Pheidole grallatrix Emery 1899
Creators: name: Salata, Sebastian
name: Fisher, Brian L.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Formicidae
Pheidole
Pheidole grallatrix

description: Pheidole grallatrix Emery, 1899
Figs 16 A–F, 27H, 28H
Pheidole grallatrix Emery, 1899: 278 (s.w.)
LECTOTYPE [designated here]: 1s., Madagascar, Toamasina, Baie d’Antongil, coll. Mocquerys, CASENT0904224, ANTC24064 (MSNG). PARALECTOTYPES: 2w., the same data as lectotype, CASENT0904225, ANTC24065 (MSNG), CASENT0101943, ANTC3397 (MHNG).
Other material. Madagascar. Antsiranana: 3w., 6.5 km SSW Befingotra, Rés. Anjanaharibe-Sud, -14.75 49.5, 875 m, B. L. Fisher et al. leg. (CASC); 1w., Forêt de Binara, 7.5 km 230° SW Daraina, -13.255 49.61667, 375 m, B. L. Fisher et al. leg. (CASC); 1w., Makirovana forest, -14.17066 49.95409, 415 m, B. L. Fisher et al. leg. (CASC); 4w., 1s., Masoala National Park, -15.32331 50.30751, 60 m, B. L. Fisher et al. leg. (CASC); 1w., 1s., Parc National de Marojejy, Manantenina River, 27.6 km 35° NE Andapa, 9.6 km 327° NNW Manantenina, -14.435 49.76, 775 m, B. L. Fisher et al. leg. (CASC); 1w., 3s., Parc National de Marojejy, Manantenina River, 28.0 km 38° NE Andapa, 8.2 km 333° NNW Manantenina, -14.43667 49.775, 450 m, B. L. Fisher et al. leg. (CASC); 1w., RNI Marojejy, 8 km NW Manantenina, -14.43333 49.78333, 450 m, E.L. Quinter leg. (CASC); 4w., SAVA Region, District of Sambava, Marojejy National Park, 5 km W of Manantenina village, 1st Camp site (Mantella), -14.43817 49.774, 487 m, M. Rin’Ha leg. (CASC); 4w., 1s., Sava Region: Parc National de Marojejy, near Manantenina River, -14.43677 49.77541, 475 m, B. L. Fisher et al. leg. (CASC). Fianarantsoa: 5w., 1s., 7.6 km 122º Kianjavato, Forêt Classée Vatovavy, -21.4 47.94, 175 m, B. L. Fisher et al. leg. (CASC); 2s., Forêt d’Ambalagoavy Nord, Ikongo, Ambatombe, -21.857068 47.37849, 625 m, Harin’Hala & Irwin leg. (CASC); 2w., JIRAMA water works near river, Ranomafana National Park, Fianarantsoa Prov., -21.2485 47.45217, 690 m, Irwin et al. leg. (CASC); 1w., radio tower, Ranomafana National Park, Fianarantsoa Prov., -21.25833 47.40717, 1130 m, Irwin et al. leg. (CASC); 1s., Ranomafana, -21.25 47.36667, A. Pauly leg. (CASC); 1w., Réserve Speciale Manombo 24.5 km 228° Farafangana, -23.01583 47.719, 30 m, B. L. Fisher et al. leg. (CASC). Toamasina: 1w., 5.3 km SSE Ambanizana, Andranobe, -15.67133 49.97395, 425 m, B. L. Fisher et al. leg. (CASC); 2w., 6.3 km S Ambanizana, Andranobe, -15.6813 49.958, 25 m, B. L. Fisher et al. leg. (CASC); 1w., Bevolota 17.1 km N Andasibe, -18.77071 48.43164, 995 m, B. L. Fisher et al. leg. (CASC); 2w., F.C. Sandranantitra, -18.04833 49.09167, 450 m, H. J. Ratsirarson leg. (CASC); 5w., 4s., Forêt d’Analava Mandrisy, 5.9 km 195º Antanambe, -16.48567 49.847, 10 m, B. L. Fisher et al. leg. (CASC); 7w., 5s., Ile Sainte Marie, Forêt Kalalao, 9.9 km 34° Ambodifotatra, -16.9225 49.88733, 100 m, B. L. Fisher et al. leg. (CASC); 2s., Manakambahiny, near Vavatenina Forest, -17.46667 49.35, A. Pauly leg. (CASC); 3w., Montagne d’Akirindro 7.6 km 341° NNW Ambinanitelo, -15.28833 49.54833, 600 m, B. L. Fisher et al. leg. (CASC); 7w., 4s., 1q., Montagne d’Anjanaharibe, 18.0 km 21° NNE Ambinanitelo, -15.18833 49.615, 470 m, B. L. Fisher et al. leg. (CASC); 1w., Montagne d’Anjanaharibe, 19.5 km 27° NNE Ambinanitelo, -15.17833 49.635, 1100 m, B. L. Fisher et al. leg. (CASC); 1s., Nosy Mangabe, 7.43 km S Maroantsetra, -15.4973 49.76223, 3 m, B. L. Fisher et al. leg. (CASC); 1w., 1s., Parc National de Zahamena, Besaky