Meranoplus malaysianus

This species has been found in litter samples from mesic forest.

Identification
Schödl (1998) - Meranoplus malaysianus is very close to Meranoplus borneensis but is distinctive by the very different pubescence, the propodeal spines mostly situated at a higher level on propodeal sides and the distinctly narrower truncated petiole.

Across the wide range of its distribution this species shows variation in the outline of the promesonotal shield, the shape of both petiole and postpetiole, and the surface of the gaster. The differences are found especially in specimens from Borneo. More collections may show this material is comprised of more than a single species.

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

Nomenclature

 * . Meranoplus malaysianus Schödl, 1998: 385, figs. 4, 18, 32 (w.q.) WEST MALAYSIA, BORNEO (East Malaysia: Sabah, Sarawak), INDONESIA (Java).
 * Type-material: holotype worker, 25 paratype workers, 3 paratype queens, 1 paratype male.
 * Type-locality: holotype Malaysia (“Malaya”): Kuala Lumpur, 8.x.1973, K.L. Univers., litter sample (B. Bolton); paratypes: 10 workers, 1 queen with same data, 3 workers Kuala Lumpur, 8.x.1973 (B. Bolton), 5 workers Malaysia: Neg. Sembilan, Pasoh Forest Res., xi.1994 (M. Brendell, K. Jackson & S. Lewis), 4 workers, 2 queens, 1 male Indonesia: Java, Depok, 7.i.1923, and 30.iii.1923 (Dammerman), 3 workers Java, Kebun Raya, Bogor, 11-31.i.1992, F192-387 (F. Ito).
 * Type-depositories: BMNH (holotype); BMNH, MCZC, NHMB, NHMW, SKYC (paratypes).
 * Status as species: Pfeiffer, et al. 2011: 47; Satria & Herwina, 2020: 83.
 * Distribution: Indonesia (Java, Sumatra), Malaysia (Peninsula, Sabah, Sarawak).

Worker
Holotype: TL: 2.75, HL: 0.6, HW: 0.65, CI: 108, SL' 45 SI- 69 PML:0.45, PW: 0.6, PMI: 133, AL: 0.55.

Paratypes: TL: 2.3 - 2.87, HL: 0.6 - 0.7, HW: 0.63 - 0.73, CI: 102 - 108, SL: 0.4 - 0.48, SI: 62 - 69, PML: 0.45 - 0.53, PW: 0.58 - 0.7, PMI: 1 14 - 136, AL: 0.5 - 0.58 (15 measured).

Mandibles striate, armed with four teeth. Mid-portion of clypeus vertical and slightly concave, covered with a rough reticulum. Lateral sides of clypeal mid-portion, where meeting lateral clypeal parts acutely boardered, occasionally denticulate, the anterior margin very narrowly margined. Frontal triangle vestigial, only an arcuate, smooth furrow between clypeus and frons apparent. Head above antennal scrobes rectangular, posteriorly parallel-sided, lateral margins above eyes slightly sinuate, anteriorly the sides of head narrowed towards clypeus. Ventral to the antennal scrobes the head similarly shaped, the genae not protruding, hardly visible from above. Frons above antennal sockets with a smooth, hyaline, transparent fenestra on each side of postero-lateral margin of clypeus. Antennal scrobes especially in posterior half with few transverse carinulae. Genae rugulose. Compound eyes situated behind, but close to middle of lateral sides of head. Maximum diameter of eye 0.16 - 0.19, with 7 - 9 ommatidia in the longest row.

The dorsal promesonotum rectangular, wider than long. The promesonotal shield distinctly margined, broadly transparent at the sides, overhanging alitrunk laterally and propodeum posteriorly. Anterior corners of pronotum acutely angled, almost rectangular. Lateral sides of pronotum parallel, slightly sinuate. At level of (invisible) promesonotal suture the promesonotal shield laterally constricted, with a transparent fenestra on each side close to the margin, and usually the transparent spot connected with the lamellate margins. Mesonotum anteriorly shortly parallel-sided as well, posteriorly angulately converging, followed by a concavity. At level of the concavity near lateral sides with a second, similarly shaped and similarly sized lamellate fenestra. Hind margin of mesonotum undulated, with very blunt paramedian projections, and with a median transverse translucent area. Declivity of propodeum entirely smooth, meeting the dorsum of alitrunk in a right angle. The suture between dorsal alitrunk and propodeum is situated exactly in point beneath mesonotal hind margin, where they meet, and thus not visible, when viewed from behind. Lateral propodeal spines short and acute, situated above middle of propodeal length.

