Rasopone lunaris

From Mackay and Mackay (2010): Most specimens have been collected from extractions of leaf litter or from a laminate fungus. Specimens have also been collected in pitfall traps. Dealate females were collected in June (Costa Rica).

Identification
From Mackay and Mackay (2010): Pachycondyla lunaris is nearly identical to Pachycondyla ferruginea. It differs in having a rectangular-shaped petiole (as seen from the side) with the anterior and posterior faces being nearly parallel (the petiole of the worker and female of P. ferruginea is narrowed towards the apex).

Pachycondyla lunaris is similar to Pachycondyla rupinicola, differing in being smaller (total length of P. rupinicola is about 7 mm) and in having a shorter scape (the scape of P. rupinicola extends significantly past the posterior lateral corner of the head). The color and the circular shaped propodeal spiracle would separate P. lunaris from all of the others in the genus.

Pachycondyla lunaris could be confused with Pachycondyla longidentata. The form of the mandible can easily separate it, the dorsum of which is striate (smooth in P. longidentata) and the apical mandibular tooth is only slightly longer than the subapical tooth (apical tooth much longer in P. longidentata). Additionally the eye of P. lunaris is relatively large (> 0.1 mm maximum diameter) as compared to the tiny eye of P. longidentata; and the subpetiolar process has a posteriorly directed flange or lobe (absent in P. longidentata).

Distribution
GUATEMALA, COSTA RICA, PANAMA, COLOMBIA, ECUADOR, TRINIDAD, FRENCH GUIANA, BRASIL, PARAGUAY. (Mackay and Mackay 2010)

Distribution based on Regional Taxon Lists
Neotropical Region: Ecuador, Paraguay.

Habitat
Pachycondyla lunaris occurs in lowland rain forest, primary wet forest, second growth rain forest, a clearing in a secondary forest, cloud forest, ridge forest and oak forest; between 40 and 1850 meters elevation. (Mackay and Mackay 2010)

Nomenclature

 *  lunaris. Ponera lunaris Emery, 1896g: 55, pl. 1, fig. 12 (w.) PARAGUAY. Mackay & Mackay, 2010: 445 (q.). Combination in Pachycondyla: Emery, 1901a: 45; in Euponera (Trachymesopus): Emery, 1911d: 85; in Trachymesopus: Kempf, 1960f: 424; in Pachycondyla: Brown, in Bolton, 1995b: 307.

Worker
From Mackay and Mackay (2010): The worker is small (total length 4 - 5.5 mm) dark reddish brown with reddish brown appendages. The mandibles are finely striate and shiny, the remainder of the ant is dull. The head length is 1.3 mm; the head width 1.1 mm. The anterior border of the clypeus is broadly convex with the medial part being straight or even slightly concave. The eyes are relatively small (maximum diameter 0.15 mm) and are located less then one maximum diameter from the anterior edge of the head (side view) and contain approximately 40 ommatidia. The scapes are relatively short and fail to reach the posterior lateral corner of the head by at least one maximum diameter of the scape. The posterior border of the head is broadly concave. The mesosoma is short and robust, the pronotal shoulder lacks any sign of a carina, the mesosoma is weakly depressed at the metanotal suture, which is poorly marked dorsally and the propodeal spiracle is circular. The petiole is rectangular-shaped with the anterior and posterior faces being nearly parallel, forming a rounded blunt apex. The gaster is angulate anteriorly with the anterior face and the posterior face of the postpetiole meeting at nearly a right angle. The stridulatory file is absent on the second pretergite, as are the arolia between the tarsal claws.

Erect hairs are sparse with a few present on the clypeus and shaft of the scape, very few are present on the dorsum of the head or posterior margin, a few are present on the dorsum of the mesosoma, dorsum of the petiole, on the subpetiolar process and all surfaces of the gaster. Very few erect and suberect hairs are present on the legs. Fine golden appressed pubescence is present on nearly all surfaces, but is only obvious on the dorsum and sides of the head, dorsum of the mesosoma and all surfaces of the gaster.

The mandibles are dull and completely striate, a furrow is present near the base, the head is punctate, the mesosoma, front of the petiole and sides are punctate and dull, the posterior face is somewhat shining, the gaster is finely punctate and glossy.

Queen
From Mackay and Mackay (2010): The female (undescribed) is approximately the same size as the worker and differs in having three ocelli and a larger eye, which is separated from the anterior edge of the head (side view) by less then one half of the maximum diameter and contains over 100 ommatidia. The mesosoma is also robust and short and contains vestiges of the wings, the propodeal spiracle is circular in shape. The anterior and posterior faces of the petiole are nearly parallel and the apex is formed into a blunt rounded surface. The remainder is as in the worker.

Male
From Mackay and Mackay (2010): Males are not known for this species.

Type Locality Information
Paraguay (Mackay and Mackay 2010)

Etymology
The name of this species is from the Latin word luna and refers to the moon-shaped petiole as seen from above. (Mackay and Mackay 2010)

Additional References

 * Emery, C. 1896a. Studi sulle formiche della fauna Neotropica. Bullettino della Società Entomologica Italiana 28:33-107.