Leptogenys bohlsi

Leptogenys bohlsi
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Ponerinae
Tribe:	Ponerini
Genus:	Leptogenys
Species group:	unistimulosa
Species:	L. bohlsi
Binomial name
Leptogenys bohlsi Emery, 1896 Specimen labels
Synonyms
Leptogenys bohlsi weiseri Santschi, 1925

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

Identification

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.

Male diagnosis

Uniquely identified among the unistimulosa species complex by the following conditions (Tozetto et al., 2022):

1. body size not very large (WL < 3.00 mm)
2. ocelli small, with the distance between compound eye and lateral ocellus in full face view somewhat more than two times longer than median or lateral ocellus width
3. ocelli close to but not surpassing posterior head margin in full face view
4. compound eyes not enlarged, with the distance between them about equal to one eye length in full-face view
5. scape no more than two times pedicel length and about the same length as clypeal length
6. mesoscutum about as long as broad
7. mesoscutum largely smooth
8. vein M+Cu-f1 reduced
9. 2r-rs shorter than Rs-f4
10. petiolar node without bulge anterad of posterodorsal corner
11. abdominal sternites AIII–VIII (gastral I–VI) sparsely pilose, without appearance of dense shaggy pads

The “small” ocelli and compound eyes are the most conspicuous combination diagnosing this species (chars 2–4).

The Leptogenys bohlsi male is associated with a worker; both ants were glued on their sides on the same cardstock. The male appears to have lost some or most of its pilosity. According to Borgmeier’s catalogue it was collected in 25.ii.33 [1933] Campinas, Goiás (Ulyssea, M. personal communication, July 2022). Although L. bohlsi workers can be similar to Leptogenys unistimulosa, the males can be easily differentiated. Even though L. bohlsi males are also smaller in size than L. unistimulosa males, the compound eyes are more widely spaced in L. bohlsi and not as bulging as in L. unistimulosa; the face (= frons) in L. bohlsi is at least three times wider than the eye maximum width in full-face view. The ocelli are smaller in L. bohlsi, with the distance between the lateral ocellus and eye greater than the maximum diameter of the median ocellus, but this varies among L. unistimulosa males. The scape in L. bohlsi is shorter than the clypeal length, while it is longer in L. unistimulosa.

Keys including this Species

• Key to New World Leptogenys
• Key to males of Leptogenys unistimulosa group

Distribution

Known from Paraguay, southern Brazil – northern Argentina.

Latitudinal Distribution Pattern

Latitudinal Range: -14.01666667° to -31.632389°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina, Brazil, Paraguay (type locality).

Distribution based on AntMaps

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.

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.

Biology

Explore Overview of Leptogenys biology  The biology of Leptogenys bohlsi 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.

• 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.

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

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.

Description

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.

References

• Albuquerque, E., Prado, L., Andrade-Silva, J., Siqueira, E., Sampaio, K., Alves, D., Brandão, C., Andrade, P., Feitosa, R., Koch, E., Delabie, J., Fernandes, I., Baccaro, F., Souza, J., Almeida, R., Silva, R. 2021. Ants of the State of Pará, Brazil: a historical and comprehensive dataset of a key biodiversity hotspot in the Amazon Basin. Zootaxa 5001, 1–83 (doi:10.11646/zootaxa.5001.1.1).
• Camargo, K.S. de. 2011. Composicao e diversidade de "Poneromorfas" (Hymenoptera, Formicidae) em duas fitofisionomias de cerrado e padroes de distribuicao de "Poneromorfas", Pseudomyrmecinae e Cephalotini (Myrmicinae) para o Brasil. Thesis, Universidade de Brasilia.
• Emery, C. 1896h. Formiciden, gesammelt in Paraguay von Dr. J. Bohls. Zool. Jahrb. Abt. Syst. Geogr. Biol. Tiere 9: 625-638 (page 627, worker described)
• 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.
• Tozetto, L., Chaul, J.C.M., Boudinot, B.E., Lattke, J.E. 2022. Review of the Leptogenys unistimulosa species group (Hymenoptera: Formicidae) with the description of a new Amazonian species. Revista Brasileira de Entomologia 66(3): e20220045 (doi:10.1590/1806-9665-rbent-2022-0045).
• Wheeler, G. C.; Wheeler, J. 1986c. Supplementary studies of ant larvae: Ponerinae. Trans. Am. Entomol. Soc. 112: 85-94 (page 89, larva described)

References based on Global Ant Biodiversity Informatics

• Cuezzo, F. 1998. Formicidae. Chapter 42 in Morrone J.J., and S. Coscaron (dirs) Biodiversidad de artropodos argentinos: una perspectiva biotaxonomica Ediciones Sur, La Plata. Pages 452-462.
• Fernández F., and T. M. Arias-Penna. 2008. Las hormigas cazadoras en la región Neotropical. Pp. 3-39 in: Jiménez, E.; Fernández, F.; Arias, T.M.; Lozano-Zambrano, F. H. (eds.) 2008. Sistemática, biogeografía y conservación de las hormigas cazadoras de Colombia. Bogotá: Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, xiv + 609 pp.
• Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
• Kempf W. W. 1978. A preliminary zoogeographical analysis of a regional ant fauna in Latin America. 114. Studia Entomologica 20: 43-62.
• Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
• Kusnezov N. 1978. Hormigas argentinas: clave para su identificación. Miscelánea. Instituto Miguel Lillo 61:1-147 + 28 pl.
• 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
• Pignalberi C. T. 1961. Contribución al conocimiento de los formícidos de la provincia de Santa Fé. Pp. 165-173 in: Comisión Investigación Científica; Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina) 1961. Actas y trabajos del primer Congreso Sudamericano de Zoología (La Plata, 12-24 octubre 1959). Tomo III. Buenos Aires: Librart, 276 pp.
• Santschi F. 1925. Fourmis des provinces argentines de Santa Fe, Catamarca, Santa Cruz, Córdoba et Los Andes. Comunicaciones del Museo Nacional de Historia Natural "Bernardino Rivadavia" 2: 149-168.
• Scott-Santos, C.P., F.A. Esteves, C.R.F. Brandao. 2008. Catalogue of "Poneromorph" ant type specimens (Hymenoptera, Formicidae) deposited in the Museu de Zoologia da Universidade de Sao Paulo, Brazil. Papeis Avulsos de Zoologia 48(11):75-88.
• Vittar, F. 2008. Hormigas (Hymenoptera: Formicidae) de la Mesopotamia Argentina. INSUGEO Miscelania 17(2):447-466
• Vittar, F., and F. Cuezzo. "Hormigas (Hymenoptera: Formicidae) de la provincia de Santa Fe, Argentina." Revista de la Sociedad Entomológica Argentina (versión On-line ISSN 1851-7471) 67, no. 1-2 (2008).
• Wild, A. L.. "A catalogue of the ants of Paraguay (Hymenoptera: Formicidae)." Zootaxa 1622 (2007): 1-55.