Tetraponera binghami

This species appears to be confined to wet forest habitats. As far as known it always nests in the live culms of bamboos, in which the ants keep scale insects as well as brood. The nesting biology has been well studied in populations from West Malaysia, in which Gigantochloa is the host bamboo (Buschinger et a/. 1994). Here T. binghami forms large monogynous colonies, occupying multiple stem internodes, and always in association with the mealybug Kermicus wroughtoni. The workers do not aggressively defend their hostplant, however. Among other intriguing behavioral observations, colony-founding queens have been demonstrated to carry coccoids between their mandibles (Klein etal. 1992), and workers have been described bailing unwanted water out of their nests by ingestion and regurgitation (Klein et al. 1993).

Identification
Ward (2001) - Characteristic features of T. binghami workers include the elongate head, prominent clypeal lobe, small eyes, well separated frontal carinae, slender mesosoma and petiole, and abundant pilosity. Compared with other Asian congeners T. binghami does not exhibit marked variation in morphology. Workers from more southern populations (Nilgiri Hills, India; West Malaysia) tend to have less elongate heads and those from southern India also have shorter petioles, but the differences are not striking.

Distribution
Tetraponera binghami ranges from Nepal to southern China and south to the Malay Peninsula. There is also an isolated population in the Nilgiri Hills of south India.

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

Biology
Buschinger et al. 1994 - Dissection of 54 stem internodes from 12 different culms of the large bamboo Gigantochloa scortechinii (height up to 25 m, diameter 8-10 cm, internode length 20-60 cm), and mapping of three colonies indicate the following demographic characteristics. Colonies are monogynous but highly polydomous (at least up to 36 internodes and up to 9 stems occupied) and very populous for a pseudomyrmecine not involved in an ant-plant mutualism. One completely censused colony had 6953 adult workers and 2079 alates (adults plus pupae). Brood is distributed from the queenright chamber to all other nest chambers. The symbiotic pseudococcids Kermicus wroughtoni are present in all inhabited internodes, with small early instar individuals prevailing numerically by far over the larger stages. The reliable honeydew supply within the internodes and the efficient architectural protection provided by the internode wall (access usually only through a 2 x 3 mm-hole) allow an unusually large colony size without being an aggressive and protective plant mutualist like other members of its subfamily with similar demographics.

Several unusual behaviors include ejection of excess water from the internodes (Klein et al. 1993) and carrying of pseudococcid larvae by young queens during the nuptial flight (Klein et al., 1992). Unlike some other ants specialized on a narrow range of plants, T. binghami does not protect its host.

Castes
Buschinger et al. 1994 - The ovaries of T. binghami show an adaptation for large colony size. Whereas generalized Pseudomyrmecinae tend to have 2 ovarioles per ovary (e.g., T. anthracina (Terron, 1970), T. modesta, Pseudomyrmex mexicanus, P. pallidus (unpubl. obs.), T. binghami queens have 10 ovarioles per ovary.

Nomenclature

 *  binghami. Sima binghami Forel, 1902c: 243 (w.q.m.) MYANMAR. Combination in S. (Tetraponera): Emery, 1921f: 25; in Tetraponera: Wheeler, W.M. 1921c: 531. Senior synonym of lindgreeni: Ward, 2001: 626.
 * lindgreeni. Sima binghami var. lindgreeni Forel, 1902c: 245 (w.) INDIA. Combination in S. (Tetraponera): Emery, 1921f: 25; in Tetraponera: Chapman & Capco, 1951: 79. Junior synonym of binghami: Ward, 2001: 626.

Worker
Ward (2001) - HW 1.06-1.27, HL 1.36-1.75, LHT 1.24-1.46, CI 0.70-0.78, FCI 0.16-0.20, REL 0.25-0.30, REL2 0.36-0.39, SI 0.62-0.66, SI3 1.62-1.84, FI 0.37-0.40, PLI 0.36-0.43, PWI 0.36-0.42, PDI 0.90-0.99, LHT/HW 1.05-1.20, CSC 24-40, MSC 34-71.

Large, slender species, with elongate head (CI <0.80); clypeus with moderately prominent median lobe, the anterior margin convex and weakly crenulate; frontal carinae well separated, the distance between them exceeding maximum scape width; eyes relatively small (see REL, REL2 and SI3 values); head capsule usually widest on anterior half and converging slightly posteriorly; posterior margin of head straight; profemur slender; lateral margins of pronotum not well defined; mesopropodeal impression well developed and elongate, the anterior half open and furnished with irregular rugulae, usually longitudinal in orientation; posterior half consisting of a shallow depression flanked by low metanotal tubercles that are discernable in profile; propodeum long and low (PDI <1.00), it dorsal face rounding gradually into the declivitous face; legs long relative to head size, LHT/HL 0.80-0.91; petiole long and slender (PLI <0.45), the node rather weakly differentiated from the anterior peduncle; petiole about 2.5x longer than broad; postpetiole about 1.4x longer than broad; metabasitarsal sulcus well developed, lying in a darkened patch of cuticle and subtended by a low ridge, occupying about 0.60-0.70x the length of the basitarsus; mesobasitarsus with a small remnant of a comparable sulcus. Integument with numerous fine punctures, the interspaces smooth and shiny; punctures on dorsum of head and mesosoma mostly 0.005-0.015 mm in diameter and separated by one to several diameters, less dense along mesosomal midline (especially on pronotal midline which is smooth and shiny); punctures on side of mesosoma finer, less conspicuous, except for dense patch on metapleuron and adjacent mesepisternum; lower malar area with coarse punctures intermixed with irregular longitudinal rugulae. Standing pilosity common and conspicuous on most of body (CSC >20, MSC >30), and grading into shorter suberect and decumbent pubescence. Black to dark brownish-black, tarsi and antennae often lighter (medium- to yellowish-brown).

Type Material
Ward (2001) - Syntypes, 6 workers, 1 alate queen, 3 males, Moulmain, Myanmar (Hodgson) ; syntypes, 3 workers, Ye Valley, Myanmar (Bingham) (MHNG); syntypes, 3 workers, N. Konkan, Myanmar (Wroughton) ; syntypes, 8 workers, 1 male, Assam, India (Smythies) (MHNG).

Determination Clarifications
In other publications this species has been referred to by the code name “Tetraponera sp. PSW-80”.