Dinoponera australis

This species has the smallest colonies (average of 14 workers) in the genus. Reproduction via gamergates, with the complete loss of the queen caste.

Identification
Lenhart et al. (2013) - Dinoponera australis is the most aberrant of the Dinoponera species because of its relatively small size, sparse non-flagellate pubescence, as well as the male characters (see below) which distinguish this species.

Worker. This species is most easily recognized by the antero-inferior corner of pronotum having a distinct tooth-like process, the pilosity being short and relatively sparse and the integument being finely micro-sculptured and dull. In addition the scape length is shorter than the head width and the total body length is under 30 mm. Dinoponera lucida could be confused with D. australis in that it also has a tooth-like process on the pronotum and can have a TBL under 30 mm, but differs in having the smooth and shiny integument, long flagellate hairs on lobe and forward slanting dorsal edge of petiole.

Male. Dinoponera australis males are recognized by their rounded head, with compound eyes, reduced ocelli and the posterior margin around the ocelli not protruding as in other species. This species is also characterized by the short, broad pygidial spine, volsella with tear-drop shaped basal lobe covered in minute teeth and aedeagus with a latero-apical fold, notches and teeth along ventral edge as shown in Fig.

Keys

 * Key to Dinoponera workers / Clave para la identificación de las obreras de Dinoponera / Chave para identificação de operários de Dinoponera
 * Key to Dinoponera males / Clave para la identificación de los machos conocidos de Dinoponera / Chave para identificação de machos de Dinoponera

Distribution
Dinoponera australis has the widest known range of the Dinoponera. This species is found in the department of Santa Cruz in Bolivia, southern Brazil in the states of Mato Grosso, Goias, Minas Gerais, São Paulo, Mato Grosso do Sul, Paraná, Santa Catarina and Rio Grande do Sul, eastern Paraguay in the departments of Itapúa, Alto Paraná and Guairá, as well as the province of Misiones in Argentina (Lenhart, Dash & Mackay, 2013).

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

Nomenclature

 *  australis. Dinoponera grandis subsp. australis Emery, 1901a: 48 (w.) PARAGUAY. Santschi, 1921g: 85 (m.). Raised to species: Borgmeier, 1937b: 227. Senior synonym of brevis: Kempf, 1971: 382. Current subspecies: nominal plus bucki, nigricolor.
 * brevis. Dinoponera australis var. brevis Borgmeier, 1937b: 227 (w.) PARAGUAY. [First available use of Dinoponera grandis subsp. australis var. brevis Santschi, 1929a: 416; unavailable name.] Junior synonym of australis: Kempf, 1971: 382.

Type Material
Lenhart et al. (2013) -Worker. BRAZIL: S. Paulo: Avanhandava [5 syntypes workers examined, ]; additional syntypes from PARAGUAY: Rio Apa, (leg.) Balzan, (leg.); ARGENTINA: Missiones, 1881, Berg (leg.), Giabibiri, Misiones, marzo 1884 G. Bove (leg.)

Worker
Lenhart et al. (2013) - (mm) (n=21) TBL: 23.42–29.31 (26.21); MDL: 3.59 – 4.31 (3.88); HL: 4.51–5.64 (4.99); HW: 4.31–5.74 (4.89); SL: 4.31–5.02 (4.73); WL: 6.25–7.69 (7.12); PL: 1.79–2.26 (2.03); PH: 2.56–3.28 (2.90); PW: 1.59–1.95 (1.75); GL: 7.28–9.64 (8.20); HFL: 5.54–6.66 (6.16).

A description of the external morphology of the worker is given by Kempf (1971): “Antennal scape length equal to, or shorter than head width. Pubescence on front of head short and inconspicuous. Gular face of head subopaque, finely reticulate-punctate throughout; the fine, arcuate striae variably developed from completely covering the undersurface of head to only vestigially shown antero-laterally or nearly absent. Sides of head reticulate-punctate, subopaque. Antero-inferior corner of pronotum dentate. Pronotal disc superficially reticulate and quite shining; paired swellings either feeble or distinct. Length of hind tibia equal to or less than head length. Petiole, in dorsal view, subquadrate, width over length proportion always more than 0.80, notably shorter and broader than in the other species; its shape…resembling that of mutica, with the upper anterior and posterior corners equally rounded; finely reticulate, somewhat shining; vertical sulcus on posterior surface either absent of more rarely vestigial to feebly developed. Terga I and II of gaster either reticulate-punctate or more superficially reticulate (in the southern range of the territory) and accordingly either subopaque or somewhat shining: fine appressed pubescence lacking completely on disc of the terga, present on the sides. Stridulatory file on acrotergite of tergum II of gaster well developed, broad and triangular, extending back to the acrotergite for about one half to two thirds of its length.”

