Strumigenys bimarginata

An Illinois specimen was collected from andropogon sod.

Identification
Bolton (2000) - A member of the clypeata group. Only two species exhibit a bicarinate clypeal margin that is clearly visible in full-face view: bimarginata and Strumigenys filirrhina. Their different clypeal and cephalic pilosities distinguish the two species (development of the clypeus is discussed in the group treatment).

Distribution based on Regional Taxon Lists
Nearctic Region: United States.



Nomenclature

 *  bimarginata. Strumigenys (Cephaloxys) bimarginata Wesson, L.G. & Wesson, R.G., 1939: 95, pl. 3, fig. 2 (w.q.) U.S.A. Combination in S. (Trichoscapa): Smith, M.R., 1947f: 587; Creighton, 1950a: 304; in Smithistruma: Smith, M.R., 1951a: 827; Brown, 1953g: 62; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 116. See also: Bolton, 2000: 103.

Worker
Bolton (2000) - TL 2.2-2.4, HL 0.58-0.61, HW 0.34-0.36, CI 62-65, ML 0.10, MI 18-22, SL 0.27-0.29, SI 76-78, PW 0.23-0.25, AL 0.52-0.55 (2 measured). Clypeus in full-face view distinctly bimarginate around its entire anterior and lateral borders; the two margins concentric, the outer (lower) margin in this view projects out beyond the inner (upper) margin. In profile the upper and lower margins seen to be separated by a marked concave peripheral groove or gutter. Hairs on clypeal margins long and fine, slightly flattened, splayed or even weakly forked apically, may be weakly curved away from the midline or somewhat posteriorly. Clypeal dorsum with all hairs more or less erect, fairly short and curved, flattened, splayed or weakly forked apically, some may curve posteriorly; no long flagellate hairs on clypeus. Flagellate hairs absent from dorsolateral margins of head; without a flagellate pair posteriorly on the cephalic dorsum. Cephalic ground-pilosity narrowly spatulate, with flattened and splayed apices, curved anteriorly or weakly anteromedially. Flagellate hairs present at pronotal h umerus, on pronotal and mesonotal dorsa, on hind basitarsus and on first gastral tergite where thay are very long, mostly longer than the petiolar peduncle.

Type Material
Bolton (2000) - Syntype worker and queen, U. S. A.: Ohio, Adams County, Cedar Mills (Wesson & Wesson) [examined].