Brachymyrmex Patagonicus (Hymenoptera: Formicidae), an Emerging Pest Species in the Southeastern United States

MacGown et al.: Brachymyrmex patagonicus, an Emerging Pest 457

BRACHYMYRMEX PATAGONICUS (HYMENOPTERA: FORMICIDAE), AN EMERGING PEST SPECIES IN THE SOUTHEASTERN UNITED STATES

JOE A. MACGOWN1, JOVONN G. HILL1 AND MARK A. DEYRUP2 1Mississippi Entomological Museum, Mississippi State University, Box 9775, MS 39762-9775

2Archbold Biological Station, P.O. Box 2057, Lake Placid, FL 33862

ABSTRACT

Brachymyrmex patagonicus Mayr is a recently introduced species that is well established in the Gulf Coast region of the United States. This species is abundant in Georgia, Florida, Al- abama, Mississippi, and Louisiana and has spread into other states. It has become a nuisance pest with occasional large infestations occurring in homes, hospitals, and other businesses. Brief descriptions and illustrations of all castes, biological and economic importance, and known distribution in the United States are given.

Key Words: exotic insects, ants, distribution, dark rover ant

RESUMEN

Brachymyrmex patagonicus Mayr es una especie introducida recientemente que esta bien establecida en la región de la Costa del Golfo de los Estados Unidos. Esta especie es abun- dante en los estados de Georgia, Florida, Alabama, Mississippi y Louisiana y se ha esparcido a otros estados. Esta hormiga ha convertido en una plaga fastidiosa con infestaciones oca- sionales grandes en hogares, hospitales y otros negocios. Se provee una descripción breve con ilustraciones de todas las castas, su importancia biológica y económica, y la distribución conocida en los Estados Unidos.

Members of the genus Brachymyrmex Mayr Brachymyrmex patagonicus is native to Argen- (Hymenoptera: Formicidae: Formicinae) are tina (Quirán et al. 2004). This species was first re- small, soft-bodied ants that are only 2.5 mm or ported from the United States as Brachymyrmex less in length (workers of most species are musculus Forel from St. Tammany Parish, Louisi- smaller), range in color from pale yellow to black- ana in 1978 from a single colony collected in 1976 ish-brown, and possess distinctive nine-seg- from sawdust beneath a recently cut live oak tree mented antennae. Most species nest in soil or in (Wheeler & Wheeler 1978). Wheeler & Wheeler rotting wood, although a few are arboreal. The ge- (1978) note that they identified the species by us- nus includes 38 species worldwide, with most oc- ing Santschi’s key to species (1923). They specu- curring in the Neotropical region (Bolton 1995). lated that it could have been introduced into the However, due to their minute size, there are likely United States through nearby New Orleans, many more undescribed species. Currently, at which is a reasonable entry point for tropical spe- least eight distinct species, four of which appear cies, although other localities, such as Mobile, Al- to be undescribed (from the southeastern United abama, or Pensacola, Florida, are just as likely. In States), are known to occur in the United States. his unpublished dissertation Naves (1976) also This genus needs revision because most species reported the presence of this species, which he re- descriptions are brief, and type specimens of ferred to as B. patagonicus from the Southeast. In many species are lost or are poorly preserved, his monograph of Pheidole of Florida, Naves some being shriveled. Although the genus was re- (1985) again mentioned B. patagonicus as occur- vised by Santschi (1923), the morphological char- ring in the southeastern United States. Although acters he used to define species were ill-defined Naves (1985), whose research was conducted in and, in many cases, were useless for differentiat- Florida, implied that this species occurred in ing species. For these reasons, species epithets Florida, subsequent faunal lists of ants for the and identifications in the genus are suspect (Dey- state failed to mention B. patagonicus (Deyrup rup 2003). Compounding this problem, there are 2003; Deyrup et al. 1989; Deyrup et al. 2000). In several known undescribed species, and undoubt- 2000 this species, then referred to as B. musculus, edly more to be discovered. However, revisions of was reported from Florida (Deyrup et al. 2000). the genus (Quirán 2005; Quirán et al. 2004) have The name B. patagonicus again reappeared in the resulted in six species being redescribed, includ- literature from collections in Louisiana when ing the type species, B. patagonicus Mayr, for Hooper-Bùi et al. (2000) mentioned it as an un- which the original types are lost. welcome house pest. A subsequent thesis on ants

