Odontomachus sp. 1

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 : 151-152

Odontomachus sp. 1 (Figs. 21 - 23, 46)

Material examined (16 workers, 2 gynes; CZW, USC): Luzon: C a ma r i n e s N o r t e: Mt. Labo - Mt. Bayabas area, 17.-18.III.2004, leg. H. Zettel & C.V. Pangantihon (382), 1 ∑. S Daet, Bicol National Park, Basud, Nalisan, 13.-14.III.2003, leg. H. Zettel, L. S. Vichozo & C. V. Pangantihon, 1 ∑, 26.II.2004, leg. H. Zettel & C. V. Pangantihon(376), 2 ∑∑, 13.III.2006, leg. H. Zettel, R. Gille & C. V. Pangantihon (446), 6 ∑∑. C a m a r i n e s S u r: Lupi, Alanao, Bahi River,14.XI.1999, leg. H. Zettel (205), 1 ∑. Sooc, 10.-12.III.2000, various local collectors (246), 1 ♀, 29.I.-10.II.2002, various local collectors (305), 1 ♀. Lupi, Sooc, Telecom, 31.III.2003, leg. C. V. Pangantihon, 2 ∑∑. Between Lupi, Sooc, Telecom and Sipocot, Tigman, 22.II. 2004, leg. C. V. Pangantihon (P42+43), 3 ∑∑.

Description of worker: Measurements: worker with smallest HW: CI 77, HL 2.88, HW 2.23, MdL 1.67, MdI 58, MsL 3.80, PnW 1.17, PtH 1.21, PtL 1.22, PtW 0.42, SI 133, SL 2.97, TL 12.38; worker with largest HW: CI 70, HL 3.30, HW 2.30, MdI 59, MdL 1.95, MsL 4.17, SI 143, SL 3.28, PnW 1.37, PtH 1.19, PtL 1.32, PtW 0.50, TL 14.13.

Structures: Head striate, striation not reaching occipital margin, fading out slightly before margin; striation left and right of median furrow weak. Striation on pronotum longitudinally oriented, closed oval circles may be visible in dorsal view (sculpture strongly resembling O. infandus ). Mesopleuron striate, although striation in the centre may be very weak. Petiole variable, rather short, dorsal surface usually straight, with short and simple petiolar spine.

Pilosity: Fine white, loose, semi-appressed pubescence on entire body, distance between hairs approximately their length. No setae on tergite 1, few setae on tergite 2, increasing in number and length towards apex of abdomen.

Colour: Dark brown, head usually lighter (towards medium brown) than rest, appendages light brown to yellowish.

Description of gyne: Measurements: gyne with smallest HW: CI 73, HL 3.33, HW 2.42, MdL 1.97, MdI 59, MsL 4.67, PnW 1.82, PtH 1.56, PtL 1.71, PtW 0.75, SI 130, SL 3.15, TL 15.25; gyne with largest HW: CI 76, HL 3.43, HW 2.60, MdL 1.93, MdI 56, MsL 4.80, PnW 1.78, PtH 1.64, PtL 1.83, PtW 0.78, SI 126, SL 3.28, TL 15.88.

Compared with O. infandus gyne, striation of head posteriorly reduced. Compared with O. sp. 1 worker, striation of mesopleuron strongly reduced, in larger gyne faint, in smaller gyne absent except for short striation in front of meso-metapleural suture.

Colour: Head, mesonotum, scutellum, metanotum, and mesopleuron light brown, contrasting with other, dark brown body parts. Petiole and gaster slightly lighter.

Distribution (Fig. 46): Endemic to the Philippines: only in southern Luzon, in a small area in Camarines Norte and Camarines Sur.

Habitats: This species is only known from dipterocarp forests, although some samples are from strongly degraded forests.

Notes: Camarines Sur is the only province with four recorded Odontomachus species, i.e., O. infandus , O. banksi , O. simillimus , and O. sp. 1. The here treated form, which is represented by rather few individuals from a relatively small area, shares some characters with O. infandus and O. banksi , but can be clearly distinguished from both. It is distinguished from O. infandus by light coloured and posteromedially not striate head and a straight petiolar spine; from O. banksi by much more developed striation on head, longitudinal loops on pronotum, and sparse pilosity; the slightly reduced striation on medial mesopleuron and the light brown gaster separates this form from both species. Although there are several similarities with O. alius sp.n., and despite zoogeographical considerations (presence of O. alius sp.n. on Catanduanes), we do not assign this Camarines population to that species, mainly because of the strikingly different shape of the petiole.