Meranoplus mucronatus

Specimens of this species were collected from rainforest leaf-litter.

Identification
Schödl (1998) – Meranoplus mucronatus, the largest species in the Oriental region, is unique by its markedly armed promesonotal shield. Species with a similar armament on the dorsal alitrunk are known only from further easterly regions.

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

Nomenclature

 *  mucronatus. Meranoplus mucronatus Smith, F. 1857a: 82, pl. 2, fig. 6 (w.) WEST MALAYSIA. Viehmeyer, 1916a: 129 (m.). See also: Schödl, 1998: 388.

Description
Schödl (1998) - TL: 5.8 - 7.1, HL: 1.4 - 1.7, HW- 1 45 - 1 7 CI- 100 - 110 SL- 1.05 - 1.2, SI: 67 - 74, PML: 1.05 - 1.3, PW: 1.3 - 1.65, PMI: 120 - 128 AL- 2-25 (20 measured). Mandibles striate, armed with four teeth. Mid-portion of clypeus distinctly concave medially smooth, laterally rugose, or entire clypeal mid-portion rugose Anterior clypeal margin frequently feebly to distinctly emarginate. Frontal triangle broadly apparent smooth and brilliant. Frons anteriorly with a translucent fenestra above antennal sockets on each side of clypeus. Lateral sides of head above antennal scrobes sinuate above eyes, narrowed towards clypeus, overhanging most of antennal scrobes. Ventral part of head (below antennal scrobes) of similar shape, genae rounded and slightly protruding indistinctly visible from above. Antennal scrobes glabrous anteriorly, occasionally longitudinally striate, and shagreened posteriorly. Genae reticulate-rugulose. Compound eyes situated behind, though close to middle of lateral sides of head. Maximum diameter of eye 0.28 - 0.34, with 14-17 ommatidia in the longest row. Promesonotum slightly wider than long, the shield overhanging sides of alitrunk laterally and propodeum posteriorly. Anterior and posterior corners of promesonotal shield each provided with a very long, acute spine, which is directed in a ca. 45 angle away from the shield. Thus the shield apparently distinctly constricted in posterior half Lateral margins each with a translucent lamellate fenestra which is frequently followed by a second one in front of, or at the base of the posterior spines. Promesonotal suture not visible. Postenor margin with a pair of paramedian short posteriorly directed occasionally bifurcate spines, and with additional shorter, occasionally also bifurcate ones Declivity of propodeum smooth, frequently with an indistinct shagreening, above lateral spines tew longitudinal rugae may occur. Propodeal spines long, very slender and arcuate considerably diverging, situated somewhat above middle of propodeal length An arcuate suture between dorsal alitrunk and propodeum is only indistinctly apparent at the top of the propodeal declivity right beneath mesonotal hind margin, when viewed from behind. Petiole in profile cuneate, in dorsal view the crest a narrow, sharp line, highest in middle when viewed from posteriorly. Anterior petiolar face covered with a pelt of very fine and short pubescence, posterior petiolar face striate, or its middle smooth, with only lateral rugae. Postpetiole nodiform, strongly reticulate-rugulose. First gastral tergite dull entirely shagreened, when studied with higher magnification consisting of a minute reticulum. Dorsum of head and promesonotum reticulate-rugulose. width of meshes ca. 100 - 150 μm Meshes near margins of shield and around base of spines distinctly elongate All dorsal surfaces covered with scattered, stiff, suberect to erect, ca. 200 - 500 μm long hairs Individuals mostly bicoloured with the head, alitrunk, petiole and postpetiole and the appendages ferrugmeus or dark brown, the gaster being darker. Uniformly dark brown to piceous individuals may occur.

Type Material
Schödl (1998) - Holotype worker (examined): "MT OPHIR 24 \ Holotype \ mucronatus Smith \ B.M. TYPE HYM. 1 1.442". Type locality: Mt. Ophir [= Gunong Ledang], Johor, Peninsular Malaysia.

References based on Global Ant Biodiversity Informatics

 * Chapman, J. W., and Capco, S. R. 1951. Check list of the ants (Hymenoptera: Formicidae) of Asia. Monogr. Inst. Sci. Technol. Manila 1: 1-327
 * Crawley W.C. 1924. Ants from Sumatra, with biological notes by Edward Jacobson. Annals and Magazine of Natural History (9)13: 380-409
 * Emery C. 1887. Catalogo delle formiche esistenti nelle collezioni del Museo Civico di Genova. Parte terza. Formiche della regione Indo-Malese e dell'Australia (continuazione e fine). [concl.]. Ann. Mus. Civ. Stor. Nat. 25(5): 427-473.
 * Emery C. 1888. Catalogo delle formiche esistenti nelle collezioni del Museo Civico di Genova. Parte terza . Formiche raccolte dal sig. Elio Modigliani in Sumatra e nell'isola Nias. Annali del Museo Civico di Storia Naturale 25: 528-534.
 * Emery C. 1893. Formicides de l'Archipel Malais. Revue Suisse de Zoologie 1: 187-229.
 * Emery, C.. "Catalogo delle formiche esistenti nelle collezioni del Museo Civico di Genova. Parte terza. Formiche della regione Indo-Malese e dell'Australia (continuazione e fine)." Annali del Museo Civico di Storia Naturale Giacomo Doria (Genova) (2) 5, no. 25 (1887): 427-473.
 * Emery, C.. "Voyage de MM. Bedot et Pictet dans l'Archipel Malais. Formicides de l'Archipel Malais." Revue Suisse de Zoologie 1 (1893): 187-229.
 * Forel A. 1903. Les Formicides de l'Empire des Indes et de Ceylan. Part X. J. Bombay Nat. Hist. Soc. 14: 679-715.
 * Forel A. 1913. Wissenschaftliche Ergebnisse einer Forschungsreise nach Ostindien ausgeführt im Auftrage der Kgl. Preuss. Akademie der Wissenschaften zu Berlin von H. v. Buttel-Reepen. II. Ameisen aus Sumatra, Java, Malacca und Ceylon. Gesammelt von Herrn Prof. Dr. v. Buttel-Reepen in den Jahren 1911-1912. Zoologische Jahrbücher. Abteilung für Systematik, Geographie und Biologie der Tiere 36:1-148.
 * Jaitrong W.; Nabhitabhata, J. 2005. A list of known ant species of Thailand. The Thailand Natural History Museum Journal 1(1): 9-54.
 * Karavaiev V. 1935. Neue Ameisen aus dem Indo-Australischen Gebiet, nebst Revision einiger Formen. Treubia 15: 57-118.
 * Khoo Y.H. 1990. A note on the Formicidae (Hymenoptera) from pitfall traps at Ulu Kinchin, Pahang, Malaysia. Malayan Nature Journal 43: 290-293.
 * 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
 * Santschi F. 1928. Fourmis de Sumatra, récoltées par Mr. J. B. Corporaal. Tijdschrift voor Entomologie 71: 119-140.
 * Santschi F. 1932. Résultats scientifiques du voyage aux Indes orientales néerlandaises de LL. AA. RR. le Prince et la Princesse Léopold de Belgique. Hymenoptera. Formicidae. Mémoires du Musée Royal d'Histoire Naturelle de Belgique. (2)4: 11-29.
 * 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.
 * Smith, F.. "Catalogue of the hymenopterous insects collected at Sarawak, Borneo; Mount Ophir, Malacca; and at Singapore, by A. R. Wallace." Journal of the Proceedings of the Linnean Society of London, Zoology 2 (1857): 42-88.
 * Wheeler W. M. 1919. The ants of Borneo. Bulletin of the Museum of Comparative Zoology 63:43-147.