Costa Rica (Jack Longino)
Lattke (1995) reports this species as a millipede specialist found in humid forests. In Corcovado National Park, I observed a worker with milliped prey. triangularis has been introduced in south Florida (Deyrup et al. 1989).
The Costa Rican records I have of this species are as follows:
Puntarenas: Sirena, Corcovado National Park, 8¡29'N, 83¡36'W, 5m (J. Longino). (1) Worker on log. (2) Single worker with millipede prey. (3) Workers on large tree trunk. (4) Canopy Ficus; dealate queen walking on branch.
Lattke (1995) reports a collection from La Selva Biological Station.
Native range. Neotropics: Costa Rica to Argentina. Introduced range. USA: Alabama, Florida, Mississippi.
Costa Rica: La Selva and Osa Peninsula.
Diagnosis among workers of introduced and commonly intercepted ants in the United States. Antenna 12-segmented. Antennal insertions at least partly covered by frontal lobes. Anterior margin of clypeus not denticulate. Eyes medium to large (greater than 5 facets); situated at or above midline of head. Mandibles triangular. Metanotum does not form a prominent convexity bordered by distinct suture lines. Propodeum armed with small teeth or denticles. Waist 1-segmented. Petiole narrowly attached to gaster; has conspicuous posterior face. Petiolar node relatively quadrate and subpetiolar process broad in profile with a blunt anterior angle and an acute posterior angle. Subpetiolar process narrow with a blunt posterior angle and lacking a distinct anterior angle. Abdominal segment 4 with deep longitudinal furrows; distinct constriction between abdominal segments 3+4. Gaster armed with sting. Tarsal claws with subapical tooth. Hind coxae armed with dorsal spine.
Gnamptogenys triangularis, and its geographic and morphological variation, is treated in the taxonomic works of Brown (1958)and Lattke (2004; Lattke et al., 2007). In particular it should be noted that the propodeal teeth vary in size from small denticles to well-formed teeth. The only other species of Gnamptogenys in North America is G. hartmani (Wheeler, W.M.), from which G. triangularis can be separated by its much larger size, shorter erect hairs, and the presence of propodeal teeth. Among other introduced ants, G. triangularis might be most confused with ponerine genera, but can be separated by the eyes which are above the midline of the head, the distinct sulcate sculpture, the coxal tooth, and the deep constriction between abdominal segments 3+4. Among commonly intercepted ants, G. triangularis is most likely confused with Ectatomma species, but can be separated by the lack of convexity and suture lines of the mesonotum, the presence of the coxal spines, and the sulcate sculpture.
Gnamptogenys triangularis is a relatively large, black ant with more reddish legs that is characterized by deep longitudinal grooves and ridges that the run the lengths of the head, mesosoma and gaster. Little is known about the ecology of the ant, other than that it is believed to be a millipede specialist and is associated with humid forests and arboreal foraging (Costello et al., 2003; Deyrup et al., 2000; Lattke et al., 2004; Longino, 2012). Gnamptogenys triangularis is native to the Neotropics, where it ranges from Costa Rica to Argentina (Lattke et al., 2007), and is introduced in Florida (Deyrup, 2003; Deyrup et al., 2000; Deyrup et al., 1989), Alabama (MacGown & Forster, 2005), and Mississippi (MacGown, 2012). The earliest known specimens from Florida (first reported as G. aculeaticoxae (Santschi)) date to 1985, and it is so rare there that it is believed to have negligible effects on the native fauna (Deyrup et al., 2000).
Taxonomic history
Emery, 1906c PDF: 113 (w.).Combination in Ectatomma (Parectatomma): Emery, 1911e PDF: 44.Combination in Gnamptogenys: Brown, 1958g PDF: 230.Status as species: Dalla Torre, 1893 PDF: 26; Emery, 1896g PDF: 46 (in key); Emery, 1906c PDF: 113; Emery, 1911e PDF: 44; Bruch, 1914 PDF: 213; Santschi, 1916e PDF: 366; Gallardo, 1918c PDF: 39; Luederwaldt, 1918 PDF: 34; Borgmeier, 1923: 59; Kusnezov, 1953c PDF: 336; Brown, 1958g PDF: 229, 323; Kusnezov, 1969 PDF: 35 (in key); Kempf, 1972b PDF: 116; Zolessi et al., 1988: 2; Bolton, 1995b: 211; Lattke, 1995 PDF: 190; Deyrup, 2003 PDF: 45; Lattke et al., 2004 PDF: 349; MacGown & Forster, 2005 PDF: 68; Lattke et al., 2007 PDF: 263 (in key); Lattke et al., 2008 PDF: 100; Deyrup, 2017: 21.Senior synonym of Gnamptogenys aculeaticoxae: Lattke, 1995 PDF: 190.Senior synonym of Gnamptogenys triangularis richteri: Brown, 1958g PDF: 230, 323; Kempf, 1972b PDF: 116; Bolton, 1995b: 211; Lattke, 1995 PDF: 190.
