Leptogenys paraensis

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

Leptogenys paraense P.jpg

Leptogenys paraense D.jpg

Specimen Label

Nothing is known about the biology of Leptogenys paraensis.

Identification

Lattke (2011) - Eyes large and bulging, occupying one-third of cephalic lateral margin; hypostomal tooth almost as long as basal mandibular width; mandible elongate slightly sinusoidal, flattened, widening apicad; head, mesosoma, and petiole black; gaster ferruginous brown; petiolar node with an acutely pointed posterior spine.

A member of the unistimulosa species group. L. paraense is very similar in appearance to Leptogenys unistimulosa, including the color pattern, but differs in the apically widening mandibles, and slightly larger average size. The striae on the posterior nodal face of L. paraense are more developed than in L. unstimulosa but the small specimen base makes this an uncertain diagnostic character.

Male Diagnosis

Uniquely identified among the unistimulosa species complex by its comparatively large body size (WL > 3.00 mm; HW > 1.40 mm) (Tozetto et al., 2022).

Recognized by the following conditions:

  1. body size very large (WL > 3.00 mm; HW > 1.40 mm)
  2. ocelli large but not grossly so, with the distance between compound eye and lateral ocellus in full face view somewhat > 1 lateral ocellus width
  3. ocelli close to or slightly surpassing posterior head margin in full face view
  4. compound eyes not grossly enlarged, distance between them slightly less than one eye length in full-face view
  5. scape robust, about 1.5–2x pedicel length, and slightly longer than clypeal length
  6. mesoscutum longer than broad
  7. mesoscutum distinctly sculptured posterad of notauli
  8. vein M+Cu-f1 one third Cu-f2 length
  9. 2r-rs longer than Rs-f4
  10. petiolar node without bulge anterad of posterodorsal corner
  11. abdominal sternites IV–VIII (gastral II–VI) sparsely hairy, without appearance of dense shaggy pads

Described by Lattke (2011), L. paraensis was known only from four workers from Pará, Brazil. Recently six workers were collected in the Nouragues Natural Reserve in French Guiana, about 780 km northwest of the type locality and 77 km southwest from Saül, where males were collected. This geographic proximity and the large size of the males support their identification as L. paraensis. As in the workers, the males of L. parensis males are much larger (WL > 3.2 mm) compared with the other males of the group, and the eye is not as bulging as in Leptogenys unistimulosa and Leptogenys elzasoares. The L. paraensis males also differ from the other two species by their robust scape and sometimes sculpted mesoscutum. However, they vary in eye size: in the French Guiana specimens the distance between the compound eye and lateral ocellus is more than the width of the medial ocellus, while in the Brazilian specimens the distance is about the same. Another difference is in the mesoscutal sculpture, in specimen DZUP 550880 it is transversely striate, while in other specimens the mesonotum is smooth with punctures. This species has a subtriangular petiole, but the summit in DZUP 550880 is rounded, while it is truncate or pointed in the other specimens studied.

Keys including this Species

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -1.7525° to -1.7525°.

 
North
Temperate
North
Subtropical
Tropical South
Subtropical
South
Temperate

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality), French Guiana.

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.
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Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.
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Biology

Explore-icon.png Explore Overview of Leptogenys biology 
The biology of Leptogenys paraensis 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 Online Catalogue of the Ants of the World.

  • paraensis. Leptogenys paraense Lattke, 2011: 215, fig. 71 (w.) BRAZIL.

Type Material

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 (other specimens, n = 4): HL 1.75 (1.70–1.80); HW 1.85 (1.80–1.90); ML 1.45 (1.45 – 1.55); EL 0.55 (0.50 – 0.50); SL 2.40 (2.40 – 2.45); PW 1.25 (1.20–1.25); WL 3.40 (3.35–3.45); PH 1.55 (1.55–1.60); PL 1.00 (1.00–1.00); DPW 0.70 (0.70– 0.75) mm. CI 1.06 (1.03–1.12); MI 0.78 (0.76–0.83); OI 0.30 (0.26–0.28); SI 1.30 (1.29–1.33); LPI 1.55 (1.55 – 1.60); DPI 0.70 (0.70 – 0.75).

Head in full-face view wider anterad than posterad, posterior margin convex, lateral margin broadly convex, almost straight, lateral cephalic margin interrupted by compound eye. Median clypeal lobe shaped as broad triangular lobe, 4 setae on apex; lateral clypeal lobe rounded, not wider than one-third median clypeal width, gradually narrowing laterad. Clypeus posteriorly bordered by transverse sulcus running from antennal sclerite to just below eye. Cephalic dorsum mostly rugose; head ventrad of eyes strigulose. Scape surpassing posterior cephalic border by almost one-half its length, punctulate with decumbent pilosity and decumbent hairs; second and fourth antennal segments subequal in length, each two-thirds as long as length of third antennal segment. Mandibles elongate, and slender, slightly sinusoidal and crossing only at apex; flattened and widening apicad, becoming slender close to apex, apical half convex, dorsum smooth and shining with sparse punctulae; a small pre-apical denticle present. Hypostomal tooth shaped as curved triangular lobe, almost as long as basal mandibular width. PF: 4,4.

Mesosoma with broadly convex promesonotal margin in lateral view, mesonotum can form distinct convexity, separate from broadly convex propodeal margin. Propodeal declivity curved, with 3 – 6 transverse carinae, no teeth. Lateral pronotum longitudinally strigulose, pronotal dorsum strigulose-punctuate; strigae arching around pronotum; mesonotum transversely strigose; propodeal spiracle elongate, facing posteriorly. Metapleural-propodeal suture well-defined but shallow, mesometapleural suture well marked, scrobiculate. Ridge separates mesopleuron from mesosternum; mesosternal sculpture mostly effaced. Meso-, metapleuron and lateral propodeal face with oblique strigulae, colliculate microsculpturing present especially on meso- and metapleuron. Mesosternal lobe broadly triangular, metasternal lobe with rounded external margin, basal margin straight; lobe leans medially.

Petiole with convex anterior margin, and straight ascending dorsal margin in lateral view, both margins joined by convexity. Node apex with acutely sharp point that overhangs mostly convex posterior margin in lateral view. Node with anterior margin almost as wide as posterior margin in dorsal view, node length greater than width, excluding posterior spine. Node longitudinally strigose laterally; posterior face with transverse strigae. Postpetiole with vertical anterior margin that becomes convex dorsad in lateral view, constriction not strongly marked; gaster mostly smooth and shining with sparse piligerous punctae. Head, mesosoma, and node black; antennae, mandibles, and legs brown to dark brown; gaster ferruginous brown to brown. Body with abundant standing and decumbent hairs.

Etymology

The species name alludes to the Brazilian state of Pará, which contains the type locality.

References