Subfamily MYRMICINAE
Tribe CREMATOGASTRINI
Crematogaster ashmeadi Mayr

Introduction
Ants in the genus Crematogaster are often referred to as acrobat ants because of their propensity to arc the gaster upward and over the alitrunk in a manner that resembles a contortionist or acrobat. They are small, monomorphic ants. Workers have an 11-segmented antenna, the presence of variably long propodeal spines, a flattened petiole, and a somewhat heart-shaped gaster. The postpetiole is attached to the dorsal surface of the gaster, and this characteristic will differentiate this genus from other genera in our area.

Diagnosis.Worker: Small, monomorphic (TL ≈ 2.5–3.0 mm), light brown to blackish; pronotal area with only a few erect setae present, which are confined to humeri; pronotal pleurae mostly unsculptured, smooth, reflective, and shiny; mesosoma with striate sculpture; head about as wide as long; 11, terminating in 3-segmented club; eyes located about midway on sides of head; propodeal spines present, short, inner margins parallel to the longitudinal body axis (in dorsal view); waist 2-segmented, petiole flattened, postpetiole attached to dorsal surface of gaster; gaster somewhat heart shaped and often upturned; sting present.

Queen: Similar in appearance to workers, but larger (≈ 7.0 mm); mesosoma enlarged and flattened dorsally; with wings or wing scars; eyes enlarged, ocelli present.

Male: Small (≈ 3.0 mm) winged, 13 antennomeres, dark brownish with a black head, head flattened, and eyes large, ocelli present.

Similar species. Two other similar species are commonly found in the same habitats, C. lineolata and C. pilosa. Crematogaster lineolata is larger, with numerous stiff, erect setae on mesosoma; more sculptured; and has elongate propodeal spines. Crematogaster pilosa is bicolored orangish brown and brownish black, is shiny in overall appearance, has erect pubescence on the head, and has longer propodeal spines.

Biology/Habitat. Ashmead’s acrobat ant is a widespread and common arboreal species in southeastern forests where it nests in trees, shrubs, vines, and various cavities in a wide variety of habitats. This widespread species is widespread in the Southeast.

Pest Status. Occasional nuisance pest, can sting, but not a serious stinging pest. It is an occasional structural pest. This species has also been reported to damage insulation boards and cause short circuits in electrical equipment. Smith (1965) reported that C. ashmeadi damaged insulated board and hard fiberboard, and removed rubber insulation from telephone wires causing short circuits. In Mississippi, workers of this species short circuited an air conditioner contactor relay (see photo above). .

Literature Cited
Smith, M. R. 1965. House-infesting ants of the Eastern United States, their recognition, biology, and economic importance. United States Department of Agriculture, Technical Bulletin No. 1326: i-105.