Odontomachus simillimus Smith, 1858

Sorger, D. M. & Zettel, H., 2011, On the ants (Hymenoptera: Formicidae) of the Philippine Islands: V. The genus Odontomachus Latreille, 1804., Myrmecological News 14, pp. 141-163 : 158-161

Odontomachus simillimus Smith, 1858 (Figs. 43 - 45, 47)

Odontomachus simillimus Smith, 1858 (description of gyne; type locality: Fiji, also recorded from Sri Lanka).

Odontomachus simillimus: Wilson 1959: 499 and Brown 1976: 165-166 (synonymies). Odontomachus haematoda (misidentifications, nec haematoda Linnaeus, 1758 from Neotropis, see Wilson (1959) and Brown (1976)): Emery 1893: 262 (distribution: Manila); Wheeler & Chapman 1925: 71 (distribution: Los Baños, Laguna; Manila; Romblon; Port Cataingan, Masbate; Dumaguete, Negros); Wheeler 1929: 37 (distribution: Los Baños, Laguna); Chapman & Capco 1951: 43 (partim, general distribution); Baltazar 1966: 239 (distribution: Luzon; Laguna, Manila; Masbate, Negros Oriental, Romblon).

Material from the Philippines examined (183 workers, 15 gynes; CSW, CZW, FMNH, NHMW, UPLB, USC, ZMUC): Luzon: L a g u n a: Los Baños, Mt. Makiling, 13.-18.XI.1992, leg. H. Zettel (1), 1 ∑. Los Baños, Mt. Makiling, 300 - 500 m, 8.-9.II.1996, leg. H. Zettel (74), 1 ∑. Los Baños, UPLB campus, 14.II.1999, leg. S. Schödl (3), 1 ∑. Los Baños, Mt. Makiling, UPLB - Mud Spring, 18.XI. 1999, leg. H. Zettel (207), 1 ∑. Los Baños, Mt. Makiling, Flat Stones ["Rocks"], 14.II.1999, leg. S. Schödl (4), 3 ∑∑, 11.II.2002, leg. H. Zettel (308), 1 ∑. C a m a r i n es N o r t e: Labo, Tulay na Lupa, Mt. Labo - Mt. Bayabas area, 17.-18. III.2004, leg. H. Zettel & C. V. Pangantihon (382), 1 ∑. Daet, Bicol NP, Nalisan, 26.II.2004, leg. H. Zettel & C. V. Pangantihon (376), 1 ∑. Camarines Sur: Lupi, Alanao, Bahi River, 14.XI.1999, leg. H. Zettel (205), 16∑∑, 3.III. 1999, leg. H. Zettel (191), 2 ∑∑. Lupi, N Sipocot, Sooc, XII.1999-I.2000, leg. S. V. Zettel (5), 1 ∑, 10.-12.III.2000, various collectors (246), 2 ∑∑, 1.-9.IV.2000, various collectors (252), 1 ♀, 10 ∑∑, 10.-21.IV.2000, various collectors (256), 1 ♀, 22.-29.IV.2000, various collectors (258), 29.II. 2004, leg. C. V. Pangantihon (P47), 2 ∑∑, 18.-23.II.2004, leg. H. Zettel & C. V. Pangantihon (374), 1 ∑, 31.III.2004, leg. C. V. Pangantihon (P68), 1 ∑, 1 ♀. Lupi, Sooc, Looban, 15.III.2004, leg. H. Zettel (381), 1 ∑. Lupi, Sooc, Bicol NP, 100 m, 22.II.2008, leg. H. Zettel (508), 1 ∑. 20 km E Naga, 3 km E Carolina, Mainit Spring ("Hydro"), 4.III. 1999, leg. H. Zettel (193), 1 ♀. A l b a y: 40 km N Legaspi, 1 km W Malilipot, Busai Falls, 23.II.1998, leg. H. Zettel (143), 1 ∑. NE Legaspi, St. Domingo, Reyes, 20.III. 1998, leg. H. Zettel (163), 1 ∑. S o r s o g o n: NE Irosin, N San Roque, Lake Bulusan, 630 m, 26.II.1998, leg. H. Zettel (146), 1 ∑. Catanduanes: S of Summit, N Narsari, 9.III. 1999, at small creek, leg. H. Zettel (198), 1 ∑. E San Andres, 11.-12.III.1999, leg. H. Zettel (200), 1 ♀, 12.III.1999, leg. F. Seyfert (26), 1 ∑. (R o m b l o n P r o v.:) Sibuyan: E Magdiwang, W Silum, Lambigan Falls, 21.XI.1994, leg. H. Zettel (69), 2 ∑∑. (R o m b l o n P r o v.:) Tablas: San Agustin, Dubduban, Busai Falls, 23.-25.XI.1994, leg. H. Zettel (70), 8 ∑∑. Mindoro: M i n d o r o O r i e n t a l: Puerto Galera, S Big La Laguna, 25.XI.1993, leg. H. Zettel (33), 1 ∑. S Puerto Galera, Big Tabinay River, 27.XI.1993, leg. H. Zettel (36), 1 ∑. Baco, Hidden Paradise, 19.