Dinoponera australis Emery

Lenhart, Paul A., Dash, Shawn T. & Mackay, William P., 2013, A revision of the giant Amazonian ants of the genus Dinoponera (Hymenoptera, Formicidae), Journal of Hymenoptera Research 31, pp. 119-164 : 133-136

Dinoponera australis Emery Figs 4E, J, O , 5D , 9D , 10D , 11D , 13

Dinoponera grandis subsp. australis Emery, 1901: 48, worker, BRAZIL: S. Paulo: Avanhandava [5 syntypes workers examined, MCSN]; additional syntypes from PARAGUAY: Rio Apa, (leg.) Balzan, (leg.); ARGENTINA: Missiones, 1881, Berg (leg.), Giabibiri, Misiones, marzo 1884 G. Bove (leg.); Santschi, 1921: 85 (male); raised to species, Borgmeier, 1937: 227.

Dinoponera grandis subsp. australis var. brevis Santschi, 1928: 416 , PARAGUAY: Reichensperger (leg.) [type worker examined, NHMB]. Unavailable name, junior synonym of Dinoponera brevis : Kempf, 1971: 387.

Subspecies.

Dinoponera australis bucki Borgmeier, 1937:228. BRAZIL: Rio Grande do Sul: Palmeira [types not available].

Dinoponera australis nigricolor Borgmeier, 1937:228. BRAZIL: Goyaz: Campinas [types not available].

Worker diagnosis.

This species is most easily recognized by the antero-inferior corner of pronotum having a distinct tooth-like process ( Fig. 1D ), the pilosity being short and relatively sparse and the integument being finely micro-sculptured and dull ( Fig. 12B ). 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 Dinoponera 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.

Description of the worker.

Measurements (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 diagnosis.

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 ( Fig. 4E ). This species is also characterized by the short, broad pygidial spine ( Fig. 4O ), volsella with tear-drop shaped basal lobe covered in minute teeth ( Fig. 10D ) and aedeagus with a latero-apical fold, notches and teeth along ventral edge as shown in Fig. 11D .

Description of the male.

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."

Description of the male genitalia.

Basal ring with thick dorso-anterior loop structures, reduced; parameres short, broad, rounded, small lobe on dorsal edge, emarginated ventro-basal edge ( Fig. 9D ); 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 ( Fig. 10D ); 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.

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 ( Fig. 13 ).

Discussion.

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 stated above which distinguish this species. The male coloration difference is the basis for the designation of the subspecies Dinoponera australis bucki and Dinoponera australis nigricolor . These may be separate species or the product of intra-specific variation, but this cannot be diagnosed here as the types designated by Borgmeier (1937) were not available to us and the extent of intra-specific variation could not be determined from the limited sample size available.

Material examined.

