Tetramorium lucyae

This species nests in the ground (upper montane forest) and appears polygynous. All available specimens were collected using the Winkler extraction method. The sampled type series comprises part or all of a nest consisting of 203 workers, two gynes, five pupae at a very advanced stage (closely resembling the imago), 13 pupae at an earlier stage (imago not fully recognizable), 33 large larvae (ca. 2.5 mm) and six small larvae (ca. 1.5 mm)—transitions between all stages present. (Sorger 2011).

Identification
Sorger (2011) - Differentiation between Tetramorium lucyae and Tetramorium flagellatum is difficult, and careful examination and measurements are necessary in order to successfully and reliably identify these species.

There are three distinguishing characters: maximum hair length (on head, mesosoma and tibiae), frons sculpture and total length (although the latter can be used only with a larger nest sample: at least 20 specimens). None of these characters should be used for identification in isolation; only a combination of all characters provides a clear picture of the distinctions between the species. A combination of MHLH, MHLM and MHLT is vital for identification; in addition, it is recommended to use a nest sample of more than 5 specimens where possible, given variation among individuals.

All measurements are in millimetres and presented as minimum-mean-maximum values.

Maximum hair lengths on head, mesosoma and tibiae: T. lucyae (0.40–0.48–0.59 MHLH; 0.46–0.51–0.58 MHLM; 0.22–0.30–0.34 MHLT) has longer hairs than T. flagellatum (0.30–0.35–0.40 MHLH; 0.34–0.41–0.44 MHLM; 0.10–0.17–0.22 MHLT) overall. Two single specimens in the studied sample overlap at a single value each: (MHLT: 0.40 mm; MHLT: 0.20 mm).

Frons sculpture: Sculpture on head frons is more longitudinally oriented in T. flagellatum. However, this differential character is subtle—longitudinal rugae on frons (right at medial depression) are more irregular (“shaky”) in T. lucyae whereas, in comparison, rugae are rather straight in T. flagellatum.

Total length: T. flagellatum (3.28–3.55–3.80 TL) is smaller than T. lucyae (3.60–3.73–3.86 TL) overall. However, since the mean TL of T. lucyae lies within the overlapping range (3.60 to 3.80 mm TL) of the two species, a nest series of at least 20 specimens is necessary in order to calculate a mean value.

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

Nomenclature

 *  lucyae. Tetramorium lucyae Sorger, 2011b: 4, figs. 4-9 (w.q.) BORNEO.

Worker
Holotype worker: HW 0.84; HL 0.86; CI 98; SL 0.67; SI 80; PW 0.60; ML 1.04; TL 3.76; MHLH 0.46; MHLT 0.30; MHLM 0.50.

Paratype workers (range of 20 workers): Worker with smallest HW: HW 0.79; HL 0.82; CI 96; SL 0.64; SI 81; PW 0.58; ML 1.00; TL 3.60; MHLH 0.40; MHLT 0.26; MHLM 0.48. Worker with largest HW: HW 0.86; HL 0.86; CI 100; SL 0.68; SI 80; PW 0.60; ML 1.04; TL 3.80; MHLH 0.46; MHLT 0.32; MHLM 0.51.

Mean values of 20 workers: TL 3.73; MHLH 0.48; MHLT 0.30; MHLM 0.51.

Head, mesosoma, petiole and postpetiole reddish brown, gaster dark brown, legs yellowish brown, antennae similar to legs but slightly darker.

Entire body (except antennae) with some very conspicuous and extremely long curved, whitish, yellow setae (0.40– 0.59 mm MHLH, 0.22–0.34 mm MHLT, 0.46–0.58 mm MHLM), also setae of varying length and appression present.

Head slightly longer than wide, sides anteriorly and posteriorly convergent; with coarse rugoreticulum (very uneven, wavy rugae), underlying microsculpture slightly reticulate, but appearing smooth and shiny overall. Occipital margin broadly concave in frontal view, anterior clypeal margin complete, without median indention. Mandibles striate. Antennal scrobes present, outlined by change in sculpture; few horizontal rugae running along frontal carinae, more distinct at anterior part, fine rugoreticulum with few cross-meshes, microsculpture punctate. Frontal carinae reaching almost to occiput.

Mesosoma in side view evenly convex, in dorsal aspect broadest at level of pronotum, where it is strongly rounded, appearing somewhat inflated; with coarse rugoreticulum, coarsest on pronotum dorsally, rugoreticulum on sides of mesosoma slightly more longitudinally oriented. Propodeal spines short, acute and straight, never reaching the petiole in lateral aspect, in dorsal view diverging, forming a ventrally rounded V. Propodeal lobes long and acute (in a few specimens slightly rounded apically), more than half as long as propodeal spines.

Petiole pedunculate, peduncle more than half as long as petiole node; with coarse and distinct rugoreticulum. Petiole in dorsal view subtrapezoidal, petiolar node rounded, in side view roughly rectangular and stout. Postpetiole in profile slightly shorter than petiole, in dorsal aspect about quarter broader than petiole; also with coarse rugoreticulum, but somewhat less distinct than on petiole. Gaster smooth and shining, microsculpture with very fine isodiametric reticulum.

Queen
Paratype. Gyne 1: HW 0.84; HL 0.86; CI 98; SL 0.66; SI 79; PW 0.86; ML 1.36; TL 4.30; MHLH 0.50; MHLT 0.36; MHLM 0.44. Gyne 2: HW 0.84; HL 0.86; CI 98; SL 0.65; SI 77; PW 0.86; ML 1.34; TL 4.28; MHLH 0.47; MHLT 0.30; MHLM 0.44.

Gynes differ from workers in the following characters (besides characters related to wings): metapleura with longitudinal striation, no cross-meshes present, larger eyes, three ocelli present.

Type Material
Holotype (worker: NHMW) and paratypes (202 workers: ABNC, BMNH, CSW, NHMW, SFDC; 2 gynes: BMNH, NHMW) from one locality: Borneo, Sarawak, Gunung Murud, “Joy Bridge”, Jambatan Sukacita, 03°56.157′N, 115°32.337′E, 2076 m, 28.xi.2008, leg. M. Pfeiffer.

Etymology
The collector of the type specimens, Dr Martin Pfeiffer, suggested dedicating this ant species to Lucy Chong (Forest Research Center, Sarawak Forestry Corporation), which I readily accepted. She has been supporting the studies of a large number of local and international biologists for a long time. This honour is also given to her as a representative of all Malaysian officials who are active in biological research and the conservation of the splendid natural heritage of Malaysia.

References based on Global Ant Biodiversity Informatics

 * Pfeiffer M.; Mezger, D.; Hosoishi, S.; Bakhtiar, E. Y.; Kohout, R. J. 2011. The Formicidae of Borneo (Insecta: Hymenoptera): a preliminary species list. Asian Myrmecology 4:9-58