Anochetus pangantihoni

Identification
Zettel (2012) - TL 4.7-4.9 mm. Head with deeply emarginated vertex; longitudinal striation restricted to stripes medial of frontal carinae. Eye moderately large, with very few minute setae. Mandible moderately long, MdI = 65-68; shaft medially with two edges, dorsal one smooth, ventral one minutely serrate; intercalary tooth minute. Pronotum smooth except for widely spaced, fine, setiferous punctures. Propodeum with 20-25 transverse costulae. Petiole with narrow node in lateral aspect, its apex narrowly rounded when seen laterally and in anterior aspect; peduncle moderately developed. Gaster tergite 1 with sparse punctures. Whole dorsum with sparse setiferation.

Anochetus pangantihoni belongs to the A. risii species group as defined by Brown (1978), where it takes an intermediate position between Anochetus modicus and Anochetus brevis both reported from the Philippines. It differs from A. brevis by absolutely and relatively longer mandibles, by absolutely larger eyes, and by a relatively long anterior peduncle of the petiole. It differs from A. modicus by sculpture of the mesonotal disc and of the propodeal dorsum, and shape of the petiole. In A. modicus the mesonotum is smooth, but in A. pangantihoni it is transversely striate. BROWN (1978) counts 30 transverse costulae for the propodeal dorsum of A. modicus, while A. pangantihoni has 20-25 costulae on the entire dorsum (including its declivitous area). Compared with the holotype of A. modicus, the petiole of A. pangantihoni is more petiolate and its node is narrower (in lateral aspect) with a slightly concave anterior slope (vs. convex in A. modicus). There is also a distinct gap in size between A. pangantihoni (4.7-4.9 mm) and the holotype of A. modicus (5.9 mm) from “Moaratoa Island” offshore Borneo. The conspecificity of a single, very small worker (4.8 mm) of A. modicus from the Philippines (Cuernos de Negros) is discussed by Brown (1978); it needs further investigation. Regarding head sculpture, the longitudinal striae are restricted to the lateral thirds of the frontal area in A. pangantihoni, obsolete in A. brevis, and filling the entire frontal area and slightly surpassing the frontal carinae posteriorly in A. modicus.

According to the description by Terayama (1989), Anochetus taiwaniensis from the island of Taiwan differs from A. pangantihoni by much larger size (TL 6.7-7.3 mm), relatively long mandibles (MdI 0.70-0.73), small denticles on the dorsal ridge of the mandibular shaft, and a distinct intercalary tooth.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Philippines.

Nomenclature

 *  pangantihoni. Anochetus pangantihoni Zettel, 2012: 159, figs. 6, 12-15 (w.) PHILIPPINES (Leyte I.).

Worker
Holotype: TL 4.75; HL 1.18; HW 1.08; CI 91; MdL 0.78; MdI 66; SL 1.01; SI 94; MsL 1.59; PnW 0.64; PtH 0.43; PtL 0.45; PtW 0.21. Measurements of paratype with smallest HW: TL 4.75; HL 1.15; HW 1.04; CI 90; MdL 0.79; MdI 68; SL 0.97; SI 93; MsL 1.63; PnW 0.60; PtH 0.40; PtL 0.43; PtW 0.20. Measurements of paratype with largest HW: TL 4.84; HL 1.19; HW 1.10; CI 92; MdL 0.79; MdI 66; SL 1.01; SI 92; MsL 1.64; PnW 0.64; PtH 0.43; PtL 0.46; PtW 0.21.

Colour: Very dark brown, almost black; anterior parts of head and in some specimens also the petiole medium brown. Mandibles and antennae pale brown. Legs brown, gradually paler towards tarsi.

Structures: Head with moderately developed ocular and temporal prominences and deeply emarginated vertex; frontal striation reduced to stripes medial of frontal carinae. Eye medium-sized, with some very short setae laterally which are not distinct in all specimens. Mandible moderately long, stout, medial plane terminating in a sharp tooth, ventral edge of plane weakly serrate; intercalary tooth minute. Antenna long and slender; scape strongly curved, distal part narrowed; flagellum rather stout, antennomere 3 slightly shorter than antennomeres 2 and 4, following antennomeres steadily increasing in length.

Mesosoma slender. Disc of pronotum smooth except for widely spaced setiferous punctures. Mesonotum with transverse striation, metanotum with longitudinal costae. Propodeum with 20-25 transverse costulae, counted along midline. Sides of thorax mostly smooth, except metapleura with some coarse costae along meso-metapleural suture and with some striation posteroventrally.

Petiole with moderately long anterior peduncle and with narrow node; in lateral aspect node with narrowly rounded apex and slightly concave anterior face, in anterior aspect apex almost pointed. Gaster smooth and shiny except for sparse setae-bearing punctures.

Type Material
Holotype (worker, ) and 13 paratypes (workers,, ) from Leyte Island, Leyte Province, Baybay, slopes of Mt. Pangasugan, behind Leyte State University, banks of Calbiga-a River, 50-100 m a.s.l., 20.-21.III.2005, leg. H. Zettel & C.V. Pangantihon (# 422)

Etymology
This species is dedicated to Clister V. Pangantihon (USCP) who collected part of the type series.