Leptogenys montuosa

Longino reports collecting a nest from beach strand vegetation at Tortuguero in a rotten branch attached to a tree close to ground level. Isopod remains were found within the nest.

Identification
Lattke (2011) - A member of the arcuata species group. Eye convex and large, spanning almost one-third lateral cephalic margin, dorso-laterally situated. Cephalic dorsum punctate, hypostomal tooth visible in cephalic full-face view, scape with suberect hairs, propleuron striate; propodeal dorsum punctate, declivity transversely striate.

Distribution
Known from Costa Rica and Panama.

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

Castes
Queens and males are unknown.

Nomenclature

 *  montuosa. Leptogenys montuosa Lattke, 2011: 150, fig. 8 (w.) PANAMA.

The head sculpture in L. montuosa varies from densely punctate (specimens from Central and NW Costa Rica) to sparsely punctate, and almost smooth posterad, with punctae limited mostly between and anterad of the compound eyes (specimens from Panama and NE Costa Rica). The Guanacaste specimens have more regular striae on the pleura and lateral propodeum than the other specimens. The single La Selva specimen is the largest of all, with rougher sculpturing and a broader head anterad than the other specimens. It was not taken into account for the above description and was labeled as Leptogenys cf. montuosa. The only other arcuata group species possibly sympatric with L. montuosa is Leptogenys donisthorpei and for differences between them the reader should refer to the Comments for L. donisthorpei. Leptogenys arcuata is smaller than L. montuosa with a mostly smooth cephalic dorsum, except for sparse piligerous punctulae; the propodeal dorsum in L. arcuata is mostly smooth, whilst in L. montuosa it has shallow but quite distinct punctures. L. arcuata lacks the presence of appressed pubescence on the cephalic dorsum as in L. montuosa. This species was recognised as JTL-004 (cf. donisthorpei) by Lattke & Longino (2009) in the Ants of Costa Rica website.

Worker
Metrics, holotype (paratypes, n = 4): HL 1.24 (1.11-1.27); HW 1.04 (0.99-1.09); ML 0.89 (0.76-0.91); EL 0.28 (0.25-0.30); SL 1.29 (1.16-1.34); PW 0.81 (0.71-0.83); WL 2.15 (1.80-2.13); PH 0.81 (0.71-0.81); PL 0.61 (0.53-0.66); DPW 0.56 (0.48-0.58) mm. CI 0.84 (0.86-0.89); MI 0.85 (0.77-0.84); OI 0.27 (0.26-0.28); SI 1.24 (1.17-1.23); LPI 1.33 (1.23-1.33); DPI 0.92 (0.88-0.92).

Head sub-rectangular in full-face view, longer than wide; lateral margins broadly curved and diverging anterad; posterior margin convex, slightly flattened medially. Eye convex and large, spanning almost one-third lateral cephalic margin. Cephalic dorsum ranging from densely punctate to sparsely punctate posterad with punctae limited to between and anterad compound eyes; fine longitudinal striae present between eye and clypeus. Scape with abundant piligerous punctae, surpassing posterior cephalic margin by more than one-fourth its length; length of antennal segments III and IV more than 2 x their respective widths. Anterior clypeal margin laterally sinusoid, medially straight to slightly convex, median process about as long as wide, margins opaque to weakly translucent, apex with 4 – 3 setae. Mandible slightly arched, parallel-sided with brief and weakly concave edentate masticatory margin, basal angle usually with denticle; mandible leaves gap between clypeus when closed, at widest more than twice the mandibular width. Scape has abundant subdecumbent hairs and decumbent pilosity. Hypostomal tooth visible in cephalic full-face view.

Mesosoma with prominent metanotal groove dividing dorsal margin in two large convexities in lateral view: promesonotum, and metanotum-propodeum. Pronotum mostly smooth and shining with some transverse rugulae on pronotal collar, and scattered punctae; propleuron striate. Mesometapleural suture well impressed. Mesopleuron varies from mostly smooth and shining with transverse striae along ventral area to mostly striate with smoother dorsomedian area; metapleural-propodeal suture well impressed. Mesonotum oval in dorsal view, smooth and shining; metanotal groove scrobiculate. Metapleuron and propodeal side rugulose, propodeal dorsum with scattered shallow punctae, declivity transversely striate; spiracle opening directed posterolaterally.

Node with anterior and posterior margins joined by convexity in lateral view; anterior margin shorter than posterior margin, dorsal margin meets posterior margin in abrupt angle; posterior margin weakly convex. Node laterally rugose; posterior face flattened, smooth and shining, distinctly separated from rest of node. Node as wide as long in dorsal view, widest posterad. Gaster smooth and shining with sparse punctulae. Head, mesosoma and abdomen black; clypeus, mandibles, antennae, and legs dark brown.

Type Material
Holotype worker. Costa Rica, Limón, Tortuguero, < 100 m, 10°35′N 83°31′W, 1. – 5.vii.1985, J. Longino 386. Deposited in the. The same pin bears two point-mounted workers, with the top worker designated as holotype. – Paratypes. Three workers with the same locality data as the holotype. One worker is on the same pin as the holotype and the two are on a single pin. All deposited in the LACM.

Etymology
The species name alludes to the name of Cerro Montuoso in Panama, a locality from which L. montuosa has been recorded.

References based on Global Ant Biodiversity Informatics

 * Lattke J. E. 2011. Revision of the New World species of the genus Leptogenys Roger (Insecta: Hymenoptera: Formicidae: Ponerinae). Arthropod Systematics and Phylogeny 69: 127-264