Strumigenys missouriensis

In Ohio colonies were found nesting in soil in forested sites.

Identification
Bolton (2000) - A member of the Strumigenys pulchella-group. Very closely related to Strumigenys reflexa but quickly distinguished as in missouriensis most or all of the large hairs on the lateral clypeal margins curve anteriorly, whereas in reflexa all hairs on the lateral clypeal margins are markedly reflexed, curving posterolaterally. See also under Strumigenys pulchella.

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



Biology
Wesson and Wesson (1939) - Four colonies and numerous stray workers were found in a cedar thicket in western Pike County, Ohio. The first workers were seen in and around some little-used gallaries of Aphaenogaster picea under a small stone, and the colony was located about 30 cm. away just beneath the humus. Two other colonies were likewise in the soil, not more than 4 cm. below the surface. The latter, however, were not visibly associated with any other ants. Scattered, stray workers were found just under the top layer of the humus. The cedar grove was located on the gently sloping base of a hill. Mingled with the cedars were a few small oaks and an occasional maple sapling. The soil was a black clay from 5 to 15 cm. deep above the limestone bed rock. Above the clay was a thick, springy layer of loose decaying cedar needles, leaves and grass. Abounding in this debris were Ponera pennsylvanica, Myrmecina graminicola, and hordes of Collembola, as well as Strumigenys. Here, in an area of 3 by 9 meters, were found S. missouriensis, Strumigenys manni, Strumigenys dietrichi, and Strumigenys venatrix.

On careful comparison of our specimens with 2 worker cotypes loaned by Dr. M. R. Smith, we find that, although some of the workers agree closely with the cotypes, there is quite a perceptible amount of variation both among workers from the same colony and among the 4 colonies found. This variation lies almost entirely in the direction of forms which differ from the cotypes in the following details: (1) the head is slightly more robust; (2) the clypeus is slightly depressed in the middle; (3) the antennal scapes are somewhat more angulate (4) the sculpture is distinctly coarser; (5) the hairs on the head are larger, especially on the clypeus, and are fewer in number.

Nomenclature

 *  missouriensis. Strumigenys (Cephaloxys) missouriensis Smith, M.R. 1931c: 701, pl. 4, fig. 14 (w.) U.S.A. Brown, 1953g: 72 (q.). Combination in S. (Trichoscapa): Smith, M.R., 1947f: 587; Creighton, 1950a: 307; in Smithistruma: Smith, M.R., 1951a: 828; Brown, 1953g: 72; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 124. Senior synonym of sculpturata: Smith, M.R. 1951a: 828; Brown, 1953g: 72. See also: Wilson, 1954: 485; Bolton, 2000: 121.
 * sculpturata. Strumigenys (Cephaloxys) sculpturata Smith, M.R. 1931c: 706, pl. 4, fig. 15 (w.) U.S.A. Combination in S. (Trichoscapa): Smith, M.R., 1947f: 587; Creighton, 1950a: 310. Junior synonym of missouriensis: Smith, M.R. 1951a: 828; Brown, 1953g: 72.

Worker
Bolton (2000) - TL 2.0-2.2, HL 0.54-0.60, HW 0.38-0.42, CI 68-72, ML 0.08-0.10, MI 13-18, SL 0.26-0.31, SI 69-75, PW 0.25-0.28, AL 0.54-0.60 (10 measured).

Anterior clypeal margin broadly shallowly convex to almost transverse. Clypeal dorsum flat to shallowly depressed, usually hairless from about centre to posterior border. Anterior clypeal margin with 1-2 pairs of hairs that curve away from the midline, directed laterally or posterolaterally; hairs on lateral clypeal margins mostly or entirely curved anteriorly. Pilosity of head and body otherwise as Strumigenys reflexa.

Type Material
Bolton (2000) - Syntype workers, U.S.A. Missouri, Columbia, 20. viii. 1929 (M. Talbot) [examined].