Aenictus paradentatus

Aenictus paradentatus occurs from low-lands to highlands (up to 1,300 m a.s.l., Doi Ang Khang, N. Thailand) and inhabits primary and disturbed forests (rarely marching even in grasslands in the mountain range of N. Vietnam). It has been observed preying on other ants such as species of Leptogenys (Vietnam, VN98-SKY-15), Oecophylla (Thailand, HKK10-06-06), Pachycondyla (Laos, WJT10-LAO16) and Pheidole (Vietnam, VN98-SKY-15), and also on termites, Macrotermes sp. (Laos, WJT10-LAO12).

Identification
A member of the pachycerus group. Jaitrong, Yamane and Wattanachai (2012) - Aenictus paradentatus and Aenictus dentatus are very similar in general appearance as they share the distinctive coarse sculpture on head and mesosoma, and the relatively long antennal scape, extending beyond the posterior margin of the head. However, they differ in several significant characters. The antennal scape is relatively shorter in A. paradentatus (SI 117 - 124) than in A. dentatus (SI 143-152). No overlap is observed in HW / SL between the species. The posterior portion of the head in full-face view is relatively broader in A. paradentatus than in A. dentatus. The first gastral tergite is weakly shagreened with smooth interspaces in the former, while it is wholly smooth and shiny in the latter. The petiole has no peduncle in the former, but has a short but distinct peduncle in the latter.

Key to Aenictus species groups / Key to Aenictus pachyerus group species

Distribution
Vietnam, Laos, and Thailand

Distribution based on Regional Taxon Lists
Oriental Region: Laos, Thailand, Vietnam.

Castes
Known only from the worker caste.

Nomenclature

 *  paradentatus. Aenictus paradentatus Jaitrong & Yamane, in Jaitrong, Yamane & Tasen, 2012: 136, figs. 6-12 (w.) THAILAND.

Worker
(holotype and paratypes). Measurements of holotype: TL 4.65 mm; HL 1.03 mm; HW 0.90 mm; SL 1.08 mm; ML 1.53 mm; PL 0.33 mm; CI 88; SI 119. Paratypes (n = 9): TL 4.55 - 4.65 mm; HL 0.95 - 1.05 mm; HW 0.80 - 0.93 mm; SL 0.93 - 1.08 mm; ML 1.50 - 1.55 mm; PL 0.33 - 0.35 mm; CI 83 - 88; SI 117 - 124.

Head in full-face view round, slightly longer than broad, with convex sides and posterior margin; occipital carina bearing distinct collar. Antenna 10-segmented; scape long, extending beyond posterolateral corner of head; funicular segment I almost as long as II, but slightly shorter than III - VI; apical segment almost as long as three previous ones. Frontal carinae well developed, fused at level of antennal base to form a single carina, extending less than half length of head, very poorly developed in posterior half. Parafrontal ridge well developed, extending 1/3 of head length; seen in profile, its anteriormost part well devel-oped and subtriangular. Clypeus short and roundly produced anteriorly, lacking anterior denticles. Mandible triangular, its masticatory margin with large apical tooth, fol-lowed by 11 - 12 denticles; basal margin of mandible lacking denticles. Mesosoma rather elongate and stout; pro-mesonotum in profile with strongly convex dorsum, sloping gradually to metanotal groove; propodeum lower and with almost straight dorsum; mesopleuron not demarcated from metapleuron; propodeal junction acutely angulated, protruding as ridge that is often slightly upward directed; declivity of propodeum shallowly concave, encircled with very narrow rim. Petiole almost as long as high without peduncle, its dorsal outline elevated posteriorly; subpetiolar process generally very low, its ventral outline weakly convex. Postpetiole seen in profile slightly larger than petiole, its dorsal outline elevated posteriorly. Gaster elliptical, narrowed anteriorly and posteriorly.

Head, mesosoma, petiole and postpetiole entirely and densely micropunctate and opaque. In addition, promesonotum dorsally rugose, laterally with approximately ten longitudinal rugae; dorsal petiolar surface with longitudi-nal or irregular rugae. First gastral segment very weakly shagreened with smooth and shiny interspaces, except in basalmost part with dense micropunctures.

Head and mesosoma with relatively dense standing hairs; length of longest pronotal hairs 0.43 - 0.45 mm. Entire body dark reddish brown or dark brown. Typhlatta spot absent.

Type Material
Holotype: worker from Doi Suthep-Pui National Park, Muang Dist., Chiang Mai Prov., N. Thailand, 20. VIII.1998, W. Jaitrong leg., WJT98-PD01 (THNHM). Paratypes: 17 workers, same data as holotype (BMNH, MCZC, MHNG, SKYC, THNHM).

Etymology
The specific epithet paradentatus is a compound word meaning "similar to dentatus". Non-type materials examined.