Strumigenys creightoni

Identification
Bolton (2000) - This species is often confused with Strumigenys bunki (rostrata-group) but length of diastema and arrangement of principal dentition is quite different; see respective group-diagnoses and discussion under bunki.

Four species in this group (Strumigenys abdita, creightoni, Strumigenys deyrupi, Strumigenys metazytes) do not have hairs on the anterior or lateral clypeal margins that are recurved or reflexed. Of these creightoni lacks erect hairs on the vertex close to the occipital margin, lacks an apicoscrobal hair, lacks a fine projecting hair at the pronotal humerus, and lacks standing pilosity on the mesonotum. In the other three species filiform or flagellate hairs are present at all these locations.

P. deyrupi separates from both abdita and metazytes as its main pilosity is entirely of long fine flagellate hairs. These occur as a pair on the vertex close to the occipital margin, a pair on the pronotal dorsum (as well as at the humeri), another pair on the mesonotum, and in numbers on the waist segments and especially the first gastral tergite. In both abdita and metazytes the hairs in many or all of these positions are stouter, simple and stiffly filiform, and at most evenly shallowly curved.

Of the last two species abdita is generally larger and its mandibles are usually longer (HL 0.53-0.60, HW 0.40-0.43, MI 17-22) than in metazytes (HL 0.51-0.52, HW 0.36-0.38, MI 16-17). Also, in abdita the anterior clypeal margin is very wide and has abruptly rounded anterolateral angles. The clypeal dorsum has broadly spatulate to spoon-shaped ground-pilosity that is very dense and conspicuous, and is very similar in shape and size to the hairs that fringe the lateral margins. Standing pilosity on the first gastral tergite is usually restricted to an apical and a basal transverse row, though some samples are known which have intermediate hairs present. By comparison metazytes has a short but very shallowly convex anterior clypeal margin that curves evenly into the lateral margins through widely rounded anterolateral angles. Its clypeal dorsum has minute inconspicuous spatulate ground-pilosity that is very much smaller than the large hairs that fringe the lateral margins. Pilosity on its first gastral tergite is more or less evenly distributed over the sclerite.

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



Nomenclature

 *  creightoni. Strumigenys (Cephaloxys) creightoni Smith, M.R. 1931c: 705, pl. 4, fig. 16 (w.) U.S.A. Brown, 1953g: 80 (q.); Brown, 1964a: 191 (m.). Combination in S. (Trichoscapa): Smith, M.R., 1947f: 587; Creighton, 1950a: 305; in Smithistruma: Smith, M.R., 1951a: 827; Brown, 1953g: 80; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 118. See also: Bolton, 2000: 118.

Worker
Bolton (2000) - TL 2.0-2.4, HL 0.54-0.61, HW 0.36-0.41, CI 66-69, ML 0.09-0.12, MI 17-21, SL 0.27-0.30, SI 69-76, PW 0.25-0.27, AL 0.54-0.58 (15 measured).

Anterior clypeal margin almost transverse to extremely shallowly convex. Clypeal dorsum with dense small spatulate hairs that are much smaller than those that fringe the lateral clypeal margins. Cephalic dorsum behind clypeus densely clothed with conspicuous spoon-shaped ground-pilosity but without standing or projecting hairs anywhere on dorsum or dorsolateral margin. Dorsal alitrunk with spoon-shaped ground-pilosity but lacking standing hairs of any form. Pronotal humerus with a somewhat enlarged spoon-shaped hair. First gastral tergite with fine flagellate hairs. Basitarsi of hind legs with 1-2 long flagellate hairs projecting from dorsal (outer) surface.

Type Material
Bolton (2000) - Lectotype worker (by designation of Brown, 1953a: 80) and paralectotype workers, U.S.A. : Alabama, Mobile, Spring Hill, l.vii.1929 (W. S. Creighton) [examined].