Pheidole glabra

The species was collected at 450 m in elevation, in rainforest. Nest was located in rotten log.

Identification
Salata and Fisher (2020) - Major: Head in full-face view square, anterior and posterior of eyes relatively straight; sides of the head with dense, short, erect pilosity; malar area with sparse to moderately dense longitudinal rugae, interspaces smooth to finely rugulose; inner hypostomal teeth distinct, big, thick, triangular, with rounded apex; outer hypostomal teeth slightly but distinctly smaller and thin, with rounded tips, and wide base; propodeal spines moderately long, with base slightly wider than top; first gastral tergite shiny and finely shagreened; body brownish black to black. Minor: Whole head with sparse foveolae, frons and malar area with few additional, indistinct, longitudinal rugae, genae and centre of frons with sculpture reduced to absent; promesonotum low, slightly convex, with relatively steep posterior declivity; mesosoma foveolate, reduced on dorsal surface of pronotum, with katepisternum, anepisternum, promesonotal declivity, and lateral surfaces of propodeum smooth; propodeal spines very short, triangular; body dark brown.

This species is most similar to Pheidole petax and Pheidole brevipilosa. Major workers. Pheidole glabra can be distinguished from P. petax by presence of erect pilosity on sides of head and lateral sides of head, and square head shape in full-face view; from P.  brevipilosa by absence of foveolate sculpture on head, well-developed outer hypostomal teeth, pronotum with reduced sculpture and presence of smooth notches on its lateral and dorsal surfaces, and propodeum with presence of smooth notches on lateral sides. Minor workers. Pheidole glabra can be distinguished from P. petax by dark brown body colouration, presence of additional indistinct, longitudinal rugae on frons and malar area, clypeus never foveolate, and reduced sculpture on frons, dorsal surface of pronotum, promesonotal declivity, and lateral surfaces of propodeum; from P.  brevipilosa by denser and longer pilosity on head, and frons, dorsal surface of pronotum, promesonotal declivity, and lateral surfaces of propodeum with sculpture reduced or absent.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 *  glabra. Pheidole glabra Salata & Fisher, 2020: 183, figs. 68A–F, 84T, 86T (w.) MADAGASCAR.

Worker
Major (N = 1): HL: 1.38; HW: 1.33; SL: 0.58; EL: 0.15; WL: 0.9; PSL: 0.2; MTL: 0.56; PNW: 0.63; PTW: 0.17; PPW: 0.61; CI: 96.3; SI: 43.8; PSLI: 14.1; PPI: 27.9; PNI: 47.1; MTI: 42.2. Head. In full-face view square, anterior and posterior of eyes relatively straight. In lateral view sub-rectangular; ventral and dorsal faces relatively flat; dorsal face indistinctly depressed posteriorly, forming indistinct transverse depression between frons and occipital lobes; inner hypostomal teeth visible. Sides of the head with dense, short, erect pilosity; whole head with dense, short, suberect to erect pilosity. Antennal scrobes indistinct and not delimited by carinulae; scrobe surface shiny, with dense to sparse, fine, longitudinal to irregular rugae, interspaces smooth to rugulae. Occipital lobes with thick, sparse, irregular rugae, interspaces smooth; frons with thick, sparse to moderately sparse, longitudinal rugae, interspaces smooth; malar area with sparse to moderately dense longitudinal rugae, interspaces smooth to finely rugulose; genae with fine, thin to indistinct rugulae. Clypeus shiny and smooth, with thin, longitudinal rugulae on the lateral sides; median notch present, wide and shallow; median longitudinal carina absent; lateral longitudinal carinae absent. Scape, when laid back, slightly surpassing the mid-length of head; pilosity decumbent to erect. Inner hypostomal teeth distinct, big, thick, triangular, with rounded apex; outer hypostomal teeth slightly but distinctly smaller and thin, with rounded tips, and wide base. Mesosoma. In lateral view, promesonotum short, angular, and relatively low, posterior mesonotum slightly steep, with indistinct tubercle-like projections; promesonotal groove absent; metanotal groove absent or indistinct; propodeal spines moderately long, with base slightly wider than top, apex rounded; humeral area with small and flat tubercles. Surface shiny, with fine and sparse rugoreticulation, pronotum with sculpture reduced, sometimes with smooth notches on lateral sides and centre of its dorsal surface; katepisternum and lateral sides of propodeum at least partially smooth. Pilosity moderately dense, long, and erect. Petiole. Shiny, with dense and fine rugulae; peduncle short, with small, rounded, horizontal lobes on its basal part; node moderately high and narrow, with convex apex, in rear view node slightly dorsoventrally concave; pilosity moderately and erect, long to moderately long. Postpetiole. Shiny, with fine and dense rugulae; short and rounded; in dorsal view sides with relatively long, acute, narrow and triangular projections; pilosity long, moderately dense, and erect. Petiole. First gastral tergite shiny and finely shagreened; pilosity moderately dense, moderately long, and erect. Colour. Unicolourous, brownish black to black; legs yellow to brown.

