Metapone vincimus

Known from two widely separated locations. In each location, specimens were found in a log with termites.

Identification
Petiolar node from above approximately as wide as long; postpetiolar sternum in side view bluntly rounded.

Taylor and Alpert (2016) - General and diagnostic features as in key (note paired anteromedian clypeal denticles, sub-parallel lateral clypeal margins, petiolar node in dorsal view approximately as wide as long, and unextended postpetiolar sternite). Eyes very small, much as described for Metapone madagascarica. Subpetiolar process more-or-less basic in structure: posterior face approximately equilaterally triangular, subpetiolar angle obtuse, its apex minutely rounded in side view. Subpetiolar extension lamellate, a shallow isosceles triangle, the posterolateral edge slightly concave in side view, the base almost as long as the subpetiolar edge.

Distribution based on Regional Taxon Lists
Malagasy Region: Madagascar.

Biology
Alpert (2007) - At least two separate M. vincimus colonies were present in the same fallen tree (local Malagasy name “Ompa”). The colonies were separated by over 5 meters along the log and workers attacked and killed members of the other colony when put together into a common foraging arena. Workers and brood were found in chambers just below the log surface in close proximity to Cryptotermes termite chambers. Colony size was small, one colony containing less than 20 workers and about 40 larvae. A queen mesosoma along with worker remains was found in a refuse chamber of this colony. Since queens are known for this species it is probable that after the death of the primary reproductive, the colony is still able to produce workers via the presence of gamergates (Hölldobler et al., 2000b).

Nomenclature

 *  vincimus. Metapone vincimus Alpert, 2007: 11, figs. 1, 2, 7, 8, 13, 14 (w.q. and w.-q. intercaste) MADAGASCAR.

Worker
Holoytpe; paratypes (n=15): HL 1.20 mm, 1.20–1.44 mm; HW 0.90 mm, 0.90–1.06 mm; ML 1.60 mm, 1.58–1.90 mm; PML 0.90 mm, 0.90–1.24 mm; PMW.64 mm, 0.60–0.76 mm; PNL 0.34 mm, 0.32–0.46 mm; PetW 0.44 mm, 0.44–0.68 mm; PPW 0.46 mm, 0.44–0.62 mm.

Worker
Head in full-face view distinctly longer than broad (CI 0.75 [0.74-0.81]), lateral margins sub-parallel, posterior margin broadly concave. Compound eyes small, reduced to about 6 weakly defined ommatidia, located near the mid-line of the head. Ocellar pits and ocelli absent. Mandibles stout, with 5 rounded teeth, increasing in size progressively towards the mandibular apices. Anterior clypeal margin with a quadrate median lobe formed into a blunt anterior edge (0.10 mm wide). The vertex with a short median suture that extends from the base to the posterior margin. Frontal carinae, widely separated, parallel and forming deep antennal scrobes. The frontal carinae originating from the posterior border of the clypeus, diverging transversely and extending posteriorly to behind the eye. Lateral clypeal lobes narrow, oblique, and separated from the genae by distinct lines continuous with the posterior border of the clypeus. A series of parallel striae begin just below the eye and extend across the posterior border of the lateral clypeal margin.

Antennae 11-segmented, the scape short and flattened dorso-ventrally, SL 0.34 mm, dorsal surface of scape with scattered erect hairs. First segment of funiculus elbowed, segments 2-7 gradually expanding before developing into a flattened, 3-segmented club. Numerous hairs on all surfaces of the funicular segments.

Mesosoma long and narrow, the promesonotum separated from the propodeum by a well- developed, complete, transverse metanotal groove. Entire mesosoma marginate to submarginate laterally, margin becoming more distinct at the propodeal corners. Propodeal dorsum nearly horizontal, passing through an abrupt concave angle to the vertical, posterior face. Petiole weakly convex dorsally. In dorsal view, the anterior margin of the petiolar node straight, the posterior margin deeply concave. Petiole ventrally with a thin, translucent median rounded keel. In profile, the anterior and posterior face of the petiole strongly concave. In profile, postpetiole almost flat dorsally. In dorsal view, anterior margin of postpetiole straight, posterior margin slightly concave, the anterodorsal corners diverging to rounded posterodorsal corners. The postpetiole joined to the gaster by a wide face, although a deep constriction exists between the two segments. Anteroventral surface of postpetiole produced into a pronounced, triangular rounded lobe or blunt tooth in side view.

