Diacamma palawanicum

Only known from the island of Palawan. The exact type locality is unknown. A non-type specimen was collected from the center of the island.

Identification
Laciny et al. (2015) - Large, slender species (TL ca. 14 mm). Trunk chiefly black, appearing grey by dense whitish pilosity. Trunk strongly striate from genae to petiole. Posterior of head longitudinally striate until hind margin; occipital margin moderately wide, laminate, ventrally short, terminating in small, acute teeth. Clypeus entirely punctured. Pronotum longitudinally striate. Striation on mesosoma sides slightly oblique. Petiole stout, its teeth long and far apart; subpetiolar process laterally and medially carinate, very densely and evenly pilose, in lateral aspect with concave outline, anterior corner much longer than posterior one. Gaster tergite 1 with extremely fine puncturation.

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

Nomenclature

 *  palawanicum. Diacamma palawanicum Emery, 1900d: 666 (footnote) (w.) PHILIPPINES.

Worker
Laciny et al. (2015) - (n = 1): TL 13.96; HW 2.32; HL 3.20; EL 0.64; SL 3.75; PH 2.00; PL 1.40; PW 1.30; SpD 0.90; SpL 0.58; WL 4.76; MTL 2.90. Indices: CI 72; SI 162; PI 70; SpDI 70; SpLI 45; EI 27.

Structures: Head elongated; sides parallel in front of eyes, strongly convex behind eyes. Eyes comparatively small. Very coarse rugae present from genae to petiole. Posterior of eyes, longitudinal rugae perpendicular to occipital margin. Occipital margin about as wide as one ruga, slightly laminate, ventrally short, terminating in small, acute teeth in lateral aspect. Clypeus with very fine puncturation, shiny, a very fine striation at base absent (syntype) or hardly recognizable; apex narrowly rounded. Mandibles with some fine striation. Pronotum with longitudinal rugae. Striation on mesosoma sides slightly oblique. Posterior face of propodeum separated from sides by distinct carinae. Petiole stout, with very coarse striation and with rather long, slender spines. Subpetiolar process very distinctive: in lateral aspect with strongly concave outline, anterior tooth much longer than posterior one; in ventral view appearing arrow-shaped, sides and mid-line sharply carinate in anterior two thirds; pilosity of short standing setae very even (not visible in the type). Gaster tergite 1 as the following tergites with very fine puncturation.

Pilosity: Standing setae on trunk mostly short, but those on vertex, underside of head, and dorsum of petiole longer. Short appressed pilosity abundant, but more scarce on dorsum of head and pronotum, giving the specimen a grey appearance. Standing setae on scape and legs also short.

Colour: Trunk black, without metallic shimmer; on gaster posterior margins of tergites and apex more or less brown. Antennae black. Mandibles and most parts of legs dark reddish brown; forecoxa black, tarsi strongly infuscated.

Type Material
Laciny et al. (2015) - 1 syntype (worker,, CASENT0903865), labelled “Palawan 1898. Doherty ex coll. Fruhstorfer”, “Typus”, “Diacamma palawanicum Emery”

References based on Global Ant Biodiversity Informatics

 * Emery, C.. "Formiche raccolte da Elio Modigliani in Sumatra, Engano e Mentawei." Annali del Museo Civico di Storia Naturale Giacomo Doria (Genova) (2) 20, no. 40 (1900): 661-722.