Holotype. Madagascar. • 1 major worker; Toamasina; Montagne d’Anjanaharibe, 19.5 km 27°NNE Ambinanitelo; -15.17833, 49.635; alt. 1100 m; 12 Mar 2003; Fisher et al. leg.; montane rainforest, ex rotten tree stump; BLF08197; CASENT0498055, bottom specimen on the pin (CASC). Paratypes. • 3w., 5s.; same data as for holotype; CASENT0498053, CASENT0872250CASENT0498054 (CASC, MHNG, PBZT).

Madagascar. –Toamasina: • 3w.; Montagne d’Akirindro 7.6 km 341°NNW Ambinanitelo; -15.28833, 49.54833; alt. 600 m; 17 Mar 2003; Fisher et al. leg.; rainforest, ex rotten stick on ground; BLF08317 (CASC). • 1s.; Montagne d’Akirindro 7.6 km 341°NNW Ambinanitelo; -15.28833, 49.54833; alt. 600 m; 17 Mar 2003; Fisher et al. leg.; rainforest, ex rotten log; BLF08377 (CASC). • 3w.; Montagne d’Anjanaharibe, 19.5 km 27°NNE Ambinanitelo; -15.17833, 49.635; alt. 1100 m; 12 Mar 2003; Fisher et al. leg.; montane rainforest, ex rotten log; BLF08172 (CASC). • 3s.; Montagne d’Anjanaharibe, 19.5 km 27°NNE Ambinanitelo; -15.17833, 49.635; alt. 1100 m; 12 Mar 2003; Fisher et al. leg.; montane rainforest, ex root mat, ground layer; BLF08186 (CASC).

Moderately large species. Major workers. Head in full-face view sub-oval, not widening posteriorly, with anterior and posterior sides slightly 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 frons with moderately dense, thin rugulae, anteriorly longitudinal and interrupted, posteromedial part with irregular rugae, interspaces shiny with sparse and indistinct irregular rugulae; lateral sides with longitudinal anteriorly to irregular posteriorly, thick, and relatively dense rugae with distinctly rugofoveolate interspaces; occipital lobes and area posterolateral from eyes never smooth; scape, when laid back, exceeding the midlength of head by three-fifths of its length; inner hypostomal teeth distinct, large, closely spaced, triangular, with rounded apex directed outward; outer hypostomal teeth lobe-like, lower and more narrow than inner hypostomal teeth, apex directed outward; inner and outer hypostomal teeth closely spaced and not connected by concavity; pronotum and mesonotum predominantly smooth with transverse rugae on dorsum and indistinct rugofoveolae on lateral sides; katepisternum and anepisternum predominantly smooth; propodeum rugofoveolate; body yellow. Minor workers. Head foveolate; area posterolateral from eyes smooth; scape, when laid back, surpassing the posterior head margin by two-fifths of its length; promesonotum moderately low and moderately short; promesonotal groove absent; propodeal spines very small and triangular; mesosoma smooth, sometimes with sparse and indistinct foveolae on lateral sides; body yellow.

Major workers. Measurements (N = 9): HL: 0.89–1.06 (0.95); HW: 0.83–1.02 (0.92); SL: 0.6–0.69 (0.65); EL: 0.12–0.14 (0.13); WL: 0.94–1.02 (0.98); PSL: 0.15–0.19 (0.16); MTL: 0.57–0.64 (0.6); PNW: 0.38–0.47 (0.42); PTW: 0.12–0.16 (0.13); PPW: 0.19–0.3 (0.24); CI: 100.5–106.4 (104.0); SI: 64.2–76.6 (71.5); PSLI: 15.5–20.0 (17.2); PPI: 47.3–61.5 (55.7); PNI: 44.7–48.5 (46.1); MTI: 59.4–71.7 (66.1).

