Pheidole decollata Forel 1892, stat. nov.
Creators: name: Salata, Sebastian
name: Fisher, Brian L.
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Formicidae
Pheidole
Pheidole decollata

description: Pheidole decollata Forel, 1892 stat. nov.
Figs 13 A–F, 27E, 28E
Pheidole oswaldi r. decollata Forel, 1892: 527 (s.w.).
LECTOTYPE: [designated here]:1s., top specimen on the pin, Madagascar, Antananarivo, Andrangoloaka Forest, coll. Sikora, CASENT0101716, ANTC3357 (MHNG). PARALECTOTYPES: 1s., bottom specimen, the same pin as lectotype, CASENT0876547, ANTC3357 (MHNG); 2w., the same data as lectotype, CASENT0101720, ANTC3358 (MHNG).
Other material. Madagascar. Antananarivo: 29w., 9s., 3 km 41° NE Andranomay, 11.5 km 147° SSE Anjozorobe, -18.47333 47.96, 1300 m, Fisher et al. leg. (CASC); 1w., Analamanga Region, District of Ankazobe, Ambohitantely, 46 km NE of Ankazobe, -18.198 47.2815, 701 m, M. Rinha leg. (CASC); 3w., Forêt de galerie, Andranorovitra, 24.0 km NNE Ankazobe, -18.11243 47.19757, 1491 m, Fisher et al. leg. (CASC); 5w., 4s., Forêt de galerie, Telomirahavavy, 23.4 km NNE Ankazobe, -18.12167 47.20627, 1520 m, Fisher et al. leg. (CASC); 5w., 2s., 1m., Mandraka, -18.91813 47.91717, 1312 m, Fisher et al. leg. (CASC); 3w., 3s., Réserve Naturelle Sohisika, Sohisika 24.6 km NNE Ankazobe, -18.10322 47.18692, 1464 m, Fisher et al. leg. (CASC); 4w., 3s., Réserve Spéciale d’Ambohitantely, Forêt d Ambohitantely, 20.9 km 72° NE d Ankazobe, -18.22528 47.28683, 1410 m, Fisher et al. leg. (CASC); Antsiranana: 2w., 1s., 2.0 km S Andrakata, -14.65 49.71667, 520 m, Fisher et al. leg. (CASC); 5w., 5s., 1q., 6.5 km SSW Befingotra, Rés. Anjanaharibe-Sud, -14.75 49.5, 875 m, Fisher et al. leg. (CASC); 1w., 7 km N Joffreville [camp 2 of Fisher], -12.33333 49.25, 360 m, R. Harin’Hala leg. (CASC); 1w., 9.2 km WSW Befingotra, Rés. Anjanaharibe-Sud, -14.75 49.46667, 1280 m, Fisher et al. leg. (CASC); 3w., 9.2 km WSW Befingotra, Rés. Anjanaharibe-Sud, -14.75 49.46667, 1200 m, Fisher et al. leg. (CASC); 2w., 1s., Ambondrobe, 41.1 km 175° Vohemar, -13.71533 50.10167, 10 m, Fisher et al. leg. (CASC); 1s., Ampasindava, Forêt d’Ambilanivy, 3.9 km 181° S Ambaliha, -13.79861 48.16167, 600 m, Fisher et al. leg. (CASC); 17w., 13s., 3m., Betaolana Forest, along Bekona River, -14.52996 49.44039, 880 m, Fisher et al. leg. (CASC); 4w., 4s., Binara Forest, -13.26392 49.59919, 1065 m, Fisher et al. leg. (CASC); 2w., 2s., Binara Forest, -13.26388 49.60141, 900 m, Fisher et al. leg. (CASC); 2w., 2s., Binara Forest, -13.26206 49.60672, 559 m, Fisher et al. leg. (CASC); 8w., 4s., 1m., 1q., Forêt Ambanitaza, 26.1 km 347° Antalaha, -14.67933 50.18367, 240 m, Fisher et al. leg. (CASC); 2w., Forêt de Binara, 9.1 km 233° SW Daraina, -13.26333 49.60333, 650-800 m, Fisher et al. leg. (CASC); 3w., 7s., Forêt de Binara, 9.4 km 235° SW Daraina, -13.26333 49.6, 1100 m, Fisher et al. leg. (CASC); 3w., Makirovana forest, -14.17066 49.95409, 415 m, Fisher et al. leg. (CASC); 2w., Makirovana forest, -14.16666 49.95, 715 m, Fisher et al. leg. (CASC); 4w., Makirovana forest, -14.16044 49.95216, 550 m, Fisher et al. leg. (CASC); 1w., Marojejy, tributary Manantenina R., -14.43333 