458 Florida Entomologist 90(3) September 2007 of Louisiana (Dash 2005) did not mention B. pat- lengths (measured from the anterior edge of the agonicus, but referred to B. obscurior Forel and pronotum to the posterior edge of the metapleural B. musculus, occurring in 3 parishes. gland) are given in lieu of overall lengths. Head The first goal was to determine whether the width was measured in full frontal view at the southeastern species named B. musculus and widest point on the head including the eyes, and B. patagonicus were actually 1 species. Specimens head length was measured in full frontal view identified as B. musculus and B. patagonicus, and from the anterior edge of the clypeus to the poste- on which the Louisiana records are based, were rior border of head. Eye length refers to the long- borrowed from the Louisiana State University Ar- est measurement of the compound eye. Measure- thropod Collection (LSUC) and were compared ments were made with a micrometer mounted in with specimens identified as B. musculus from a 10× eyepiece on a Leica MZ16 stereomicroscope Georgia, Florida, Alabama, Mississippi, Louisi- at 50× (for females) and 100× (for males and work- ana, and Texas. All of these specimens appeared to ers). Drawings were made with a drawing tube be the same species. Additionally, specimens from mounted on a Leica MZ16 stereomicroscope. LSUC identified as B. obscurior also appeared to be this species, not B. obscurior. The next goal was RESULTS to assign the proper name to this species. The original descriptions of both B. musculus as a race of Diagnosis of the Worker (Figs. 1 and 4) B. tristis Mayr by Forel (1899) and B. patagonicus by Mayr (1868) are brief, and of little use for iden- Size minute, mesosomal length 0.43-0.51 mm tification. However, the redescription of B. patag- (n = 10). Head and mesosoma medium brown to onicus (Quirán et al. 2004), which includes all blackish-brown, gaster usually blackish-brown, castes, is much more detailed, and appears to often darker than head and mesosoma, tarsi and closely match our southeastern species. To verify mandibles pale, and antennae brownish-yellow. this tentative identification, representatives of all Head slightly longer than wide, covered with fine castes were sent to Estela Quirán, who identified pubescence, and with a few longer erect hairs; an- them as B. patagonicus, the name that we use in tennal scapes surpassing occipital border of head this publication. We suggest, therefore, that all by 1/5 their total length; eyes relatively large, references to B. musculus in North America be re- about as long as length of malar space and placed ferred to as B. patagonicus. This has no bearing on at approximately the middle third of side of head; the taxonomic status of B. musculus, originally de- 3 tiny, barely visible ocelli present. Promesono- scribed from Costa Rica (Bolton 1995). tum with 3-9 (usually 4-6) stout, erect hairs Although B. patagonicus recently was re- present dorsally, with fine pubescence that does described from Argentinian specimens (Quirán et not obscure the shiny sheen of integument. al. 2004), a few errors in the publication concern- Gaster with scattered, long, erect hairs, especially ing measurements give an impression that the along the edges of the tergites, and with sparse, overall lengths of workers and queens are less decumbent hairs, separated by about 1/3 to 2/3 than they actually are. Additionally, the castes their length. have not been illustrated except for the heads of the male and worker, mesosoma of worker, and Diagnosis of Female (Figs. 3 and 6) some male genitalic structures. Therefore, a brief diagnosis and illustration of each caste is given Mesosomal length 1.24-1.42 mm (n = 10). Con- here to aid in identifying this species in the colorous light brown. Head wider than long, with United States. A common name of “dark rover abundant, fine pubescence, and with long erect ant” is proposed for the species. hairs present; large compound eyes located at middle of side of head; 3 large ocelli present; fron- MATERIALS AND METHODS tal lobes well developed; scapes surpassing occipital border by 1/4 their length. Mesosoma with Ants for this study were collected as part of moderately dense, fine pubescence, and 30-40 larger surveys of Formicidae in Florida (Deyrup long erect hairs (about 3-4 times length of fine pu- 2003), Alabama (MacGown & Forster 2005), and bescence); anepisternum and katepisternum sep- Mississippi (MacGown et al. 2005; MacGown & arated by a distinct suture, with erect hairs Brown 2006), with additional collecting trips present. Forewing with pterostigma; hind wing made to southern Georgia, Arkansas, Louisiana, with 7 hammuli. Gaster with moderately dense, and Texas. Specimens were collected in 90% etha- fine pubescence, and erect hairs along apical nol, and representatives were pinned and labeled. edges of sternites and tergites. Vouchers are deposited in the Archbold Biological Station Collection (ABSC) and the Mississippi Diagnosis of Male (Figs. 2 and 5) Entomological Museum (MEM). The gaster of B. patagonicus is soft and often Mesosomal length 0.8 mm (n = 2). Head dark shrivels when pinned. Consequently, mesosomal brown to blackish-brown, rest of body, including