Head. In full-face view sub-oval, not widening posteriorly, with anterior and posterior sides slightly convex (Fig. 62B). 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 moderately dense, thin rugulae, anteriorly longitudinal and interrupted, posteromedial part with irregular rugae, interspaces shiny with sparse, indistinct, and irregular rugulae; lateral sides with longitudinal anteriorly to irregular posteriorly, thick, and relatively dense rugae with distinctly rugofoveolate interspaces. Occipital lobes with sparse, thick and irregular rugae; interspaces with fine rugofoveolae. Gena with relatively dense, thick, and longitudinal rugae and smooth to indistinctly rugofoveolae interspaces. Area posterolateral from eyes with thin and fine rugofoveolae, posteriormost parts with reduced sculpture and smooth notch. 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 three-fifths of its length; pilosity subdecumbent to erect (Fig. 62B, D). Inner hypostomal teeth distinct, large, closely spaced, triangular, with rounded apex directed outward; outer hypostomal teeth lobe-like, lower and more narrow than inner hypostomal teeth, apex directed outward; inner and outer hypostomal teeth closely spaced not connected by concavity (Fig. 64T). Mesosoma. In lateral view, promesonotum short, angular, and moderately low, posterior mesonotum moderately steep, mesonotal process indistinct, tubercle-like or absent; promesonotal groove absent; metanotal groove indistinct; propodeal spines moderately long, moderately wide, with acute apex; humeral area laterally weakly produced (Fig. 62D). Surface shiny; pronotum and mesonotum predominantly smooth with transverse rugae on dorsum and indistinct rugofoveolae on lateral sides; katepisternum and anepisternum predominantly smooth; propodeum rugofoveolate. Pilosity relatively dense, long, and erect (Fig. 62D, F). Petiole. Shiny with fine and dense rugofoveolae; node smooth, low, triangular, with rounded and thin apex, in rear view node dorsoventrally slightly convex; pilosity moderately sparse and erect (Fig. 62D, F). Postpetiole. Shiny and smooth; in dorsal view oval, lateral margins medially with two dentate projections; pilosity long, moderately sparse and erect (Fig. 62D, F). Gaster. Shiny and smooth; pilosity moderately dense, long, and erect (Fig. 62D, F). Colour. Yellow; mandibles and gaster slightly darker (Fig. 62D, F).

Minor workers. Measurements (N = 6): HL: 0.54–0.58 (0.56); HW: 0.45–0.48 (0.47); SL: 0.58–0.61 (0.6); EL: 0.1–0.11 (0.11); WL: 0.69–0.73 (0.71); PSL: 0.07–0.09 (0.07); MTL: 0.48–0.51 (0.49); PNW: 0.31–0.33 (0.32); PTW: 0.07–0.09 (0.08); PPW: 0.12–0.13 (0.13); CI: 117.4–121.1 (118.7); SI: 126.5–131.0 (128.4); PSLI: 12.0–15.0 (13.7); PPI: 58.7–71.1 (63.4); PNI: 65.7–69.0 (67.2); MTI: 101.7–109.2 (104.9).

Head. Cephalic margin indistinctly convex or straight (Fig. 62A). Pilosity relatively sparse, long, decumbent to suberect. Sculpture foveolate; area posterolateral from eyes smooth. 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 (Fig. 62A, C). Mesosoma. In lateral view, promesonotum moderately low and moderately short, arched; promesonotal groove absent; metanotal groove indistinct; propodeal spines very small and triangular (Fig. 62C). Sculpture smooth, sometimes with sparse and indistinct foveolae on lateral sides. Pilosity very sparse, moderately long, and erect (Fig. 62C, E). Postpetiole. Short, low, and relatively flat; with few short, erect setae (Fig. 62C, E). Gaster. With sparse, erect pilosity (Fig. 62C, E). Colour. Yellow, vertex slightly darker (Fig. 62C, E).

Malagasy for yellow in reference to the body colouration.

The species was collected between 600–1100 m in elevation, in rainforest and montane rainforest. Nests were located in rotten logs, root mats, rotten tree stumps, and rotten sticks on the ground.

Pheidole vony sp. nov. is a member of a group of species characterised by body colouration bright yellow to orange in majors and yellow in minors, head sub-oval, not widening posteriorly with sides not convex or convex indistinctly, and medial part of frons with longitudinal and interrupted rugae on the anterior part and distinctly irregular rugae on the posterior one. The group includes three taxa: P. vony sp. nov., P. befotaka sp. nov., and P. mamiratra sp. nov. Pheidole vony sp. nov. is known from two localities in Toamasina: Montagne d’Anjanaharibe and Montagne d’Akirindro, and its distribution doesn’t overlap with two remaining members of the group. Morphologically P. vony sp. nov. is most similar to P. mamiratra sp. nov., known only from Station Forestière Angavokely in Antananarivo. Major workers of P. vony sp. nov. differ from P. mamiratra sp. nov. in medial part of frons with moderately dense and thin rugae and inner hypostomal teeth large and triangular, with rounded apex directed outward and outer hypostomal teeth lobe-like, lower, and more narrow than inner hypostomal teeth; minors differ in more distinctly foveolate head sculpture. However, minor and major workers of P. vony sp. nov. can be also confused with P. sparsa sp. nov., known from Bemanevika in Mahajanga, and P. hazo sp. nov., described from the vicinity of Antananarivo. Majors of P. vony sp. nov. differ from P. sparsa sp. nov. and P. hazo sp. nov. in median frons with thinner and irregular rugae and more irregular sculpture on lateral sides of frons; minor workers differ in smaller propodeal spines, lack of promesonotal groove, strongly reduced sculpture of mesosoma, and head lacking additional, indistinct rugulae.