Male
Lenhart et al. (2013) - A description of the external morphology of the male is given in Kempf (1971): “Head…with smaller eyes, the maximum interocular width being greater than their diameter; with smaller ocelli not protruding above the posterior border of head when seen in full-face view; antennal scape very short, less than twice as long as broad; funiculi without standing hairs; petiole distinctly shorter although variable in outline…; pygidium with a very short spine, not projecting beyond the long cerci; hypopygidium apically broadly truncate, the truncation either straight, or convex, or concave.”

Genitalia. Basal ring with thick dorso-anterior loop structures, reduced; parameres short, broad, rounded, small lobe on dorsal edge, emarginated ventro-basal edge; cuspis volsellaris with few bumps or teeth, digitus volsellaris with numerous small circular bumps at distal lateral face, tuft of setae on ventro-distal side of broad cusp, large tear-shaped lobe on basal ventral corner, covered in minute teeth; penis valve of aedeagus with lateral arm of apodeme at anterior border, no ventral concavity under ridge at base of apodeme, dorsal edge rounded, sloping posteriorly, ventro-anterior triangular projection followed by circular notch, ventral projecting tooth, smaller hemispherical notch with sclerotized border, thin, finely serrated distal edge, noticeable lateral apical fold with slight serration ending ventrally in serrated ridge, rounded un-serrated lobe at distal apex of valve.

See also Tozetto & Lattke (2020).

