A revision of the giant Amazonian ants of the genus Dinoponera (Hymenoptera, Formicidae) Author Lenhart, Paul A. Department of Entomology, Texas A & M University, 2475 TAMU, College Station, Texas USA Author Dash, Shawn T. Department of Biological Sciences, University of Texas at El Paso, 500 West University Avenue, El Paso, Texas 79968 Author Mackay, William P. Department of Biological Sciences, University of Texas at El Paso, 500 West University Avenue, El Paso, Texas 79968 text Journal of Hymenoptera Research 2013 2013-03-20 31 119 164 http://dx.doi.org/10.3897/jhr.31.4335 journal article http://dx.doi.org/10.3897/jhr.31.4335 1314-2607-31-119 10404A9C126A44C8BD485DB72CD3E3FF 632BFFBC244FFF88656EFFBEFF8DFFA7 574808 Dinoponera mutica Emery Figs 1E, F , 12B , 13 Dinoponera grandis subsp. mutica Emery, 1901: 48 Syntype workers, BRAZIL: Mato Grosso, Germain (leg.) (MCSN) [examined] (specific locality of Rondonopolis proposed by Kempf (1971) ; Wheeler, G.C. and Wheeler, J. 1952: 607 (larvae.); raised to species Kempf, 1971: 378. Worker diagnosis. Dinoponera mutica is identified by its smooth and shiny integument with a bluish luster ( Fig. 12A ), a rounded pronotal corner lacking a tooth-like process ( Fig. 1E ), gular striations on the ventral surface of the head, long and flagellate pubescence, scape length longer than head width and petiole with even dorsal corners ( Fig. 1F ). Description of the worker. Measurements (mm) (n=12) TBL: 29.42-32.34 (30.99); MDL: 4.10-5.48 (4.71); HL: 5.13-6.30 (5.65); HW: 5.13-5.64 (5.39); SL: 5.43-6.05 (5.72); WL: 7.53-8.61 (8.20); PL: 2.26-2.67 (2.41); PH: 2.82-3.38 (3.17); PW: 1.54-1.90 (1.76); GL: 8.61-11.99 (10.06); HFL: 7.18-8.00 (7.60). A description of the morphology of the worker is given in Kempf (1971) : " Antennal scape remarkably longer than head width. Pubescence on front and vertex generally longer and denser than in gigantea, but lacking the golden luster on longipes. Gular face smooth and shiny, with fine, more or less distinct striation antero-laterally and antero-mesially (sometimes nearly effaced). Sides of head smooth and shining in spite of the very fine, superficial microsculpture which is reticulate-punctate. Antero-inferior corner of pronotum obtusely angulate or rounded. Pronotal disc smooth and shiny, lacking irregular fossae and wrinkles; the paired swellings rather weakly expressed. Tarsus I of hind leg decidedly longer than head width. Petiole of distinctive shape ... , shorter than that of gigantea and longipes, but width-length proportion still under 0.08; anterior and posterior upper corners subequally rounded; smooth and shining; vertical sulcus on posterior face usually obsolete, present only in one Bolivian specimen. Terga I and II of gaster very indistinctly, superficially and finely reticulate-punctate yet quite smooth and shining, lacking the dense foviolae of longipes on disc where the pubescence is likewise scarce. Stridulatory file well-developed, triangular but short, visible only when acrotergite of tergum II is fully exposed ." Male. Unknown. Distribution. Dinoponera mutica is found in central South America in the Brazilian states of Rondonia , Mato Grosso, Goias and Mato Grosso do Sul, in eastern Bolivia and northwest Paraguay ( Fig. 12 ). Discussion . Dinoponera mutica is a valid species based on our study. Dinoponera quadriceps is the closest to Dinoponera mutica in terms of morphological characters and is not synonymized in this work because of the differences stated in the diagnosis above. Males of Dinoponera mutica may provide further support for separation from Dinoponera quadriceps . Dinoponera quadriceps has a finely micro-sculptured integument which is not shiny ( Fig. 12B ), lacks gular striations and has a petiole which bulges on the dorso-anterior edge. Dinoponera longipes and Dinoponera hispida may also be confused with Dinoponera mutica but this species lacks the dense golden pubescence of the former, or the short, stiff setae and forward bulging petiole of the latter. Material examined. BRAZIL, MATO GROSSO DO SUL: Corumba (1 w, MCZC); Urucum, Corumba (3 w, 23-29.xii.1919, LACM, CUIC); RONDONIA : 7 km NW Costa Marques (1 w, 16.xi.1986, R Wilkerson, FSCA); Schmitt Ranch (1 w, ix.1996, R. Rogers, PALC). BOLIVIA, SANTA CRUZ: Perseverancia (1 w, 18.iii.1990, P Bettella, LACM). PARAGUAY, BOQUERON : Enciso (1 w, T. del Sinne, CWEM).