Pheidole itremo

The species was collected between 1410-1620 m in elevation, in montane forest and montane rainforest. Nests were located in rotten logs and root mats.

Identification
Salata and Fisher (2020) - A member of the Pheidole sikorae species group. Moderately large species. Major: Head in full-face view sub-oval, widening posteriorly, with anterior and posterior sides convex, in lateral view sub-oval; ventral and dorsal faces convex; sides of the head with moderately dense, moderately long, suberect to erect pilosity; medial part of frons with thick, dense, longitudinal, and interrupted rugae and smooth interspaces, posteromedial frons with more irregular rugae directed slightly outward; lateral sides with thick and dense rugae, interspaces shiny and smooth or indistinctly rugulate; rugae longitudinal on anterolateral sides and more irregular on posterolateral sides; area posterolateral from eyes without smooth notches; scape, when laid back, exceeding the midlength of head by one-fifth of its length; inner hypostomal teeth distinct, large, closely spaced, triangular, with rounded apex directed upward; outer hypostomal teeth lobe-like, wider than inner teeth and approximately the same height; inner and outer hypostomal teeth closely spaced and connected by indistinct concavity; mesosoma with fine rugofoveolae; pronotum with rugofoveolae sparser and additional thin and transverse rugae; gaster smooth; body brown. Minor: Head smooth; posterolateral sides of frons with sparse and indistinct foveolae; scape, when laid back, surpassing the posterior head margin by two-fifths of its length; promesonotum moderately high and short, arched; promesonotal groove absent; propodeal spines minute and triangular; mesosoma smooth and shiny; body yellowish brown.

Pheidole itremo, known from Fort d'Atsirakambiaty in Fianarantsoa and Fort d'Ambohitantely in Antananarivo, is most similar to Pheidole sava, described from Parc National de Marojejy in Antsiranana. Major workers of P. itremo can be separated based on darker body colouration, presence of moderately dense, moderately long, suberect to erect pilosity on sides of the head, medial frons with smooth interspaces, finely rugofoveolae mesosoma lacking smooth notches; minor workers can be separated based on predominantly smooth head with posterolateral sides of frons with sparse and indistinct foveolae, and entirely smooth mesosoma.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Nomenclature

 * . Pheidole itremo Salata & Fisher, 2020: 77, figs. 34A–F, 63P, 65P (w.) MADAGASCAR.

Worker
Major (N = 6): HL: 1.14-1.24 (1.18); HW: 1.16-1.21 (1.17); SL: 0.64-0.69 (0.66); EL: 0.12-0.14 (0.13); WL: 0.99-1.06 (1.03); PSL: 0.18-0.2 (0.19); MTL: 0.65-0.68 (0.66); PNW: 0.51-0.54 (0.52); PTW: 0.15-0.17 (0.16); PPW: 0.28-0.34 (0.31); CI: 98.3-103.3 (100.8); SI: 53.7-58.8 (56.0); PSLI: 15.5-16.9 (16.1); PPI: 43.0-56.6 (51.5); PNI: 42.7-46.2 (44.3); MTI: 54.6-57.7 (56.6).