River, -17.75244 48.85321, 760 m, B. L. Fisher et al. leg. (CASC); 6w., 3s., Parc National Mananara-Nord, 7.1 km 261° Antanambe, -16.455 49.7875, 225 m, B. L. Fisher et al. leg. (CASC); 5w., Parcelle E3 Tampolo, -17.28104 49.43012, 10 m, B. L. Fisher et al. leg. (CASC); 2w., Parcelle K7 Tampolo, -17.28333 49.41667, 10 m, B. L. Fisher et al. leg. (CASC); 6w., 3s., Parcelle K 9 Tampolo, -17.175 49.268, 10 m, B. L. Fisher et al. leg. (CASC); 4w., 1s., Res. Ambodiriana, 4.8 km 306° Manompana, along Manompana river, - 16.67233 49.70117, 125 m, B. L. Fisher et al. leg. (CASC); 1w., Reserve Betampona, Camp Rendrirendry 34.1 km 332° Toamasina, -17.924 49.19967, 390 m, B. L. Fisher et al. leg. (CASC); 1w., Réserve Spéciale Ambatovaky, Sandrangato river, -16.7633 49.26692, 520 m, B. L. Fisher et al. leg. (CASC); 4w., Réserve Spéciale Ambatovaky, Sandrangato river, -16.81739 49.29402, 360 m, B. L. Fisher et al. leg. (CASC); 3w., 6s., 2m., S.F. Tampolo, 10 km NNE Fenoarivo Atn., -17.2825 49.43, 10 m, B. L. Fisher et al. leg. (CASC); 5w., 5s., Sahafina forest 11.4 km W Brickaville, -18.81445 48.96205, 140 m, B. L. Fisher et al. leg. (CASC); 1w., 1s., Tampolo, -17.28333 49.41667, 10 m, B. L. Fisher et al. leg. (CASC); 1w., Torotorofotsy, -18.77048 48.43043, 1005 m, B. L. Fisher et al. leg. (CASC). Toliara: 6w., Anosy Region, Anosyenne Mts, 29.33 km NW Manantenina, -24.13993 47.07418, 540 m, B. L. Fisher et al. leg. (CASC); 1w., Parc National Andohahela, Col de Tanatana, 33.3 km NW Tolagnaro, -24.7585 46.85367, 275 m, B. L. Fisher et al. leg. (CASC).
Geographic range. Madagascar, widely distributed across rainforest on the eastern part of the island.
Diagnosis. Major workers. Head in full-face view sub-rectangular, not widening posteriorly, with lateral margins slightly convex; side of head with moderately sparse, short, appressed to subdecumbent pilosity; frons with thin and sparse costulae that sometimes arch posterolaterally on the posterior part; interspaces between costulae smooth to indistinctly punctate; occipital lobes sometimes partially smooth, with thin rugopuncta that weaken posteriorly and arch posterolaterally; scape, when laid back, exceeding the midlength of head by two-fifths of its length; inner hypostomal tooth indistinct, low and bulge-like; outer hypostomal tooth lobe-like, higher than inner tooth, top directed posteriorly; inner and outer hypostomal tooth closely spaced and not connected by concavity; promesonotum short, angular and low; posterior mesonotum smoothly declining towards propodeum; mesonotal process distinct and tubercle-like; mesosoma smooth, only posterolateral sides of pronotum, katepisternum, and propodeum sometimes with sparse and thick rugulae; gaster smooth; body reddish brown to brown. Minor workers. Occiput elongated into a long, narrow neck terminating in a distinct nuchal collar; head sculpture smooth; scape, when laid back, exceeding the posterior head margin by half of its length; promesonotum very low, long, and slightly arched; promesonotal groove present; metanotal groove distinct; propodeal spines long and thin; mesosoma smooth; body brown to dark brown.
Description. Major workers. Measurements (n=10): HL: 2.04–2.36 (2.26); HW: 1.87–2.21 (2.09); SL: 1.55– 1.68 (1.63); EL: 0.25–0.28 (0.26); WL: 1.84–2.19 (2.08); PSL: 0.39–0.48 (0.44); MTL: 1.8–2.03 (1.92); PNW: 0.69–0.83 (0.76); PTW: 0.21–0.24 (0.23); PPW: 0.49–0.58 (0.53); CI: 104.1–110.5 (107.8); SI: 73.8–83.6 (77.8); PSLI: 17.8–20.9 (19.6); PPI: 39.4–46.2 (42.8); PNI: 34.9–38.4 (36.1); MTI: 87.9–96.3 (91.5).
