Leptogenys rasila

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Leptogenys rasila
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Ponerinae
Tribe: Ponerini
Genus: Leptogenys
Species: L. rasila
Binomial name
Leptogenys rasila
Lattke, 2011

Leptogenys rasila P.jpg

Leptogenys rasila D.jpg

Specimen Label

Nothing is known about the biology of Leptogenys rasila.

Identification

Lattke (2011) - Head in full-face view elongate, subrectagular, lateral margin broadly convex; head widest just posterad of eyes; mesonotum 3 × wider than long in dorsal view; node in dorsal view longer than wide, anterior face straight to weakly convex, half as wide as posterior margin; lateral margin weakly concave; anterodorsal margin of abdominal segment III forms more or less continuous convexity in lateral view.

A member of the pusilla species group. This species can be confused with Leptogenys iheringi, but L. iheringi is smaller, has a more elongate petiolar node as seen from above, the mesonotum is not as transverse (width not quite twice its length), the eye length is more than one-fourth the lateral cephalic margin when seen in cephalic full-face view, and the mesopleural carina is poorly developed or effaced. The distribution ranges of the two species are also quite disjunct, with L. iheringi only known from SE Brazil.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Ecuador (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

The biology of Leptogenys rasila is poorly known.

The Leptogenys genus page has more details about the general biology of ants in this genus, some of which is summarized in what follows. New World species have relatively small ranges, generally occur in humid forests and prey on isopods. Colonies may occur in high densities on a local scale, with up to 5 or 6 species present. Nest size tends to be small with just 20 or 30 individuals in a mature colony. Nests of most species may be found in rotten wood on the ground, usually within cavities in logs or large branches, and also beneath bark. Wood-soil and rock-soil interfaces are another common nesting location, as well as rock crevices, and a few species may nest directly in the soil. Reproduction is most commonly via ergatoid females and, in many species, may include egg-laying workers.

Castes

Queens and males are unknown.

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • rasila. Leptogenys rasila Lattke, 2011: 197, fig. 51 (w.) ECUADOR.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Metrics, holotype (paratypes, n = 2): HL 1.00 (0.96–0.98); HW 0.60 (0.60–0.60); ML 0.44 (0.42– 0.44); EL 0.16 (0.14–0.14); SL 0.96 (0.94–0.96); PW 0.54 (0.54 – 0.56); WL 1.50 (1.50 – 1.50); PH 0.56 (0.54 – 0.54); PL 0.56 (0.58 – 0.60); DPW 0.36 (0.36 – 0.36) mm. CI 0.60 (0.61 – 0.63); MI 0.73 (0.70 – 0.73); OI 0.27 (0.23 – 0.23); SI 1.60 (1.57–1.60); LPI 1.00 (0.90–0.93); DPI 0.64 ( 0.60 – 0.62).

Head in full-face view elongate, sides sub-parallel, lateral margin broadly convex; head widest just posterad of eyes; posterior margin weakly convex; median clypeal lobe triangular with acute apex, uniformly tapering, no apical setae; cephalic dorsum mostly smooth and shining with sparse punctulae; eyes weakly convex, closer to cephalic capsule mid-length than to mandibular insertion, dorsolaterally situated on head, diameter less than one-fourth lateral cephalic margin. Mandible shuts tight against clypeus; elongate, basal and external margin mostly parallel; masticatory border edentate, basal angle sometimes with small denticle; dorsal mandibular surface smooth and shining with sparse punctae. Clypeus with oblique striae close to antennal fossa, some piligerous tubercles present close to median carina, laterally mostly smooth. Scape smooth and shining with abundant piligerous punctulae, surpasses posterior cephalic border by more than one-fourth its length; frontal lobe covers less than half of condyle; basal funicular segments cylindrical with weakly marked constrictions separating each segment; antennal segment III longer than either II or IV, length of segments II and III over twice respective width; segment IV twice longer than wide.

Mesosoma with shallow and broad metanotal groove in lateral view, separating convexities formed by promesonotum and propodeum. Anterodorsal pronotal margin convex, posterodorsal margin weakly convex; dorsal propodeal margin weakly convex to straight, curvature of propodeum stronger towards declivity; tooth low and rounded, dorsal margin jagged; mesosomal sides mostly smooth and shining except for fine, oblique striae along posteroventral corners; mesometapleural suture well impressed, scrobiculate, widens close to metathoracic spiracle; metapleural-propodeal suture absent; mesonotum 3 × wider than long, anterior margin convex, metanotal groove smooth; declivity with transverse strigulae; mesopleural carina well developed, weakly widening anterodorsad. Mesopleuron with few rugulae ventrally and rugulae around bulla; propodeal spiracle oval, posterodorsally facing. Propodeal declivity mostly with coarse transverse striae, broad smooth and shining transverse sulcus present next to petiolar insertion.

Petiolar node with highest point posterad in lateral view; anterior margin broadly convex, brief, anterodorsal long, weakly convex, inclined; posterior margin broadly curved; subpetiolar process subrectangular in lateral view, with anterior lobe smaller than posterior lobe. Node in dorsal view longer than wide, anterior face straight to weakly convex, half as wide as posterior margin; lateral margin weakly concave. Gaster smooth and shining with sparse piligerous punctulae; anterodorsal margin of abdominal segment III forms more or less continuous convexity in lateral view; constriction between abdominal segments III and IV well marked. Body mostly dark brown; mandibles, antennae, legs, and gastral apex slightly clearer; head, mesosoma, node, and gaster with scattered suberect to erect short hairs, no appressed pubescence; procoxa in lateral view smooth and shining; tibial apices lacking setae.

Type Material

Holotype worker. Ecuador, Pichincha, Centro Científico Río Palenque, 21.xii.1980, Sonia Sandoval. One worker deposited in Museu de Zoologia da Universidade de Sao Paulo. – Paratypes. Two workers on the same pin as the holotype also deposited in MZSP.

The type series are 3 point-mounted workers on same pin, the holotype being the top specimen, and the base of its point has been marked red.

References