Neoponera concava

One of the few specimens of this species was collected from a winkler sample.

From Mackay and Mackay (2010): The worker of Neoponera concava is very similar to those of Neoponera venusta and Neoponera schultzi, but can be easily separated as the anterior face of the postpetiole of the latter two species is not strongly concave. Additionally these two species lack the well-developed angulate lobe, which overhangs the clypeus of N. concava. Most of the mesopleuron of N. concava is smooth and glossy, which easily separates it from the worker of N. schultzi in which the entire mesopleuron is covered with horizontal striae. The anterior margin of the clypeus of N. venusta does not have a well-developed sharp lobe, which overhangs the remainder of the clypeus as it does in N. concava. The males and females of the three species are unknown.

Identification
The sharp point on the clypeus N. concava could cause confusion with Rasopone becculata, but the concave anterior face of the postpetiole in N. concava would easily separate them. The form of the anterior face of the postpetiole of N. concava could cause confusion with Neoponera procidua and even Pachycondyla harpax, in which the anterior face of the postpetiole is concave. The well-defined malar carina would separate N. concava from both of these species, which lack the carina.

Distribution
BRASIL (Mackay and Mackay 2010)

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Nomenclature

 *  concava. Pachycondyla concava Mackay & Mackay, 2010: 261, figs. 87, 88, 189, 387-390 (w.) BRAZIL. Combination in Neoponera: Schmidt & Shattuck, 2014: 151

Worker
The worker is a small (total length 5 mm) black ant with red appendages and a red-tipped gaster. The mandibles have nine teeth; the medial lobe of the clypeus is angulate and overhangs the anteclypeus. The head length (including the lobe of the clypeus) is 1.15 mm; the head width is 0.95 mm. The eyes (maximum diameter 0.26 mm) are located anteriorly on the head slightly more than ½ diameter from the anterior margin of the head. The malar carina is well developed and extends nearly to the middle of the inner border of the eye. The scape (1.15 mm) extends approximately ⅓ length past the posterior lateral corner of the head. The head is slightly narrowed anteriorly, the posterior lateral margins are rounded and the posterior margin is slightly concave. The carina is moderately developed on the side of the pronotum and partially overhangs the side. The mesosoma is depressed at the metanotal suture. The propodeal spiracle is circular. The petiole is relatively narrow when viewed in profile with a straight or slightly concave anterior face; the broadly rounded posterior face meets the anterior face near the anterior edge of the apex. The posterior face is separated from the side by a carina. The subpetiolar process has a small anterior ventrally directed angle followed by short concave region and a rounded lobe posteriorly. The anterior face of the postpetiole is strongly concave and forms an acute angle with the dorsal face. The stridulatory file is well developed on the second pretergite, the arolia are moderately developed.

Erect hairs are present on the mandibles, the clypeus, the dorsal surface of the head, the sides of the head, the posterior margin, the scape (where the hairs are approximately equal in length to the diameter of scape), on the dorsum of the mesosoma, petiole and all surfaces of the gaster. Appressed pubescence is very sparse; a few appressed golden hairs are obvious on the head, the mesosoma and gaster.

The mandibles are smooth and glossy with scattered punctures, the medial lobe of the clypeus is covered with longitudinal striae, the head is heavily and densely punctate, but the punctures are in rows forming poorly defined striae. The punctures on the dorsum of the pronotum are coarse and align in definite rows forming striae, which are mostly longitudinal, but somewhat concentric around the center of the pronotum. The sculpture of the mesonotum is similar, but with less obvious striae. The dorsum of the propodeum is mostly smooth and glossy, the side of the pronotum below the carina is very smooth and glossy as is most of the mesopleuron (a few striae are present near the dorsal edge), the upper part of the propodeum is covered with coarse striae, and the lower third is glossy.

The upper part of the anterior face the petiole is smooth and glossy, the lower half has transverse striae, the side of the petiole is mostly glossy, the posterior surface is smooth and glossy on sides of the upper ⅓, the lower ⅔ is covered with transverse striae. The gaster is densely punctate, but smooth and glossy between the punctures.

Queen
Queens are not known for this species.

Male
Males are not known for this species.

Type Material
Holotype worker, 2 paratype workers (, MCZC). Rebio, UNA-BA, 22-10-92, Col. Ivan C. 45798. One paratype worker REBIO/IBDF, UNA-BA, Data - Nov. ’89, Col. M. C. Alves, 4333 (MCZC).

Etymology
From Latin, concavus, meaning concave, referring to the anterior face of the postpetiole.