700m, 17.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A-02-2-07 ; Chiapas, 2km SE Custepec , 15.7208 -92.95097 ± 50m, elev. 1520m, 17.v.2008, mesophil forest, sifted litter, LLAMA#Wa-A-02-1-35 ; Chiapas, 2km SE Custepec , 15.72085 -92.95097 ± 50m, elev. 1520m, 17.v.2008, mesophil forest, sifted litter, LLAMA#Wa-A-02-1-34 ; Chiapas, 2km SE Custepec , 15.72098 -92.95095 ± 50m, elev. 1520m, 17.v.2008, mesophil forest, sifted litter, LLAMA#Wa-A-02-1-31 ; Chiapas, 2km SE Custepec , 15.72098 -92.95054 ± 50m, elev. 1520m, 17.v.2008, mesophil forest, sifted litter, LLAMA#Wa- A-02-1-22 ; Chiapas, 2km SE Custepec , 15.72096 -92.9502 ± 50m, elev. 1520m, 17.v.2008, mesophil forest, sifted litter, LLAMA#Wa-A-02-1-11 ; Chiapas, 2km SE Custepec , 15.721 -92.95036 ± 50m, elev. 1520m, 17.v.2008, mesophil forest, sifted litter, LLAMA#Wa-A-02-1-04 ; Chiapas, 3km SE Custepec , 15.71603 -92.93808 ± 50m, elev. 1700m, 17.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A-02-2-19 ; Chiapas, 3km SE Custepec , 15.71569 -92.93849 ± 50m, elev. 1700m, 17.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A-02-2-09 ; Chiapas, 3km SE Custepec , 15.71607 -92.93812 ± 50m, elev. 1700m, 17.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A- 02-2-17 ; Chiapas, 3km SE Custepec , 15.71585 -92.93811 ± 50m, elev. 1700m, 17.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A-02-2-23 ; Chiapas, 5km NNW Coapilla , 17.18326 -93.15208 ± 50m, elev. 1915m, 25.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A-04-2-08 ; Chiapas, 3km SE Custepec , 15.71485 -92.93823 ± 50m, elev. 1700m, 17.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A-02-2-50 ; Chiapas, 3km SE Custepec , 15.71494 -92.93823 ± 50m, elev. 1700m, 17.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A-02-2-48 ; Chiapas, 3km SE Custepec , 15.71554 -92.93815 ± 50m, elev. 1700m, 17.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A- 02-2-30 ; Chiapas, 3km SE Custepec , 15.71576 -92.93812 ± 50m, elev. 1700m, 17.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A-02-2-25 ; Chiapas, 3km SE Custepec , 15.7158 -92.93811 ± 50m, elev. 1700m, 17.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A-02-2-24 ; Chiapas, 3km SE Custepec , 15.71528 -92.938 ± 50m, elev. 1700m, 17.v.2008, 2° mesophil forest, sifted litter, LLAMA#Wa-A-02-2-37 .

Etymology: The species epithet combines ‘ brevis ’ (L. = short) and ‘ scapus ’ (L. = stalk), referring to the relatively short antennal scapes of this species.

Notes: Nylanderia breviscapa workers most closely resemble those of N. austroccidua but with a more compact overall appearance, relatively shorter scapes that barely surpass the posterior margin of the head, and meso- and metacoxae that are about the same color as the mesosoma. The known range of this species is limited to high elevation forests in the southern state of Chiapas, Mexico ( Fig. 2B).