49.75, 750 m, Quinter & Nguyen leg. (CASC); 1w., Masoala National Park, -15.3014 50.22776, 280 m, Fisher et al. leg. (CASC); 2w., 1s., Nosy Be, Réserve Naturelle Intégrale de Lokobe, 6.3 km 112° ESE Hellville, -13.41933 48.33117, 30 m, Fisher et al. leg. (CASC); 13w., 2s., Parc National de Marojejy, Antranohofa, 26.6 km 31° NNE Andapa, 10.7 km 318° NW Manantenina, -14.44333 49.74333, 1325 m, Fisher et al. leg. (CASC); 3w., 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, Fisher et al. leg. (CASC); 27w., 10s., Parc National de Marojejy, Manantenina River, 28.0 km 38° NE Andapa, 8.2 km 333° NNW Manantenina, -14.43667 49.775, 450 m, Fisher et al. leg. (CASC); 6w., Parc National Montagne d’Ambre [1st campsite], 960 m, Irwin et al. leg. (CASC); 1w., Parc National Montagne d’Ambre [lemur trail], 975 m, R. Harin’Hala leg. (CASC); 4w., Parc National Montagne d’Ambre [Petit Lac road], -12.533333, 49.166667, 1125 m, R. Harin’Hala leg. (CASC); 1s., Parc National Montagne d’Ambre, 12.2 km 211° SSW Joffreville, - 12.59639 49.1595, 1300 m, Fisher et al. leg. (CASC); 12w., 9s., 1q. Parc National Montagne d’Ambre, 3.6 km 235° SW Joffreville, -12.53444 49.1795, 925 m, J. Boutin leg. (CASC); 2w., 1s., Parc National Montagne d’Ambre, Antomboka, -12.51269 49.17807, 970 m, Fisher et al. leg. (CASC); 2w., 1s., Parc National Montagne d’Ambre, Lac maudit, -12.58502 49.15147, 1250 m, Fisher et al. leg. (CASC); 2w., 1s., 1q., Parc National Montagne d’Ambre, Mahasarika, -12.53176 49.17662, 1135 m, Fisher et al. leg. (CASC); 1w., 1s., Parc National Montagne d’Ambre, Roussettes, -12.52574 49.17238, 1025 m, Fisher et al. leg. (CASC); 3w., 3s., Prov. Antsiranana R.S. Manongarivo 17.3 km 218° SW Antanambao, -14.02167 48.41833, 1580 m, Fisher et al. leg. (CASC); 1s., R.S. Manongarivo, 12.8 km 228° SW Antanambao, -13.97667 48.42333, 780 m, Fisher et al. leg. (CASC); 3w., 3s., R.S. Manongarivo, 14.5 km 220° SW Antanambao, -14 48.43167, 1220 m, Fisher et al. leg. (CASC); 1w., 1s., R.S. Manongarivo, 14.5 km 220° SW Antanambao, -13.99833 48.42833, 1175 m, Fisher et al. leg. (CASC); 3w., 3s., R.S. Manongarivo, 14.5 km 220° SW Antanambao, -13.99833 48.42833, 1175 m, Fisher et al. leg. (CASC); 4w., 1s., Réserve Spéciale d’Ambre, 3.5 km 235° SW Sakaramy, -12.46889 49.24217, 325 m, Fisher et al. leg. (CASC); 1w., RNI Marojejy, 10 km NW Manantenina, -14.43333, 49.76667, 750 m, E.L. Quinter leg. (CASC); 1w., RNI Marojejy, 8 km NW Manantenina, -14.43333 49.78333, 450 m, E.L. Quinter leg. (CASC); 2w., Sakalava Beach [vegetated beach dunes], -12.26972 49.39167, 10 m, R. Harin’Hala leg. (CASC); 4w., 1s., 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); 2w., 1s., 1q., Sava Region: Parc National de Marojejy, Manantenina River, 21.3 km 27.0° NE Andapa, - 14.43686 49.74291, 1350 m, Fisher et al. leg. (CASC); 3w., 1s., 1m., Sava Region: Parc National de Marojejy, Manantenina River, 28.0 km 24.8° NE Andapa, -14.43461 49.76074, 780 m, Fisher et al. leg. (CASC); 4w., 2s., 1m., Sava Region: Parc National de Marojejy, Manantenina River, 28.0 km 24.8° NE Andapa, -14.43461 49.76074, 780 m, Fisher et al. leg. (CASC); 2w., 1s., 1m., Sava Region: Parc National de Marojejy, Manantenina