Neoponera rugosula

From Mackay and Mackay (2010): Two series from Perú (Colpa Quebrada, Sotilejo) were collected in Cecropia sp. plants. The specimens collected in quarantine were in the orchid Cattleya mossiae [Orchidaceae]. Specimens from Venezuela were intercepted at Hoboken, New Jersey (USA) on Cattleya orchids [Orchidaceae], 23-x-1946, 9-i-1946 and 9-i-1947.

Identification
From Mackay and Mackay (2010): The worker and female of N. rugosula are very similar to those of Neoponera unidentata, but can be separated by the more coarse punctures on the dorsum of the pronotum, the prominent obliquely transverse striae on the side of the propodeum and the horizontal striae on the side of the petiole. The striae on the latter two structures are nearly always missing on workers and females of N. unidentata and if they are present, they do not cover the entire surface. The anterior border of the postpetiole is more concave than it is in N. unidentata.

The concavity of the posterior face of the petiole of the specimens of N. rugosula from Venezuela could cause confusion with the Colombian Neoponera recava. They can be easily separated as N. recava is much smaller (total length 6.5 mm) and the petiole, especially the posterior face, is smooth and glossy, not sculptured as in N. rugosula.

The male of N. rugosula is essentially identical to that of Neoponera moesta. Striae are poorly developed on the side of the propodeum of males of N. rugosula and essentially absent on the side of the petiole. The Neoponera rugosula male can be separated from the male of N. unidentata by the swollen medial region of the clypeus, which appears as an angle when the head is viewed in profile.

Distribution
COSTA RICA, ECUADOR, PERU, VENEZUELA, BRASIL, BOLIVIA (Mackay and Mackay 2010)

Distribution based on Regional Taxon Lists
Neotropical Region: Bolivia, Brazil, Ecuador, Peru.

Habitat
This species was found in a wet forest along a river. (Mackay and Mackay 2010)

Nomenclature

 * laevinodis. Neoponera laevinodis André, 1902: 14 (w.q.) PERU. Junior synonym of rugosula: Emery, 1911d: 72.
 *  rugosula. Neoponera unidentata var. rugosula Emery, 1902c: 30 (w.) PERU. Mackay & Mackay, 2010: 501 (m.). Combination in Neoponera: Schmidt & Shattuck, 2014: 151. Senior synonym of laevinodis: Emery, 1911d: 72. Junior synonym of unidentata: Brown, 1957e: 232. Revived from synonymy: Mackay & Mackay, 2010: 499.

Worker
From Mackay and Mackay (2010): The worker is a medium-sized (total length 8 mm) dark reddish brown ant with brown or orange appendages. The mandibles have approximately 11 teeth, which alternate in size. The anterior border of the clypeus is convex with a medial lobe, which overhangs the anteclypeus. The posterior lateral corners of the head are angulate and the posterior margin is concave. The head length is 1.6 - 1.75 mm; the head width 1.5 - 1.6 mm. The malar carina is present and sharp. The eye (maximum diameter 0.40 - 0.45 mm) is approximately one diameter from the anterior margin of the head. The scape (1.5 - 1.6 mm) extends approximately the first funicular segment past the posterior lateral corner of the head. The sides of the head are convex and slightly narrowed anteriorly, slightly wider at a point just posterior to the eyes and the posterior border is concave. The carina on the pronotal shoulder is very sharp and slightly overhangs the side of the pronotum. The mesosoma is only slightly depressed at the metanotal suture, which is not evident on the dorsum of the mesosoma. The propodeal spiracle is elongated. The anterior face of the petiole is vertical and meets the broadly rounded posterior face at the anterior edge of the apex. The posterior face of the petiole is strongly outlined by sharp lateral carinae and is convex, possibly flat or even strongly concave. The subpetiolar process consists of a downward directed angle anteriorly followed by a concave region and a broadly rounded lobe at mid length, which gradually diminishes in width posteriorly. The anterior face of the postpetiole is concave and meets the dorsal face at a rounded angle. The stridulatory file is well-developed on the second pretergite. The arolia are poorly developed.