The first gastric segment almost as long as the remaining gastral segments combined. Gaster with numerous hairs arising from foveae, surface between foveae smooth and shiny. Coxae stout and bulbous. Femora swollen and laterally compressed, the ventral surface longitudinally grooved for the reception of the tibia. Tibia also stout and partly compressed. Protibia armed apically with 1 small spine and a large pectinate spur. Mesotibia with a small, barely pectinate spur, and 3 stout apical teeth. Apical tarsomere on all legs with simple claws.

Sculpture: Clypeus, frons, genae and antennal scrobes covered with fine, longitudinal striae, essentially parallel, but which fade posteriorly, leaving the vertex, occiput and posterior part of the genae smooth and shining, interrupted only by prominent punctures. Centrally two parallel striae forming a groove that extends from the clypeal border to just beyond the limits of the frontal carinae. Entire dorsum of mesosoma longitudinally striate. Dorsal surface of petiole with hair-bearing punctures. Postpetiole and gaster with similar but finer punctures. All areas of the body, including the legs and antennae, smooth and shiny.

Pilosity: Short, scattered, erect yellow hairs on all surfaces of head and mesosoma, many hairs arising from punctures on the vertex, occiput and petiole. Hairs longer on mandibles, anterior margin of the clypeus, lateral surfaces of legs and lower surfaces of petiole and gaster. Pilosity most abundant on postpetiole and gaster.

Color: Head, mandibles and postpetiole dark reddish brown, the mesosoma and gaster a lighter brown. Petiole, legs and antennae light yellowish brown.

Queen
Queen-worker intermorph. Same characters as worker apart from being larger in most dimensions, darker and having relatively larger postpetiole. Ocelli absent.

Queen. Same as worker with the following exceptions: Larger size, additional thoracic sclerites, HL 1.20 mm; HW 0.98 mm; AL 2.20 mm; PW 0.46 mm; PNL 0.44 mm, dealate and uniformly black in color. Three ocelli present and large compound eyes.

Type Material
Holotype worker from MADAGASCAR, 30km N of Antalaha, 3km W to a hill, near Amboangy, 50 m, 14°39’53.3”N, 50°11’26.5”E, 29.VII.2000, secondary rainforest, in log with termite Cryptotermes kirbyi, G. Alpert, P. Rabeson and E. Rajeriarison, #2278. Deposited in. Paratype workers. 15 workers and 1 queen-worker intermorph, collected from the same nest series as the holotype. Alate queen found in same locality on 24.I.1991. Paratypes have been deposited in the following collections; Los Angeles County Museum of Natural History, Los Angeles, California, USA, ; California Academy of Sciences, San Francisco, California, USA, ; Bohart Museum of Entomology, University of California, Davis, California, USA, ; The Natural History Museum, London, England ; Australian National Insect Collection, Canberra, Australia ; and the National Museum of Natural History, Smithsonian Institution, Washington, D.C., USA,. Paratypes and voucher specimens including larvae are deposited in the Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA, (MCZC). Cryptotermes termite voucher specimens have been deposited in the American Museum of Natural History, New York, USA, ; the Natural History Museum, London, England (BMNH); and the Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts, USA, (MCZC).

Etymology
The specific name, vincimus = “we succeed”, is in recognition of the joint effort expended in discovering this species. Extremely hard logs were searched by axe for weeks before finally locating the ants and associated termites.

References based on Global Ant Biodiversity Informatics

 * Alpert G. D. 2007. A review of the ant genus Metapone Forel from Madagascar. Memoirs of the American Entomological Institute 80: 8-18.
 * Taylor R. W., and G. D. Alpert. 2016. The myrmicine ant genus Metapone Forel (Hymenoptera: Formicidae): a global taxonomic review with descriptions of twelve new species. Zootaxa 4105(6): 501-545.