Leptogenys bohlsi

Lenko (1966) observed workers of this species preying upon isopods.

Identification
Key to Leptogenys of the New World

Lattke (2011) - Eyes large and bulging, occupying one-third of cephalic lateral margin; hypostomal tooth triangular and almost as long as basal mandibular width; scape surpasses posterior cephalic margin by one-fourth to one-third its length; mandible arched, slender and elongate, of uniform width; head, mesosoma, and petiole black, gaster brown; petiolar node with apical tooth usually tapering to blunt point.

A member of the unistimulosa species group.

Distribution
Known from Paraguay, southern Brazil – northern Argentina.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Brazil, Paraguay.

Castes
Queens and males are unknown.

Nomenclature

 *  bohlsi. Leptogenys bohlsi Emery, 1896h: 627 (w.) PARAGUAY. Wheeler, G.C. & Wheeler, J. 1986c: 89 (l.). Senior synonym of weiseri: Lattke, 2011: 214.
 * weiseri. Leptogenys bohlsi st. weiseri Santschi, 1925e: 153, fig. 1 (w.) ARGENTINA. Junior synonym of bohlsi: Lattke, 2011: 214.

Lattke (2011) - Compared with Leptogenys unistimulosa, the head is weakly anteriorly divergent in L. bohlsi. The scape can be much longer in L. unistimulosa, but in L. bohlsi the scape surpasses the posterior cephalic margin by one-third to one-fourth its length, whilst in L. unistimulosa this distance is one-half the scape length. The petiolar tooth is usually bluntly pointed in L. bohlsi, but specimens with acutely pointed nodes are not infrequent. The ocular malar margin is usually convex but not bulging as in L. unistimulosa. Other aspects taken into account for separating the two species can be consulted in the discussion for L. unistimulosa. The Goiás specimens have a narrowed head but conserve an acutely pointed petiolar spine. The Fazenda Sta. Blanca series is smaller and has almost semiparallel lateral cephalic margins, with punctuation, no rugulae on the head, and the scape surpasses the posterior cephalic border by less than one-fourth its length. The Cuiaba samples are from a nest taken in campo cerrado close to a stream under bark near the base of a rotten stump. Santschi (1925) separated Leptogenys weiseri from L. bohlsi on account of lacking lateral clypeal lobes. The median clypeal lobe in L. weiseri type series is comparatively broader and does not meet the rest of the clypeus at an angle as in L. bohlsi. This diagnostic character is rendered useless by a nest series from São Paulo with individuals showing both clypeal shapes.

Worker
Lattke (2011) - Metrics (n =10): HL 1.21–1.35; HW 1.04– 1.18; ML 0.78 – 0.91; EL 0.28 – 0.41; SL 1.27 – 1.48; PW 0.78 – 0.86; WL 2.07 – 2.37; PH 0.96 – 1.06; PL 0.58 – 0.66; DPW 0.51–0.61 mm. CI 0.85–0.88; MI 0.76– 0.80; OI 0.25–0.32; SI 1.20–1.30; LPI 0.00–1.70; DPI 0.80 – 0.96.

Head longer than wide in full-face view, posterior margin convex, lateral margin broadly convex, wider anterad than posterad, weakly divergent anterad; eyes large occupying over fourth of lateral cephalic margin, vertexal carina visible; clypeus converges to bluntly triangular median lobe with 3–4 apical setae, more sometimes present. Clypeus with parallel converging striae; hypostomal teeth distinctly visible, triangular; cephalic dorsum ranging from mostly smooth and shining to rugulose-punctate; mandible slender, well separated from median clypeus and semi-parallel, only slightly widening towards apex, dorsum smooth and shining, masticatory border edentate except for pre-apical tooth and apical tooth. Deep sulcus present posterad of frontal lobes, extending to mid eye height. Cephalic dorsum punctuate to rugulose-punctate, punctae separated by distance equal their diameter, sparser posterad. Scape surpasses posterior cephalic border by one-fourth to one-third its length; first and third funicular segments each more than half length of second segment. Scape smooth to variolate, with abundant punctulae, appressed pubescence and decumbent pilosity.

Mesosoma with deep and abrupt metanotal groove in lateral view. Dorsal pronotal margin very broadly convex with metanotum ranging from not notably differentiated to distinct; dorsal propodeal margin broadly convex to straight, separated from declivity by blunt angle. Pronotal dorsum mostly smooth with scattered punctae, and low arching striae, both attenuated posterad. Lateral propodeum with longitudinal strigulae; mesometapleuron and most of lateral propodeal face with parallel oblique strigulae, becoming smooth dorsad. Mesometapleural suture broad and shallow; metapleural-propodeal suture weakly impressed. Mesopleural carina thickest anterad, gradually becoming finer ventrad; propodeal spiracle elongate, opening posterolaterally directed. Declivity with transverse strigulae, without lobes or teeth; propodeal dorsum with low transverse strigulae, more impressed anterad than posterad. Metanotal groove with few striae, not scrobiculate.

Petiole with convex anterior margin in lateral view, curving to straight dorsal margin that ends in blunt to acutely pointed tooth that projects beyond posterior margin almost one-fourth node length, tooth forms approximate 30 degree angle with longitudinal axis. Posterior margin not sinuate but slightly convex; sides with longitudinal to oblique striae; posterior face flat and sharply separated from lateral margin. Node longer than wide in dorsal view, with posterior tooth abruptly projecting from posterior margin; anterior face and anterodorsal median strip of node tends to smooth. Gaster smooth and shining; anterior postpetiolar margin convex in lateral view, broadly convex anterad, more curved dorsad. Mesosoma, node, and gaster with abundant decumbent, and semi-erect hairs; cephalic dorsum with appressed pilosity. Head, mesosoma, and node black; gaster, mandibles, antennae, and legs brown.

Type Material
Lattke (2011):

Syntype workers: Paraguay (J. Bohls) (MCSN) [examined].

Leptogenys bohlsi st. weiseri. Syntype workers: Argentina, Santa Fe, Fives Lille (Weiser) (MHNG) [examined].

The type series in Genova consists of 2 workers glued on their sides on cardboard, one specimen above the other on the same pin. The label reads: Paraguay, Bohls; Typus; Bohlsi n sp; MCSN.

Additional References

 * [[Media: Lattke 2011.pdf|Lattke, J.E. 2011. Revision of the New World species of the genus Leptogenys Roger (Insecta: Hymenoptera: Formicidae: Ponerinae). Arthropod Systematics & Phylogeny, 69, 127-264. PDF]]