Erect and suberect hairs are abundant on the mandibles, dorsal and ventral surfaces of the head, sides of the head, posterior margin, shaft of the scape, dorsum of the mesosoma, dorsum of the petiole and all surfaces of the gaster; the hairs on the legs are mostly suberect and sparse. Appressed pubescence is present on the head, dorsum of the mesosoma, anterior and posterior faces of the petiole and all surfaces of the gaster.

The mandibles are finely striate and weakly shining with scattered punctures. The medial angulate lobe on the clypeus has longitudinal striae. The head is densely punctate with the punctures being arranged in somewhat poorly defined striae, which diverge posteriorly. The dorsum of the pronotum is covered with moderately coarse punctures, which are arranged in poorly defined transverse striae, the side of the pronotum and the mesopleuron are finely sculptured and weakly shining. The punctures on the mesonotum and dorsum of the propodeum are not as well defined, the side of the pronotum is finely punctate smooth and glossy. The mesopleuron has poorly defined horizontal striae, the side of the propodeum has well defined coarse striae, which are obliquely horizontal. The anterior face of the petiole is smooth and glossy (finely punctate), the sides of the petiole have poorly defined horizontal striae, mostly concentrated mid height, the posterior surface is finely punctate and shiny. The gaster is finely punctate and shining.

Specimens from Venezuela (USNM) are unusual as most of the series has a strongly concave posterior face of the petiole. This appears to be an artifact and they are considered to be P. rugosula.

Queen
From Mackay and Mackay (2010): The female is a moderate sized (total length 8.5 mm) dark reddish brown specimen with lighter brown appendages. The mandibles have 12 or 13 teeth. The head is similar to that of the worker with the length being 1.8 mm and the width 1.7 mm. The eye (maximum diameter 0.5 mm) is located less than one diameter from the anterior edge of the head. The ocelli are small with the median ocellus (0.10 mm) located more than two diameters from the lateral ocellus (diameter 0.06 mm). The scape (1.6 mm) extends 1½ funicular segments past the posterior lateral corner of the head. The carina on the pronotal shoulder is sharp and slightly overhangs the side of the pronotum; the propodeal spiracle is elongate. The petiole and postpetiole are similar to those of the worker.

The pilosity is similar to that of the worker.

The sculpture is similar to that of the worker with the obliquely horizontal striae on side of the propodeum and with fine striae on the side of petiole.

Male
From Mackay and Mackay (2010): The male (undescribed) is a small (total length 6 mm) dark brown specimen. The clypeus is swollen (viewed in profile) and partly overhangs the anterior border of the clypeus. The eyes are moderate in size (maximum diameter in side view 0.59 mm), separated from the lateral ocellus by about ½ of the eye diameter (0.24 mm) as seen obliquely from the side and above. The median ocellus (diameter 0.14 mm) is separated from the lateral ocellus (0.14 mm) by 1 diameter. The pronotal shoulder is swollen but does not form a distinct carina. The Mayrian furrows are well developed and meet in the middle of the scutum. The propodeal spiracle is elongated. The petiole is unlike that of the worker and female and is nearly conical with a slightly convex anterior face and a broadly convex posterior face, which form the highest point near the middle of the apex. The subpetiolar process consists of a lobe, which gradually diminishes in width posteriorly. The anterior face of the postpetiole is broadly rounded into the dorsal face.

Erect hairs are present on all surfaces of the head, the mesosoma, the petiole and the gaster; the hairs on the legs are mostly suberect and not abundant. The middle tibia has three suberect hairs on the outer surface, the posterior tibia has seven hairs on the outer surface and two hairs on the inner margin.

The clypeus and head are very finely punctate and weakly shining. The punctures on the mesosoma are mostly fine, but a few striae are located on the posterior edge of the katepisternum and on the side of the propodeum. The side of the petiole has very poorly defined horizontal striae. The gaster is finely punctate and weakly shining.

Type Material
Perú

Etymology
The species name is derived from the Latin word ruga, meaning wrinkle and the diminutive ulus, together meaning small wrinkles, referring to the sculpture on the dorsum of the pronotum. (Mackay and Mackay 2010)