Head. In full-face view sub-rectangular, not widening posteriorly with lateral sides slightly convex (Fig. 16B). In lateral view sub-oval, not depressed posteriorly; ventral and dorsal margins convex; inner hypostomal tooth visible. Side of head with moderately sparse, short, appressed to subdecumbent pilosity; head dorsum with relatively dense, long, decumbent to erect pilosity. Frons with thin and sparse costulae that sometimes arch posterolaterally on the posterior part; interspaces between costulae smooth to indistinctly punctate. Occipital lobes sometimes partially smooth; with thin rugopuncta that weaken posteriorly arch posterolaterally. Gena with dense and thick costulae; interspaces between costulae distinctly punctate. Sides posterolateral from eyes with dense and thin microreticulae that weaken posteriorly. Center of clypeus shiny and indistinctly punctate, lateral sides with weakly developed rugulae; median notch present, moderately wide and shallow; median longitudinal carina present; lateral longitudinal carinae present. Scape, when laid back, exceeding the midlength of head by two-fifths of its length; pilosity subdecumbent to erect (Fig. 16B, D). Inner hypostomal tooth indistinct, low and bulge-like; outer hypostomal tooth lobe-like, higher than inner tooth, top directed posteriorly; inner and outer hypostomal tooth closely spaced and not connected by concavity (Fig. 27H). Mesosoma. In lateral view, promesonotum short, angular and low; posterior mesonotum smoothly declining towards propodeum; mesonotal process distinct and tubercle-like; promesonotal groove absent; metanotal groove absent; propodeal spines long, narrow and with acute top; humeral tubercle weakly produced (Fig. 16D). Surface shiny and smooth; posterolateral sides of pronotum, katepisternum, and propodeum sometimes with sparse and thick rugulae. Pilosity moderately dense, short, and erect (Fig. 16D, F). Petiole. Smooth; in rear view node dorsoventrally convex medially (Fig. 16D, F). Postpetiole. Shagreened; dorsum with slightly sparser sculpture (Fig. 16D, F). Gaster. Shiny and smooth; pilosity moderately sparse, moderately long, and erect (Fig. 16D, F). Color. Reddish brown to brown, antennae and legs yellowish brown (Fig. 16D, F).
Description. Minor workers. Measurements (n=10): HL: 0.99–1.22 (1.04); HW: 0.58–0.77 (0.62); SL: 1.51– 1.9 (1.6); EL: 0.16–0.19 (0.17); WL: 1.27–1.58 (1.38); PSL: 0.22–0.29 (0.25); MTL: 1.4–1.77 (1.51); PNW: 0.42– 0.55 (0.46); PTW: 0.08–0.11 (0.1); PPW: 0.14–0.2 (0.16); CI: 159.4–175.0 (167.8); SI: 246.5–269.5 (258.3); PSLI: 21.8–25.0 (23.8); PPI: 51.6–79.4 (63.5); PNI: 71.0–77.1 (74.4); MTI: 230.6–258.9 (243.3).
Head. In full-face view oval, posterior region elongated into long, narrow neck terminated by distinct nuchal collar (Fig. 16A). Pilosity relatively sparse, moderately long, subdecumbent to erect. Sculpture shiny and smooth; antennal sockets with few indistinct and curved posterolaterally rugulate; interspaces between rugulae smooth. Clypeus with median longitudinal carina absent; two lateral longitudinal carinae absent. Scape, when laid back, exceeding the posterior head margin, neck not included, by half of its length; pilosity dense, subdecumbent to erect (Fig. 16A, C). Mesosoma. In lateral view, promesonotum very low, long, and slightly arched; promesonotal groove present; metanotal groove distinct; propodeal spines long, thin, and triangular (Fig. 16C). Sculpture smooth. Pilosity very sparse, short, and erect (Fig. 16C, E). Petiole. Peduncle with ventral face straight (Fig. 16C, E). Gaster. With sparse and erect pilosity (Fig. 16C, E). Color. Brown to dark brown, legs and antennae brighter (Fig. 16C, E).
Biology. The species was collected between 3–1130 m elevation, in rainforest, littoral forest, montane rainforest, low elevation rainforest, an open area near a stream, tropical dry forest, mixed tropical forest, and on a sandy beach. Nests were located in rotten logs, soil, root mats, and under stones. Workers were collected from sifted litter and tree trunks.
Comments. Majors of P. grallatrix are most similar to P. bessonii, P. atsirakambiaty, and P. voreios and can be easily separated based on smooth mesosoma in which the posterolateral sides of pronotum, katepisternum, and propodeum may be sparsely rugulate. In contrast, P. bessonii, P. atsirakambiaty, and P. voreios have entirely sculptured mesosoma. Minors of P. grallatrix are most similar to P. zirafy and can be separated based on smooth mesosoma. In contrast, P. zirafy has dense and thin rugoreticulae on lateral sides of propodeum, anepisternum, and katepisternum. Distribution of P. grallatrix overlaps only with P. zirafy and P. voreios.
description: Published as part of Salata, Sebastian & Fisher, Brian L., 2020, The ant genus Pheidole Westwood, 1839 (Hymenoptera: Formicidae) in Madagascar-taxonomic revision of the bessonii species-group, pp. 1-64 in Zootaxa 4843 (1) on pages 33-36, DOI: 10.11646/zootaxa.4843.1.1, http://zenodo.org/record/4405729