The Ants of northern piedmont

Here is a synopsis of the ants of northern Piedmont with a focus on the mesic mixed hardwood forest habitat. Here I consider the counties of Fairfax and Prince William as Piedmont, rather than Coastal Plain.

The mesic mixed hardwood forest is a staple forest in Northern Piedmont. The trees consist primarily of beech, oak, and hickory, but many other species may be found. See https://www.dcr.virginia.gov/natural-heritage/natural-communities/nctb4 for more information on the forests of Virginia.

The species Camponotus pennsylvanicus, Camponotus chromaiodes, and Formica subsericea are the most commonly found by the casual observer due to their large size and diurnal habits (although Camponotus are more prevalent at night, large colonies will often send out foragers during the day as well). Rocks are often widespread throughout these forests and may be flipped to reveal many species of ants. In particular, Aphaenogaster rudis and Camponotus castaneus are the most common species under rocks. I have also found species such as Brachymyrmex depilis, Myrmecina americana, Strumigenys rostrata, Strumigenys pergandei, Aphaenogaster fulva, Brachyponera chinensis, Nylanderia flavipes, Nylanderia faisonensis, Formica pallidefulva, Formica subsericea, Ponera pennsylvanica, Hypoponera opacior, Lasius americanus, Lasius aphidicola, Lasius claviger, Lasius interjectus, Lasius nearcticus, Prenolepis imparis, Stigmatomma pallipes, and Solenopsis molesta beneath rocks in this habitat. In fallen wood, I have found Aphaenogaster fulva, Aphaenogaster tennesseensis, Camponotus chromaiodes, Camponotus pennsylvanicus, Strumigenys rostrata, Proceratium crassicorne, Ponera pennsylvanica, Camponotus subbarbatus, Lasius americanus, Lasius aphidicola, Aphaenogaster rudis, Aphaenogaster lamellidens, Nylanderia faisonensis, Nylanderia flavipes, and Brachyponera chinensis. In nuts, I have found Tapinoma sessile, Temnothorax curvispinosus, Temnothorax longispinosus, and Camponotus subbarbatus in this habitat. Strumigenys rostrata, Temnothorax ambiguus, and Strumigenys pilinasis may also be commonly found. Also present are leaf litter species such as Stenamma impar and several species of Strumigenys and arboreal species such as Aphaenogaster tennesseensis, Crematogaster ashmeadi, Colobopsis obliqua, Colobopsis mississippiensis, Camponotus nearcticus, Camponotus caryae, Camponotus discolor, Camponotus snellingi, Aphaenogaster mariae, and Dolichoderus plagiatus may also be found. Myrmica punctiventris and Myrmica spatulata were also found, although nesting habitat was not noted. Common species in open/sandy areas such as Tetramorium immigrants, Lasius neoniger, Lasius muprhyi, Lasius latipes (?), Lasius speculiventris (?), Lasius brevicornis, Crematogaster lineolata, Formica pallidefulva, Monomorium minimum, Pheidole bicarinata, Pheidole tysoni, Pheidole pilifera, Trachymyrmex septentrionalis, Dorymyrmex bureni, Solenopsis carolinensis, Forelius pruinosus, Formica dolosa, and Formica incerta may be sparse or completely absent throughout this habitat. Ants common in other habitats (in damper, marshy regions, Crematogaster pilosa, Crematogaster vermiculata, Dolichoderus mariae, Dolichoderus taschenbergi, Dolichoderus pustulatus) are sparse or absent from MMHF.

Regarding specific species:

Formica subintegra may be locally abundant throughout these forests. It may be commonly found raiding Formica subsericea nests.

Formica exsectoides is locally abundant throughout northern Piedmont. One of the most well-known populations is at Patuxent Research Refuge, where hundreds of colonies with plenty of mounds are present throughout the refuge.

Polyergus spp., like Formica subintegra, may be locally abundant. These species are obligate parasites.

Neivamymrex spp. are not present in Northern Virginia. Although it is unlikely they were present in NoVA in the first place, as their northernmost range in Virginia seems to be around Richmond, human development has resulted in their regional extinction if they were ever present in the area.

Formica difficilis and Formica querquetulana may have been common throughout open fields and prairies in Northern Piedmont. Due to European colonization, the Native Americans who had set controlled burns for much of the Holocene were killed or forced to move west. Thus, with the lack of controlled burns, the grassland habitat has dwindled greatly allowing the forest to creep in and replace it. Due to a lack of proper habitat, F. querquetulana may be regionally extinct in Northern Virginia and F. difficilis may be soon to follow if this trend continues.

Temnothorax pergandei is locally abundant in sandier open areas throughout northern Virginia. This large, distinctive species is unlike any other Temnothorax in our area, appearing more like a tiny Aphaenogaster than a Temnothorax. In the south, this species is one of the most common species and has several distinct morphs. In our area, I have only seen the black morph.

Temnothorax ambiguus is a common species in the schaumii-group. Flights occur at around the same time as its sister species Temnothorax curvispinosus. It differs as it is primarily ground nesting, the propodeal spines are distinctly shorter (equal distance apart as length of spines, whereas curvispinosus has longer spines than distance apart).

Temnothorax texanus is an arenicolous species. I have not seen it present in our area.

Temnothorax schaumii should be relatively common throughout the northern Piedmont, although I have not seen them in the region. In Mississippi, I found workers foraging on vines and on bark of live trees.

Camponotus caryae is a common species in our area. Both males and queens regularly come to blacklights and flights occur after Camponotus nearcticus. Queens are distinctly smaller (approx. 1 mm smaller) and have distinct malar setation.