The Ant Hymenoptera Formicidae Fauna of Black Belt

The Ant (Hymenoptera: Formicidae) Fauna of Black Belt Prairie Remnants in Mississippi and Alabama Jo. Vonn G. Hill and Richard L. Brown Mississippi Entomological Museum, Mississippi State University, Box 9775, Mississippi State MS 39762 Introduction Prior to European settlement the southeastern United States had several regions dominated by grasslands or prairie (De. Selm and Murdock 1993, Peacock and Schauwecker 2003). One such region, called the “Black Belt, ”extends in an arc from Mc. Nairy County, Tennessee to Russell County, Alabama, and contains a heterogeneous landscape of prairies and several types of forest. Surveys conducted by the General Land Office in the 1830’s suggest that prairies once covered at least 144, 000 hectares of the Black Belt (Barone 2005). Since that time, it has been estimated that 99% of these prairies have been lost by suppression of fire, erosion, and agricultural and urban development, much like the midwestern prairies (Noss et al. 1995). The Mississippi Natural Heritage Program gives Black Belt Prairie remnants a ranking of S 1, meaning they are "critically imperiled" within the state due to extreme rarity or factors making their biota vulnerable to extirpation (Mississippi Museum of Natural Science 2002). Today small remnants of these prairies may be found along roadsides, fencerows, gas, rail, and powerline right of ways, and on marginal lands not suitable for agriculture. These remaining prairie remnants support a diverse and distinct flora and fauna including endemic species of insects as well as populations of plants and insects that otherwise are found primarily in the Great Plains. Ants are typically the most dominant and influential force in terrestrial ecosystems, and as such, may be among the most promising groups of animals for inclusion in community-based studies due to their contributions to ecosystem function (Hölldobler and Wilson 1990) Given the ecological importance of ants, documentation of the ant fauna of endangered ecosystems, such as the Black Belt Prairie, could provide useful information for guiding current management and future conservation/restoration projects in those systems. Results A total of 53 ant species and the hybrid fire ant, Solenopsis invicta x richteri, representing 6 subfamilies and 25 genera were collected (Table 1). The imported fire ants (S. invicta and S. invicta x richteri) and Brachymyrmex patagonicus Mayr were the only exotic species collected. The most diverse subfamilies included the Myrmicinae with 28 species and the Formicinae with 14 species. The most diverse genera were Pyramica with six species and Pheidole with five species The species collected at the most sites was Monomorium minimum (Buckley) (23 sites), followed by Forelius mccooki (Roger) (17 sites) and Pheidole tysoni Forel and Solenopsis molesta (Say) (16 sites both). Imported fire ants were collected at all the sites with the hybrid fire ant, S. invicta x richteri, occurring at the sites from Plum Creek northward (16 sites), while the red fire ant, S. invicta Buren was collected south of the Plum Creek site (7 sites). Two species found in this survey, Hyponera inexorata (Wheeler) and Pheidole lamia Wheeler, are new state records for Alabama. The number of species at sites ranged from a low of three at the County Road 37 site to highs of 28, 26, and 24, at the Osborn, Crawford, and Tombigbee sites (Figure 2) respectively. The mean number of species per site was 12. 35, and 10 of the sites contained at least this many species. Methods Twenty-three prairie remnants located throughout the Black Belt (Figure 1) were surveyed from June 2003 through July 2007. Sites were chosen based on their accessibility and their relative lack of anthropogenic disturbance. Almost all of the sites are within or near the boundaries of known historic prairies, as described by Barone (2005) based on General Land Office plat maps from the 1830’s and 1840’s. (Figure 1. ). Sites were sampled multiple times across seasons and years using a variety of collecting techniques including hand collecting, baiting, litter sampling, and the use of pitfall traps, to ensure that the sites had been sample effectively. Specimens were collected in 90% ethanol, then were pinned, labeled, and identified. Pitfall trap samples taken from the Osborn and Crawford sites in the 1990’s by the Mississippi Entomological Museum (MEM) were also searched for additional species that may occur in prairie remnants. Voucher specimens were deposited in the MEM. 3 Figure 2. Black Belt Prairie remnant in Tombigbee National Forest. (Site 5) Figure 3. Major worker of Pheidole pilifera in prairie remnant in Tombigbee National Forest. Table 1. The list presented is arranged by subfamily, tribe, and genus according to Bolton (2003). Names follow Bolton (1995), except Dorymyrmex, which follows Snelling (1995); Pyramica, which follows Bolton (2000); and Pheidole, which follows Wilson (2003). Site numbers and locations are given in Figure 1. An * denotes that this species was found in the collection of the MEM from pitfall traps run in the early 1990’s. Family Formicidae Subfamily Dolichoderinae Dolichoderus pustulatus Mayr: Sites 7*, 11*, 22. Dorymyrmex smithi Mc. Cook: Sites 17, 21. Forelius mccooki (Mc. Cook) (Fig. 4. 