Pheidole fisaka

The species was collected between 725–865 m in elevation, in rainforest. Nests were located in rotten logs.

Identification
Salata and Fisher (2020) - Major: Small species: HL: 1.01-1.0; HW: 0.99-0.98, WL: 0.8-0.76; head in full-face view sub-rectangular, anterior of eyes straight, posterior of eyes convex; sides of the head with moderately dense, short, erect pilosity; antennal scrobes indistinct and not delimited by carinulae; scrobe surface shiny, foveolate with thick, longitudinal to irregular, and long rugae; inner hypostomal teeth distinct, moderately high, closely spaced, triangular, with rounded apex and wide base; outer hypostomal teeth thinner and narrower than inner hypostomal teeth, dentate; gaster finely shagreened; body yellowish brown. Minor:. Head foveolate, genae smooth; promesonotum low, convex, short, with posterior declivity smoothly declining towards propodeum; propodeal spines minute; mesosoma foveolate, lateral sides of pronotum and propodeum with fading sculpture, katepisternum smooth.

Pheidole fisaka is most similar to Pheidole binara. Major workers. Pheidole fisaka differs from P. binara in smooth surface between rugae on frons and katepisternum and fading foveolae on propodeal dorsum. Minor workers. Pheidole fisaka differs from P. binara in shorter and more convex promesonotum, and lateral sides of pronotum and propodeum with fading foveolae and smooth katepisternum.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Worker
Minor

Major

Nomenclature

 *  fisaka. Pheidole fisaka Salata & Fisher, 2020: 214, figs. 79A–F, 84R, 86R (w.) MADAGASCAR.

Worker
Major (N = 2): HL: 1.01-1.0; HW: 0.99-0.98; SL: 0.44-0.45; EL: 0.13-0.13; WL: 0.8-0.76; PSL: 0.17-0.14; MTL: 0.440.44; PNW: 0.58-0.54; PTW: 0.16-0.14; PPW: 0.39-0.35; CI: 98.5-97.7; SI: 44.5-46.2; PSLI: 17.1-13.6; PPI: 40.6-40.5; PNI: 58.0-55.0; MTI: 44.6-45.3. Head. In full-face view longer than wide, anterior of eyes straight, posterior of eyes convex; slightly widening posteriorly. In lateral view sub-rectangular; ventral and dorsal faces relatively flat; dorsal face finely depressed posteriorly, forming shallow, transverse depression between frons and occipital lobes; inner hypostomal teeth visible. Sides of the head with moderately dense, short, erect pilosity; whole head with dense, short, suberect to erect pilosity. Antennal scrobes indistinct and not delimited by carinulae; scrobe surface shiny, foveolate with thick, longitudinal to irregular, and long rugae. Occipital lobes shiny, with thick, irregular rugae, interspaces with distinct, irregular rugulae; frons with moderately dense, thick and longitudinal rugae, interspaces smooth to rugo-foveolate in the posterior part; genae shiny, with dense and thin, irregular rugoreticulation; malar area with thin, longitudinal, dense rugoreticulation. Centre of clypeus shiny and smooth, lateral sides with longitudinal rugulae; median notch present, wide, and shallow; median longitudinal carina absent; lateral longitudinal carinae present. Scape, when laid back, reaching the midlength of head; pilosity suberect. Inner hypostomal teeth distinct, moderately high, closely spaced, triangular, with rounded apex and wide base; outer hypostomal teeth thinner and narrower than inner hypostomal teeth, dentate. Mesosoma. In lateral view, promesonotum low and arched, posterior mesonotum steep, without tubercle-like projections; promesonotal groove absent; metanotal groove absent; propodeal spines short, triangular, with rounded apex and wide base; humeral area laterally well produced. Surface shiny, with fine and moderately dense foveolae and additional rugoreticulation on the lateral sides of propodeum; dorsal surface of promesonotum with fading foveolae; katepisternum smooth. Pilosity moderately dense and long, erect. Petiole. Shiny and with fine foveolae; peduncle short, with indistinct horizontal lobes on its basal part; node relatively high, triangular, with rounded apex, in rear view node slightly dorsoventrally concave; pilosity moderately sparse and erect. Postpetiole. Shiny, finely shagreened; in dorsal view sides with moderately long, acute, and triangular projections; pilosity long, moderately long, and erect. Petiole. Shiny and finely shagreened; pilosity dense, moderately long, and erect. Colour. Yellow; frons, occipital lobes; dorsal surface of mesosoma and gaster yellowish brown 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 = 2): HL: 0.43-0.43; HW: 0.4-0.39; SL: 0.38-0.37; EL: 0.09-0.08; WL: 0.48-0.48; PSL: 0.07-0.06; MTL: 0.28-0.29; PNW: 0.25-0.25; PTW: 0.06-0.06; PPW: 0.09-0.09; CI: 92.9-91.8; SI: 95.0-93.1; PSLI: 15.2-14.5; PPI: 68.5-63.4; PNI: 62.3-63.9; MTI: 70.5-73.0. Head. Occipital margin straight or indistinctly concave; occipital carina absent. Pilosity moderately dense, short, suberect to erect. Head foveolate; genae smooth. Clypeus foveolate; median longitudinal carina absent; absence of two lateral longitudinal carinae. Scape, when laid back, reaching the posterior head margin; pilosity erect. Mesosoma. In lateral view, promesonotum low, convex, short, with posterior declivity smoothly declining towards propodeum; promesonotal groove absent; metanotal groove indistinct; propodeal spines minute, triangular, with acute apex. Sculpture foveolate; lateral sides of pronotum and propodeum with fading sculpture; katepisternum smooth. Pilosity moderately sparse, moderately long, and erect. Petiole. Peduncle very short and thin; with few short, erect setae. Postpetiole. Short, low and convex; with moderately short, erect setae. Petiole. With sparse, erect pilosity. Colour. Yellow.

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; Toamasina; Ankerana; -18.40062, 48.81311; alt. 865 m; 17 Jan 2012; B.L. Fisher et al. leg.; CASENT0274930. Paratype. Madagascar. 1w.; same data as for holotype; BLF27851, CASENT0923180 (CASC).

Etymology
Malagasy for flat, in reference for shape of the head in major workers.