Aenictus pilosus

The type locality is located in the hinterland (1400m alt.).

Identification
A member of the ceylonicus group. Aenictus pilosus is most similar in general appearance to Aenictus wilaiae.

Key to Aenictus species groups / Key to southeastern Asian Aenictus ceylonicus group species

Distribution
Philippines (Luzon and Mindanao)

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

Castes
Known only from the worker caste.

Nomenclature

 *  pilosus. Aenictus pilosus Jaitrong & Wiwatwitaya, 2013: 205, figs. 15A-C (w.) PHILIPPINES.

Worker
(holotype and paratypes, n = 6). TL 2.70–2.80 mm; HL 0.60–0.63 mm; HW 0.50–0.53 mm; SL 0.48–0.50 mm; ML 0.93–0.95 mm; PL 0.24–0.25 mm; CI 83–88; SI 90–95.

Head in full-face view subrectangular, clearly longer than broad, sides weakly convex, and posterior margin almost straight or feebly convex. Antennal scape reaching 2/3 of head length. Frontal carinae fused at the level of antennal base to form a single carina, slightly extending beyond the level of posterior margin of torulus. Parafrontal ridge almost absent. Anterior clypeal margin weakly concave, lacking denticles and concealed by curved anterior extension of frontal carina. Masticatory margin of mandible with large acute apical tooth followed by a medium-sized subapical tooth, 2-3 denticles, and a medium-sized basal tooth; basal margin almost straight. Maximum width of gap between anterior clypeal margin and mandibles about 2.6 times as broad as maximum width of mandible. Promesonotum strongly convex dorsally and sloping gradually to metanotal groove; metanotal groove indistinct; mesopleuron not clearly demarcated from metapleuron. Propodeum in profile relatively long with almost straight dorsal outline; propodeal junction angulated, nearly right-angled; declivity of propodeum shallowly concave, and encircled with a rim; metapleural gland bulla relatively large, its maximum diameter about 2.5 times as long as distance between propodeal spiracle and metapleural gland bulla. Petiole slightly longer than high, elevated posteriorly; subpetiolar process generally very low, with its anteroventral corner acutely angulate, and ventral margin feebly concave. Postpetiole slightly smaller than petiole, with its dorsal outline convex.

Head and gaster smooth and shiny; basal half of antennal scape densely microreticulate but apical half smooth and shiny; mandible finely striate. Promesonotum smooth and shiny except for anteriormost portion punctate; mesopleuron with slightly irregular rugae; metapleuron, and propodeum wrinkled and reticulate. Petiole entirely reticulate; postpetiole superficially reticulate and shiny. Basal 1/3 of femora sculptured, apical 2/3 (swollen area) smooth and shiny; tibiae microreticulate, partly smooth and shiny.

Head and mesosoma dorsally with relatively dense standing hairs; longest pronotal hair 0.33–0.35 mm long; legs with dense long decumbent hairs. Head reddish brown; antenna, mandible, mesosoma, petiole and postpetiole dark reddish brown; gaster and legs yellowish brown.

Type Material
Holotype. PHILIPPINES: Worker from Philippines, Luzon, Mountain Prov., Sagada, Bokong waterfall, 1400 m alt., 19.II.1999, leg. A. Schulz, (NHMW). Paratypes. Seventeen workers, same data as holotype (NHMW).

Etymology
The specific epithet “pilosus” is a Latin word meaning pilose. This refers to long decumbent hairs on the legs.