MacGown et al.: Brachymyrmex patagonicus, an Emerging Pest 459

Figs. 1-3. Proﬁle views of Brachymyrmex patagonicus: (1) worker, (2) alate male, and (3) dealate female. Scale bar equals 1.0 mm.

460 Florida Entomologist 90(3) September 2007

Figs. 4-6. Full-face views of Brachymyrmex patagonicus: (4) worker, (5) male, and (6) female. Scale bar equals 0.5 mm.

appendages, very light brown. Head wider than length, ﬁrst segment of funiculus enlarged, al- long, with ﬁne, sparse pubescence, lacking erect most globular, wider than succeeding segments; hairs except on mouthparts, and with smooth, eyes large, about 1/2 length of head, and located shiny integument; frontal lobes reduced; scapes on lower half of head; 3 large, prominent, raised surpassing occipital border by more than 1/5 their ocelli present. Mesosoma with sparse pubescence

MacGown et al.: Brachymyrmex patagonicus, an Emerging Pest 461

and shiny integument, lacking erect hairs. Hind tensive recreation areas of state parks, gas sta- wing with 5 or 6 hammuli. Gaster shiny, lacking tions, restaurants, grocery stores, and along high- pubescence, with scattered erect hairs on last few way edges. As is the case with many other pest sternites and tergites. plants and animals, this species appears to act as an invasive organism that is likely to return Similar Species quickly whenever there are attempts to control it or other species of ants. It has been reported that In the United States, B. patagonicus is most this species may be found in higher numbers after similar to B. obscurior, another exotic species. imported fire ant suppression has taken place Workers differ in the size of the eye, which is about (Dash et al. 2005). This does not imply that popu- the length of the malar space in B. patagonicus, lations of this species are excluded in areas where and conspicuously shorter than the malar space large populations of fire ants are present, as re- in B. obscurior. Additionally, the gaster of B. pata- cent surveys of ants in the Southeast by the MEM gonicus has scattered pubescence, giving it a more have found this species to be abundant in areas shiny appearance, whereas B. obscurior has more with high numbers of imported fire ants. We have dense pubescence. An undescribed species of Bra- observed this species nesting side-by-side and chymyrmex recorded from Florida (referred to as B. freely roaming about with both Solenopsis invicta brevicornis Emery in some publications-Deyrup Buren and S. invicta × richteri on numerous occa- 2003; Deyrup et al. 2000) is also dark brown in sions and have seen no obvious correlation of its color, but lacks erect hairs on the body. Another un- abundance to that of the fire ants’ presence and described, brown colored species, known only from abundance. 2 queens from Arkansas, differs from B. patagoni- This species is considered a nuisance pest spe- cus in that the queens are tiny, approximately the cies, as both alates and foraging workers may en- size of typical workers (pers. comm., Lloyd Davis). ter houses, hospitals, schools, or other man-made Brachymyrmex heeri Forel is another similar spe- structures to forage and/or nest. Occasionally cies that could be potentially found in the United these infestations may be quite large, with nests States, but has not been found here yet. Workers of being found in the structure of the buildings, espe- this species are brownish-yellow and lack ocelli. cially in bathrooms and kitchens, in light sockets Other species of Brachymyrmex found in the and in electrical outlets, inside cinder blocks of ex- United States are yellowish in color. terior walls, and under shingles. During recent years (2005-2006), the Department of Entomology Biology and Economic Importance and Plant Pathology at Mississippi State Univer- sity has had more requests by pest control opera- This species nests in a variety of habitats, both tors in Mississippi about this species than all other natural and disturbed. Natural habitats include ant species totaled together. Pest control operators pine forests (with nests often in loose bark at the have found this species in very high numbers in bases of the tree trunks), beaches (with nests at hospitals and other businesses, especially in met- the bases of plants), mixed forests (nests in soil, ropolitan areas, and have expressed difficulty in dead wood, and litter), and prairie remnants controlling it. This may be partly due to the fact (nests in soil, accumulations of organic litter, and that many indoor infestations of foraging workers grass thatch). In disturbed areas, nests of B. pat- may be coming from outdoor nests some distance agonicus are especially frequent in landscaping from control efforts. As in the case of B. obscurior mulch, a habitat that is increasing exponentially and other ants whose alates fly into openings in throughout the Southeast, and which positions buildings or clutter up swimming pools, there may colonies to make forays into buildings. In dis- be no effective control of alate patagonicus where turbed areas it also nests in soil under objects on the ambient population is high, except by restrict- the ground (stones, bricks, railroad ties, lumbers, ing access. The attention received by this ant may or a variety of other objects), under grass at edges be more associated with its novelty than with any of lawns and parking lots, in leaf litter, at the harm it causes, as it does not cause structural bases of trees, in rotting wood, in piles of dead damage, bite, sting, or transmit disease, nor has it wood, and in accumulations of trash. Colonies been shown to invade stored foods. As a nuisance may contain many hundreds of workers packed species, however, invading buildings and causing into a small sheltered area. Where this species is annoyance, patagonicus shows considerable po- found, colonies are often abundant and even may tential, perhaps comparable to the effects of Tapi- be found within a few centimeters from one an- noma melanocephalum (Fabricius) in tropical and other. The social structure of B. patagonicus has subtropical regions. not been studied, but apparently separate colo- The diet of Brachymyrmex patagonicus is nies show considerable mutual tolerance. thought to consist largely of honeydew from vari- In many sites the occurrence of B. patagonicus ous insects, especially subterranean homopterans appears to be centered around urban areas or (Dash et al. 2005). They undoubtably supplement places frequented by people, such as the more in- their diet with other food sources and will readily

462 Florida Entomologist 90(3) September 2007 come to sweet baits such as honey or cookies. ported as B. musculus), 23 counties in Florida, but Workers of these ants can be commonly seen scur- reported to be widespread throughout (Deyrup rying about during the day as they forage. Female 2003-reported as B. musculus), 27 counties in Al- and male alates have been collected from mid abama (MEM; MacGown and Forster 2005-re- May through early Aug. ported as B. musculus), 31 counties in Mississippi (MEM), and 15 parishes in LA (MEM; Wheeler & Distribution (Fig. 7) Wheeler 1978). In May of 2007, two transects were made Since its ﬁrst report in the United States, across central Georgia by the MEM, and B. patag- B. patagonicus has become extremely common onicus was found to be abundant. It is likely that and abundant in the Gulf Coast states, and in the this species is abundant throughout the entire last few years its range in the southeastern southern half of Georgia, although the northern United States has grown considerably. In a study limit of its distribution in the state is not known. (Storz & Tschinkel 2004) of the spread of another The easternmost record from Georgia, in exotic South American ant species, Pheidole ob- Chatham County, borders South Carolina, and it scurithorax Naves, B. patagonicus (referred to as is probable that this species occurs there as well. B. musculus in their publication) was also re- In Florida, B. patagonicus appears to be much ported. They made collections along a transect more common in the northern portions of the through 46 counties and parishes in Georgia, state, whereas in Alabama and Mississippi it is Florida, Alabama, Mississippi, and Louisiana and most common in the southern halves of the states, found this species in Thomas County, Georgia; with scattered northern records. The earliest Liberty and Santa Rosa Counties, Florida; Es- known collection date of B. patagonicus from Mis- cambia and Baldwin Counties, Alabama; Pike sissippi is 1977, which is only 1 year later than and George Counties, Mississippi; and did not the earliest published record of this species in the ﬁnd it in Louisiana. It is now known to occur in 27 United States. Surprisingly, that record is from counties in Georgia (MEM; Ipser et al. 2004-re- Holly Springs, Marshall County, located in ex-

