Nesomyrmex paquisha Pazmiño-Palomino, Troya and Arredondo, 2025

Pazmiño-Palomino, Alex, Troya, Adrián & Arredondo, Brandon S., 2025, Nesomyrmex paquisha: a new rough tree ant species from the isolated Cordillera del Cóndor, Ecuador, Journal of Natural History 59 (17 - 20), pp. 1181-1208 : 1185-1190

Nesomyrmex paquisha Pazmiño-Palomino, Troya and Arredondo sp. n.

( Figures 2 , 3 , 4 , 9 ) LSID: urn:lsid:zoobank.org:act:EB116414-E406-4884-A5B7-7EA3BA87DD8A

Type material

Holotype. ECUADOR: 1 ☿; Zamora Chinchipe, C. Cóndor, Paquisha alto, T1 ; − 3.916°S, − 78.493°W; 1815 m; 17 March 2008; A. Troya leg.; fogging; MEPNINV30070 ( MEPN).

Paratypes. ECUADOR: same data as holotype; 1☿ MEPNINV30071 ( ICN); 1☿ MEPNINV30066 ( MEPN), 4☿ MEPNINV40013 ( MEPN); 1☿ MEPNINV39787 ( MZSP); 1☿ MEPNINV39970 ( MECN); 1☿ MEPNINV4120 ( ZFMK); 1♀ MEPNINV30065 ( MECN) • same data as holotype, except: T2 ; − 3.918°S, − 78.499°W; 18 March 2008; 3☿ MEPNINV39994 ( MEPN), 3☿ MEPNINV39995 ( MEPN), 3☿ 1♀ MEPNINV40025 ( MEPN); 2☿ MEPNINV39994–1 ( DZUP); 3☿ MEPNINV40025-2 ( CBUMAG); 2☿ MEPNINV40025-3 ( MNHN); 2☿ MEPNINV40025-1( MCZC) .

Additional material examined. – 2☿; ECUADOR: Morona Santiago, C . Cóndor, El Quimi, − 3.5°S, − 78.39°W; 2007 m.; 1 July 2017.;fogging. In tepui. A. Suárez, A. Troya leg; MEPN.

Etymology

The species name refers to the type locality, Paquisha, at Cordillera del Cóndor, Ecuadorian southern Amazon, where the type series originates. Paquisha town has a remarkable biodiversity, and is the type locality of numerous endemic species of flora and fauna. In 1995 this place witnessed a war conflict between Peru and Ecuador; for this reason it is also an important locality for the history of both countries. The specific epithet is a noun in apposition, thus invariable (International Code of Zoological Nomenclature: Art. 31.2.1, Art. 34.2.1).

Diagnosis

Scape, when pulled back, does not reach posterior margin of head; 12 antennomeres; mesosomal profile straight; metanotal groove present; in lateral view, propodeal spine length (PSL) shorter than eye length (EL); petiole obovoid without prominent tubercles

(in dorsal view); pospetiolar dorsal sculpture rugose; first tergum of gaster microreticulate.

Description Worker holotype ( Figure 2 )

Measurements

Holotype. EL = 0.2; HL = 0.94; HW = 0.81; ML = 0.39; PH = 0.41; PPH = 0.29; PPL = 0.26; PPW = 0.37; PSL = 0.12; PTH = 0.31; PTL = 0.33; PTW = 0.27; PW = 0.53; SL = 0.71; WL = 1.23 . Paratype workers (n = 11). EL = 0.19–0.22; HL = 0.87–1.07; HW = 0.76–0.90; ML = 0.31–0.39; PH = 0.35–0.41; PPH = 0.24–0.29; PPL = 0.24–0.27; PPW = 0.26–0.38; PSL = 0.12–0.13; PTH = 0.26–0.31; PTL = 0.27–0.33; PTW = 0.27–0.3; PW = 0.47–0.59; SL = 0.65–0.71; WL = 1.12–1.4 .

