Pristomyrmex pangantihoni

Pristomyrmex pangantihoni is the second Pristomyrmex  species recorded from Mindoro.

Identification
Zettel & Laciny (2015) - worker: Predominantly black, moderately large species, TL = 4.8. Head with large punctures that are sparse dorsally, and relatively dense on genae and posterolaterally of eyes. Frontal carinae short, hardly exceeding antennal fossae; antennal scrobes absent. Clypeus dorsally without sculpture; ventral surface with small medial tooth; anterior margin with 7–8 small denticles medially and two pairs of blunt teeth laterally. Scape relatively short (SI = 95–97). Masticatory margin of mandible with four teeth and diastema. Dorsum of mesosoma smooth and polished. Pronotum with pair of short, but distinct teeth (PSL1 0.15–0.17), which are clearly shorter than propodeal spines (PSL2 0.26–0.28). Petiole stout, anterior face of node continuous with dorsal surface of peduncle. Both petiolar node and postpetiole with several setae of varying length. First gastral tergite without erect setae.

Pristomyrmex pangantihoni belongs to the Pristomyrmex quadridens group and is similar and probably closely related to Pristomyrmex collinus. The two species share most of the structural characteristics used in the key by Zettel (2006) and have similar surface structures. Another similar species is P. quadridens. Whereas P. collinus is endemic to the northern and central Philippines (records from Luzon, Tablas, Panay, and Negros), P. quadridens is distributed on New Guinea and the Moluccas and reaches the Philippines in the southeast (Leyte) (Wang 2003, Zettel 2006). Pristomyrmex pangantihoni differs from both species by black colour, longer pronotal and propodeal spines, higher number of setae on both petiole and postpetiole, and much larger size (measurements partly taken from Wang 2003 and Zettel 2006): TL of P. pangantihoni 4.8 mm, of P. collinus and P. quadridens 3.3–4.1 mm; HW of P. pangantihoni 1.32–1.33 mm, of P. collinus and P. quadridens 0.77–0.94 mm. The puncturation on the head of P. pangantihoni is more strongly developed than in P. collinus, but not as foveolate as in P. quadridens. Also the shape of the petiole is intermediate between the two species. Pristomyrmex distinguendus another similar species of Luzon and Leyte, can be distinguished by brown colour, small size, long frontal carinae, distinct antennal scrobes, and very short pronotal and propodeal teeth.

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

Nomenclature

 *  pangantihoni. Pristomyrmex pangantihoni Zettel & Laciny, 2015: 2, figs. 1-4 (w.) PHILIPPINES.

Worker
Holotype worker: TL 4.8, HL 1.27, HW 1.32, CI 104, SL 1.25, SI 95, EL 0.22, AL 1.21, PSL1 0.17, PSL2 0.28, PW 0.77, PPW 0.34, PPL 0.39, PPI 87. Paratype worker: TL 4.8, HL 1.29, HW 1.33, CI 103, SL 1.29, SI 97, EL 0.22, AL 1.21, PSL1 0.15, PSL2 0.26, PW 0.79, PPW 0.36, PPL 0.40, PPI 93.

Structures: Head smooth and polished, with large punctures on dorsum, genae, and pos-terolaterally of eyes. Frontal carinae short, hardly exceeding frontal fossae. Antennal scrobes and frontal lobes not developed; antennal insertion entirely exposed. Clypeus dorsally without me-dian carina, ventrally with distinct central tooth; anterior margin with 7–8 small denticles in mid-dle and two pairs of blunt teeth at sides. Labrum apically with pair of small tubercles. Mandibles smooth and shiny; masticatory margin of mandible with four teeth: strongest apical + second strongest (hardly shorter) preapical + long diastema + two small basal teeth of similar size; basal margin of mandible with slight dilatation at mid-length, but lacking distinct tooth. Palp formula 1, 3. Antennal scapes short, when lying on dorsum of head, slightly surpassing posterior margin of head. Eyes containing 11 ommatidia in longest row. Profile shape of mesosoma, petiole and postpetiole as in Figure 3. Dorsum of mesosoma slightly convex, smooth and polished except for a few scattered fine hair pits. Pronotum with pair of relatively strong teeth; propodeum with pair of spines that are distinctly longer than pronotal teeth. Mesopleural ridge almost straight, anteriorly not protruded into distinct tooth. Metapleural lobes subtriangular, acute. Petiole, postpetiole, and gaster smooth and shiny. Petiole in profile with moderately long peduncle, node without distinct angles. Postpetiole in profile rounded dorsally, in dorsal view broadening from front to back.

Pilosity: Dorsal surfaces of head, mesosoma, petiolar node, and postpetiole with numerous, moderately long setae. First gastral tergite lacking erect or suberect setae. Clypeus with forward projecting setae between teeth and with four pairs of long setae at sides of medial part. Scapes and tibiae with numerous erect setae.

Colour: Almost entirely black; clypeus, labrum, mandibles, antennae, and tarsi brown.

Type Material
Holotype (worker) and paratype (worker) labelled “Philippines: Mindoro Or. Roxas, San Vicente, Taugad Diit, Taugad Daka Forest 27.IX.2014, leg. C. V. Pangantihon (P513)”. The holotype will be deposited in the National Museum Manila, the paratype in the first author’s collection. Type locatlity: Philippines, Mindoro Island, Mindoro Oriental province, municipality of Roxas, barangay San Vicente, sitio Taugad Diit, Taugad Daka Forest, ca. 400–500 m a.s.l., ca. 12°38’ N, 121°20’ E.