-20.XI. 1993, leg. H. Zettel (27), 1 ∑. Cebu: Cebu City, Talamban, University of San Carlos campus, 12.-16.XI.2003, leg. C. V. Pangantihon, 2 ∑∑, 19.IV.2004, leg. C. V. Pangantihon, 3 ∑∑. Talamban, University of San Carlos campus, dormitory, 22.V.2005, leg. C. V. Pangantihon (P154), 1 ♀. W Cebu City, Minglanilla, Camp 7, near creek and waterfall, 16.XI. 2003, leg. H. Zettel & C. V. Pangantihon (358), 2 ∑∑. S Badian, Matutinao, Kawasan Falls, 2-50 m, 23.-24.II.1997, leg. H. Zettel (116), 6 ∑∑. Malapuyug, Monteneza, 0 - 10 m, 13.XI.2003, leg. C. V. Pangantihon (P353), 2 ∑∑. (C e b u P r o v.:) Bantayan: Atop-Atop, N Santa Fe, coast, 18. X.2004, leg. C.V. Pangantihon (P388), 1 ∑. Siquijor: Lazi, Po-o River, 1.III.1997, leg. H. Zettel (121), 2 ∑∑. Lazi, Po-o River, near Cambugahay Falls, 22.X.2004, leg. C. V. Pangantihon (P392), 2 ∑∑. Bandila-an NP, Lodge - Little Waterfall, 23.X.2004, leg. C. V. Pangantihon (P395), 2 ∑∑. Samar: W e s t e r n S a m a r: E Basey, Sohoton National Park, at Sohoton River, 29.1.2000, leg. S. Schödl (2), 1 ∑. Leyte: L e y t e P r o v.: N Tacloban, Babatngon, Busay Falls, 28.I.2000, leg. S. Schödl (1), 9 ∑∑, leg. H. Zettel (220), 1 ∑. Baybay, ViSCA, along coast line, 12.II.2000, leg. S. Schödl (15), 4 ∑∑. Baybay, ViSCA campus, Mt. Pangasugan, 100 m, secondary forest, 31.I.2000, leg. S. Schödl (4), 1 ∑. Baybay, ViSCA, Mt. Pangasugan, above Forestry Department, 250 m, 11.II.2000, leg. S. Schödl (14), 2 ♀♀, 2 ∑∑. Baybay, Mt. Pangasugan, along Lago-Lago River, 50 - 250 m, secondary forest, 1.II.2000, leg. S. Schödl (5), 2 ∑∑, 1 ♀. Baybay, Mt. Pangasugan, Calbiga-a River, 50 - 200 m, 12.II.2000, leg. H. Zettel (236), 1 ∑, 50 - 100 m, 20.-21.III.2005, leg. H. Zettel & C. V. Pangantihon (422), 1 ∑. S o u t h e r n L e y t e: San José, 14.I.1945, leg. E. Ray (90) (Chicago-NHM), 1 ∑. N Maasin, at small stream E Lonoy, 20.XI.2003, leg. H. Zettel & C. V. Pangantihon (362), 3 ♀♀. Ibarra, Divisoria, near small creek, 21.XI. 2003, leg. H. Zettel & C. V. Pangantihon (363), 1 ∑. Camiguin: W Mambajao, Katibawasan spring area, 350 - 400 m, 13. and 15.III.2010, leg. H. Zettel & C. V. Pangantihon (515), 1 ∑. W Mambajao, Benon, between Saran and Kampanan, 500 - 800 m, 16. and 18.III.2010, leg. H. Zettel & C. V. Pangantihon (516), 1 ∑. (S u r i g a o d e l N o r t e P r o v.:) Dinagat: 6.8 km along round north of Dinagat proper, Busay, 3.II.2000, leg. S. Schödl (6), 7 ∑∑. (S u r i - g a o d e l N o r t e:) Bayagnan: southwest coast, 7. II.2000, leg. S. Schödl (10), 22 ∑∑. (S u r i g a o d e l N o r t e:) Hikdop: south and southwest coast, 5.II.2000, leg. S. Schödl (8), 23 ∑∑, leg. H. Zettel (227), 2 ∑∑. Mindanao: S u r i g a o d e l S u r: Tandag, San Antonio, 25. X.2010, leg. C.V. Pangantihon (P366), 1 ∑. Tawi-Tawi: Bongao, Lapid Lapid, at Manalik Channel, 20.XI.1961, Noona Dan Expedition, 4 ∑∑. (P a l a w a n P r o v.) Busuanga: 5 km NW Coron, Mabentangen Forest Reserve, 1.-7.II.1999, leg. H. Zettel (170), 7 ∑∑. Palawan: Brooke's Point, Uring-Uring, 25.VIII.1961, Noona Dan Expedition, 3 ∑∑, 1 ♀. Mantalingajan Range, Mt. Balabag, 2800 ft (= ca. 850 m a.s.l.), 4.V.1947, leg. F.G. Werner, Chicago-NHM - Philippine Zoological expedition 1946- 47, 1 ∑. (Palawan Prov.:) Balabac: Dalawan Bay, 10. and 12.X.1961, Noona Dan Expedition, 2 ♀♀.