River, 28.1 km 25.7° NE Andapa, -14.43553 49.76463, 680 m, Fisher et al. leg. (CASC); 5w., 3s., 2q., Sava Region: Parc National de Marojejy, near Manantenina River, -14.43677 49.77541, 475 m, Fisher et al. leg. (CASC). Fianarantsoa: 6w., 2s., 2 km W Andrambovato, along river Tatamaly, -21.51167 47.41, 1075 m, Fisher et al. leg. (CASC); 2w., 40 km S Ambalavao, Rés. Andringitra, -22.21667 46.96667, 1275 m, Fisher et al. leg. (CASC); 1w., 1q., 43 km S Ambalavao, Rés. Andringitra, -22.23333 47, 825 m, Fisher et al. leg. (CASC); 2w., 1s., 45 km S Ambalavao, -22.21667 47.01667, 720 m, Fisher et al. leg. (CASC); 7w., 4s., 1q., 45 km S. Ambalavao, -22.21667 47.01667, 785 m, Fisher et al. leg. (CASC); 5w., 3s., 7.6 km 122º Kianjavato, Forêt Classée Vatovavy, -21.4 47.94, 175 m, Fisher et al. leg. (CASC); 2w., 1s., 8.0 km NE Ivohibe, -22.42167 46.89833, 1200 m, Fisher et al. leg. (CASC); 2w., 9.0 km NE Ivohibe, -22.42667 46.93833, 900 m, Fisher et al. leg. (CASC); 1s., dry wash, 1 km E of Isalo National Park Interpretive Center, Fianarantsoa Prov., -22.62667 45.35817, 885m, R.Harin’Hala leg.(CASC); 1s., Forêt d’Ambalagoavy Nord, Ikongo, Ambatombe, -21.857068 47.37849, 625 m, R. Harin’Hala leg. (CASC); 1w., Forêt d’Atsirakambiaty, 7.6 km 285° WNW Itremo, -20.59333 46.56333, 1550 m, Fisher et al. leg. (CASC); 3w., Forêt d’Atsirakambiaty, 7.6 km 285° WNW Itremo, -20.59333 46.56333, 1550 m, Fisher et al. leg. (CASC); 4w., 2s., Forêt de Vevembe, 66.6 km 293° Farafangana, -22.791 47.18183, 600 m, 23-Apr-2006, rainforest, transition to montane forest, Fisher et al. leg. (CASC); 3w., 4s., Parc National Befotaka-Midongy, Papango 27.7 km S Midongy-Sud, Mount Papango, -23.83517 46.96367, 940 m, Fisher et al. leg. (CASC); 2w., 2s., Parc National Befotaka-Midongy, Papango 28.5 km S Midongy-Sud, Mount Papango, -23.84083 46.9575, 1250 m, Fisher et al. leg. (CASC); 1w., Parc National d’Isalo, 9.1 km 354° N Ranohira, -22.48167 45.46167, 725 m, Fisher et al. leg. (CASC); 10w., 2s., Parc National de Ranomafana, Vatoharanana River, 4.1 km 231° SW Ranomafana, -21.29 47.43333, 1100 m, Fisher et al. leg. (CASC); 2w., 1s., Parc Nationale Ranomafana: Talatakely, -21.24833 47.42667, Griswold et al. leg. (CASC); 8w., 1s., R.S. Ivohibe 8.0 km E Ivohibe, -22.48333 46.96833, 1200 m, Fisher et al. leg. (CASC); 2w., 1s., R.S. Ivohibe, 7.5 km ENE Ivohibe, -22.47 46.96, 900 m, Fisher 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., Ranomafana National Park, Talatakely area, 0.4 km WSW of Park Entrance, -21.41667 47.68333, 900 m, D.H. & K.M. Kavanaugh leg. (CASC); 1w., Vohiparara broken bridge, Fianarantsoa Prov., -21.22617 47.36983, 1110 m, R. Harin’Hala leg. (CASC); 1s., Vohiparara Kidonavo 1, -21.22632 47.37007, 1100 m, V. C. Clark leg. (CASC). Mahajanga: 28w., 3m., 3q., Region Sofia, Ampotsidia, -14.42935 48.69863, 1193 m, Fisher et al. leg. (CASC); 11w., Region Sofia, Ampotsidia, -14.40775 48.70201, 1625 m, Fisher et al. leg. (CASC); 6w., 2m., Region Sofia, Ampotsidia, -14.41592 48.71118, 1364 m, Fisher et al. leg. (CASC); 4w., 1m., 1q., Region Sofia, Ampotsidia, -14.42188 48.72083, 1400 m, Fisher et al. leg. (CASC); 2w., 3s., Réserve Spéciale