Fig. 7. Map of the southeastern United States showing the known distribution of Brachymyrmex patagonicus. MacGown et al.: Brachymyrmex patagonicus, an Emerging Pest 463 treme north Mississippi and bordering Tennessee ana: Caddo, East Baton Rouge, Jackson, Lincoln, near the Memphis area. It has not yet been re- Madison, Natchitoches, Orleans, Quachita, ported from Tennessee, but it will likely expand Rapides, Richland, Sabine, Tangipahoa, Vernon, its range to this state, if it is not already found and Winn Parishes (MEM); St. Tammany Parish there. In a recent thesis documenting the ants of (Wheeler and Wheeler 1978). Texas: Smith Louisiana (Dash 2005), this species was only re- County (MEM). ported in Louisiana from 3 parishes (reported as B. musculus and B. obscurior). Recent collections DISCUSSION by the MEM have revealed that this species is now widespread in that state. The MEM also col- Although B. patagonicus is a relatively recent lected this species in 2006 in 2 counties in south- introduction to the United States, it is now well ern Arkansas. In a paper documenting the distri- established and abundant in both natural and bution of ants of Texas (O’Keefe 2000), B. patag- disturbed areas throughout much of the South- onicus was not reported from the state. However, east, especially in Georgia, Florida, Alabama, during a collecting expedition in Jul, 2006 by the Mississippi, and Louisiana. To give an indication MEM, which traversed Texas from east to west, it of how common B. patagonicus is within its range was collected at one locality in Smith County, in is the fact that the authors have usually been able the eastern portion of the state. This species was to find workers of this species at new localities also collected in 2004 on the grounds of a hotel within 5 minutes by simply stopping at gas sta- near the Tucson Airport in Pima County, Arizona tions, motels, restaurants, and other such busi- (M.A.D., unpublished data). Considering the cli- nesses, and searching at the edges of parking lots, matic regimes under which this species thrives in at edges of grass areas, on tree trunks, exteriors southeastern North America and southern South walls of buildings, or on bare ground. Random America, there is no obvious reason why B. patag- stops at highways and rural roadsides have re- onicus should not extend its range through the vealed similar abundance and ease of detecting entire Gulf Coast, and through the states border- this species. ing Mexico, at least in irrigated urban and subur- A major reason for the success of B. patagoni- ban areas. cus in the United States may be its ability to The distribution by county and parish in the thrive in a variety of habitats, especially dis- southeastern United States of B. patagonicus turbed sites. Other contributing factors could be based on specimens examined and literature its ability to coexist with a variety of other domi- records is given below (also see Fig. 7). Gaps in nant ant species, such as Dorymyrmex bureni the distribution map do not imply absence of this (Trager), S. invicta, Pheidole moerens Wheeler, species, but may reflect a lack of collecting. Geor- and P. obscurithorax. This is similar to other spe- gia: Appling, Brooks, Chatham, Chattahoochee, cies of Brachymyrmex, which also usually occur Crisp, Decatur, Dodge, Early, Emanuel, Grady, where there are many other ant species that are Houston, Jeff Davis, Laurens, Muscogee, Peach, larger, faster, more hard-bodied, and armed with Stewart, Sumter, Talbot, Tattnall, Taylor, Telfair, stingers and more powerful mandibles. It is diffi- Thomas, Toombs, Treutlen, Webster, and Wilcox cult to avoid the conclusion that this species may Counties (MEM); Seminole County (Ipser et al. be protected by potent chemicals. 