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

 * . Recurvidris browni Bolton, 1992: 43, figs. 1, 3 (w.) BORNEO (East Malaysia: Sarawak; Indonesia: Kalimantan), WEST MALAYSIA.
 * Type-material: holotype worker, 32 paratype workers.
 * Type-locality: holotype Malaysia: Sarawak, 4th Division, G. Mulu Nat. Park, RGS Expd., Long Pala, 5.x.1977, lowland rainforest, forest floor (B. Bolton); paratypes with same data.
 * Type-depositories: BMNH (holotype); BMNH, MCZC (paratypes).
 * Status as species: Bolton, 1995b: 377; Pfeiffer, et al. 2011: 51; Jaitrong & Wiwatwitaya, 2015: 106 (redescription); Jaitrong, Tokeeree, et al. 2019: 59 (in key).
 * Distribution: Indonesia (Kalimantan), Malaysia (Peninsula, Sarawak), Thailand.

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. .

References based on Global Ant Biodiversity Informatics

 * Bolton B. 1992. A review of the ant genus Recurvidris (Hym: Formicidae), a new name for Trigonogaster Forel. Psyche 99: 35-48.
 * Fayle T.M., Bakker, L., Cheah, C., Ching, T.M., Davey, A., Dem, F., Earl, A., Huaimei, Y., Hyland, S., Johansson, B., Ligtermoet, E., Lim, R., Lin, L.K., Luangyotha, P., Martins, B.H., Palmeirim, A.F., Paninhuan, S., Rojas, S.K., Sam, L., Sam, P.T.T., Susanto, D., Wahyudi, A., Walsh, J., Weigl, S., Craze, P.G., Jehle, R., Metcalfe, D. & Trevelyan, R. 2011. A positive relationship between ant biodiversity (Hymenoptera: Formicidae) and rate of scavenger-mediated nutrient redistribution along a disturbance gradient in a south-east Asian rain forest. Myrmecological News 14: 5-12.
 * Huong N. T. T., P. V. Sang, and B. T. Viet. 2015. A preliminary study on diversity of ants (Hymenoptera: Formicidae) at Hon Ba Nature Reserve. Environmental Scientific Conference 7: 614-620.
 * Jaitrong W., and D. Wiwatwitaya. 2015. The species of the ant genus Recurvidris Bolton, 1992 (Hymenoptera: Formicidae: Myrmicinae) in Thailand. Halteres 6: 104-112.
 * Kishimoto-Yamata K., F. Hyodo, M. Matsuoka, Y. Hashimoto, M. Kon, T. Ochi, S. Yamane, R. Ishii, and T. Itioka. 2012. Effects of remnant primary forests on ant and dung beetle species diversity in a secondary forest in Sarawak, Malaysia. Journal of Insect Conservation DOI 10.1007/s10841-012-9544-6
 * Mezger D., and M. Pfeiffer. 2011. Partitioning the impact of abiotic factors and spatial patterns on species richness and community structure of ground ant assemblages in four Bornean rainforests. Ecography 34: 39-48.
 * Mezger D., and M. Pfeiffer. 2011. Partitioning the impact of abiotic factors and spatial patterns on species richness and community structure of ground assemblages in four Bornean rainforest. Ecography 34: 39-48.
 * Pfeiffer M., D. Mezger, and J. Dyckmans. 2013. Trophic ecology of tropical leaf litter ants (Hymenoptera: Formicidae) - a stable isotope study in four types of Bornean rain forest. Myrmecological News 19: 31-41.
 * Pfeiffer M., and D. Mezger. 2012. Biodiversity Assessment in Incomplete Inventories: Leaf Litter Ant Communities in Several Types of Bornean Rain Forest. PLoS ONE 7(7): e40729. doi:10.1371/journal.pone.0040837
 * 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
 * Philpott S.M., P. Bichier, R.A. Rice, and R. Greenberg. 2008. Biodiversity conservation, yield, and alternative products in coffee agroecosystems in Sumatra, Indonesia. Biodivers. Conserv. 17: 1805-1820. Data obtained from Stacy Philpott
 * Woodcock P., D. P. Edwards, R. J. Newton, C. Vun Khen, S. H. Bottrell, and K. C. Hamer. 2013. Impacts of Intensive Logging on the Trophic Organisation of Ant Communities in a Biodiversity Hotspot. PLoS ONE 8(4): e60756. doi:10.1371/journal.pone.0060756
 * Woodcock P., D. P. Edwards, T. M. Fayle, R. J. Newton, C. Vun Khen, S. H. Bottrell, and K. C. Hamer. 2011. The conservation value of South East Asia's highly degraded forests: evidence from leaf-litter ants. Phil. Trans. R. Soc. B. 366: 3256-3264.
 * Woodcock P., D.P. Edwards, T.M. Fayle, R.J. Newton, C. Vun Khen, S.H. Bottrell, and K.C. Hamer. 2011. The conservation value of South East Asia's highly degraded forests: evidence from leaf-litter ants. Phil. Trans. R. Soc. B 366: 3256-3264.
 * Wriedt J., D. Mezger, L. Chong, and M. Pfeiffer. 2008. Observations on the foraging behaviour of Myrmicaria brunnea subcarinata (Smith) (Hymenoptera: Formicidae) in a tropical rainforest in Sarawak (Malaysia). Asian Myrmecology 2: 109-120.