Marotandrano, Marotandrano 48.3 km S Mandritsara, -16.28322 48.81443, 865 m, Fisher et al. leg. (CASC); 1w., 1s., 1q., Toamasina, 5.3 km SSE Ambanizana, Andranobe, -15.67133 49.97395, 425 m, Fisher et al. leg. (CASC); 1w., 2s., 6.8 km S Ambanizana, -15.68333, 49.8, 25 m, Fisher et al. leg. (CASC); 1w., 2s., 6.9 km NE Ambanizana, Ambohitsitondroina, -15.58506 50.00952, 825 m, Fisher et al. leg. (CASC); 1w., 2s., 6.9 km NE Ambanizana, Ambohitsitondroina, - 15.56667 50, 1000 m, Fisher et al. leg. (CASC); 1w., Ambanizana, Parc National Masoala, -15.57167 50.00611, 800-897 m, Andriamalala et al. leg. (CASC); 1w., 1s., Ambanizana, Parc National Masoala, -15.57222 50.00694, 930-1110 m, Andriamalala et al. leg. (CASC); 1s., Ambatovy, 12.4 km NE Moramanga, -18.83937 48.30842, 1080 m, Fisher et al. leg. (CASC); 1w., 1s., Ambatovy, 12.4 km NE Moramanga, -18.84773 48.29568, 1000 m, Fisher et al. leg. (CASC); 1w., Ambatovy, 12.4 km NE Moramanga, -18.85813 48.28488, 1040 m, Fisher et al. leg. (CASC); 1w., Analamay, -18.80623 48.33707, 1068 m, Fisher et al. leg. (CASC); 3w., Andasibe National Park, botanic garden near entrance, West of ANGAP office, -18.925172 48.418651, 1025 m, Irwin et al. leg. (CASC); 1w., F.C. Didy, -18.19833 48.57833, 960 m, H. J. Ratsirarson leg. (CASC); 2w., F.C. Sandranantitra, -18.04833 49.09167, 450 m, H. J. Ratsirarson leg. (CASC); 4w., 1s., Forêt Ambatovy, 14.3 km 57° Moramanga, -18.85083 48.32, 1075 m, Fisher et al. leg. (CASC); 1w., Manakambahiny, near Vavatenina Forest, -17.46667 49.35, A. Pauly leg. (CASC); 1w., Montagne d’Akirindro 7.6 km 341° NNW Ambinanitelo, -15.28833 49.54833, 600 m, Fisher et al. leg. (CASC); 5w., 1s., Montagne d’Anjanaharibe, 18.0 km 21° NNE Ambinanitelo, -15.18833 49.615, 470 m, Fisher et al. leg. (CASC); 3w., 2s., Montagne d’Anjanaharibe, 19.5 km 27° NNE Ambinanitelo, -15.17833 49.635, 1100 m, Fisher et al. leg. (CASC); 1w., P.N. Mantadia, -18.79167 48.42667, 895 m, H. J. Ratsirarson leg. (CASC); 2w., 2s., Parc National de Zahamena, Besaky River, -17.75244 48.85321, 760 m, Fisher et al. leg. (CASC); 2w., Parc National Mananara-Nord, 7.1 km 261° Antanambe, -16.455 49.7875, 225 m, Fisher et al. leg. (CASC); 1w., Reserve Betampona, Camp Vohitsivalana, 37.1 km 338 ° Toamasina, -17.88667, 49.2025 520 m, Fisher et al. leg. (CASC); 3w., 1s., Réserve Nationale Intégrale Betampona, Betampona 35.1 km NW Toamasina, -17.91801 49.20074, 500 m, Fisher et al. leg. (CASC); 1w., 1s., Sahafina forest 11.4 km W Brickaville, -18.81445 48.96205, 140 m, Fisher et al. leg. (CASC); 2w., Toliara, 10 km NW Enakara, Rés. Andohahela, -24.56667 46.81667, 430 m, Fisher et al. leg. (CASC); 4w., 1s., 11 km NW Enakara, Rés. Andohahela, -24.56667 46.83333, 800 m, Fisher et al. leg. (CASC); 1w., 2s., 11 km NW Enkara, Rés Andohahela, -24.56667 46.81667, 950 m, Fisher et al. leg. (CASC); 1w., 13 km NW Enakara, Rés. Andohahela, -24.55. 