Aphaenogaster carolinensis, full face view of worker. (MISS, Oktibbeha Co.) (photo by Ryan Whitehouse and Joe A. MacGown)

Aphaenogaster carolinensis, lateral view of worker. (MISS, Oktibbeha Co.) (photo by Ryan Whitehouse and Joe A. MacGown)

Aphaenogaster carolinensis, dorsal view of worker. (MISS, Oktibbeha Co.) (photo by Ryan Whitehouse and Joe A. MacGown)

Aphaenogaster carolinensis, full face view of dealate queen. (MISS, Noxubee Co.) (photo by Ryan Whitehouse and Joe A. MacGown)

Aphaenogaster carolinensis, lateral view of dealate queen. (MISS, Noxubee Co.) (photo by Ryan Whitehouse and Joe A. MacGown)

Aphaenogaster carolinensis, dorsal view of dealate queen. (MISS, Noxubee Co.) (photo by Ryan Whitehouse and Joe A. MacGown)

Aphaenogaster carolinensis, full face view of alate queen. (MISS, Oktibbeha Co.) (photo by Ryan Whitehouse and Joe A. MacGown)

Aphaenogaster carolinensis, lateral view of alate queen. (MISS, Oktibbeha Co.) (photo by Ryan Whitehouse and Joe A. MacGown)

Aphaenogaster carolinensis, dorsalview of alate queen. (MISS, Oktibbeha Co.) (photo by Ryan Whitehouse and Joe A. MacGown)

Aphaenogaster carolinensis, full face view of male. (MISS, Oktibbeha Co.) (photo by Joe A. MacGown)

Aphaenogaster carolinensis, lateral view of male. (MISS, Oktibbeha Co.) (photo by Joe A. MacGown)

Aphaenogaster carolinensis, dorsal view of male. (MISS, Oktibbeha Co.) (photo by Joe A. MacGown)

Introduction
Ants in the genus Aphaenogaster are medium sized to large, slender with long legs and antennae, usually have propodeal spines (a few species lack spines), have 12 segmented antennae with the last 4 segments forming a weak club. The genus is widespread in North America and species nest in rotting wood, under bark, and in soil.

Diagnosis.Worker: Slender, medium sized (TL ≈ 3.5–5.5 mm), body reddish to yellowish brown, legs lighter yellowish brown; head, mesosoma, and waist with punctate sculpture, sculpture stronger on mesopleura and propodeum, gaster and legs shiny; entire body with scattered erect, white setae; shorter appressed setae scattered on head. Head longer than wide, elongate ovate, convex posteriorly, low occipital carina present; mandibles triangular; apical tooth the longest, followed by 3–4 smaller teeth and 6–7 denticles; frontal carina not covering antennal bases; scape not bent at base, scapes surpassing posterior margin of head about ¼ of its length; 12 antennomeres, apical four antennomeres forming a loose club; eyes large, located on sides of head at midway point; ocelli absent. Mesosoma not entire (in profile view), promesonotum and propodeum elevated above the metanotum; metanotal suture distinct, with transverse striae; propodeal dorsum flattened, not angled; declivity gently sloped, about 35°–45°; propodeal spines short, triangular, directed upward; legs long, mid and hind tibia with a single simple spur. Waist two-segmented; petiole pedunculate with raised triangular node, flattened ventrally; postpetiole with short peduncle, with raised globular node, flattened ventrally. Sting atrophied.

Queen: Larger than worker (TL ≈ 7.0–7.5 mm); color similar to worker, but often darker; sculpture on head, mesosoma, and waist similar to worker, but stronger, mesopleura mostly unsculptured; numerous short, light colored, erect setae present on entire body, more numerous and shorter than in worker; pubescence sparse and mostly noticeable on head. Head only slightly longer than wide, posterior margin slightly convex but not nearly as rounded as in worker; mandible similar in shape and dentition to worker; antennae similar to worker but scape wider and shorter, surpassing posterior margin of head by about 1/5 of its length; eyes enlarged, larger than worker; ocelli present. Mesosoma enlarged, rounded parallelogram shaped, mesoscutum broadly rounded anteriorly; propodeum gently sloped from mesoscutellum toward spines which are short, triangular and directed posteriorly; declivity steeper than in worker (about 60°). Wings, if present; transparent; forewing with stigma, with closed costal, basal, subbasal, discal, and two submarginal cells. Waist similar to worker but more robust.

Male: Small, about the size of worker (TL ≈ 5.0 mm), winged, dark brownish with a black head, legs yellowish brown; head with punctate sculpture, remainder of body mostly lacking sculpture,  shiny; a few scattered erect setae on head, mesosoma, and waist, setae more abundant on gaster but not dense; appressed pubescence on head and body sparse. Head slightly longer than wide, posterior margin convex, head flattened from front to back; mandibles well developed, triangular, elongate, with 5 to 6 teeth; clypeal margin convex; scape short, subequal to antennomeres II-III; antennae with 13 antennomeres with XI–X111 slightly enlarged; eyes extremely large, about ½ the length of head, located on lower half of head; three large ocelli present. In lateral view thorax enlarged, rounded square, and elevated above propodeum, mesoscutum broadly curved anteriorly and projecting over pronotum; propodeal dorsum flattened, longer than declivity which is steep (70–80 °); propodeum lacking spines, instead having slight protuberances. Wings clear, forewing with six closed cells as in queen. Waist segments with both nodes rounded and less raised than in worker and queen; parameres curved, triangular.

Similar species. Workers of A. fulva are dark brown, with mesonotum elevated and with a depression in the middle, have longer spines that are directed upward, and coxae have transverse striae (absent in A. carolinensis); A. lamellidens workers are larger, with a distinctive toothed lobe on frontal carina, and often with black banded legs; A. picea are brownish black, have a less elongate head, longer propodeal spines, and only found at high elevations in the southeastern USA; A. rudis has less elongate head and longer propodeal spines; and A. tennesseensis islarger and has long curved propodeal spines.

Biology/Habitat. This is a common ant in wooded habitats throughout the Southeast where it nests in small colonies in the soil, that often extend into rotting wood. Alates have been collected in early to mid-June.

Pest Status: Members of this genus have atrophied stingers and thus, are not stinging pests, and because this species typically nests in the soil, it is not considered a structural pest.

Distribution
Widespread throughout the Southeast.