Adelomyrmex bispeculum

Known only from the cloud forests of Monteverde, Costa Rica.

Identification
Longino (2012) - With the characters of Adelomyrmex tristani, differing in the presence of an expansive, completely flat, smooth, shining space on anterolateral head, from level of compound eye across to frontal carina, anteriorly to clypeus, with abrupt transition to strong rugose sculpture on rest of face; petiolar and postpetiolar nodes smooth and shining, without coarse rugae.

Key to Adelomyrmex of the New World mainland

Distribution based on Regional Taxon Lists
Neotropical Region: Costa Rica.

Biology
Longino (2012) - This species occurs in montane cloud forest. It is known only from three nest collections in the cloud forest of Monteverde, Costa Rica, and not from any of the many Winkler samples that have been taken at the site. The nests were collected at 1400 m and 1675 m elevation. One nest was under a stone on the forest floor. It was a 1 cm diameter chamber that contained a few workers and brood. Two additional nests were found in close proximity in a shaded, moss-covered clay bank along a trail. The bank material was moderately friable, not stiff clay. For one nest, the entrance was a horizontal turret, about 1 cm long and 1 cm outer diameter, 5 mm inner diameter. The turret was of fresh material, with a rough surface of adhering particles. A large lower chamber extended 2–3 cm into the bank. A smaller upper chamber, about 1 cm long, had an entrance in the ceiling of the lower chamber. Most workers and brood were in the upper chamber; a few workers were in the lower chamber. The nest contained one dealate queen, 17 workers, and brood. A similar nest was about 50 cm higher on the bank. The internal structure was nearly identical to the first nest, but it lacked a turret; the entrance was a simple hole in the bank. This second nest contained 76 workers and brood.

Nomenclature

 *  bispeculum. Adelomyrmex bispeculum Longino, 2012: 13, figs. 9, 13, 21 (w.q.) COSTA RICA.

Worker
HW 0.54–0.59 (n=3); mandible with differentiated masticatory and basal margins; masticatory margin with 5–6 teeth; basal margin sinuous with a distinct basal tooth and notch between tooth and condyle; dorsal surface of mandible largely smooth and shining, with a few faint longitudinal striae and several large piligerous puncta; in full face view, lateral clypeal teeth project from beneath clypeal shelf; lateral clypeal teeth forming juncture between anterior (ventral) margin of clypeus and transverse carina that forms clypeal shelf; hypostomal tooth absent; compound eye composed of 8–9 ommatidia; face with longitudinally oriented, parallel linear rugae, barring smooth space described in diagnosis.

Short anterior face of pronotum meeting dorsal face at obtuse angle, separated by a low, simple transverse ruga; promesonotum evenly and shallowly convex; metanotal groove impressed; propodeal spines short, triangular, acute at tip; space between propodeal spines a broad concavity without distinct dorsal and posterior faces, smooth and shiny with 3–4 transverse rugae, strongest anteriorly; rugae of dorsal promesonotum and side of mesosoma mostly with strong, longitudinally oriented, parallel linear rugae; petiolar and postpetiolar nodes rounded, smooth and shining, without rugae; postpetiole in dorsal view about as long as wide, evenly rounded posteriorly; gastral dorsum smooth and shining.

Scape with abundant subdecumbent pubescence; clypeus and frontal carinae with long erect setae; posterior and posterolateral margins of head with long erect setae; mid and hind tibia with abundant subdecumbent pilosity but lacking any differentiated erect setae; in profile, dorsal surfaces of head, mesosoma, and gaster with relatively short, dense subdecumbent to suberect setae; FSH about 0.04–0.06, FSI 0.07–0.11 (n=3).

Color dark brown to black.

Queen
Similar to worker except for queen-specific characters of large compound eyes, ocelli, and enlarged mesosoma with queen-typical sclerites; pronotum smooth medially, laterally with a few faint rugulae; dorsal mesonotum completely smooth and shining; scutellum smooth and shining medially, longitudinally rugose laterally; katepisternum smooth and shining; anepisternum smooth ventrally, longitudinally rugose dorsally; side of propodeum longitudinally rugose.

Type Material
Holotype worker. Costa Rica, Alajuela: 4km ENE Monteverde, 10.31716 −84.7761 ±10 m, 1675 m, 23 Dec 2010 (J. Longino#7220) [CAS, unique specimen identifier CASENT0618512]. Paratypes (workers): same data as holotype [BMNH, CASENT0627886], [EAPZ, CASENT0627887], [ECOSCE, CASENT0627888], [ICN, CASENT0627890], [INBIO, CASENT0627891], [LACM, CASENT0627894], [MCZC, CASENT0627883], [MZSP, CASENT0627884], [UCD, CASENT0627889], [UNAM, CASENT0627892], [USNM, CASENT0627885], [UVGC, CASENT0627893]

Etymology
Two mirrors, referring to the shiny patches on the face.