46.8, 1250 m, Fisher et al. leg. (CASC); 2w., 1s., 13 km NW Enkara, Rés Andohahela, - 24.56667 46.81667, 1000 m, Fisher et al. leg. (CASC); 6w., 4s., 1m., Anosy Region, Anosyenne Mts, 29.33 km NW Manantenina, -24.13993 47.07418, 540 m, Fisher et al. leg. (CASC); 3w., 3s., Forêt Ivohibe 55.0 km N Tolagnaro, -24.569 47.204, 200 m, Fisher et al. leg. (CASC); 4w., 2s., 1q., Forêt Ivohibe 55.6 km N Tolagnaro, -24.56167 47.20017, 650 m, Fisher et al. leg. (CASC); 2w., 3s., Grand Lavasoa, 25.9 km W Tolagnaro, -25.08767 46.749, 450 m, Fisher et al. leg. (CASC); 4w., 3s., Parc National Andohahela, Col de Tanatana, 33.3 km NW Tolagnaro, - 24.7585 46.85367, 275 m, Fisher et al. leg. (CASC); 1w., 1s., Parc National Andohahela, Manangotry, 33.8 km NW Tolagnaro, -24.75117 46.85783, 575 m, Fisher et al. leg. (CASC); 13w., 7s., Parc National d’Andohahela, Col du Sedro, 3.8 km 113° ESE Mahamavo, 37.6 km 341° NNW Tolagnaro, -24.76389 46.75167, 900 m, Fisher et al. leg. (CASC); 7w., 3s., Parc National d’Andohahela, Manampanihy River, 5.4 km 113° ESE Mahamavo, 36.7 km 343° NNW Tolagnaro, -24.76389 46.76683, 650 m, Fisher et al.leg.(CASC); 1w., 1s., Réserve Spéciale d’Ambohijanahary, Forêt d’Ankazotsihitafototra, 34.6 km 314° NW Ambaravaranala, -18.26 45.41833, 1100 m, Fisher et al. leg. (CASC); 19w., 11s., Réserve Spéciale d’Ambohijanahary, Forêt d’Ankazotsihitafototra, 35.2 km 312° NW Ambaravaranala, -18.26667 45.40667, 1050 m, Fisher et al. leg. (CASC).
Geographic range. Madagascar, widely distributed mostly across the central and eastern parts of the island.
Diagnosis. Major workers. Head in full-face view sub-rectangular, slightly widening posteriorly, with lateral margins relatively straight; side of head with dense, long, suberect to erect pilosity; medial frons with sparse and thick costulae; interspaces between costulae indistinctly punctate; frons laterally with thick and sparse rugae; interspaces between rugae distinctly punctate; occipital lobes punctate with sparse and weakly developed rugae; scape, when laid back, exceeding the midlength of head by one-fifth of its length; inner hypostomal tooth distinct, bulge-like; outer hypostomal tooth lobe-like, moderately high and wide, with top arching posterolaterally; median tooth absent; promesonotum short, angular, and moderately low; posterior mesonotum smoothly declining towards propodeum; mesonotal process indistinct and tubercle-like; mesosoma microreticulate; lateral sides of pronotum, propodeum, and katepisternum with additional, thin and transverse rugae; gaster smooth; body yellowish orange to brown. Minor workers. Occiput not elongated; nuchal collar indistinct; head sculpture distinctly to indistinctly punctate and fading posteriorly to the vertex, gena mostly or entirely smooth; scape, when laid back, exceeding the posterior head margin by two-fifths of its length; promesonotum moderately low, moderately long, and arched; promesonotal groove present; metanotal groove distinct; propodeal spines thin and very small to small; mesosoma punctate; body yellow to brown.
Description. Major workers. Measurements (n=10): HL: 1.54–1.7 (1.6); HW: 1.49–1.61 (1.53); SL: 1.04– 1.09 (1.06); EL: 0.15–0.18 (0.17); WL: 1.49–1.6 (1.54); PSL: 0.22–0.27 (0.24); MTL: 1.12–1.21 (1.17); PNW: 0.59–0.64 (0.62); PTW: 0.17–0.21 (0.18); PPW: 0.35–0.43 (0.39); CI: 101.9–107.8 (104.3); SI: 64.8–71.4 (68.9); PSLI: 12.8–16.6 (15.1); PPI: 39.2–42.0 (40.2); PNI: 38.5–42.0 (40.2); MTI: 69.4–80.5 (76.5).
