Leptogenys erugata

Lattke (2011) - Nests have been found in humid forested sites, including shade cocoa plantations, at ground level in rotting wood such as branches or logs. They are found from almost sea level to 1200 m above sea level. Specimens have also been taken in leaf litter samples. Reaction upon disturbance to the nest is to run and hide in surrounding litter.

Identification
Lattke (2011) - Eye laterally placed, relatively flattened, separated from mandibular insertion by one diameter; mandible mostly parallel-sided but slightly widening apicad, dorsum smooth and shining, sparsely punctate; cephalic dorsum mostly smooth and shining with sparse piligerous punctulae. Scape smooth with abundant piligerous punctulae, surpasses posterior cephalic border by less than one-third its length.

A member of the quiriguana species group. This species can be confused with the Central American species Leptogenys quiriguana, which has distinct triangular denticles on the propodeum in contrast to the unarmed propodeum of L. erugata. Examined samples of L. erugata from Colombia differ from the Venezuelan samples in a scape with pilosity of uniform length, slightly more punctae on the cephalic dorsum, and the promesonotal margin more flattened in lateral view. L. erugata from Falcón, Venezuela (both localities in the humid Serranía de San Luis) have the propodeal spiracle rounded and laterally placed on the mesosoma, but other populations tend to have the spiracle oval and facing posterolaterally, with the cuticle posterad of the spiracle indented.

Distribution
Known from northern Colombia and northern Venezuela.

Distribution based on Regional Taxon Lists
Neotropical Region: Colombia, Venezuela.

Castes
Male unknown.

Nomenclature

 *  erugata. Leptogenys erugata Lattke, 2011: 202, fig. 58 (w.q.) VENEZUELA.

Worker
Metrics, holotype (other specimens, n = 4): HL 1.11 (1.06 – 1.16); HW 0.78 (0.76 – 0.83); ML 0.58 (0.56 – 0.61); EL 0.15 (0.15–0.15); SL 0.99 (0.94–1.01); PW 0.63 (0.63 – 0.68); WL 1.67 (1.57 – 1.72); PH 0.71 (0.63 – 0.73); PL 0.58 (0.56–0.61); DPW 0.51 (0.48–0.51) mm. CI 0.70 (0.69 – 0.72); MI 0.74 (0.71 – 0.73); OI 0.19 (0.18 – 0.20); SI 1.26 (1.21 – 1.26); LPI 1.22 (1.14 – 1.22); DPI 0.87 (0.83–0.91).

Head subrectangular in full-face view; wider anterad than posterad; both posterior and lateral margins broadly convex, almost straight; vertexal carinae narrow, but visible throughout most of posterior cephalic margin; eye laterally placed, relatively flattened, diameter less than one-fourth lateral cephalic margin, separated from mandibular insertion by one diameter; anterior clypeal margin with broadly triangular median lobe, apex bluntly pointed; lateral clypeal lobe narrow; clypeus laterally smooth, medially with longitudinal strigae. Scape smooth with abundant piligerous punctulae, surpassing posterior cephalic border by less than one-third its length; second and third antennal segments approximately same length; fourth antennal segment shorter, more than half the length of segment three. Mandible shuts tight against clypeus, elongate, mostly parallel-sided but slightly widening apicad; mandibular dorsum smooth and shining, sparsely punctate; cephalic dorsum mostly smooth and shining with sparse piligerous punctulae. PF: 4,3.

Mesosoma with two very broad convexities in lateral view; promesonotum forms continuous convexity, posterior one-fourth of mesonotum drops abruptly into promesonotal suture; dorsal propodeal margin weakly convex, almost straight; dorsal propodeal margin almost 2 × length of declivitous margin. Mesosoma mostly smooth and shining; mesonotum wider than long. Cervix with transverse striae; mesonotum wider than long in dorsal view; prosternal process with posterior minute denticle in lateral view. Mesometapleural suture well impressed, scrobiculate; metapleural propodeal suture wanting; propodeal spiracle small, rounded to oval, laterally to posterolaterally facing; mesopleuron with anterior crest, widening anterad close to pronotum; propodeum unarmed.

Petiole subquadrate in lateral view; dorsal margin convex, highest posterad; posterior margin straight to very broadly convex; triangular ventral tooth present; anterior margin slightly less than half as long as posterior margin in dorsal view; node and gaster smooth and shining. Node subquadrate in dorsal view; anterior margin convex, more than half as wide as posterior margin, posterior margin straight medially to convex laterally; procoxa smooth and shining in lateral view; stridulitrum present. Pygidium with or without brief longitudinal crest. Head, thorax, and most of abdomen dark brown to almost black; antenna and mandible brown; legs and apical gastral segments ferruginous brown. Body with sparse short standing hairs, no appressed pilosity; scape with abundant decumbent pilosity and hairs.

Queen
Lighter colored than worker, mostly ferruginous brown; dorsal propodeal margin more convex in lateral view; node compressed in lateral and dorsal views.

Type Material
Holotype worker. Venezuela, Falcón, 2 km ESE Curimagua, 11°10′N 69°35′W, 1150 m, 19.vii.1993, J. Lattke 1513. One worker deposited in. – Paratypes. From the same nest as the holotype: 1w, 1w , 1w 1q MIZA.

Etymology
The species name alludes to the smooth integument of this species. It is derived from the Latin, erugatus, for smooth.

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
 * Rodriguez E. R., and J. E. Lattke. 2012. Diversidad de hormigas en un gradiente altitudinal de la cordillera de la Costa, Venezuela. Boletín de la Sociedad Entomológica Aragonesa (S.E.A.) 50: 295?304.