Pheidole ensifera

The species was collected between 30–1343 m in elevation, in littoral and tropical dry rainforest and in-transition humid forest. Nests were located in litter (leaf mould, rotten wood), rotten logs and branches on the ground, and rotting tree stumps.

Identification
Salata and Fisher (2020) - A member of the Pheidole ensifera species group. Major. Body size moderate: HL: 1.63-1.74 (1.69), HW: 1.43-1.51 (1.46), WL: 1.05-1.2 (1.11); propodeal spines very long (PSL: 0.31-0.37 (0.34)); head in full-face view rectangular, with lateral sides relatively straight, only their posteriormost part slightly convex; sides of the head with sparse, long, suberect pilosity; occipital lobes shiny, smooth or with very fine and sparse rugoreticulation; inner hypostomal teeth distinct, closely spaced, lobe-like, with rounded apex and wide base; outer hypostomal teeth bigger and wider than inner hypostomal teeth, lobe-like, with tops directed outward; inner and outer teeth closely spaced and connected by concavity. Minor:. Body size moderate: HL: 0.58-0.69 (0.63), HW: 0.56-0.67 (0.6), WL: 0.76-0.87 (0.8); propodeal spines long (PSL: 0.18-0.22 (0.2)); scape, when laid back, surpassing posterior head margin by one-fifth of its length; lateral sides of head and malar area shiny, smooth or with indistinct, sparse rugulae, sculpture weakening posteriorly; vertex, genae and frons smooth; mesosoma foveolate.

Major workers. Pheidole ensifera differs from other members of the group in shiny and smooth to finely rugoreticulate occipital lobes and genae and relatively low and short promesonotum. Minor workers. Pheidole ensifera differs from other members of the group in surface of pronotum and mesonotum never smooth and with fine to moderately dense foveolae.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Worker
Minor

Nomenclature

 *  ensifera. Pheidole ensifera Forel, 1897c: 197 (s.w.) MADAGASCAR.

Worker
Salata and Fisher (2020) - Major (N = 10): HL: 1.63-1.74 (1.69); HW: 1.43-1.51 (1.46); SL: 0.67-0.73 (0.7); EL: 0.17-0.19 (0.18); WL: 1.05-1.2 (1.11); PSL: 0.31-0.37 (0.34); MTL: 0.66-0.71 (0.69); PNW: 0.58-0.67 (0.61); PTW: 0.15-0.19 (0.17); PPW: 0.46-0.54 (0.5); CI: 85.6-88.8 (87.0); SI: 46.5-50.1 (47.9); PSLI: 18.8-22.5 (20.4); PPI: 30.0-36.9 (34.1); PNI: 40.2-44.6 (41.7); MTI: 44.3-48.7 (47.2). Head. In full-face view rectangular, with lateral sides relatively straight, only their posteriormost part slightly convex. In lateral view elongate and oval; ventral and dorsal faces slightly convex; inner hypostomal teeth visible. Sides of the head with sparse, long, suberect pilosity; whole head with moderately sparse, long, suberect to erect pilosity. Antennal scrobes indistinct and not delimited; scrobe surface shiny, with dense to sparse, fine, longitudinal to irregular rugulae. Occipital lobes and genae shiny, smooth or with very fine and sparse rugoreticulation; frons with sparse, thick, and longitudinal rugae, interspaces with very fine and sparse rugulae, sculpture weakening posteriorly; malar area with sparse to moderately sparse, thick, and longitudinal rugae, interspaces with fine and dense rugulae. Centre of clypeus smooth and shiny, lateral sides with longitudinal rugae; median notch present, narrow and shallow to moderate; median longitudinal carina absent; lateral longitudinal carinae absent. Scape, when laid back, slightly surpass the midlength of head; pilosity decumbent to erect. Inner hypostomal teeth distinct, closely spaced, lobe-like, with rounded apex and wide base; outer hypostomal teeth bigger and wider than inner hypostomal teeth, lobe-like, with tops directed outward; inner and outer teeth closely spaced and connected by concavity. Mesosoma. In lateral view, promesonotum short, angular and relatively low, posterior mesonotum convex, with low tubercle-like projection; promesonotal groove absent; metanotal groove absent; propodeal spines long, thin, massive basally, with acute apex; humeral area laterally weakly produced. Surface shiny, with fine to thin, dense rugoreticulation, sculpture weakening on dorsum, sometimes propodeum with smooth patch on its dorsal surface. Pilosity sparse, long, and erect. Petiole. Shiny; peduncle shagreened, long, without horizontal lobes on its basal part; node smooth, low, and thick, triangular, with rounded apex, in rear view node slightly convex; pilosity sparse and erect. Postpetiole. Shagreened; in dorsal view sides with short, acute, and triangular projections; pilosity long, sparse and erect. Petiole. Shagreened, most often on the whole surface; pilosity moderately sparse, long, and erect. Colour. Unicolourous, reddish brown to dark brown, malar area and lower parts of frons with colouration brighter that the rest of the body.