2004—reported as B. musculus). Florida: Ala- Because colonies can fit into a small space, chua, Bradford, Calhoun, Clay, Dade, Escambia, they easily could be transported by man from site Franklin, Gadsden, Highlands, Hillsborough, to site, making it likely that this species will in- Holmes, Jackson, Leon, Liberty, Madison, Mon- crease its range further. This hypothesis is sup- roe, Okaloosa, Osceola, Putnam, Santa Rosa, Tay- ported by isolated collections in the northern lor, Wakulla, and Walton Counties (ABSC, MEM). parts of both Alabama and Mississippi where this Alabama: Baldwin, Bibb, Butler, Choctaw, species was collected in landscaped areas of state Clarke, Coffee, Conecuh, Covington, Dale, Dallas, parks, campuses, or other public areas, but not Escambia, Geneva, Houston, Lee, Lowndes, Ma- yet found in more natural areas. Several isolated con, Marengo, Marion, Mobile, Monroe, Mont- populations in Mississippi have been found in gomery, Russell, Shelby, Sumter, Tuscaloosa, mulch, which may have been transported from ar- Washington, and Wilcox Counties (MEM; eas where this species was already common. MacGown & Forster 2005-reported as B. muscu- It is unclear what affect, if any, this species will lus). Mississippi: Clarke, Copiah, Covington, have on native species in the area, but based on Forrest, Franklin, George, Greene, Hancock, Har- its abundance where it is now established, it rison, Hinds, Jackson, Jasper, Jefferson Davis, might have some negative impact. In many areas Lauderdale, Leake, Lowndes, Madison, Marion, in the southern portions of Alabama and Missis- Marshall, Newton, Oktibbeha, Pearl River, Perry, sippi, this species, along with several other intro- Pike, Rankin, Smith, Scott, Stone, Warren, duced species including Linepithema humile Wayne, and Wilkinson Counties (MEM). Arkan- (Mayr), Pyramica membranifera (Emery), Cy- sas: Ashley and Union Counties (MEM). Louisi- phomyrmex rimosus (Spinola), S. invicta, P. moe- 464 Florida Entomologist 90(3) September 2007 rens, and P. obscurithorax, are now the most com- FOREL, A. 1899. Hymenoptera. III. Formicidae. Biol. monly found ants. Its effect, if any, on honeydew- Centrali-America. H. R. Porter. Dulau & Co., Lon- producing sap-sucking insects is also unknown. It don. 160 pp., 4 pl. also will be interesting to see how B. patagonicus HOOPER-BÙI, L. M., H. M. STORY, AND A. M. PRAN- interacts with the related, exotic species, B. ob- SCHKE. 2000. “Brachymyrmex patagonicus and B. de- pilis: Unwelcome Housepests in Louisiana”. Proc. scurior, over the next few years. Enormous popu- National Conference on Urban Entomol. Fort Lau- lations of B. obscurior are found in southern Flor- derdale, FL. ida, and this ground nesting species might com- IPSER, R. M., M. A. BRINKMAN, W. A. GARDNER, AND pete with B. patagonicus for food resources, and to H. B. PEELER. 2004. A survey of ground-dwelling a lesser extent, nesting sites. Brachymyrmex pat- ants (Hymenoptera: Formicidae) in Georgia. Florida agonicus shows the explosive increase and spread Entomol. 87: 253-260. that is typical of some recently imported species, MACGOWN, J. A., AND J. A. FORSTER. 