Introduction

Formica pallidefulva, the field ant, is a large, shiny, reddish to dark brown species that may be found in a variety of habitats in eastern North America into the Midwest. Colonies are in the soil, mostly underground, but in open areas they may build mounds in and around grass clumps. Nests of this species may be raided by slave-making ants such as Formica pergandei and Polyergus montivagus (Trager 2013).

Taxonomic History (Antcat.org)
Formica pallidefulva Latreille, 1802 valid.

Diagnosis
Formica pallidefulva could be confused with other species in the species group including F. biophilica, F. dolosa, and F. incerta, but can generally be distinguished from these species by the reduced setation and pubescence.

Identification
Worker: Large (total length about 6.0–7.0 mm); shiny, reddish brown to occasionally darker brown; a few erect setae present on head at posterior edge and clypeal margin, erect setae sparse or lacking on dorsum of mesosoma, and gaster with numerous (but not dense) erect setae; pubescence on entire body limited, not obvious, fine, not obscuring the sheen of the integument; head longer than wide; antenna elongate with 12 antennomeres, lacking club; eyes large, located above the midpoint of head; three ocelli present; mesosoma distinctly and broadly depressed between promesonotum and propodeum; propodeum broadly rounded, lacking spines or other adornment; waist, with a single node; acidopore present.

Queen. Similar in appearance to workers, but larger (about 10.0 mm TL); mesosoma enlarged and flattened dorsally; with wings or wing scars; eyes enlarged, ocelli present.

Male. Large, winged, 13 antennomeres, orangish brown, eyes greatly enlarged, ocelli present, mandibles present, gaster elongate.  

Biology and Economic Importance
Formica pallidefulva is widespread and common in open forested habitats in the southeastern United States. It nests in the soil and colonies often extend aboveground into mounds (Trager et al. 2007).

Formica pallidefulva is a host for several slave-making ant species including  Formica creightoni, F. pergandei, F. puberula, F. rubicunda, F. subintegra, and Polyergus montivagus (King & Trager, 2007; Trager, 2013; de la Mora et al., 2021).

Pest Status
This species does not sting and is not considered to be a pest species.

Distribution
U.S. Distribution: Eastern North America into midwestern USA (antmaps.org and.MEM).
Southeastern U.S. Distribution: Found in all southeastern states (antmaps.org and MEM).

Acknowledgments
Funding for the ant work being done by the MEM in the Southeast has been provided from several sources including the National Institute of Food and Agriculture, United States Department of Agriculture, under Project No. MIS-012040, the Mississippi Agricultural and Forestry Experiment Station at Mississippi State University, with support from State Project MIS-311080, NSF Grants BSR-9024810 and DFB-9200856, the Tombigbee National Forest (U.S. Forest Service), the Noxubee Wildlife Refuge, Mississippi Natural Heritage Program Research Grant, USDA Forest Service Agreement No. 08-99-07-CCS-010, the William H. Cross Expedition Fund, and primarily by the USDA-ARS Areawide Management of Imported Fire Ant Project (2001-2014) and USDA-ARS Areawide Management Invasive Ants Project. Additionally, special cooperation has been provided by State Parks, National Forests, National Wildlife Refuges, the Natchez Trace Parkway, and from various private landowners in the region.

Literature Cited

de la Mora, A., Sankovitz, M., Purcell, J. 2020. Ants (Hymenoptera: Formicidae) as host and intruder: recent advances and future directions in the study of exploitative strategies. Myrmecological News 30: 53–71.

King J. R., and J. C. Trager. 2007. Natural history of the slave making ant, Polyergus lucidus, sensu lato in northern Florida and its three Formica pallidefulva group hosts. Journal of Insect Science 7: Article 42: 14 pp.

Trager, J. C. 2013. Global revision of the dulotic ant genus Polyergus (Hymenoptera: Formicidae, Formicinae, Formicini). Zootaxa 3722 (4):50–548. 

Trager J. C., J. A. MacGown, and M. D. Trager. 2007. Revision of the Nearctic endemic Formica pallidefulva group. Memoirs of the American Entomological Institute 80: 610–636.