Gnamptogenys triangularis is a Neotropical species of ants in the subfamily Ectatomminae. Native to the forests of South and Central America, G. triangularis is a predatory ant that feeds on millipedes. In its native range, this species is known from Buenos Aires, Argentina in the south to Costa Rica in the north, with records from eight countries in South America, and two countries of Central America. The first records of G. triangularis outside its native range came from Florida beginning in 1985 and Alabama in 1996.[1]
Based on its South American range, it appears that G. triangularis has the potential to spread to forests throughout much of the southeastern United States. There are no documented impacts of G. triangularis, and it seems unlikely that this species will ever become a major pest.[1]
G. triangularis was originally described by Mayr as Ectatomma triangulare in Uruguay in 1887.[2][3] Junior synonyms include Ectatomma triangulare richteri, described in 1913 in Argentina and Ectatomma aculeaticoxae,[4] described from Haute Carsevenne, French Guiana in 1921 (now Alto Rio Calçoene, Brazil).[5]
Gnamptogenys triangularis is a relatively large, black ant with more reddish legs that is characterized by deep longitudinal grooves and ridges that the run the lengths of the head, mesosoma and gaster. Little is known about the ecology of the ant, other than that it is believed to be a millipede specialist and is associated with humid forests and arboreal foraging.[6]
Gnamptogenys triangularis and Gnamptogenys hartmani are the only two members of the subfamily Ectatomminae known to occur in the southeastern United States. These very distinctive ants can be recognized immediately by the deep horizontal grooves covering the entire head and body. G. triangularis workers are ~5.0 mm in length and dark brown. Females are similar in appearance to workers, but are slightly larger (~5.5 mm in length) and have brownish gray colored wings. Males are approximately the same length as females (~5.5 mm), but are wasp-like in appearance and differ considerably from workers and females. The deep horizontal grooves characteristic of the genus are mostly absent except on the face and first gastral tergite. Sides of head, pronotum, much of the mesonotum, and gaster have reduced sculpture and are shiny, and the remainder of mesosoma and petiole are rugoreticulate. Males are bicolored with the head and mesosoma dark reddish black to black, petiole dark reddish brown, and gaster reddish orange. The legs, antennal scape, and first segment of funiculus are orangish red, the remainder of funiculus is gray, and the wings are dusky gray. In comparison, Gnamptogenys hartmani workers are 3.5–4.0 mm and pale reddish brown. Females are ~5 mm and similar in appearance to workers. Males are approximately the same size as females, but horizontal grooves are greatly reduced, and overall they are shinier in appearance. The entire body is reddish brown, legs and scapes are yellowish brown, and the funiculus is dark colored.[7]
Records of G. triangularis come from eight countries in South America (all except Chile, French Guiana, and Paraguay), and the two southernmost countries of Central America (Panama and Costa Rica). Because there are no discernible geographic barriers, it seems very likely that the native range of G. triangularis also extends into forest habitats in French Guiana, Paraguay, and farther north in Central America, but has not yet been recorded in these areas due to its rarity.[8] In its exotic range, G. triangularis is now known from Florida, Alabama and Mississippi. Based on its South American range, it is possible that G. triangularis could spread to forests throughout much of the southeastern United States, perhaps as far north as Richmond, Virginia and Lexington, Kentucky.[5]
In both its native and exotic ranges, G. triangularis inhabits forests and preys on millipedes. There are no known impacts of G. triangularis, even though if this species was having a localized impact on millipede populations, it seems unlikely that this would have been detected. Nonetheless, it seems unlikely that this species will ever become a major pest.[5]
This article incorporates text from a scholarly publication published under a copyright license that allows anyone to reuse, revise, remix and redistribute the materials in any form for any purpose: MacGown, J. A.; Wetterer, J. K. (2012), "Geographic Spread of Gnamptogenys triangularis (Hymenoptera: Formicidae: Ectatomminae)", Psyche, 2012: 1–4, doi:10.1155/2012/571430 Please check the source for the exact licensing terms.Gnamptogenys triangularis is a Neotropical species of ants in the subfamily Ectatomminae. Native to the forests of South and Central America, G. triangularis is a predatory ant that feeds on millipedes. In its native range, this species is known from Buenos Aires, Argentina in the south to Costa Rica in the north, with records from eight countries in South America, and two countries of Central America. The first records of G. triangularis outside its native range came from Florida beginning in 1985 and Alabama in 1996.
Based on its South American range, it appears that G. triangularis has the potential to spread to forests throughout much of the southeastern United States. There are no documented impacts of G. triangularis, and it seems unlikely that this species will ever become a major pest.
