Protalaridris loxanensis

The few known specimens of P. loxanensis have been taken from sifted leaf litter samples in cloud forests and secondary vegetation above 2000 m near the southern Ecuadorian town of Loja. The site is mostly secondary vegetation ranging from trees forming a loose canopy approximately 15 m high to more open bracken-fern dominated understorey with scattered trees and shrubs. This species is sympatric with Protalaridris leponcei at Reserva Biológica San Francisco.

Identification
Lattke et al. (2018) - Worker: Mandibular shaft relatively short and stocky, base relatively wide in full length view, rapidly tapering apicad; dorsal mandibular margin with 6–7 preapical teeth. Anterior margin of scape with 5–6 erect hairs; lateral labral margin with three hairs, two basal short lanceolate hairs directed laterally and long anterior hair directed anterolaterally. Abdominal tergite IV with 18–20 subdecumbent spatulate hairs.

Besides the characters used in the key, Protalaridris armata and Protalaridris loxanensis may be separated on account of the following: The mandibles in Protalaridris armata lack a dorsal row of preapical teeth as present in Protalaridris loxanensis; the labrum is relatively much larger in Protalaridris armata with a deep anteromedian concavity whilst in Protalaridris loxanensis the anterior labral margin bears a weak median emargination at most. Protalaridris armata has small, but distinct, posterolateral cephalic lobes that form a different surface from the mostly convex vertex between the vertexofrontal ridge and occipital carina. Protalaridris loxanensis lacks such lobes and has a uniformly convex vertex. The antennal scrobe is nonexistant in Protalaridris loxanensis making for a uniformly concave ventral margin in a transverse section of the head at eye level, whilst in Protalaridris armata the same section is mostly convex but with a lateral concavity because of the antennal scrobe. In lateral view the eye in Protalaridris armata is situated on a narrow surface between the cephalic dorsum and the antennal scrobe whilst in Protalaridris loxanensis the eye is situated on a broad cuticular surface. The setae along the anterior scape margin in Protalaridris armata, when seen laterally, are arched and in dorsal view tend to be feather-shaped, contrasting with the straight setae in Protalaridris loxanensis that progressively widen to a truncate apex. In Protalaridris armata these setae are placed between a narrow furrow formed by two longitudinal parallel ridges that run along the anteroventral scape surface, in contrast with the scape in Protalaridris loxanensis that lacks such ridges. A transverse section of the scape in Protalaridris armata has a convex anterodorsal margin, but in Protalaridris loxanensis the dorsal margin forms a right angle with the anterior margin.

Distribution based on Regional Taxon Lists
Neotropical Region: Ecuador.

Nomenclature

 *  loxanensis. Protalaridris loxanensis Lattke, in Lattke et al., 2018: 285, figs. 7a-e, 8 (w.q.) ECUADOR.

Worker
Holotype (paratype): HL 0.78 (0.76); HW 0.84 (0.87); ML 0.51 (0.43); EL 0.06 (0.04); SL 0.43 (0.41); PW 0.51 (0.45); WL 0.77 (0.69); PH 0.22 (0.20); PL 0.43 (0.45); DPW 0.22 (0.33) mm. CI 1.08 (1.15); MI 0.61 (0.49); OI 0.07 (0.05); SI 0.51 (0.47); LPI 0.52 (0.45); DPI 0.75 (0.52).

Head slightly wider than long in dorsal view; posterior margin mostly transverse with weak median emargination, occipital lobe inconspicuous, lateral cephalic margin posterior to eye convex; head widest at posterior one fourth, cephalic lateral margins converging anteriorly; clypeus with small shining posteromedian area. Eye reduced, but distinct, apparently 3–5 partially fused ommatidia, facing anterolaterally, separated from antennal fossa along lateral cephalic margin by not more than 2 diameters, separated from dorsal face by not more than one diameter in lateral cephalic view.

Cephalic dorsum mostly broadly concave in lateral view with short posterior convexity that curves posteriorly to form cephalic posterior margin and broadly convex ventral margin; lateral cephalic surface continuously curves with ventral surface; scrobe shallow and inconspicuous, ending anterad of compound eye. Cephalic cross-section at compound eye approximately bowl shaped with dorsal surface forming a mostly horizontal line on top of broad convexity. Cephalic dorsum mostly weakly areolate-rugulose, commonly encrusted with dirt and debris that obscure cuticle; dorsum traversed by arching, broadly concave carina that laterally curves anterad to posterior margin of antennal fossa, defining elongate posterior cephalic region elevated above anterior median cephalic region. Frons with weakly raised median swelling. Cephalic dorsum with short appressed spatulate ground hairs; occiput areolate, posterolateral region areolate-rugulose; ventral surface mostly areolate to areolate-rugulose, posterolaterally densely punctulate and shining.

Mandibles form complex cradle or cage mainly bound by the main axis of each mandible as well as one prominent ventral tooth. Mandible in full length view progressively tapers apicad, mostly straight until base of apical tooth, at which it bends mesad. Base of mandible at cephalic insertion expands into flange with smooth rim and areolate dorsal surface. Mandible relatively short and robust, dorsum mostly with scattered rugulae and short arched hairs that point anterad on dorsal and internal margins; appressed pilosity present, directed aLabrum totally visiblepicad; ventral mandibular surface mostly shining, weakly sculpted. Mandibular dorsal margin forms weak obtuse angle with dorsal cephalic surface in cephalic lateral view, ventral tooth points ventrally, mostly straight, its length under 1/3 that of mandible. Dorsal mandibular margin with 6–7 preapical short and acute teeth. Mandibular ventral margin with 4 preapical teeth (1–4), teeth 1 and 3 overlapping counterparts of other mandible. Tooth 1 (basal-most) massive and mesoventrally directed, tooth 3 large and medially directed. Teeth 2 & 4 short and acute: one between large teeth and other close to base of apical tooth. Basal tooth in dorsal view tapering apicad; in anterior view relatively straight with decumbent tooth along anterodorsal margin. Single long hair, almost as long as basal tooth, inserted just apicad of basal tooth and subparallel to it. Mandibular apical tooth dark brown shining and sharply pointed.