Petiole in lateral view tapered, the crest obliquely and narrowly truncate. Anterior petiolar face smooth, the dorsum and lateral sides rugulose, the posterior face smooth, with occasional longitudinal rugae. Postpetiole nodiform, reticulate-rugulose, weaker so in specimens from Borneo. First gastral tergite entirely smooth, with only an occasional faint shagreening around hair-pits (type material), or with variably developed shagreening in specimens from Borneo.

Dorsum of head and promesonotal shield densely reticulate-rugulose. Width of meshes on both ca. 30 - 60 μm. Lateral margins and hind margin of the shield smooth, except for some rugae. Entire dorsal surface covered with dense, suberect to erect, regular whitish pubescence (ca. 100 - 150 μm), and with only occasional slightly longer hairs of ca. 200 μm length. Colour of individuals uniformly pale (type material) to dark brown.

Queen
Paratype: TL: 3.0 - 3.1, HL: 0.65 - 0.7, HW: 0.7, CI: 100 - 108, SL: 0.43 - 0.45, SI: 61 - 64, PW: 0.7 - 0.73, AL: 0.75; widest diameter of compound eye 0.180 - 0.185, with 10 ommatidia in the longest row. Distance between inner margins of lateral ocelli 0.214 - 0.220 (3 measured).

Type Material
Holotype worker, "litter sample K.L. Univers. \ MALAYA Kuala Lumpur 8.X.73 B.Bolton"; paratypes: 10 workers, 1 queen, same locality data as holotype (BMNH, )- 3 workers, "Berlese funnel \ MALAYA K. Lumpur 8.X.1973 B Bolton \ Meranoplus sp det B Bolton 1974" (, NHMW); 5 workers, "MALAYSIA Neg. Sembilan Pasoh For. Res. xi. 1994 Mitt sample M.Brendell K.Jackson S.Lewis (BMNH, NHMW); 4 workers, 2 queens, 1 male (head missing) "Damm Depok 7.1. [1 ex. 30.111.] 1923 \ MCZ Museum of Comparative Zoology" (MCZC, NHMW)- 3 workers "Fl 92-387 \Kebun Raya Bogor W-Java INDONESIAN, Jan 1 1-31 1992 F. Ito (CSYK, NHMW). Type locality: Kuala Lumpur, Malaysia.

Etymology
Named after Malaysia, from where the first specimens of this little species showed up during this survey.

References based on Global Ant Biodiversity Informatics

 * Hashimoto Y., Y. Morimoto, and M. Mohamed. 2003. Species List of Ground and Leaf Litter Ants Collected in Lower Kinabatangan. Pp 13-18. In Lower Kinabatangan Scientific Expedition 2002, 176 pp. ISBN-13: 983-2369-11-8
 * Hashimoto Y., and M. Mohamed. 2011. Ground-dwelling ant diversity in Maliau Basin, Borneo: evaluation of hand-sorting methods to estimate ant diversity. Tropics 19(2): 85-92.
 * Ito, F.; Yamane, S.; Eguchi, K.; Noerdjito, W. A.; Kahono, S.; Tsuji, K.; Ohkawara, K.; Yamauchi, K.; Nishida, T.; Nakamura, K. 2001. Ant species diversity in the Bogor Botanic Garden, West Java, Indonesia, with descriptions of two new species of the genus Leptanilla (Hymenoptera, Formicidae). Tropics 10:379-404.
 * 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.0040800
 * 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
 * Schödl S. 1998. Taxonomic revision of Oriental Meranoplus F. Smith, 1853 (Insecta: Hymenoptera: Formicidae: Myrmicinae). Annalen des Naturhistorischen Museums in Wien. B, Botanik, Zoologie 100: 361-394.
 * 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.