Aenictus latifemoratus

Specimens from West Sumatra and Sarawak were collected in relatively good rainforests from columns on the forest ﬂoor.

Identification
A member of the silvestrii species group. Aenictus jarujini is very similar and closely related to A. latifemoratus but the two are easily separated by the following characters: number of antennal segments (9 in A. jarujini; 8 in A. latifemoratus); shape of petiolar node (node subrectangular and relatively low, posteriorly margined with a rim in A. jarujini; node without a distinct rim in A. latifemoratus), condition of subpetiolar process (very low in A. jarujini; well developed and subtriangular in A. latifemoratus); sculpturing on head (strongly macropunctate in posterior dorsal half of head, other regions only weakly macropunctate in A. jarujini; strongly macropunctate or recticulate exten¬sively on dorsum and sides of head in A. latifemoratus).

Key to Aenictus species groups / Key to Aenictus silvestrii group species

Distribution
Borneo (Sarawak), West Sumatra, and West Java

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia.

Castes
Known only from the worker caste.

Nomenclature

 *  latifemoratus. Aenictus latifemoratus Terayama & Yamane, 1989: 600, figs. 3-6 (w.) INDONESIA (Sumatra). See also: Jaitrong & Yamane, 2010: 331.

Worker
Jaitrong and Yamane (2010) - One paratype: TL 3.9 mm; HL 0.93 mm; HW 0.85 mm; SL 0.60 mm; ML 1.33 mm; MTL 0.63 mm; PL 0.28 mm; CI 92; SI 71. Nontype material (n = 5): TL 3.8–4.0 mm; HL 0.92–0.97 mm; HW 0.85–0.85 mm; SL 0.60–0.63 mm; ML 1.25–1.35 mm; MTL 0.63–0.65 mm; PL 0.27–0.33 mm; CI 90–95; SI 69–71.

Head slightly longer than broad, with weakly convex sides; seen in full-face view its posterior margin weakly convex; occiput with a well-demarcated collar bearing many carinae. Antenna 8-segmented; scape extending slightly beyond the midlength of head in full-face view; antennal segments II-III slightly broader than long or as broad as long; IV-VIII distinctly longer than broad, each bing broadened apically; VIII c. 2.0¥ as long as broad. Frontal carinae narrow and extending half length of head, sharply elevated and darkened in anterior half, and low and vestigial in posterior half. Clypeus short and roundly produced anteriorly, lacking anterior teeth. Mandible with apical tooth large and curved, followed by a series of 7–9 denticles; basal margin of mandible lacking denticles. Promesonotum in proﬁle distinctly convex dorsally; propodeum lower than promesonotum, and its dorsal outline straight; propodeal junction acutely angulate; declivity of propodeum shallowly concave, encircled with a rim. Seen from side, petiole subrectangular, anteriorly weakly convex; its anterior face encircled with a sharp rim; subpetiolar process well developed and sub-triangular; postpetiole as long as petiole, seen from above distinctly broadened posteriorly, in proﬁle roundly convex above, anteroventrally produced as a blunt angle directed downward and forward. Gaster elongate-elliptical, narrowed anteriorly and posteriorly.

Head almost wholly with macropunctures (somewhat reticulate) except for areas along frontal carinae; inter-spaces and bottoms with dense small punctures; macropunctues on sides of head sparser than in other regions. Mandible with very dense micropunctures, but smooth apically and along masticatory margin. Upper face of antennal scape basally with dense micropunctures and apically much smoother. Dorsum of mesosoma sculptured as in dorsum of head, but with sparser macro-punctures. Petiole with a weak reticulum superimposed with very dense small punctures (a condition similar to that of propodeal dorsum); postpetiole with dense small punctures. Gaster smooth and shining except for extreme base. Femora and tibiae smooth and shining.

Body with relatively sparse standing hairs mixed with sparse short hairs over the surface; length of the longest pronotal hair approximately 0.23 mm. Head, mesosoma and waist reddish brown to dark brown; gaster and legs yellow; mandibles blackish brown.

Type Material
Jaitrong and Yamane (2010) - Holotype worker and a paratype worker from Maninjau, W. Sumatra, Indonesia deposited in MZB, and a paratype deposited in SKYC (examined).