Head. In full-face view sub-oval, widening posteriorly, with anterior and posterior sides convex. In lateral view sub-oval; ventral and dorsal faces convex; inner hypostomal teeth visible. Sides of the head with moderately dense, moderately long, suberect to erect pilosity; whole head with dense, long, decumbent to erect pilosity. Medial part of frons with thick, dense, longitudinal, and interrupted rugae and smooth interspaces, posteromedial frons with rugae more irregular and directed slightly outward; lateral sides with thick and dense rugae, interspaces shiny and smooth or indistinctly rugulate; rugae longitudinal on anterolateral sides and more irregular on posterolateral sides. Occipital lobes with thinner, irregular rugae and smooth to indistinctly rugoreticulate interspaces. Area posterolateral from eyes with irregular to longitudinal, relatively thick to thin rugulae and rugoreticulate interspaces. Gena with relatively dense, thick, longitudinal rugae and smooth to indistinctly rugoreticulate interspaces. Centre of clypeus smooth and shiny, lateral sides with indistinct rugulae; median notch present, moderately wide, and shallow; median longitudinal carina present; lateral longitudinal carinae absent. Scape, when laid back, exceeding the midlength of head by one-fifth of its length; pilosity subdecumbent to erect. Inner hypostomal teeth distinct, large, closely spaced, triangular, with rounded apex directed upward; outer hypostomal teeth lobe-like, wider than inner teeth and approximately the same height; inner and outer hypostomal teeth closely spaced and connected by indistinct concavity. Mesosoma. In lateral view, promesonotum short, angular, and moderately low, posterior mesonotum moderately steep, mesonotal process very indistinct, tubercle-like; promesonotal groove absent; metanotal groove absent; propodeal spines moderately long, with moderately narrow base and acute apex; humeral area laterally weakly produced. Surface shiny with fine rugofoveolae; pronotum with rugofoveolae sparser and additional thin and transverse rugae. Pilosity moderately sparse, long, and erect. Petiole. Shiny with fine foveolae; node smooth to finely foveolate, triangular, with rounded and thick apex, in rear view node dorsoventrally straight to slightly convex; pilosity moderately sparse and erect. Postpetiole. Shiny and foveolate; dorsum with reduced sculpture and smooth notch; in dorsal view oval, lateral margins medially with two dentate projections; pilosity long, moderately sparse, and erect. Gaster. Shiny and smooth; pilosity dense, long, and erect. Colour. Brown; legs yellow.

The following characters are found in most Pheidole sikorae species-group majors in Madagascar (Salata and Fisher 2020b). These characters also occur in , except for any differences noted in the paragraph above. Dorsal face of head in lateral view not depressed posteriorly; 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 absent; promesonotum strongly convex, well above the level of propodeum; petiolar peduncle with small horizontal lobes on its basal part; postpetiole short with slightly convex dorsum; petiolar peduncle without horizontal lobes on its basal part; body unicolourous.

Minor (N = 10): HL: 0.54-0.59 (0.56); HW: 0.46-0.5 (0.48); SL: 0.59-0.63 (0.6); EL: 0.1-0.13 (0.11); WL: 0.68-0.74 (0.71); PSL: 0.06-0.1 (0.08); MTL: 0.45-0.5 (0.47); PNW: 0.3-0.35 (0.32); PTW: 0.08-0.1 (0.08); PPW: 0.13-0.16 (0.14); CI: 115.7-121.8 (117.9); SI: 120.4-131.4 (125.6); PSLI: 11.8-17.0 (14.0); PPI: 49.4-67.0 (58.5); PNI: 65.8-71.0 (68.2); MTI: 94.5-101.7 (99.2).

Head. Cephalic margin indistinctly convex. Pilosity relatively sparse, long, decumbent to suberect. Sculpture shiny and smooth; posterolateral sides of frons with sparse and indistinct foveolae; antennal sockets with few thick, curved outward rugae and smooth interspaces. Clypeus with median longitudinal carina absent; two lateral longitudinal carinae absent. Scape, when laid back, surpassing the posterior head margin by two-fifths of its length; pilosity dense, subdecumbent to erect. Mesosoma. In lateral view, promesonotum moderately high and short, arched; promesonotal groove absent; metanotal groove distinct; propodeal spines minute and triangular. Sculpture shiny and smooth. Pilosity moderately sparse, long, and erect. Gaster. With sparse, erect pilosity. Colour. Yellowish brown.

The following characters are found in most Pheidole sikorae species-group minors in Madagascar (Salata and Fisher 2020b). These characters also occur in , except for any differences noted in the paragraph above. Antennal sockets shallow; frontal lobes absent; occipital carina 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, with node moderately low, triangular, and small, with few short, erect setae; petiolar peduncle with ventral face slightly convex; postpetiole smooth, short, low, and slightly convex, with few short, erect setae; gaster smooth and shiny; body unicolourous.

Type material
Holotype. Madagascar. 1 major worker; Fianarantsoa; Fort d'Atsirakambiaty, 7.6 km 285°WNW Itremo; -20.59333, 46.56333; alt. 1550 m; 22 Jan 2003; Fisher et al. leg.; montane rainforest, ex rotten log; BLF07251; CASENT0491584, top specimen on the pin. Paratypes. 6w., 1s.; same data as for holotype, CASENT0872249, CASENT0491586, CASENT0491585 (CASC,, ).

Etymology
From the type locality.