Unless otherwise noted above, the following characters occur in this species, and the majority of Pheidole majors of Madagascar described by Salata and Fisher 2020a. Antennal sockets shallow; frontal lobes absent; head in full-face view with distinct median concavity; antenna 12-segmented, with 3-segmented club; masticatory margin of mandible with large, stout apical and preapical teeth, followed by a long diastema and then a short and crenulate tooth just before the rounded basal angle; outer surface of mandible mostly smooth and shining, sometimes with weak and sparse foveolae; antennal scrobes present; promesonotum strongly convex, well above the level of propodeum; postpetiole short with slightly convex dorsum; ventral process absent.

Minor (N = 1): HL: 0.53; HW: 0.47; SL: 0.52; EL: 0.1; WL: 0.59; PSL: 0.1; MTL: 0.4; PNW: 0.32; PTW: 0.07; PPW: 0.11; CI: 88.4; SI: 111.4; PSLI: 18.0; PPI: 64.3; PNI: 68.9; MTI: 84.1. Head. Occipital margin straight or indistinctly concave; occipital carina indistinct, weakly developed. Pilosity moderately dense, long, erect. Whole head with sparse foveolae, frons and malar area with few additional, indistinct, longitudinal rugae, genae and centre of frons with sculpture reduced to absent. Clypeus shiny, rugoreticulate; median longitudinal carina absent; two lateral longitudinal carinae absent. Scape, when laid back, surpassing the posterior head margin by one-fifth of its length; pilosity erect. Mesosoma. In lateral view, promesonotum low, slightly convex, with relatively steep posterior declivity; promesonotal groove absent; metanotal groove indistinct; propodeal spines very short, triangular, apex acute. Sculpture foveolate, reduced on dorsal surface of pronotum, with katepisternum, anepisternum, promesonotal declivity, and lateral surfaces of propodeum smooth. Pilosity sparse, long, and erect. Petiole. Peduncle short and thin with ventral face slightly convex; node low, globular, and small; with few long, erect setae. Postpetiole. Moderately long, low, and convex; with few short, erect setae. Petiole. With moderately sparse, erect pilosity. Colour. Unicolourous, dark brown.

Unless otherwise noted above, the following characters occur in this species, and the majority of Pheidole minors of Madagascar described by Salata and Fisher 2020a. Antennal sockets shallow; frontal lobes absent; head in full-face view oval, posterior and anterior of eyes convex; antenna 12-segmented, with 3-segmented club; humeral area not developed; clypeus smooth and shiny; its anterior margin regularly convex; promesonotum well above the level of propodeum; petiole smooth; petiole with node moderately low, triangular and small postpetiole smooth; gaster smooth and shiny.

Type Material
Holotype. Madagascar. •1 major worker; Toliara; Grand Lavasoa, 25.9 km W Tolagnaro; -25.08767, 46.749; alt. 450 m; 30 Nov 2006; B.L. Fisher et al. leg.; BLF15399, CASENT0122911. Paratype. Madagascar. •1 w.; same data as for holotype; CASENT0235037 (CASC).

Etymology
Latin for smooth, in reference to reduced sculpture of minor workers.