2005. A prelimi- especially those that thrive in the ever-expanding nary list of the ants (Hymenoptera: Formicidae) of zone of habitats profoundly disturbed by human Alabama. Entomol. News 116: 61-74. MACGOWN, J. A., R. L. BROWN, AND J. G. HILL. 2005. An activities. It is not known whether this will lead annotated list of the Pyramica (Hymenoptera: For- to permanently high population levels, or micidae: Dacetini) of Mississippi. J. Kansas Ento- whether some form of biotic resistance will even- mol. Soc. 78: 285-289. tually catch up with this species. MACGOWN, J. A., AND R. L. BROWN. 2006. Survey of Ants (Hymenoptera: Formicidae) of the Tombigbee National Forest in Mississippi. J. Kansas Entomol. ACKNOWLEDGMENTS Soc. 79: 325-340. MAYR, G. L. 1868. Formicidae novae americannae col- We thank Linda Hooper-Bùi and Lee Womack (LSU) lectae a Prof. P. de Strobel. Ann. Soc. Nat. Modena 3: for the loan of Louisiana specimens and Estela Quirán 161-178. for verification of specimens and useful comments. Spe- NAVES, M. A. 1976. A Monograph of the Genus Pheidole cial cooperation has been provided by State Parks, Na- in Florida (Hymenoptera: Formicidae). Ph.D. Disser- tional Forests, National Wildlife Refuges, the Natchez tation, University of Florida. 120 pp. Trace Parkway, and from various private landowners in NAVES M. A. 1985. A monograph of the genus Pheidole the Southeast. This research was supported by Missis- in Florida (Hymenoptera: Formicidae). Insecta sippi Agricultural and Forestry Experiment Station Mundi 1: 53-90. State Project MIS-311080, the USDA-ARS Areawide O’KEEFE, S. T., J. L. COOK, T. DUDEK, D. F. WUNNEBUR- Management of Imported Fire Ant Project (Richard L. GER, M. D. GUZMAN, R. N. COULSON, AND S. B. VIN- Brown, P.I.), and the Georgia Department of Natural Re- SON. 2000. The distribution of Texas ants. sources (JoVonn G. Hill and Joe A. MacGown, Co-P.I.s). Southwestern Entomol. 22: 1-92. QUIRÁN, E. M. 2005. El Género Neotropical Brachy- REFERENCES CITED myrmex Mayr (Hymenoptera: Formicidae) en la Ar- gentina. II: Redescripción de las especies B. admotus BOLTON, B. 1995. A New General Catalogue of the Ants Mayr, B. brevicornis Emery y B. gaucho Santschi. of the World. Harvard University Press, Cambridge, Neotropical Entomol. 4: 761-768. MA, USA. 504 pp. QUIRÁN, E. M., J. J. MARTÍNEZ, AND A. O. BACHMANN. DASH, S. 2005. Species Diversity and Biogeography of 2004. The Neotropical genus Brachymyrmex Mayr, Ants (Hymenoptera: Formicidae) in Louisiana, with 1868 (Hymenoptera: Formicidae) in Argentina. Re- Notes on Their Ecology. M.S. Thesis, Louisiana State description of the type species, B. patagonicus Mayr, University, Baton Rouge, LA. v + 290 pp. 1868; B. bruchi Forel, 1912 and B. oculatus Santschi, DASH, S. T., L. M. HOOPER-BÙI, AND M. A. SEYMOUR. 1919. Acta Zoológica Mexicana (n.s.) 20: 273-285. 2005. The Pest Ants of Louisiana: A Guide to Their SANTSCHI, F. 1923. Revue des fourmis du genre Brach- Identification, Biology and Control. Louisiana State ymyrmex Mayr. Annals del Museo Nacional de Histo- University Agricultural Center Communications, ria de Buenos Aires 31: 650-678 + 4 plates. Baton Rouge. 24 pp. STORZ, S. R., AND W. R. TSCHINKEL. 2004. Distribution, DEYRUP, M. 2003. An updated list of Florida ants (Hy- spread, and ecological associations of the introduced menoptera: Formicidae). Florida Entomol. 86: 43-48. ant Pheidole obscurithorax in the southeastern DEYRUP, M., L. DAVIS, AND S. COVER. 2000. Exotic ants United States. J. Insect Sci. 4: 1-11. in Florida. Trans. American Entomol. Soc. 126: 293- WHEELER, G. C., AND J. WHEELER. 1978. Brachymyrmex 326. musculus, a new ant in the United States. Entomol. DEYRUP, M., C. JOHNSON, G. C. WHEELER, AND J. News 89: 189-190. WHEELER. 1989. A preliminary list of ants of Florida. Florida Entomol. 72: 91-101.