Material from other countries examined: 175 workers and 6 gynes (CZW, NHMW) from Sri Lanka, India (Nicobar Isl.), Malaysia (Peninsular), Indonesia (Nias, Sulawesi, Irian Jaya), Papua New Guinea, Samoa, and New Caledonia.

Description of worker: Measurements: worker with smallest HW: CI 83, HL 1.97, HW 1.63, MdI 53, MdL 1.05, MsL 2.43, SI 108, SL 1.77, PnW 0.87, PtH 0.75, PtL 0.64, PtW 0.38, TL 7.63; worker with largest HW: CI 82, HL 2.52, HW 2.07, MdI 53, MdL 1.33, MsL 2.93, PnW 1.13, PtH 0.89, PtL 0.99, PtW 0.52, SI 106, SL 2.20, TL 11.06.

Structures: Mandibles short and stout, with very fine denticles, sometimes completely edentate but always with three apical teeth (intercalary tooth slightly shorter than apical and subapical teeth). Apex of mandibles with some setae. Mandibles mostly smooth, some fine ridges / striae may occur, with fine white pubescence, hair pits distinct. Head in dorsal view rectangular, longer than wide, broadest at level of eyes which do not surpass outline of head. Dorsum of head striate, striation almost reaching nuchal carina (at dorsal margin, area of about the width of the scape, smooth). Eyes located dorsolaterally in first third of head. Mesosoma elongate in dorsal view, broadest at level of pronotum. Pronotum with round striation, often slightly oval or longitudinal in centre, but some entire circles always visible in dorsal view. Mesonotum and propodeum with transverse striation (slightly coarser on propodeum). Mesopleuron smooth in centre, some striation at margins. Metanotal spiracle inconspicuous, situated dorsolaterally. Petiole short and straight, conspicuously "tear-shaped" in frontal view, broad with short petiolar spine, posteriorly flat with transverse striation. Gaster rounded to oval; anterior part of first tergite evenly convex in lateral aspect, without impression; first tergite smooth, second with some reticulation, at least anteriorly.

Pilosity: Fine white semi-appressed pubescence on entire body, very dense on appendages including petiole, on mesosoma, head and gaster distance between hairs approximately their length. Few standing setae on pronotum, several standing hairs on gaster increasing in length towards apex of abdomen. Some isolated hairs on head venter and one pair of standing setae on head dorsum.

Colour: Body, including all appendages, dark brown (almost black in some specimens).

Description of gyne: Measurements: gyne with smallest HW: CI 87, HL 2.27, HW 1.97, MdI 57, MdL 1.30, MsL 2.93, PnW 1.60, PtH 1.00, PtL 0.78, PtW 0.49, SI 107, SL 2.10, TL 9.88; gyne with largest HW: CI 85, HL 2.47, HW 2.10, MdI 54, MdL 1.33, MsL 3.13, PnW 1.65, PtH 1.02, PtL 0.88, PtW 0.61, SI 104, SL 2.18, TL 10.31.

Structures: Differs only in the following characters: pronotum with transverse striation, mesonotum with longitudinal striation, scutellum shiny, sexual female morph-specific characters (wing insertions, mesosoma and gaster bigger).

Notes: Odontomachus simillimus can be easily recognised even in the field by small size, dark colour, proportionally large head and short scape. In the Philippines, there is no other species with a short, truncate subapical tooth of the mandible (Fig. 43), and none with fine reticulation on visible part of gaster tergite 2 (but note that the anterior part of tergite 2 which is usually covered by tergite 1 is also reticulate in other species).

Odontomachus simillimus is surprisingly uniform over its large distribution area. It is distinguished from the second Old World species, O. troglodytes from Africa, Madagascar, and the Seychelles, by its smooth gaster tergite 1.

Distribution (Philippines: Fig. 47): Widely distributed from India to Polynesia (Wilson 1959, Brown 1976), "undoubtedly many of the island records represent accidental introductions by man" (Brown 1976: 87). No distribution limit in the Philippines; records from 21 islands (19 in this study).

Habitats: Odontomachus simillimus is a common species which also can be found in open or moderately to strongly disturbed habitats, like coastal areas, coconut groves, villages, and even lawns on university campuses. It usually does not enter dense forests, but can be occasionally found on banks of stream running through forests. According to collections by Chapman in eastern Negros, the species can be found from sea level up to an elevation of 900 m (Wheeler & Chapman 1925).