Tetraponera laeviceps

This species appears to be an opportunistic colonist of dead plant cavities. I have found colonies in dead twigs of Hibiscus tiliaceus, Gnetum sp., Premna serratifolia, Ximenia americana, and unidentified vines, shrubs and small trees. There are also records of workers from the foliage and trunks of recently felled rainforest trees, in both New Guinea and Cape York in northern Australia. (Ward 2001)

Identification
Ward (2001) - Workers of T. laeviceps can be distinguished from those of related species by: (1) the relatively large punctures on the head (0.010-0.015 mm in diameter), separated by one or more diameters, with the interspaces smooth and shiny; (2) the moderate distance between the frontal carinae (MFC approximately equal to maximum scape width); (3) the relatively large eyes (see ocular indices); (4) the elevated propodeum; and (5) the relatively slender petiole. As here interpreted, T. laeviceps is a polytypic species, showing considerable variation in head shape, sculpture, width of the pronotum, configuration of the propodeum, and shape of the petiole. The syntype workers of T. laeviceps conform to the following facies (with measurements given for the syntype in OXUM): rather broad shiny head (CI 0.86), narrow pronotum without well-developed humeral angles (PrWM/HW 0.60, PrWM/MTW c. 1.15), relatively low propodeum (PDI c. 1.13), and short petiole (PLI 0.59; PL/HW 0.69). In contrast the worker types of Tetraponera humerosa and Tetraponera platynota have the pronotum more expanded laterally, the propodeum more conspicuously elevated, and the petiole more elongate (PLI c. 0.45 in T. platynota); the head is broad in T. humerosa (CI c. 0.90), more elongate in platynota (CI 0.84). Available non-type specimens include a panoply of intermediate phenotypes, suggesting the existence of a single variable species, although most specimens tend to have rather broad pronota and long petioles. More material is needed from the poorly sampled western part of the distribution (Irian Jaya and Maluku). If future investigation does indicate that there are two species here, then the name T. humerosa (with junior synonyms platynota and Tetraponera dentifera) is available for the form with the prominent humeri and elongate petiole. Possible morphometric differences between the two forms are indicated below. It is worth stressing that sample sizes for these measurements are small, n = 3 for T. laeviceps (s.s.) and n = 18 for T. humerosa-like workers, with most of the latter coming from Papua New Guinea and all of the T. laeviceps (s.s.) from farther west. As more material accumulates, especially from geographically intermediate locations, these differences may disappear.

T. laeviceps (s.s.) PrWM/HW 0.59-0.60; PLIHW 0.68-0.69; PLILHT 0.84-0.90; DPW/HW 0.30-0.34

T. humerosa-like PrWM/HW 0.62-0.69; PLIHW 0.81-0.96; PLILHT 0.96-1.11; DPW/HW 0.35-0.44

Distribution
Ward (2001) - T. laeviceps ranges from Maluku to the Solomon Is, south through the main island of New Guinea to northern Australia.

Distribution based on Regional Taxon Lists
Australasian Region: Australia. Indo-Australian Region: Indonesia, New Guinea, Solomon Islands.

Habitat
Habitat records include secondary forest, littoral vegetation, and rainforest.

Nomenclature

 *  laeviceps. Pseudomyrma laeviceps Smith, F. 1859a: 145 (w.) INDONESIA (Aru I.). Combination in Sima: Mayr, 1876: 111; in S. (Tetraponera): Emery, 1921f: 26; in Tetraponera: Smith, F. 1877b: 69; Donisthorpe, 1932c: 455. [Misspelled as leviceps by Dalla Torre, 1893: 54.] Senior synonym of dentifera, humerosa, platynota: Ward, 2001: 630.
 * humerosa. Sima humerosa Emery, 1900d: 674 (footnote) (w.) NEW GUINEA. Combination in S. (Tetraponera): Mann, 1919: 306; in Tetraponera: Chapman & Capco, 1951: 80. Junior synonym of laeviceps: Ward, 2001: 630.
 * dentifera. Sima (Tetraponera) dentifera Karavaiev, 1933c: 266 (q.) INDONESIA (Aru I.). Combination in Tetraponera: Chapman & Capco, 1951: 79. Junior synonym of laeviceps: Ward, 2001: 630.
 * platynota. Sima (Tetraponera) platynota Karavaiev, 1933c: 269, fig. 16 (w.) INDONESIA (Wammer I.). Combination in Tetraponera: Chapman & Capco, 1951: 81. Junior synonym of laeviceps: Ward, 2001: 630.

Worker
Ward (2001) - HW 0.75-0.91, HL 0.86-1.10, LHT 0.63-0.78, CI 0.81-0.87, FCI 0.12-0.16, REL 0.40-0.45, REL2 0.46-0.53, SI 0.52-0.60, SI3 1.02-1.20, FI 0.43-0.51, PLI 0.45-0.59, PWI 0.40-0.49, PDI 1.11-1.34, LHT/HW 0.77-0.87, CSC 1-25, MSC 4-42.

Medium-sized species, with relatively broad head; clypeus short, its anteromedial portion protruding only slightly beyond level of the anterolateral clypeal margin; distance between frontal carinae approximately equal to maximum scape width; eye relatively large (see REL and REL2 values); scape length exceeding eye length; profemur moderately robust (see FI values); pronotum slightly to strongly expanded laterally (PrWM/MTW 1.15-1.37), its anteromedial surface varying from convex to slightly concave; lateral pronotal margins present, blunt-edged; mesopropodeal impression well marked but short, consisting of a pit-shaped depression, flanked by lateral ridges; propodeum usually conspicuously elevated, always notably higher than wide (PDI > 1.10), its dorsal face varying in profile from strongly convex and peaking far forward, above the propodeal spiracle, to broadly convex and somewhat flattened; dorsal face of propodeum rounding gradually into declivitous face; petiole relatively slender (PLI <0.60, PWI <0.50), with well differentiated anterior peduncle and node; petiole somewhat variable in size and shape (PL/HW 0.68-0.96, PL/HL 0.59-0.80, DPW/MTW 0.61-0.86; see also range of PLI and PWI values); postpetiole approximately as long as wide; metabasitarsal sulcus well developed, lying in a darkened patch of cuticle and adjacent to a low carina that occupies about 0.3-0.6x the length of the basitarsus. Integument with numerous small-medium punctures, interspaces smooth and shiny; larger punctures on dorsum of head and mesosoma 0.010-0.015 mm in diameter and separated by one to several diameters (occasionally denser on the pronotum); sculpture weaker elsewhere on mesosoma and petiole; integument largely smooth and shiny on side of pronotum, anterior part of mesepisternum, and side of petiole; postpetiole and gaster finely puncticulate, sublucid; lower malar area rugulopunctate. Standing pilosity varying from sparse to moderately common (see range of esc and MSC values), when common then often grading into shorter, subdecumbent pubescence; appressed pubescence common on most of body, especially dense on postpetiole and abdominal tergites. Black to dark brownish-black, appendages variably lighter (scape, protibia and tarsi often contrastingly yellow-brown).

Type Material
Ward (2001) - Syntypes, 3 workers, Aru, Indonesia (Wallace).