Odontomachus alius, Sorger, D. M. & Zettel, H., 2011

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 : 152-153

Odontomachus alius sp.n. (Figs. 5, 11, 17, 46)

Etymology: Latin for "the other", this name refers to the fact that samples of this species were already recognized as "different" by Brown (1976) (but remained unnamed). The name is also inspired by the popular American TV show "Lost".

Type locality: Cebu, west of Cebu City, Minglanilla, Camp 7, 10° 16' N, 123° 45' E.

Type material: Holotype (worker, USC): Cebu: west of Cebu City, Minglanilla, Camp 7, secondary forest near small creek , 16.XI.2003, leg. H. Zettel & C. V. Pangantihon ( 358 ). Paratypes (101 workers, 2 gynes, CSW, CZW, NHMW, UPLB, USC): Cebu: same locality data as holotype, 4 ∑∑. Cebu City, Tabunan, Cantipla-I, forest reserve, ca. 800 m, 23.IX.2006, leg. C. V. Pangantihon (P250), 1 ∑, 18.II.2007, leg. H. Zettel (473), 1 ∑, 28.IX.2007, leg. C. V. Pangantihon (P270), 2 ∑∑, 8.II.2008, leg. H. Zettel & C. V. Pangantihon (503), 1 ∑, 19.-20.IX.2008, leg. C. V. Pangantihon (P301), 4 ∑∑, 1 ♀, 20.-24.VII.2009, leg. C. V. Pangantihon (P327), 2 ∑∑. Dalaguete, Mantalungon, 29.-30. VIII.2010, leg. C. V. Pangantihon (P361), 1 ∑. Dalaguete, Mantalongon, Dingayup River, 4.XI.2010, leg. H. Zettel & C. V. Pangantihon (524), 5 ∑∑. Bohol: Bilar, Man Made Forest, 29.XI.2005, leg. C. V. Pangantihon (P427), 4 ∑∑. Leyte: L e y t e: E Ormoc, Lake Danao area, 11.III.1998, leg. H. Zettel (158), 2 ∑∑, 13.II.2000, leg. S. Schödl (16), 19 ∑∑, 13.II.2000, leg. H. Zettel (237), 3 ∑∑. Baybay, ViSCA/ LSU, Mt. Pangasugan, Calbiga-a River, 50 - 200 m, 12.II. 2000, leg. H. Zettel (236), 13 ∑∑, 20.-21.III.2005, leg. H. Zettel & & C. V. Pangantihon (422), 12 ∑∑. Biliran: Almeria, Kabungasan, Mt. Panamao, Upper, 15.XI.2009, leg. C. V. Pangantihon (P334), 1 ∑. Samar: W e s t e r n S a m a r: east of Basey, Sohoton National Park, banks of Sohoton River, 29.I.2000, leg. S. Schödl (2), 13 ∑∑, leg. H. Zettel (221), 9 ∑∑. Catanduanes: east of San Andres, below Lu Yong cave, 11.-12.III.1999, leg. H. Zettel (200), 2 ∑∑, 1 ♀, 12.III.1999, leg. F. Seyfert (26), 1 ∑, 12.IV.2000, leg. H. Zettel (254), 1 ∑.

Description of worker: Measurements: holotype worker: CI 69, HL 3.37, HW 2.32, MdI 60, MdL 2.03, MsL 4.27, PnW 1.38, PtH 1.38, PtL 1.44, PtW 0.53, SI 150, SL 3.48, TL 14.81; paratype worker with smallest HW: CI 68, HL 2.67, HW 1.80, MdI 58, MdL 1.53, MsL 3.47, PnW 1.03, PtH 1.02, PtL 1.11, PtW 0.46, SI 154, SL 2.77, TL 11.75; paratype worker with largest HW: CI 77, HL 3.40, HW 2.62, MdI 64, MdL 2.17, MsL 4.60, PtH 1.46, PtL 1.58, PtW 0.62, PnW 1.50, SI 136, SL 3.55, TL 15.56.

Structures: Head striate, but striation not reaching nuchal carina. Pronotum with variable fine striation, either transversely oriented or with roundish or longitudinal loops. Mesopleuron with fine transverse striation. Petiolar spine S-shaped, very long, acute, slightly bent backwards. Gaster low anteriorly, strongly flattened, impression distinct, often linear.

Pilosity: Pubescence sparse, short.

Colour: Bicoloured; head and gaster light brown to almost yellowish, contrasting with dark brown mesosoma and petiole.

Description of gyne: Measurements: gyne with smallest HW: CI 73, HL 3.43, HW 2.52, MdI 52, MdL 1.80, MsL 4.73, PnW 1.80, PtH 1.53, PtL 1.57, PtW 0.75, SI 131, SL 3.30, TL 16.56; gyne with largest HW: CI 75, HL 3.47, HW 2.62, MdI 56, MdL 1.95, MsL 5.20, PnW 1.95, PtH 1.91, PtL 1.80, PtW 0.77, SI 124, SL 3.25, TL 16.00.

Compared with O. infandus gyne, striation of head strongly reduced posteriorly. Compared with worker, striation of mesopleuron strongly reduced, in larger gyne absent except for striation in front of meso-metapleural suture, in smaller gyne almost totally absent, except most dorsal area.

Colour: Head, mesonotum, scutellum, metanotum, and mesopleuron pale, yellowish to very light brown, contrasting strongly with other brown body parts. Petiole and gaster light brown, similar to worker.

Distribution (Fig. 46): Endemic to the Philippines, recorded from the islands of Catanduanes, Samar, Biliran, Leyte, Bohol, and Cebu.

Habitats: Collected in lowland dipterocarp forests, some of the forests remnant patches or strongly degraded.

Notes: We characterize workers of O. alius sp.n. by the following combination of characters: Head distinctly and gaster notably lighter coloured than mesosoma. Head with extended striation (relatively short in specimens from Catanduanes), but never reaching nuchal carina medially. Mesopleuron without smooth area (although striation is faded in some individuals). Petiole with long, S-curved spine.

Odontomachus alius sp.n. is a variable species with five distinct island-endemic forms from (I) Cebu, (II) Bohol, (III) Leyte and Biliran, (IV) Samar, and (V) Catanduanes. Odontomachus sp. 1 from southern Luzon may also belong to this species, but its characters do not comfortably fit the pattern (see discussion for Odontomachus sp. 1). Each of these forms is relatively stable in its set of characters, and they may as well be treated as subspecies or morphologically weakly differentiated species. There is a distinct trend of changing characters from Cebu eastwards and northwards. The pronotum sculpture changes from transversely striate (Cebu) to roundish or transverse loops (Bohol) to longitudinal loops (other islands). The gaster is lightest (yellowish brown) in specimens from Cebu and Bohol, and darkest in specimens from Samar and Catanduanes. The striation of the temporal prominences is most strongly extended in specimens from Cebu, Bohol, Leyte, and Biliran, intermediate in specimens from Samar, and distinctly reduced in specimens from Catanduanes. This trend contrasts with the parapatric populations of O. philippinus on Negros with completely smooth temporal prominences and of O. infandus on southern Luzon with completely striate temporal prominences.