Neoponera carinulata

From Mackay and Mackay (2010): Longino (1997) reports that this species is a common arboreal ant foraging in the canopy of mature rain forests. The workers run very rapidly on tree trunks and are difficult to collect. The sting is painful (Baena, 1993).

Identification
From Mackay and Mackay (2010): Workers of P. carinulata could be separated from other members of the crenata species complex as the highest point on the apex of the petiole is approximately in the middle. Pachycondyla carinulata could only be confused with Pachycondyla goeldii  in which the petiole has a similar shape. In both species the malar carina is well developed as is the pronotal carina, which overhangs the side of the pronotum. Pachycondyla carinulata differs in having the dorsum of the head densely punctate and dull, whereas the head of P. goeldii is weakly punctate and moderately shining. Pachycondyla carinulata could be confused with Pachycondyla oberthueri, but can be separated as the highest point on petiole is not near the posterior edge, the mandibles are finely striate, not smooth and glossy and it is nearly black with reddish legs, not reddish brown with yellow legs as in P. oberthueri. Pachycondyla carinulata can be distinguished from the similar Pachycondyla coveri  from Perú as the punctures on the dorsum of the pronotum are coarse and form poorly defined transverse striae. The punctures on the dorsum of the pronotum of P. coveri are very fine leaving the remainder of the pronotum smooth and glossy.

The workers of the new Costa Rican species Pachycondyla antecurvata could be confused with those of P. carinulata. They can be easily separated as the highest point on the petiole of P. antecurvata is anterior to the midpoint, that of P. carinulata is at the midpoint.

Pachycondyla carinulata race azteca was not seen, but based on the description, it does not appear to differ from the typical P. carinulata and is thus synonymized. Forel (1909) separated  Pachycondyla carinulata gibbinota from the typical P. carinulata by the evenly convex propodeum. Comparison of two type workers with typical P. carinulata worker shows there is no difference and this subspecies is thus synonymized.

Distribution
Mexico through central South America.

Distribution based on Regional Taxon Lists
Neotropical Region: Belize, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guatemala, Guyana, Honduras, Mexico.

Habitat
From Mackay and Mackay (2010): This species can be found in disturbed habitats such as a cocoa plantation as well as on mountain pine ridges. Longino (1997) reports it is widespread in mature rain forests from sea level to 1300 m. It was collected in the twilight zone of a cave less than 20 m from the entrance (Reddell and Cokendolpher, 2001).

Biology
From Mackay and Mackay (2010): Pachycondyla carinulata often nests in rotten trunks. Longino (1997) reports that they nest opportunistically in almost any small cavity, such as under epiphytes, in small pieces of deadwood and in dead hollow stems. He found a nest in two internodes of a Cecropia insignis sapling. Wheeler (1942) found this species nesting in the living internodes and fistulose stems of Patima formicaria as well as in dead twigs. All of the nests that Longino observed were small with few workers.

Pachycondyla carinulata is mimicked by the salticid spider Myrmarachne parallela (Reiskind, 1977).

Nomenclature

 *  carinulata. Ponera carinulata Roger, 1861a: 4 (q.) GUYANA. Emery, 1890a: 73 (w.); Mann, 1916: 412 (w.). Combination in Pachycondyla: Roger, 1863b: 18; in Neoponera: Emery, 1901a: 47; in Pachycondyla: Brown, in Bolton, 1995b: 303; in Neoponera: Schmidt & Shattuck, 2014: 151. Senior synonym of azteca, gibbinota: Mackay & Mackay, 2010: 232.
 * azteca. Pachycondyla carinulata r. azteca Forel, 1899c: 11 (w.) PANAMA. Combination in Neoponera: Emery, 1901a: 47; in Pachycondyla: Brown, in Bolton, 1995b: 303. Junior synonym of carinulata: Mackay & Mackay, 2010: 228.
 * gibbinota. Neoponera carinulata subsp. gibbinota Forel, 1909a: 246 (w.) GUATEMALA. Combination in Pachycondyla: Brown, in Bolton, 1995b: 305. Junior synonym of carinulata: Mackay & Mackay, 2010: 228.

Worker
From Mackay and Mackay (2010): The worker is a relatively small (total length up to 7 mm) dark reddish ant with reddish brown mandibles and appendages. The anterior medial edge of the clypeus forms a blunt angle. The malar carina is present, but not greatly developed. The eyes are located slightly less than one maximum diameter from the anterior edge of the head (side view). The scape extends about two funicular segments past the posterior lateral corner. The pronotal shoulder is formed into a sharp carina, which slightly overhangs the side of the pronotum. The metanotal suture is present, but is not depressed and barely breaks the sculpture on the dorsum of the mesosoma. The propodeal spiracle is elongated. The anterior and posterior faces of the petiole are nearly parallel on the lower half; the anterior face abruptly bends and forms an obliquely sloping dorsal face, which meets the posterior face at an angle in the middle of the petiole. The posterior face is convex and rounded. The stridulatory file is present on the dorsum of the gaster. The metasternal process consists of two closely spaced lobes.

Erect hairs are numerous on most surfaces, including the head, the scape, the dorsum of the mesosoma, the petiole and all surfaces of the gaster, the hairs on the tibiae are abundant and mostly suberect, all hairs are bright golden-yellow. Appressed golden yellow pubescence is also abundant on the dorsum of the head, dorsum of the mesosoma, the dorsum of the petiole and dorsum of the gaster. Other surfaces such as the ventral surface of the head, the sides of the mesosoma and the petiole also have golden appressed hairs, which are not as numerous.

The head and the dorsum of the mesosoma are densely and evenly punctate appearing like a thimble, the side of the mesosoma is weakly sculptured with fine punctures and is partially smooth and shining. The anterior half of the petiole is mostly punctate and weakly shining, the posterior face is glossy and polished. The gaster is finely punctate, but the sculpture is difficult to see because of the dense golden appressed pubescence.

Queen
From Mackay and Mackay (2010): The female (undescribed) is a small (total length 8 mm) black ant with yellow legs. The head length is 1.7 mm by 1.6 mm wide. The eye (maximum diameter 0.44 mm) is located less than ½ of the length from the anterior edge of the head (side view). The scape (length 1.5 mm) extends about the first funicular segment past the posterior lateral corner of the head. The pronotal carina is sharp and overhangs the side of the pronotum. The propodeal spiracle is elongated. The petiole is similar to that of the worker, with both the anterior and posterior faces convex and meeting at a sharp angle in the middle of the apex. The posterior lateral edges of the posterior face are sharp and form a carina. The stridulatory file is well developed.

Erect hairs are relatively short (0.2 mm) and moderately abundant on most surfaces, including the scapes. The hairs on the tibiae are mostly suberect and sparse. Appressed silver pubescence is sparse, but covers most surfaces.

The mandibles are covered with fine striae and scattered punctures, and are dull, as is the remainder of the ant. The head and most surfaces are densely covered with small punctures. The side of the pronotum is weakly shining and the posterior face of the petiole is mostly smooth and glossy, except for the upper edge, which is punctate.

Male
Males are not known for this species.

Type Locality Information
Brasil: Minas Gerais, São João D’el Rey (Mackay and Mackay 2010)

Etymology
The name is derived from Latin, carina¸ meaning keel and the ulata making it the diminutive, thus the name means “little keel”, probably referring to the carina on the pronotal shoulder. (Mackay and Mackay 2010)