References based on Global Ant Biodiversity Informatics

 * Billen J. P. J., C. R. F. Brandão, and R. V. S. Paiva. 1995. Morphology and ultrastructure of the pygidial gland of the ant Dinoponera australis (Hymenoptera, Formicidae). Papeis Avulsos de Zoologia (São Paulo) 39: 209-216.
 * Borgmeier T. 1923. Catalogo systematico e synonymico das formigas do Brasil. 1 parte. Subfam. Dorylinae, Cerapachyinae, Ponerinae, Dolichoderinae. Archivos do Museu Nacional (Rio de Janeiro) 24: 33-103.
 * Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
 * Bruch C. 1914. Catálogo sistemático de los formícidos argentinos. Revista del Museo de La Plata 19: 211-234.
 * Caldart V. M., S. Iop, J. A. Lutinski, and F. R. Mello Garcia. 2012. Ants diversity (Hymenoptera, Formicidae) of the urban perimeter of Chapecó county, Santa Catarina, Brazil. Revista Brasileira de Zoociências 14 (1, 2, 3): 81-94.
 * Christianini A. V., A. J. Mayhé-Nunes, and P. S. Oliveira. 2012. Exploitation of Fallen Diaspores By Ants: Are There Ant-Plant Partner Choices? Biotropica 44: 360-367.
 * Christianini A. V., and P. S. Oliveira. 2013. Edge effects decrease ant-derived benefits to seedlings in a neotropical savanna. Arthropod-Plant Interactions 7: 191-199.
 * 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.
 * Emery C. 1901. Notes sur les sous-familles des Dorylines et Ponérines (Famille des Formicides). Annales de la Société Entomologique de Belgique 45: 32-54.
 * Emery C. 1911. Hymenoptera. Fam. Formicidae. Subfam. Ponerinae. Genera Insectorum 118: 1-125.
 * Favretto M. A., E. Bortolon dos Santos, and C. J. Geuster. 2013. Entomofauna from West of Santa Catarina State, South of Brazil. EntomoBrasilis 6 (1): 42-63.
 * 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.
 * Gallardo A. 1918. Las hormigas de la República Argentina. Subfamilia Ponerinas. Anales del Museo Nacional de Historia Natural de Buenos Aires 30: 1-112.
 * Ilha C., J. A. Lutinski, D. Von Muller Pereira, F. R. Mello Garcia. 2009. Riqueza de formigas (Hymenoptera: Formicidae) de Bacia da Sanga Caramuru, municipio de Chapeco-SC. Biotemas 22(4): 95-105.
 * Kempf W. W. 1971. A preliminary review of the ponerine ant genus Dinoponera Roger (Hymenoptera: Formicidae). Studia Entomologica 14: 369-394.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Kusnezov N. 1956. Claves para la identificación de las hormigas de la fauna argentina. Idia 104-105: 1-56.
 * Lenhart, P. A.; Dash, S. T.; and Mackay, W. P. 2013. A revision of the giant Amazonian ants of the genus Dinoponera (Hymenoptera, Formicidae). Journal of Hymenoptera Research 31: 119-164
 * Lutinski J. A., B. C. Lopes, and A. B. B.de Morais. 2013. Diversidade de formigas urbanas (Hymenoptera: Formicidae) de dez cidades do sul do Brasil. Biota Neotrop. 13(3): 332-342.
 * Lutinski J. A., F. R. Mello Garcia, C. J. Lutinska, and S. Iop. 2008. Ants diversity in Floresta Nacional de Chapecó in Santa Catarina State, Brazil. Ciência Rural, Santa Maria 38(7): 1810-1816.
 * Maravalhas J., and H. L. Vasconcelos. 2014. Revisiting the pyrodiversitybiodiversity hypothesis: long-term fire regimes and the structure of ant communities in a Neotropical savanna hotspot. Journal of Applied Ecology 51: 1661-1668.
 * Monnin, R., F.L.W. Ratnieks and C.R.F. Brandao. 2003. Reproductive Conflict in Animal Societies: Hierarchy Length Increases with Colony Size in Queenless Ponerine Ants. Behavioral Ecology and Sociobiology 54(1):71-79
 * Paiva R. V. S., and C. R. F. Brandão. 1995. Nests, worker population, and reproductive status of workers, in the giant queenless ponerine ant Dinoponera Roger (Hymenoptera Formicidae). Ethology Ecology and Evolution 7:297-312.
 * Ribas C. R., J. H. Schoereder, M. Pic, and S. M. Soares. 2003. Tree heterogeneity, resource availability, and larger scale processes regulating arboreal ant species richness. Austral Ecology 28(3): 305-314.
 * Rosa da Silva R. 1999. Formigas (Hymenoptera: Formicidae) do oeste de Santa Catarina: historico das coletas e lista atualizada das especies do Estado de Santa Catarina. Biotemas 12(2): 75-100.
 * Santoandre S., J. Filloy, G. A. Zurita, and M. I. Bellocq. 2019. Ant taxonomic and functional diversity show differential response to plantation age in two contrasting biomes. Forest Ecology and Management 437: 304-313.
 * Santos I. S., J. H. C. Delabie, J. G. Silva, M. A. Costa, L. A. C. Barros, S. G. Pompolo, and C. S. F. Mariano. 2012. Karyotype differentiation among four Dinoponera (Formicidae: Ponerinae) species. Florida Entomologist 95(3): 737-742.
 * Santschi F. 1912. Quelques fourmis de l'Amérique australe. Revue Suisse de Zoologie 20: 519-534.
 * Santschi F. 1921. Ponerinae, Dorylinae et quelques autres formicides néotropiques. Bulletin de la Société Vaudoise des Sciences Naturelles 54: 81-103.
 * Santschi F. 1929. Sur quelques nouvelles fourmis du Brésil (Hym. Form.). Deutsche Entomologische Zeitschrift 1928: 414-416.
 * Ulyssea M.A., C. E. Cereto, F. B. Rosumek, R. R. Silva, and B. C. Lopes. 2011. Updated list of ant species (Hymenoptera, Formicidae) recorded in Santa Catarina State, southern Brazil, with a discussion of research advances and priorities. Revista Brasileira de Entomologia 55(4): 603-611.
 * Vittar, F. 2008. Hormigas (Hymenoptera: Formicidae) de la Mesopotamia Argentina. INSUGEO Miscelania 17(2):447-466
 * Wild, A. L.. "A catalogue of the ants of Paraguay (Hymenoptera: Formicidae)." Zootaxa 1622 (2007): 1-55.
 * Zolessi L. C. de, Y. P. Abenante, and M. E. de Philippi. 1988. Lista sistematica de las especies de Formicidos del Uruguay. Comun. Zool. Mus. Hist. Nat. Montev. 11: 1-9.
 * Zolessi L. C. de; Y. P. de Abenante, and M. E. Philippi. 1989. Catálogo sistemático de las especies de Formícidos del Uruguay (Hymenoptera: Formicidae). Montevideo: ORCYT Unesco, 40 + ix pp.
 * da Silva, R.R., C.R.F. Brandao, and R. Silvestre. 2004. Similarity Between Cerrado Localities in Central and Southeastern Brazil Based on the Dry Season Bait Visitors Ant Fauna. Studies on Neotropical Fauna and Environment 39(3):191-199.