Aenictus binghamii

Wilson (1964): Dr Schneirla (in litt.) described the colony he discovered at Pak Chong, Thailand, in his notes as follows: "In dry tropical evergreen forest with moderate sub-humus moisture, under moderate cover. A long column of Aenictus returns with booty (mainly brood and adults of various ant species) from two well separated caches on the south side of a forest trail, junction with another peripheral raiding 20 m. to the north. At 9:30 a.m., traffic is mainly outward on the latter branch. At 10:10 a.m. the entire north-south route has reversed its direction outward (to the south), with brood-carrying throughout its first half (and a minority of booty-carriers) from a large surface cluster under roots and dry leaves at the north-terminus. At 10:25 a.m. the entire line mainly carries brood, ending at one of the caches to the south, forming a cluster under leaves and rubble. At 10:50 a.m. the queen passed, contracted and running under her own power, near the head of a 2.5 m. long entourage of workers, brood-laden except for the few cm. just behind her. Worker larvae plentiful, estimated to be 1/4 developed. Brood-carrying ended at 11:15 a.m., the emigration itself at 11:50 a.m. General behavior and circumstances very similar to those of a colony of Aenictus laeviceps in the nomadic phase."

Identification
A member of the laeviceps species group. Jaitrong and Yamane (2011) - A. binghami is similar to Aenictus siamensis in having an entirely sculptured mesosoma but is consirerably larger than the latter (HW 0.90–0.95 mm vs. 0.63–0.70 mm). The entire pronotum is finely and densely reticulate and opaque in A. binghami, while it is very superficially reticulate and somewhat shiny in A. siamensis. Femora of all legs are rather smooth in A. siamensis, but microreticulate in A. binghami.

Distribution
Vietnam, Laos, Myanmar, and Thailand.

Distribution based on Regional Taxon Lists
Oriental Region: Bangladesh, India, Laos, Myanmar, Thailand, Vietnam. Palaearctic Region: China.

Biology
According to our observations, Aenictus binghami inhabits highly varied habitats such as primary seasonal forest (hill evergreen forest, dry evergreen forest, mixed deciduous forest, and savanna), secondary forest, and open areas and plantations near the forest edge. A bivouac, including a foundress queen, was found under a stone during night in Cuc Phuong National Park, Vietnam (VN98-SKY-24). We observed this species preying on other ants such as Anoplolepis, Camponotus, Cerapachys, Leptogenys, and Polyrhachis. (Jaitrong and Yamane 2011).

Castes
Notes on the queen being seen in the field but to date only workers have been described.

Nomenclature

 *  binghami. Aenictus binghaniri Forel, 1900b: 76 (w.) MYANMAR. Aenictus binghami: Forel, 1901e: 382, justified emendation of spelling. Senior synonym of gatesi: Wilson, 1964a: 450.
 * gatesi. Aenictus binghami var. gatesi Wheeler, W.M. 1927b: 42 (w.) MYANMAR. Junior synonym of binghami: Wilson, 1964a: 450. See also: Jaitrong & Yamane, 2011: 25.



Worker
Jaitrong and Yamane (2011) - Measurements. Worker lectotype and paralectotypes (n = 6): TL 4.85–5.05 mm; HL 0.98–1.03 mm; HW 0.90–0.95 mm; SL 0.93–0.95 mm; ML 1.63–1.73 mm; PL 0.35–0.38 mm; CI 88–95; SI 100–105.

Redescription (lectotype and paralectotypes). Head in full-face view slightly longer than broad, with sides convex and posterior margin almost straight; occipital margin bearing a carina. Antennal scape relatively long, but not reaching the posterolateral corner of head; antennal segments II–X each longer than broad; II almost as long as each of III–IV. Frontal carina short, a little extending beyond the level of the posterior margin of torulus. Parafrontal ridge almost absent or very weak. Anterior margin of clypeus convex, bearing 6–7 denticles. Masticatory margin of mandible with a large apical tooth followed by a medium-sized subapical tooth, 6–7 denticles, and a medium-sized basal tooth; basal margin sinuate with a series of 3–4 ill-defined denticles. Promesonotum in profile convex dosally and sloping gradually to metanotal groove; propodeum in profile with its dorsal outline almost straight or feebly convex; propodeal junction obtusely angular; declivity of propodeum shallowly concave, encircled with a rim. Petiole distinctly longer than high, elevated posteriorly; subpetiolar process well developed and triangular, its apex directed downward and backward; postpetiole almost as long as petiole, with its node convex dorsally.

Head entirely smooth and shiny. Antennal scape microreticulate and subopaque, slightly shiny. Mesosoma entirely microreticulate and opaque, except for a very small patch on pronotum which is feebly shiny; reticular diameters on pronotum larger than elsewhere. In addition, mesonotum bearing a few irregular longitudinal rugae. Petiole punctate and opaque; postpetiolar dorsum smooth and shiny; lateral face shagreened with smooth and shiny interspaces. Femora entirely microreticulate except for basal portion micropunctate; tibiae microreticulate. Head with some short standing hairs in addition to two long hairs on vertex; mesosoma with relatively sparse standing hairs mixed with sparse suberect short hairs over the surface; length of the longest pronotal hair 0.35-0.40 mm. Entire body dark reddish-brown, with a relatively large typhlatta spot on occipital corner.

Type Material
Jaitrong and Yamane (2011) - Six syntype workers (two pins, three workers on each) from Burma, Assam (, examined). One worker among them (top on a pin) is selected as the lectotype, the others as paralectotypes.