Welcome to the new AntWeb!

We here at AntWeb have been busy working on our newest (and most ambitious) version of the site - and there are lots of great new things! Which means there are lots of changes (don't worry, they're all for the best).

And we've put together a handy little guide to show you all the new features and enhancements - why don't you have a quick look to check out all the new features and enhancements?

No thanks
Current View: Global: All Antweb
Change View
Cite this page

Citing AntWeb

X

To cite this page, please use the following:

· For print: . Accessed

· For web:

Species: Brachymyrmex patagonicus   Mayr, 1868 

Classification:
Download Data

See Also:

Brachymyrmex patagonicus atratula

Taxonomic History (provided by Barry Bolton, 2014)

Brachymyrmex patagonicus Mayr, 1868b PDF: 164 (w.m.) ARGENTINA. Neotropic. AntCat AntWiki

Taxonomic history

Emery, 1906c: 179 (q.).
Senior synonym of Brachymyrmex atratula: Quirán, et al. 2004: 275.

Overview:

Brachymyrmex patagonicus (the Dark Rover Ant) is the type species of the genus, and is a small, shiny, light brown to dark brown species with reduced pilosity. The original type material used by Mayr (1868) to describe the B. patagonicus cannot be located, prompting the species to be redescribed based on Chilean material also examined and determined by Mayr (Quiran et al., 2004). The redescription was part of a larger effort to clear up the confusion surrounding Brachymyrmex taxonomy (Quirn, 2005;2007), but several errors concerning the erroneously small size of the workers and queens of B. patagonicus were also published (MacGown et al., 2007). Brachymyrmex patagonicus is native to at least the South America region of the Neotropics (Quiran et al., 2004), and is introduced to the southeastern United States (MacGown et al., 2007), and at least the Netherlands in Europe (Boer & Vierbergen, 2008). A review of B. patagonicus as an emerging pest species in the Gulf Coast region of the United States provides a thorough account of the taxonomy, invasion history and biology (MacGown et al., 2007). The authors suggest that B. patagonicus shows considerable potential as a nuisance species, perhaps comparable to the effects Tapinoma melanocephalum has in tropical and subtropical regions.

Distribution:

Native Range (Quiran et al., 2004): Argentina, Paraguay, Bolivia, Brasil (RS, SP, RJ, AM), Guianas, Venezuela.
Introduced Range. Netherlands. USA: Arizona, Alabama, Georgia, Florida, Louisiana, Mississippi, Missouri, Texas.

In Paraguay: Amambay, Boquern, Canindey, Central, Concepcin, Cordillera, Itapa, Misiones, eembuc, Paraguar, Pte. Hayes

Biology:

The first record B. patagonicus in the United states, from Louisiana in 1978, was misidentified as B. musculus (Wheeler & Wheeler, 1978). The species continued to be referred to under that name in publications, including subsequent faunal lists for Florida (Deyrup, 2003; Deyrup et al., 2000), until MacGown et al. (2007) determined that all records of B. musculus in the region in fact referred to B. patagonicus.

The species nests in a variety of both natural and disturbed habitats. Natural habitats reported from MacGown et al. (2007) include pine forests (with nests often in loose bark at the bases of the tree trunks), beaches (with nests at the bases of plants), mixed forests (nests in soil, dead wood, and litter), and prairie remnants (nests in soil, accumulations of organic litter, and grass thatch). In disturbed areas, nests of B. patagonicus are especially frequent in landscaping mulch, a habitat that is increasing exponentially throughout the Southeast, and which positions colonies to make forays into buildings. In disturbed areas it also nests in soil under objects on the ground (stones, bricks, railroad ties, lumbers, or a variety of other objects), under grass at edges of lawns and parking lots, in leaf litter, at the bases of trees, in rotting wood, in piles of dead wood, and in accumulations of trash.

The diet of B. patagonicus is thought to consist largely of honeydew harvested from a diversity of insects, especially subterranean hemipterans (Dash et al., 2005), and are attracted to sweet baits such as honey or cookies (MacGown et al., 2007).  

Colonies of B. patagonicus may contain many hundreds of workers packed into a small sheltered area, and colonies are often abundant and may be found within a few centimeters from one another (MacGown et al., 2007). The social structure of B. patagonicus has not been studied, but apparently separate colonies show considerable mutual tolerance (MacGown et al., 2007). Although it has been reported that B. patagonicus may be found in higher numbers subsequent to the suppression of Solenopsis invicta (Dash, 2004), the species is also known to coexist with both S. invicta and S. invicta x S. richteri (MacGown et al., 2007).