Head

In frontal view, subquadrate, longer than broad (CI: 86), lateral margins narrower anteriorly, under the eyes level; corners of posterior margin rounded; posterior margin straight; frontal carina reaching anterior eye border at midlength. Anterior median portion of clypeus forming broad lobe anteriorly with anterior margin slightly convex forming rounded angle with lateral portions. Inner margin of mandible with five to six teeth. Eyes convex, placed at lateral margins under the mid-height of cephalic capsule, with 14 ommatidia across maximum length. Antenna with 12 antennomeres; scape when pulled back not reaching posterior margin of head (SI: 87); scape gradually widening apically; basal and apical portion slightly curved; antennal club with three antennomeres; apical antennomere about same length as the second and third subsequent antennomeres together.

Mesosoma

In lateral view, mesosoma dorsum forming low convexity, almost straight, interrupted by well-impressed metanotal groove; propodeal declivity inclined anterad. In dorsal view, anterior margin of pronotum convex, bounded by weak carina; dorsal anterolateral margin convex. Promesonotum forming a continuous surface bounded posteriorly by a metanotal groove, well-impressed; in lateral view, promesonotal suture present, well-impressed. Mesopleural groove absent. Propodeal spines conical, straight, about as long as maximum eye length, forming approximately 90° angle with propodeal declivity; outer margin of propodeal spiracle circular, opening directed posterad, placed at about 1.5 spiracle diameters below propodeal dorsal margin, about twice the size of petiolar spiracle; propodeal lobe rounded.

Metasoma

In dorsal view, petiole obovoid, diverging posterad, width of dorsoanterior margin about half the size of posterior margin; lateral margins without evident tubercles or spines, except by a weakly developed lobe in the anterolateral margin, placed just above petiolar spiracle; in lateral view, petiole trapezoidal; dorsal margin of peduncle forming a continuous line with the anterodorsal margin of the petiolar node, tracing an angle of 40°; nodal margin slightly convex, almost straight, dorsoposterior margin straight, posterior margin convex; raised tubercles absent; posterior margin forming 110° angle with dorsal margin; subpetiolar process approximately the same length as the maximum opening diameter of the propodeal spiracle, subtriangular with acute tip, tracing an angle of 40° aprox. between faces anterior and posterior of the process. Postpetiole oval, wider than long; in lateral view, postpetiole globose, nearly as height as broad. Length of first tergite of gaster about 3/5 of its total length.

Sculpture

Dorsal and lateral surfaces of head, mesosoma, procoxa, petiole and postpetiole with anastomosed striae (costae in anastomosis). Leg surfaces, except coxae, microreticulate, although appearing smooth and shiny at first glance, microreticulation only noticeable under magnification higher than 80×. Clypeus with longitudinal costae, shining. Dorsal surface of mandibles with weak longitudinal striae. Scape smooth. First gastral tergum completely microreticulate, only noticeable under magnification higher than 60×.

Pilosity and colour

Tegument mostly dark brown, body pilosity whitish; dorsal surface of body with flattened, erect setae, and sparse simple appressed setae, mostly separated by distance equal to or greater than length of each seta. Cephalic capsule with 8 to 10 erect setae restricted to anterior margin of clypeus and posterior margin of head occipital corners. Scapes covered with fine, decumbent short setae, erect setae absent. Longest erect setae of promesonotum, petiole and postpetiole, similar in size to length of antennal pedicel. Smaller setae scattered along body dorsum, equal in size to opening of propodeal spiracle. Propodeal spines without erect pilosity. Legs brown with lighter shade than rest of body, covered with fine, short decumbent setae separated by distance similar to their length. Erect simple setae on gastral surface separated by distance greater than their length.

Figures

Figure 2. Nesomyrmex paquisha sp. n. Worker holotype. (A) frontal view; (B) labels; (C) lateral view; (D) dorsal view. Scale bars = 1 mm. Images by A. Troya.

Figure 3. Nesomyrmex paquisha sp. n. dealate Queen (Gyne). (A) frontal view; (B) dorsal view; (C) lateral view. Scale bars = 1 mm, except (A). Images by A. Troya.

Figure 4. Habitat of Nesomyrmex paquisha sp. n., Cordillera del Cóndor, southern Ecuador. (A) sandstone plateau at Paquisha, close to the political border with Peru. Note the bushy, tepuilike vegetation typical of the area; (B) military campsite near the foothill of the plateau; (C) application of the pyrethroid-based insecticide canopy fogging method. Images by A. Troya.

Figure 9. Distribution of Nesomyrmex paquisha sp. n. and new Nesomyrmex species records in Ecuador. Image by the authors.