Recurvidris browni

Recurvidris browni has been collected in lowland rainforests in Sundaland (W. Malaysia, Sarawak and Kalimantan) (Bolton, 1992). In south Thailand it was found inhabiting lowland evergreen rainforest, south of the Isthmus of Kra. A single colony from Nakhon Si Thammarat Province (WJT07-TH675) was collected by sifting leaf litter. (Jaitrong and Wiwatwitaya 2015)

Identification
Jaitrong and Wiwatwitaya (2015) - Recurvidris browni belongs to the Recurvidris recurvispinosa species group (sensu Bolton, 1992) that has the following characteristics: basal tooth on masticatory margin of mandible is enlarged and usually blunt, truncated or bidenticulate apically; basal margin of mandible unarmed; propodeal declivity with infradental lamella that links the spine to metapleural lobe. This species is closely related to Recurvidris williami, sharing the same form of mandibular dentition. R. browni is notably larger, has more slender propodeal spines. Furthermore, R. williami has a strongly reticulate-punctate sculpture, which is absent in R. browni.

Distribution
Indonesia (Kalimantan), Malaysia (Sarawak and W. Malaysia), and Thailand.

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

Nomenclature

 *  browni. Recurvidris browni Bolton, 1992: 43, figs. 1, 3 (w.) BORNEO.

Worker
Jaitrong and Wiwatwitaya (2015) - (n = 12): TL 2.50-2.60 mm, HW 0.53-0.56 mm, HL 0.56-0.58 mm, SL 0.50-0.51 mm, PW 0.28-0.30 mm, ML 0.73-0.76 mm, CI 91-97, SI 91-97.

Head in full-face view round and almost as long as broad, with posterior margin strongly convex. Eye 0.12 mm in maximum diameter, with seven ommatidia along the longest axis. Antennal scape extending posteriorly, reaching posterolateral corner of head. Masticatory margin of mandible with five teeth, fifth (basal) tooth much larger than fourth, blunt or truncate apically; basal margin of mandible unarmed. Clypeus with indistinctly paired carinae. Mesosoma slender; promesonotum in profile weakly convex dorsally and sloping gradually to metanotal groove. Propodeum in profile with weakly convex dorsal outline; recurved propodeal spine long and narrow. Propodeal declivity with a fine but distinct infradental lamella or ridge linking propodeal spine to metapleural lobe. Peduncle of petiole relatively long, with its dorsal outline distinctly concave and ending posteriorly in sharp angle, its ventral outline weakly convex with long acute subpetiolar process.

Dorsum of head superficially reticulate, with some short fine longitudinal rugulae near mandibular base. Pronotum and mesonotum glassy smooth and shiny; mesopleuron, metapleuron, and propodeum finely reticulate; propodeal spines sculptured. Petiole and postpetiole finely punctate. Gaster smooth and shiny.

Head with relatively dense hairs that are very short; promesonotum sparsely with longer hairs (less than ten hairs); longest pronotal hairs 0.10-0.13 mm long; hairs absent from propodeal dorsum. Petiole with two short dorsal pairs of hairs. Postpetiole with three short dorsal pairs and one short ventrolateral pair of hairs. Body colour yellow.

Type Material
Jaitrong and Wiwatwitaya (2015) - Holotype and 32 paratype workers from E. Malaysia, Sarawak, 4th Div. G. Mulu Nat. Pk., RGS Expd., Long Pala, lowl. Rainfor., forest floor, 5.x.1977, B. Bolton leg. .