Brachymyrmex patagonicus is considered a nuisance pest, primarily because altaes and foraging workers may enter houses, hospitals, schools and other man-made structures to forage and/or nest (MacGown et al., 2007). The species can occur in very high numbers, especially in metropolitan areas, and pest control operators have expressed difficulty controlling it. However, there are no reports thus far of B. patagonicus causing structural damage, bites or stings, transmitting disease, nor invading food stores.

Identification:

Brachymyrmex patagonicus can be distinguished from most other introduced members of the genus by the following combination of characters: (1) sparse pubescence on the first gastral tergite, (2) antennal scapes exceeding posterior margin of head by at least 1/5 their length, (3) erect hairs on the pronotum and mesonotum, (4) eye length approximately equal to malar length, and (5) shiny brown in color. In North America, the species is most readily confused with B. obscurior, but can be separated by the sparser pilosity on the gaster and the larger eyes.

Redescription from MacGown et al. 2007
Diagnosis of Male. Size minute, mesosomal length 0.43-0.51 mm ( n = 10). Head and mesosoma medium brown to blackish-brown, gaster usually blackish-brown, often darker than head and mesosoma, tarsi and mandibles pale, and antennae brownish-yellow. Head slightly longer than wide, covered with fine pubescence, and with a few longer erect hairs; antennal scapes surpassing occipital border of head by 1/5 their total length; eyes relatively large, about as long as length of malar space and placed at approximately the middle third of side of head; 3 tiny, barely visible ocelli present. Promesonotum with 3-9 (usually 4-6) stout, erect hairs present dorsally, with fine pubescence that does not obscure the shiny sheen of integument. Gaster with scattered, long, erect hairs, especially along the edges of the tergites, and with sparse, decumbent hairs, separated by about 1/3 to 2/3 their length.  

Diagnosis of Female. Mesosomal length 1.24-1.42 mm ( n = 10). Concolorous light brown. Head wider than long, with abundant, fine pubescence, and with long erect hairs present; large compound eyes located at middle of side of head; 3 large ocelli present; frontal lobes well developed; scapes surpassing occipital border by 1/4 their length. Mesosoma with moderately dense, fine pubescence, and 30-40 long erect hairs (about 3-4 times length of fine pubescence); anepisternum and katepisternum separated by a distinct suture, with erect hairs present. Forewing with pterostigma; hind wing with 7 hammuli. Gaster with moderately dense, fine pubescence, and erect hairs along apical edges of sternites and tergites.  

Diagnosis of Male. Mesosomal length 0.8 mm ( n = 2). Head dark brown to blackish-brown, rest of body, including appendages, very light brown. Head wider than long, with fine, sparse pubescence, lacking erect hairs except on mouthparts, and with smooth, shiny integument; frontal lobes reduced; scapes surpassing occipital border by more than 1/5 their length, first segment of funiculus enlarged, almost globular, wider than succeeding segments; eyes large, about 1/2 length of head, and located on lower half of head; 3 large, prominent, raised ocelli present. Mesosoma with sparse pubescence Figs. 4-6. Full-face views of Brachymyrmex patagonicus: (4) worker, (5) male, and (6) female. Scale bar equals 0.5 mm. and shiny integument, lacking erect hairs. Hind wing with 5 or 6 hammuli. Gaster shiny, lacking pubescence, with scattered erect hairs on last few sternites and tergites.

Taxonomic Notes:

From Quiran (2004). Type series: In the original publication, Mayr included the description of the worker and the male, but did not mention the number of specimens studied nor where the material was housed. Mayr identified several specimens from Chile and labeled them as "type", but they were not used in the original description so they cannot be considered as "syntypes".

Notes:

(Dutch vernacular name: Patagonische negenspriet)

References:

Boer, P. & Vierbergen, B. (2008) Exotic ants in The Netherlands (Hymenoptera: Formicidae). Entomol. Ber. (Amsterdam), 68, 121-129.

Dash, S.T. (2004) Species diversity and biogeography of ants (Hymenoptera: Formicidae) in Louisianna, with notes on their ecology. M.S. thesis, Louisiana State University. v + 290 p.

Dash, S.T., Hooper-Bui, L.M. & Seymour, M.A. (2005) The pest ants of Louisiana. A guide to their identification, biology, and control. Louisiana State University, Louisiana Agricultural Experiment Station, Louisiana Cooperative Extension Service, Pub. 2915

Deyrup, M. (2003) An updated list of Florida ants (Hymenoptera: Formicidae). Florida Entomol., 86, 43-48.
Deyrup, M., Davis, L. & Cover, S. (2000) Exotic ants in Florida. Trans. Am. Entomol. Soc., 126, 293-326.

