Tetraponera attenuata

Specimens of T attenuata whose labels include habitat information indicate occurrences in “lowland rainforest”, “primary rainforest”, “primary dipterocarp forest”, “lower montane mixed dipterocarp forest”, “hilltop dipterocarp forest”, “second-growth forest” and (male only) “mangrove”. There are a few colony series from dead twigs or dead branches, indicating that this species has generalist nesting habits. (Ward 2001)

Identification
Ward (2001) - This species can be recognised by the broad head, elongate petiole, and dense covering of suberect pubescence and standing pilosity on most of the body. Workers from northern populations of T. attenuata tend to have more widely separated frontal carinae, smaller eyes, a shorter petiole and a longer metabasitarsal sulcus. But the relevant indices (FCI, REL, REL2, PLI and PWI) overlap substantially, and the variation appears to be clinal in nature. Queens of T. attenuata show comparable geographical variation in the same features. In addition, the queens vary in the shape of the clypeus (anterolateral teeth variably developed, occasionally absent) and the size of the malar pit (varying from well developed to absent), but variation in these latter traits does not show a clear-cut geographical pattern.

Distribution
Ward (2001) - Tetraponera attenuata ranges from northeast India to southern China, south to Sumatra, Java, and Borneo. The only Philippines records come from Palawan. A single dealate queen has also been taken on Okinawa in Japan.

Distribution based on Regional Taxon Lists
Indo-Australian Region: Borneo, Indonesia, Malaysia, Philippines. Oriental Region: Cambodia, India, Laos, Myanmar, Thailand, Vietnam. Palaearctic Region: China, Japan.

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 Kermieus 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. attenuata does not protect its host.

Klein, R.W., D. Kovac, A. Schellerich and U. Maschwitz, 1992. Mealybug-carrying by swarming queens of a Southeast Asian bamboo-inhabiting ant. Naturwissenschaften 79:422-423. Klein, R. W., U. Maschwitz and D. Kovac, 1993. Flood control in ants: a Southeast Asian bamboo-dwelling Tetraponera (Hymenoptera: Formicidae: Pseudomyrmecinae) bails water from its internode-nests. Ins. Soc. 40: in press.

Castes
Buschinger et al. 1994 - The ovaries of T. attenuata 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. attenuata queens have 10 ovarioles per ovary.

Nomenclature

 *  attenuata. Tetraponera attenuata Smith, F. 1877b: 71 (w.) BORNEO. Wheeler, W.M. 1919e: 144 (q.m.). Combination in Sima: André, 1892b: 53; in Tetraponera: Wheeler, W.M. 1919e: 65. Senior synonym of tenuissima: Forel, 1912n: 55; of birmana, thagatensis: Ward, 2001: 622.
 * tenuissima. Sima attenuata var. tenuissima Emery, 1900d: 675, fig. 5 (w.q.) INDONESIA (Sumatra). Junior synonym of attenuata: Forel, 1912n: 55.
 * birmana. Sima birmana Forel, 1902c: 245 (q.) MYANMAR. Bingham, 1903: 112 (w.). Combination in S. (Tetraponera): Emery, 1921f: 25; in Tetraponera: Chapman & Capco, 1951: 79. Junior synonym of attenuata: Ward, 2001: 622.
 * thagatensis. Sima attenuata var. thagatensis Forel, 1902c: 249 (w.) INDIA. Combination in S. (Tetraponera): Emery, 1921f: 27; in Tetraponera: Wheeler, W.M. 1924b: 5; Chapman & Capco, 1951: 82. Junior synonym of attenuata: Bingham, 1903: 112; revived from synonymy as subspecies of nigra: Forel, 1909d: 226; raised to species: Forel, 1912n: 55; returned to junior synonymy of attenuata: Ward, 2001: 622.

Worker
Ward (2001) - HW 0.97-1.48, HL 1.07-1.67, LHT 0.97-1.47, CI 0.84-0.94, FCI 0.11-0.15, REL 0.29-0.34, REL2 0.32-0.38, SI 0.61-0.76, SI3 1.84-2.11, FI 0.33-0.40, PLI 0.38-0.47, PWI 0.29-0.44, PDI 0.97-1.06, LHT/HW 0.93-1.08, CSC 10-26, MSC 6-44.

Relatively large and slender species, with broad head (CI >0.82); clypeus short, its anteromedial margin varying from broadly convex to straight; anteromedial margin of clypeus joining anterolateral margin in a smooth curve or (less commonly) at a slight angle; frontal carinae moderately well separated, the distance between them exceeding basal scape width; eyes relatively small (see REL and REL2 values), scape length about twice eye length; lateral margins of head rounding broadly into posterior margin; profemur slender; pronotum usually lacking prominent lateral margins; mesopropodeal impression wellmarked, long and open, flanked by low metanotal tubercles that are usually not prominent in profile; propodeum about as high as wide, dorsal face rounding gradually and continously into the declivitous face; legs long relative to head size, LHT/HL 0.84-0.96; petiole somewhat variable in shape but always rather long and slender (PLI <0.48), often markedly so, and with a well differentiated anterior peduncle and node; petiole more than twice as long as broad; postpetiole 1.1-1.4x longer than broad; metabasitarsal sulcus lying in a darkened patch of cuticle subtended by a raised ridge, occupying about 0.15-0.30 the length of the basitarsus. Integument with numerous fine punctures, the interspaces (sub)lucid and smooth or weakly reticulate; punctures on dorsum of head and mesosoma mostly 0.005-0.015 mm in diameter (pronotal punctures sometimes larger) and separated by one to several diameters; punctures on side of mesosoma finer, less conspicuous; lower malar area with coarse punctures intermixed with irregular longitudinal rugulae. Standing pilosity common (see CSC and MSC values), the hairs up to 0.30-0.35 mm long, and tending to grade into shorter suberect and decumbent pubescence which forms a dense cover on most of the body, including the mesosoma dorsum and petiole. Black to dark brownish-black, scape and first several funicular segments often lighter (medium to yellowish-brown).

Type Material
Ward (2001) - Syntype (unique?), worker, Sarawak (labeled 'Sar.'), Malaysia.