ARGENTINA, MISIONES: Iguazú (1 w, 4-10.x.1927, RC and EM Shannon, USNM); Iguazú Falls (2 w, 20-22.i.1920, CUIC); Loreto (1 w, N Kusnezov, USNM); Loreto malaise trap in subtropical wet forest (3 w, i.2001, P Fidalgo, FSCA); Parque Nacional Iguazú (3 w, 24.xii.1988, DH and AC Kistner, LACM); Parque Nacional Iguazú Cantera old gravel pit at forest edge 200m (18 w, 8.xii.1990-6.i.1991, S and J Peck, FMNH); Parque Nacional Iguazú Puerto Canoas hill forest 200m (30 w, 8.xii.1990-6.i.1991, S and J Peck, FMNH); Parque Nacional Iguazú Puerto Canoas river forest 180m (35 w, 2 m, 8.xii.1990-6.i.1991, S and J Peck, FMNH); Puerto Iguazú 100m (1 w, 25.xi-8.xii.1983, A Bordón, MCZC); Santo Pipó (1 w, N. Kusnezov, MCZC); locality not specified (1 w, USNM).BOLIVIA, SANTA CRUZ: Ayacucho (1 w, 13.x.1987, P Bettella, LACM); Buena Vista (1 w, 8.iv.1950, LE Pena, CUIC); Buena Vista (1 w, 20.ii.1999, L Stange, FSCA); Lomas de Arena Biol. Park (4 w, 10.ii.1999, LA Stange, FSCA); Velasco, Santa Cruz de la Sierra (1 w, J Steinbach, MCZC); Santa Cruz de la Sierra (1 w, 23.iv.1989, G Morales, LACM). BRAZIL, GOIAS: Anápolis (1 w, 12.ii.1936, G Fairchild, MCZC); 24 km E Formoso (1 w, 29.v.1956, FS Truzal, LACM); (1 w, 30.iv.1956, FS Truxal, LACM); Parque Nacional da Chapada dos Veadeiros (1 w, 29.xi.1989, J Cuellar, LACM); Parque Nacional da Chapada dos Veadeiros 18-24km N of Alto Paraiso 1400-1500m (1 w, 2-5.x.1985, SE Miller, LACM), Parque Nacional da Chapada dos Veadeiros, 18-24km N of Alto Paraiso 1400-1500m(1 w, 22.iv.1956, FS Truxal, LACM); MATO GROSSO: Rio das Mortes nr. São Felix do Araguaia (1 w, 1944, JV Ca, MCZC); MATO GROSSO DO SUL: 24 km W Campo Grande loose on ground (1 w, 7.xi.1989, WP Mackay, CWEM); 6 km SE Campo Grande nest in soil (2 w, 8.xi.1989, WP Mackay, CWEM); 8 km SE Ponta Purá, loose on ground (2 w, 15.xi.1989, WP Mackay, CWEM); 3 km NW Taunay, loose on ground (1 w, 17.xi.1989, WP Mackay, CWEM); Urucum, Corumbá (1 w,23-29.xii.1919, CUIC); SÃO PAULO: Corumbataí, loose on ground(1 w, 6.xi.1989, WP Mackay, CWEM); RIO GRANDE DO SUL: Passo Fundo (1 w,10.iii.1939, PA Berry, USNM). PARAGUAY, ALTO PARANÁ: Villa Encarnación (1 w, 10.i.1905, CASC); GUAIRÁ: Rogue González (1 w, 14.i.1995, B. Garcete and Alex Wild, LACM).

Figures

Figure 1. Features of Dinoponera workers. A Head, frontal view B-C Occiput of head, oblique antero-lateral view D-E Pronotum, lateral view F-H Petiole, lateral view. A-B Dinoponera longipes C Dinoponera hispida D Dinoponera gigantea. E-F Dinoponera mutica G Dinoponera hispida H Dinoponera lucida.

Figure 4. Features of Dinoponera males. A-E Head, frontal view F-J Right scape, first and second funicular segments, frontal view K-O Pygidial spine, dorsal view A, F, K Dinoponera gigantea B, G, L Dinoponera quadriceps C, H, M Dinoponera longipes D, I, N Dinoponera snellingi E, J, O Dinoponera australis.

Figure 5. Wings of known males. A Dinoponera quadriceps B Dinoponera snellingi C Dinoponera gigantea D Dinoponera australis E Dinoponera longipes.

Figure 9. Dinoponera rightbasiparamere / paramere of known males, lateral view. A Dinoponera quadriceps B Dinoponera snellingi C Dinoponera gigantea D Dinoponera australis E Dinoponera longipes.

Figure 10. Dinoponera rightvolsella of known males, lateral view. A Dinoponera quadriceps B Dinoponera snellingi C Dinoponera gigantea D Dinoponera australis E Dinoponera longipes.

Figure 11. Dinoponera rightpenis valves from the aedeagus of known males. A Dinoponera quadriceps B Dinoponera snellingi C Dinoponera gigantea D Dinoponera australis E Dinoponera longipes.

Figure 12. Worker head, oblique antero-lateral view illustrating microsculpturing difference. A Dinoponera mutica (this smooth integument type is also found in Dinoponera lucida, Dinoponera longipes and Dinoponera hispida) B Dinoponera quadriceps (this rough integument type is also found in Dinoponera gigantea and Dinoponera australis).

Figure 13. Distribution map of Dinoponera species. Symbols in black are records added by this study; open symbols are from literature sources (Kempf 1971, 1975, Araujo et al. 1990, Peeters et al. 1999, Monnin and Peeters 1999, Fourcassie and Oliviera 2002, Monnin et al. 2003, Mariano et al. 2004, Araujo and Rodriques 2006, Marques-Silva et al. 2006).