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 ).

Figures

FIGURE 2. Distributions of species: (A) N. austroccidua in the United States and northern Mexico, (B) species found across southern Mexico and Mesoamerica, and (C) N. docilis in South America. Maps were created using GPS coordinates listed in Table S1 and from the Global Ant Biodiversity Informatics (GABI; Guénard et al. 2017) database.

FIGURE 71. Line drawings of male gonopods of N. austroccidua, N. breviscapa, N. contraria, N. cf. docilis, N. lazulina, and N. usul.

FIGURES 8–10. Nylanderia breviscapa holotype worker (USNMENT01131317). Lateral, full-face, and dorsal view of the body.

FIGURES 11–12. Nylanderia breviscapa paratype queen (USNMENT01131869). Full-face and lateral view of the body.

FIGURES 13–16. Nylanderia breviscapa paratype male (USNMENT01131870). Full-face and lateral view of the body; ventral and dorsal view of the genital capsule.