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 = 10): HL: 0.58-0.69 (0.63); HW: 0.56-0.67 (0.6); SL: 0.6-0.67 (0.63); EL: 0.1-0.12 (0.11); WL: 0.76-0.87 (0.8); PSL: 0.18-0.22 (0.2); MTL: 0.46-0.52 (0.49); PNW: 0.37-0.44 (0.39); PTW: 0.08-0.12 (0.09); PPW: 0.13-0.18 (0.14); CI: 92.5-100.9 (95.4); SI: 101.4-107.1 (104.5); PSLI: 29.0-34.1 (31.4); PPI: 56.3-67.0 (61.2); PNI: 63.0-67.6 (65.2); MTI: 79.2-83.2 (81.7). Head. Occipital margin straight or indistinctly concave; occipital carina indistinct, weakly developed. Pilosity moderately dense, long, suberect to erect. Lateral sides of head and malar area shiny, smooth or with indistinct, sparse rugulae, sculpture weakening posteriorly; vertex, genae, and frons smooth; antennal sockets with sparse, sometimes interrupted carinae curved outward. Clypeus with median longitudinal carina absent; two lateral longitudinal carinae present. Scape, when laid back, surpassing posterior head margin by one-fifth of its length; pilosity suberect to erect. Mesosoma. In lateral view, promesonotum convex; promesonotal groove absent; metanotal groove indistinct; propodeal spines moderately long, massive basally, with acute apex. Pronotum and mesonotum with fine to moderately dense foveolate, sometimes foveolae weakening on the dorsal surface; katepisternum, anepisternum, and propodeum with thicker and denser foveolae. Pilosity moderately sparse, long and erect. Petiole. Shiny; peduncle rugulae relatively long and thin; node smooth, relatively high, triangular; with few long, erect setae. Postpetiole. With indistinct regulate; short and convex; with few long, erect setae at the anterior edge. Petiole. With sparse and erect setae. Colour. Unicolourous, brown to 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

 * Lectotype (designated by Salata & Fisher, 2020): major worker (top specimen, CASENT0101780): Madagascar, Antsiranana, Nosy Be, coll. Voeltzkow (MHNG) [examined].
 * Paralectotypes: 1 major worker (CASENT0810540, bottom specimen, the same pin as lectotype) (MHNG) [examined], 2 minor workers (1 pin, CASENT0101650) (MHNG) [examined], 2 minor workers (1 pin, CASENT0923207) (MHNG) [examined], 3 major workers (1 pin, CASENT0923208) (MHNG) [examined], 3 major workers (1 pin, CASENT0923209) (MHNG) [examined]: the same data as lectotype.

References based on Global Ant Biodiversity Informatics

 * Fisher B. L. 1997. Biogeography and ecology of the ant fauna of Madagascar (Hymenoptera: Formicidae). Journal of Natural History 31: 269-302.
 * Fisher B. L. 2003. Formicidae, ants. Pp. 811-819 in: Goodman, S. M.; Benstead, J. P. (eds.) 2003. The natural history of Madagascar. Chicago: University of Chicago Press, xxi + 1709 pp.
 * Forel A. 1897. Ameisen aus Nossi-Bé, Majunga, Juan de Nova (Madagaskar), den Aldabra-Inseln und Sansibar, gesammelt von Herrn Dr. A. Voeltzkow aus Berlin. Mit einem Anhang über die von Herrn Privatdocenten Dr. A. Brauer in Marburg auf den Seychellen und von Herrn Perrot auf Ste. Marie (Madagaskar) gesammelten Ameisen. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft 21: 185-208.
 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. IX. A synonymic list of the ants of the Malagasy region. Bulletin of the American Museum of Natural History 45: 1005-1055