MacGown, J.A., Hill, J.G. & Deyrup, M.A. (2007) Brachymyrmex patagonicus (Hymenoptera: Formicidae), an emerging pest species in the southeastern United States. Florida Entomol., 90, 457-464.
Mayr, G. (1868) Formicidae novae Americanae collectae a Prof. P. de Strobel. Annu. Soc. Nat. Mat. Modena, 3, 161-178.

Quiran, E. (2005) El genero Neotropical Brachymyrmex Mayr (Hymenoptera: Formicidae) en la Argentina. II. Redescripcin de las especies B. admotus Mayr, de B. brevicornis Emery y B. gaucho Santschi. Neotrop. Entomol., 34, 761-768.

Quiran, E. (2007) El Genero Neotropical Brachymyrmex Mayr (Hymenoptera: Formicidae) en la Argentina. III. Redescripcin de las especies: B. aphidicola Forel, de B. australis Forel y B. constrictus Santschi. Neotrop. Entomol., 36, 699-706.

Quiran, E.M., Martnez, J.J. & Bachmann, A.O. (2004) The Neotropical genus Brachymyrmex Mayr 1868 (Hymenoptera: Formicidae) in Argentina. Redescription of the type species, B. patagonicus Mayr 1868; B. bruchi Forel, 1912 and B. oculatus Santschi, 1919. Acta Zool. Mex. (N.S.), 20, 273-285.

Wheeler, G.C. & Wheeler, J. (1978) Brachymyrmex musculus, a new ant in the United States. Entomol. News, 89, 189-190.

Taxon Page Author History

On 2012-06-05 12:01:29 Eli Sarnat modified References
On 2012-06-05 12:01:00 Eli Sarnat modified References
On 2012-06-05 11:57:56 Eli Sarnat modified References
On 2012-06-05 11:57:29 Eli Sarnat modified References
On 2012-06-05 11:56:45 Eli Sarnat modified References
On 2012-06-05 11:55:32 Eli Sarnat modified Overview
On 2012-06-05 11:55:10 Eli Sarnat modified Identification
On 2012-06-05 11:51:02 Eli Sarnat modified Biology
On 2012-06-05 11:49:47 Eli Sarnat modified Distribution
On 2012-06-05 11:49:13 Eli Sarnat modified Distribution
On 2012-06-05 11:48:30 Eli Sarnat modified Distribution
On 2012-06-05 11:46:46 Eli Sarnat modified Distribution
On 2012-06-05 11:46:08 Eli Sarnat modified Distribution
On 2012-06-05 11:45:35 Eli Sarnat modified Distribution
On 2012-06-05 11:44:46 Eli Sarnat modified Overview
On 2012-06-05 11:44:24 Eli Sarnat modified Overview
On 2012-06-05 11:43:16 Eli Sarnat modified Overview
On 2012-06-05 09:46:16 Eli Sarnat modified Identification
On 2012-06-05 09:43:25 Eli Sarnat modified Identification
On 2012-06-05 08:52:16 Eli Sarnat modified Taxonomic Notes
On 2011-03-31 23:46:13 Eli Sarnat modified Distribution
On 2011-03-31 23:46:13 Eli Sarnat modified Biology

Taxonomic Treatment (provided by Plazi)

Forel, A., 1895:
- Un peu plus poilu que le type dont je ne puis du reste le distinguer. Il est fort curienx de trouver un Brachymyrmex , genre exclusivement neotropique, a la Reunion. II est donc tres probable qu'il s'agit d'une importation recente par les vaisseaux.

Wild, A. L., 2007:
Amambay, Boquerón , Canindeyú , Central, Concepción , Cordillera, Itapúa , Misiones, Ñeembucú , Paraguarí , Pte. Hayes (ALWC, IFML, INBP, LACM, MHNG, NHMW). Literature records: Cordillera(Forel 1906, Forel 1909).

Specimen Habitat Summary

Found most commonly in these habitats: 4 times found in residential area, 1 times found in inside building, 1 times found in coastal dune remant, 1 times found in botanical gardens, 1 times found in Gallery forest edge, 1 times found in urban landscaping

Collected most commonly using these methods or in the following microhabitats: 00 times collected dead, 14, 2 times hand collecting

Elevations: collected from 4 - 390 meters, 94 meters average

Type specimens: Type (?) of Brachymyrmex patagonicus: casent0915732

(-1 examples)



See something amiss? Send us an email.
Enlarge Map