Head. In full-face view sub-rectangular, slightly widening posteriorly, with lateral sides slightly convex (Fig. 13B). In lateral view sub-oval, not depressed posteriorly; ventral and dorsal margins convex; inner hypostomal tooth not visible. Side of head with dense, long, suberect to erect pilosity; head dorsum with relatively dense, long, suberect to erect pilosity. Medial frons with sparse and thick costulae; interspaces between costulae indistinctly punctate. Frons laterally with thick and sparse rugae; interspaces between rugae distinctly punctate. Occipital lobes punctate with sparse and indistinct rugae. Gena with dense and moderately thick costulae; interspaces between costulae mostly punctate. Sides posterolateral from eyes microreticulate with additional network of thin and sparse rugulae. Center of clypeus shiny with weakly developed rugulae, lateral sides with distinct 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 one-fifth of its length; pilosity subdecumbent to erect (Fig. 13B, D). Inner hypostomal tooth distinct, bulge-like; outer hypostomal tooth lobe-like, moderately high and wide,, with top arching posterolaterally; median tooth absent (Fig. 27E). Mesosoma. In lateral view, promesonotum short, angular, and moderately low; posterior mesonotum smoothly declining towards propodeum; mesonotal process indistinct and tubercle-like; promesonotal groove absent; metanotal groove indistinct; propodeal spines moderately long with moderately wide base and acute top; humeral tubercle weakly produced (Fig. 13D). Surface microreticulate; lateral sides of pronotum, propodeum, and katepisternum with additional thin and transverse rugae. Pilosity dense, long, and erect (Fig. 13D, F). Gaster. Shiny and smooth; pilosity moderately sparse, long, and erect (Fig. 13D, F). Color. Yellowish orange to brown, antennae and legs yellow (Fig. 13D, F).
Description. Minor workers. Measurements (n=9): HL: 0.72–0.91 (0.85); HW: 0.54–0.66 (0.62); SL: 0.99– 1.13 (1.09); EL: 0.11–0.15 (0.13); WL: 0.99–1.19 (1.12); PSL: 0.08–0.14 (0.12); MTL: 0.93–1.04 (0.99); PNW: 0.34–0.47 (0.42); PTW: 0.09–0.13 (0.11); PPW: 0.16–0.23 (0.19); CI: 131.0–142.5 (138.0); SI: 171.1–183.7 (176.6); PSLI: 10.3–15.6 (13.8); PPI: 51.1–60.9 (56.7); PNI: 63.1–72.7 (68.8); MTI: 152.0–173.5 (160.4).
Head. In full-face view oval, posterior region not elongated; nuchal collar weakly developed (Fig. 13A). Pilosity relatively sparse, moderately long, subdecumbent to erect. Sculpture distinctly to indistinctly punctate, fading posteriorly; vertex and gena mostly or entirely smooth. Clypeus with median longitudinal carina absent; two lateral longitudinal carinae absent. Scape, when laid back, exceeding the posterior head margin by two-fifths of its length; pilosity dense, subdecumbent to erect (Fig. 13A, C). Mesosoma. In lateral view, promesonotum moderately low and moderately long and arched; promesonotal groove present; metanotal groove distinct; propodeal spines very small to small, thin, and triangular (Fig. 13C). Sculpture punctate. Pilosity sparse, long, and erect (Fig. 13C, E). Gaster. With sparse and erect pilosity (Fig. 13C, E). Color. Yellow to brown, legs and antennae usually brighter than the rest of the body (Fig. 13C, E).
Biology. The species was collected between 10–1625 m elevation, in montane rainforest, rainforest, montane ravine forest, montane shrubland, disturbed gallery montane forest, tropical forest, and montane forest. Nest were located in rotten logs, branches, and sticks on the ground, and dead twigs above the ground. Workers were collected from sifted litter.
Comments. Pheidole decollata is most similar to sympatric P. oswaldi. Its major workers can be separated based on the short, angular, and moderately low promesonotum and moderately large inner hypostomal tooth. In contrast, majors of P. oswaldi have a moderately long, angular, and very low promesonotum and small inner hypostomal tooth. Minors of P. decollata have the posterior region of the head not elongated and the promesonotum is moderately long, moderately low, and angular. Minor workers of P. oswaldi have slightly elongated posterior region of head, and moderately long, angular, and very low promesonotum.
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 23-28, DOI: 10.11646/zootaxa.4843.1.1, http://zenodo.org/record/4405729