Xymmer muticus

Known from sampling of litter and soil in rainforest and savannah habitats. Little else is know about the biology of this species.

Identification
The worker mandibles, shape of the head and general body form are most similar to Amblyopone, Prionopelta and Stigmatomma.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Central African Republic, Ghana, Ivory Coast, Nigeria.

Nomenclature

 * . Stigmatomma (Xymmer) muticum Santschi, 1914d: 311, fig. 2 (w.) NIGERIA.
 * Type-material: 4 syntype workers.
 * Type-locality: Nigeria: Ibadan (F. Silvestri).
 * Type-depository: NHMB.
 * [Note: Baroni Urbani, 1973b: 126, records only 1 syntype in NHMB; it is assumed the other 3 are in the Silvestri collection in DEUN.]
 * Combination in Xymmer: Wheeler, W.M. 1922a: 758;
 * combination in Amblyopone: Brown, 1960a: 168;
 * combination in Xymmer: Yoshimura & Fisher, 2012a: 19.
 * Status as species: Wheeler, W.M. 1922a: 758; Brown, 1960a: 168; Bolton, 1995b: 62.
 * Distribution: Cameroon, Central African Republic, Democratic Republic of Congo, Gabon, Ghana, Ivory Coast, Nigeria.

Worker
Yoshimura & Fisher (2012) - TL 3.5 mm, including mandibles. Colour brownish-red; mandibles, antennae and legs more yellowish. Shiny; smooth with very fine but quite dense puncturation. Hairs limited to a very few around the mouth and gastral apex. Pubescence all over quite abundant but not concealing the sculpturation. Head a fifth longer than wide, a quarter more narrow behind than in front; sides slightly arcuate, near straight and posterior border distinctly concave. Blind, sometimes a rudimentary facet at the posterior third. Frontal carinae set well apart; clypeus rectangular four times wider than long. Frontal notch very narrow. Scape reaching the posterior quarter of the head. All funiculus segments wider than long. Mandibles shiny, densely punctate, narrow, length about three-quarters that of the head; external border near straight in basal four-fifths before the strongly convex apical fifth. Internal border slightly convex and with eight teeth strong and simple (rarely bifurcate) with the space between second and third bigger than between others. Thorax dorsum flat and sub-bordered. Pronotum a quarter longer than wide. Mesonotum and propodeum fused, about three times longer than wide, with almost straight sides. Propodeum dorsum more distinctly bordered behind, passing into the declivity with a sharp curve. Declivity, straight from one side to the other, convex from above to bottom in the lower third, concave basally. Petiole node a third longer than wide, sides somewhat convex, higher in front than behind. Without ventral process but with a very low simple tubercle. First segment of gaster shorter than petiole, high than long and as long as the posterior width. This species is characterized by the clypeus having no armament and being lobed.

Type Material
Yoshimura & Fisher (2012) - Lectotype worker from Nigerie S. lbadan, Nigeria, Silvestri. Det. Santchi 1913 : CASENT0217322.

References based on Global Ant Biodiversity Informatics

 * Belshaw R., and B. Bolton. 1994. A survey of the leaf litter ant fauna in Ghana, West Africa (Hymenoptera: Formicidae). Journal of Hymenoptera Research 3: 5-16.
 * Belshaw R., and B. Bolton. 1994. A survey of the leaf litter ant fauna in Ghana, West Africa (Hymenoptera: Formicidae). Journal of Hymenoptera Research. 3: 5-16.
 * Brown W. L., Jr. 1960. Contributions toward a reclassification of the Formicidae. III. Tribe Amblyoponini (Hymenoptera). Bull. Mus. Comp. Zool. 122: 143-230.
 * Dejean A., J. L. Durand, and B. Bolton. 1996. Ants inhabiting Cubitermes termitaries in African rain forest. Biotropica 28(4): 701-713.
 * Gotwald W. H., Jr., and J. Lévieux J. 1972. Taxonomy and biology of a new West African ant belonging to the genus Amblyopone (Hymenoptera: Formicidae). Ann. Entomol. Soc. Am. 65: 383-396.
 * Kone M., S. Konate, K. Yeo, P. K. Kouassi, and K. E. Linsenmair. 2012. Changes in ant communities along an age gradient of cocoa cultivation in the Oumé region, central Côte dIvoire. Entomological Science 15: 324339.
 * Levieux J. 1972. Etude du peuplement en fourmis terricoles d'une savane preforestiere de Cote d'Ivoire. Revue d'Ecologie et de Biologie du Sol 10(3): 381-428.
 * Lévieux J. 1972. Les fourmis de la savane de Lamto (Côte d'Ivoire): éléments de taxonomie. Bulletin de l'Institut Fondamental d'Afrique Noire. Série A. Sciences Naturelles 34: 611-654.
 * Santschi F. 1914. Formicides de l'Afrique occidentale et australe du voyage de Mr. le Professeur F. Silvestri. Bollettino del Laboratorio di Zoologia Generale e Agraria della Reale Scuola Superiore d'Agricoltura. Portici 8: 309-385.
 * Wheeler W. M. 1922. Ants of the American Museum Congo expedition. A contribution to the myrmecology of Africa. VIII. A synonymic list of the ants of the Ethiopian region. Bulletin of the American Museum of Natural History 45: 711-1004
 * Yeo K., S. Konate, S. Tiho, and S. K. Camara. 2011. Impacts of land use types on ant communities in a tropical forest margin (Oumé - Cote d'Ivoire). African Journal of Agricultural Research 6(2): 260-274.