Labrum totally visible in frontal view, lateral extremes of base may be partially obscured by mandibles; shape subquadrate to weakly bilobed, lateral margin convex, anterior margin with median concavity of variable development, labrum wider posterad than anterad. Ventral surface mostly shining, dorsal surface sculpted, not shining. Lateral labral margin with three flattened hairs, two basal, short lanceolate hairs directed laterally and anterior long flagellate hair directed anterolaterally. Anterior margin with 4 flattened hairs, two lateral elongate lanceolate hairs directed anteriorly and median pair of short, converging or subparallel lanceolate hairs. Palpal formula unknown. Scape in dorsal view longitudinally rugulose, subparallel, slightly wider basad than apicad, internal margin broadly concave, external margin broadly convex, anterobasal lobe weakly expanded anterad, dorsum lacking hairs except for sparse erect pubescence. Cross-section of scape at mid-length subrectangular, dorsal margin broadly convex, ventral margin mostly straight, external margin concave, internal margin convex; external scape anteroventral margin bearing 5–6 spatulate, apically truncate hairs; additional short arched hair placed close to basal angle; remaining pilosity sparse, short, and simple. Head ventrolaterally punctulate, ventromedially rugose.

Mesosomal dorsum in lateral view broadly convex, dorsal propodeal margin very brief; propodeal tooth relatively short, broadly triangular to acutely triangular, posterior base prolonged as lamella. Mesosomal dorsal and dorsolateral surfaces rugulose, with numerous decumbent ground hairs, mostly directed posteromesad. Most of lateral pronotum, mesopleuron, and propodeum punctate, punctae not as dense on metapleuron; katepisternum lacking transverse rugulae, mesosomal lateral surface without standing pilosity. Pronotum with anterior transverse rugae that separate collar region, collar with longitudinal carinae; promesonotal suture indistinguishable.

Petiolar node convex to subquadrate in lateral view, anterior petiolar margin weakly concave, anteroventral process lacking, postpetiolar dorsal margin in lateral view broadly convex. Petiolar node and postpetiole transverse in dorsal view; postpetiole weakly concave anteriorly and convex posteriorly, dorsum of petiolar node and postpetiole areolate-rugulose with posteriorly directed appressed, ground hairs. Dorsal margin of abdominal tergum IV broadly convex in lateral view, ventral margin of sternite IV markedly convex; tergum densely punctulate, space between depressions less than their diameters; pilosity on tergite IV consisting of 18–20 arched subdecumbent spatulate hairs forming 6 longitudinal rows, appressed ground pilosity present. Abdominal tergum IV with transverse carina along anterodorsal margin that separates dorsum from very narrow transverse anterior surface. First gastral ventrum with densely punctate, sparsely clothed by decumbent hairs pointing posterad. Tarsal claws simple, long and slender; legs stout, not elongate; protibial apex with spatulate hair anterolaterally, plus smaller single arched hair just posterad; rest of hairs on protibia short, arched. Mesotibial apex with two spatulate hairs, metatibial apex with single spatulate hair, lateral surface of meso- and metatarsi each with two longitudinal rows of oblong hairs. Body mostly ferruginous brown, gaster darker; apex of mandible and ventral mandibular tooth, brown.

Queen
Measurements. HL 0.76; HW 0.83; ML 0.56; EL 0.15; SL 0.43; PW 0.57; WL 1.00; PH 0.24; PL 0.43; DPW 0.44 mm. CI 1.10; MI 0.67; OI 0.18; SI 0.51; LPI 0.57; DPI 1.04.

Head very much as in worker but with 3 ocelli, lateral ocellus directed laterodorsad, median ocellus directed anterad. Compound eye large, 12–15 ommatidia across, clearly visible in cephalic frontal view. Pronotal margin vertical in lateral view, mesonotum with anterior convex margin and mostly flat dorsally. Mesonotum with mostly longitudinal rugulae. Petiolar node relatively smaller, lower, and with peduncle more elongate than in worker. Mesosoma laterally densely punctate. Propodeal tooth triangular with posterior keel weakly convex. Gastral tergum with over 50 slender spatulate standing hairs, ventrum with abundant slender hairs; very sparse appressed pilosity also present on gaster. See genus description and discussion for venation.

Type Material
Holotype worker (point-mounted; to be deposited in ): ECUADOR. Loja: Reserva El Madrigal, –4.0466° –79.1758°, 6.3 km SSE of Loja, 2350 m, 5.III.2015, J. Lattke 3708. Found by sifting leaf litter. Paratypes: ECUADOR. Loja: Reserva El Madrigal, –4.0466° –79.1758°, 6.3 km SSE of Loja, 2350 m, 28.VIII.2014, J. Lattke 3590-5. One point-mounted worker found by sifting leaf litter and deposited in (ARCE). ECUADOR. Zamora-Chinchipe: Reserva Biológica San Francisco, –3.9823° –79.0835°, 13 km E of Loja, 2070 m, 24.III.2011, hand-collected, T. Delsinne coll.,, specimen-ID 46586-01 from sample 46586. One point-mounted alate queen presently in, to be deposited in.

Etymology
The species epithet is an adjective in the nominative singular derived from “Loxa”, the old Spanish name for the town of Loja, Ecuador, not far from the type locality. It translates into “from Loja”.