Holotype. Madagascar. • 1 major worker; Fianarantsoa; Parc National Befotaka-Midongy, Papango 27.7 km S Midongy-Sud, Mount Papango; -23.83517, 46.96367; alt. 940 m; 14 Nov 2006; B. L. Fisher et al. leg.; rainforest, ex rotten log; BLF14842; CASENT0119419 (CASC). Paratype. • 1w.; same data as for holotype, CASENT0923275 (CASC).

Minute species. Major workers.HL < 0.9 mm and WL < 0.7 mm; head in full-face view sub-oval, slightly widening posteriorly, with anterior and posterior sides convex, in lateral view sub-oval; ventral and dorsal faces convex; body blackish brown; sides of head with moderately dense, moderately short, suberect pilosity; entire head distinctly sculptured, medial part of frons with thick, longitudinal, and dense rugae and distinctly rugulate interspaces, rugae more irregular and directed slightly outward on posteromedial part; scape, when laid back, exceeding the midlength of head by one-fifth of its length; mesosoma distinctly foveolate, promesonotum with additional sparse, thin, and irregular rugae on dorsum; katepisternum and propodeum with sparser foveolae; 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 not connected by concavity; base of first gastral tergite smooth. Minor workers.HL < 0.5 mm and WL < 0.6 mm, scape, when laid back, exceeding the posterior head margin by less than one-fifth of its length; propodeal spines reduced to small tubercles; head relatively oval; frons with sparse and moderately thick, short, and predominantly longitudinal rugulae fading medially; vertex with transverse, sparse, moderately thick, and short rugulae; area posterolateral from eyes smooth; body dark yellow; mesosoma smooth.

Major workers. Measurements (N = 1): HL: 0.89; HW: 0.91; SL: 0.5; EL: 0.12; WL: 0.74; PSL: 0.15; MTL: 0.46; PNW: 0.45; PTW: 0.12; PPW: 0.3; CI: 96.8; SI: 54.5; PSLI: 17.4; PPI: 40.5; PNI: 49.2; MTI: 50.0.

Head. In full-face view sub-oval, slightly widening posteriorly, with anterior and posterior sides convex (Fig. 45B). In lateral view sub-oval; ventral and dorsal faces convex; inner hypostomal teeth visible. Sides of the head with moderately dense, moderately short, suberect pilosity; whole head with dense, long, decumbent to erect pilosity. Medial part of frons with thick, longitudinal, and dense rugae and distinctly rugulate interspaces, rugae more irregular and directed slightly outward on posteromedial part; lateral sides with thick, sparse, and irregular rugae with distinctly rugofoveolate interspaces. Occipital lobes with dense, irregular rugae and distinctly rugoreticulate interspaces. Area posterolateral from eyes with dense rugofoveolae and additional sparse and irregular rugae. Gena with relatively sparse and 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 absent; lateral longitudinal carinae absent. Scape, when laid back, exceeding the midlength of head by one-fifth of its length; pilosity subdecumbent to erect (Fig. 45B, D). 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 not connected by concavity (Fig. 64C). Mesosoma. In lateral view, promesonotum short, angular, and moderately high, posterior mesonotum moderately steep, mesonotal process very indistinct, tubercle-like; promesonotal groove absent; metanotal groove absent; propodeal spines moderate, with wide base and acute apex; humeral area produced (Fig. 45D). Surface shiny and distinctly foveolate; promesonotum with additional sparse, thin, and irregular rugae on dorsum; katepisternum and propodeum with sparser foveolae. Pilosity moderately sparse, moderately long, and erect (Fig. 45D, F). Petiole. Shiny with dense foveolae; node finely foveolate, triangular, with rounded and thin apex, in rear view node dorsoventrally convex; pilosity moderately sparse and erect (Fig. 45D, F). Postpetiole. Shiny and foveolate; dorsum with reduced sculpture; in dorsal view oval, lateral margins medially with two dentate projections; pilosity long, moderately sparse, and erect (Fig. 45D, F). Gaster. Shiny and smooth; pilosity moderately dense, moderately short, and erect (Fig. 45D, F). Colour. Blackish brown with yellow legs and antenna (Fig. 45D, F).

Minor workers. Measurements (N = 1): HL: 0.48; HW: 0.42; SL: 0.44; EL: 0.09; WL: 0.57; PSL: 0.05; MTL: 0.34; PNW: 0.29; PTW: 0.06; PPW: 0.12; CI: 114.8; SI: 105.7; PSLI: 11.0; PPI: 50.8; PNI: 70.0; MTI: 81.4.

Head. Cephalic margin slightly concave (Fig. 45A). Pilosity relatively sparse, moderately long, decumbent to subdecumbent. Sculpture shiny; frons with sparse and moderately thick, short, and predominantly longitudinal rugulae fading medially; vertex with transverse, sparse, moderately thick, and short rugulae; area posterolateral from eyes smooth; 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, exceeding the posterior head margin by less than one-fifth of its length; pilosity dense, subdecumbent to erect (Fig. 45A, C). Mesosoma. In lateral view, promesonotum moderately high and short, arched; promesonotal groove absent; metanotal groove distinct; propodeal spines reduced to small tubercles (Fig. 45C). Sculpture smooth; promesonotal dorsum with very sparse, short, and transverse rugulae; propodeum with indistinct and irregular, sparse rugae. Pilosity sparse, moderately long, and erect (Fig. 45C, E). Gaster. With sparse, erect pilosity (Fig. 45C, E). Colour. Dark yellow (Fig. 45C, E).

From the type locality.

The species was collected at 940 m in elevation, in rainforest. Nest was located in a rotten log.

Pheidole midongy sp. nov. belongs to the group of species characterised by small body size (major workers: HL < 1.05 mm, WL < 0.9 mm and minor workers HL < 0.5 mm, WL < 0.6 mm), sub-oval, slightly widening posteriorly head with anterior and posterior sides convex in major workers, and minor workers with yellow to brown body colouration and head foveolate or predominantly smooth and relatively oval. The group includes six species: P. havoana sp. nov., P. kely sp. nov., P. parvula sp. nov., P. parvulogibba sp. nov., P. volontany sp. nov., and P. midongy sp. nov. Because of dark body colouration P. midongy sp. nov., described form Parc National Befotaka-Midongy in Fianarantsoa, is most similar to P. volontany sp. nov., known from Forêt Classée d’Analavelona in Toliara. Major workers of P. midongy sp. nov. differ from P. volontany sp. nov. in frons with thick, longitudinal, and dense rugae and distinctly rugulate interspaces, and sides of the head with moderately dense, moderately short, and suberect pilosity; minor workers differ in frons with sparse and moderately thick, short, and predominantly longitudinal rugulae, vertex with transverse, sparse, and moderately thick short rugulae, oval head shape, and brighter body colouration.