1): Sites 2 -7, 10 -12, 14 -18, 20 -22. Tapinoma sessile (Say) (Fig. 4. 2): Sites 3, 10, 11. Subfamily Formicinae Lasius neoniger Emery: Site 11. Brachymyrmex depilis Emery: Sites 2, 14, 15, 20, 22 Brachymyrmex patagonicus Mayr: Sites 13, 21 -23. Paratrechina arenivaga (Wheeler): Sites 5, 7, 11, 12, 14, 16. Paratrechina vividula (Nylander): Sites 1 -4, 7, 8, 11 -22. Prenolepis imparis Emery: Sites 5, 12. Camponotus castaneus (Latreille): Sites 5, 7, 11. Camponotus decipiens Emery: Sites 5, 15. Camponotus impressus (Roger): Site 7. Camponotus mississippiensis Smith: Sites 12, 13, 19. Formica dolosa Buren: Sites 1, 2, 4, 5, 12, 13, 15, 16, 18. Polyergus montivagus Wheeler: Site 5. Subfamily Pseudomyrmecinae Pseudomyrmex pallidus (Smith): Sites 17, 20, 22. Pseudomyrmex seminole Ward: Sites 20, 21. Subfamily Ponerinae Hypoponera inexorata (Wheeler) (Fig. 4. 6): Sites 6, 7, 13, 15, 19, 20. Hypoponera opaciceps (Mayr): Sites 1, 15, 16, 19, 21. Hypoponera opacior (Forel): Sites 3, 5, 7, 10 -19, 22. Ponera pennsylvanica Buckley: Sites 2, 4, 5, 7, 8, 11. Subfamily Proceratiinae Proceratium pergandei (Emery): Site 7. Subfamily Myrmicinae Pyramica bimarginata (Wesson & Wesson): Site 7*. Pyramica creightoni (Smith): Sites 11, 12, 22. Pyramica dietrichi (Smith): Sites 11, 14, 17. Pyramica margaritae (Forel): Site 21. Pyramica membranifera (Emery): Site 20. Pyramica ornata (Mayr): Site 7. Pyramica talpa (Weber): Sites 7, 11, 12, 13, 17, 22. Strumigenys louisianae Roger: Sites 7, 8, 11. Cyphomyrmex rimosus (Spinola): Sites 21, 22. Trachymyrmex septentrionalis (Mc. Cook): Sites 5, 7, 11. Monomorium minimum (Buckley): Sites 1 - 23. Solenopsis invicta Buren: Sites 16 -23. Solenopsis invicta x richteri (Fig. 4. 5): Sites 1 -15. Solenopsis c. f. molesta (Say) : Sites 1, 2, 5, 7 -15, 18, 20 -22. Solenopsis picta Emery: Site 7. Aphaenogaster carolinensis Wheeler: Sites 2, 11. Aphaenogaster flemingi Smith: Site 5. Aphaenogaster treatae Forel: Sites 5, 7, 11, 15. Pheidole bicarinata Mayr: Sites 6, 12, 15, 18. Pheidole dentata Mayr: Sites 1, 2, 5, 6, 7, 8, 11, 12, 15, 22. Pheidole lamia Wheeler: Site 15. Pheidole pilifera Roger (Figs. 3, 4. 3): Sites 5, 7, 11. Pheidole tysoni Forel: Sites 1, 2, 4 -9, 11 -13, 16, 18, 20 -22. Crematogaster ashmeadi Mayr: Sites 7, 13. Crematogaster lineolata (Say) (Fig. 4. 4): Sites 2, 5 -7, 11, 15, 17, 21, 22. Crematogaster missuriensis Emery: Sites 1, 5, 8, 11 -13, 17. Crematogaster pilosa Emery: Sites 5, 21, 22. Temnothorax curvispinosus (Mayr): Sites 7, 12, 15. Temnothorax pergandei (Emery): Sites 2, 5 -7, 11. Myrmecina americana Emery: Sites 5, 7, 11, 13, 18, 20, 22. Literature Cited Barone, J. A. 2005. Historical presence and distribution of prairies in the Black Belt of Mississippi and Alabama. Castanea 70: 170 -183. De. Selm, H. R. and N. Murdock. 1993. Grass-dominated communities. Pp. 87 -141. In Martin, W. H. , S. G. Boyce, and A. C. Echternacht (eds. ). Biodiversity of the Southeastern United States: Upland Terrestrial Communities. John Wiley and Sons, Inc. New York. 373 pp. Holldöbler, B. and E. O. Wilson. 1990. The Ants. Harvard University Press. Cambridge, MA. 732 pp. Mississippi Museum of Natural Science. Natural Heritage Inventory: Global and State Rankings. http: //www. mdwfp. com/museum/html/research/ranking. asp. Accessed April, 2002. Noss, R. F. , E. T. La. Roe III, and J. M. Scott. 1995. Endangered ecosystems of the United States: a preliminary assessment of loss and degradation. United States Department of Interior, National Biological Service, Biological Report 28. Washington D. C. Peacock, E. and T. Schauwecker. (eds) 2003. Blackland Prairies of the Gulf Coastal Plain: Nature, Culture, and Sustainability. University of Alabama Press, Tuscaloosa, AL. 348 pp. Acknowledgements Figure 1. Map of historical prairie remnants based on General Land Office Surveys in the 1930’s (from Barone 2005) with site number, location, and, in parentheses, the number of ant species collected during this survey. Figure 4. Selected species of ants: 1. Forelius mccooki (Mc. Cook) 2. Tapinoma sessile (Say) 3. Pheidole pilifera (Roger) 4. Crematogaster lineolata (Say) 5. Solenopsis invicta x richteri 6. Hypoponera inexorata (Wheeler). This project was supported by the Mississippi Experiment Station Project MIS-311080, USDA-ARS Areawide Management of the Imported Fire Ant Project, and National Science Foundation grants BSR-90204 and DEB 9200856. We thank Joe Mac. Gown for his aid in verifying identifications and help producing the poster. We thank Sarah Mc. Clure, Rebecca Jones, and Savannah Duckworth for their assistance in specimen preparation. We also thank the various public land owners and public land managers who allowed collections to be made on their lands. Figure 1 was primarily produced by John Barone.