Strumigenys hyalina

Identification
Some Ohio and Indiana samples were previously included in Strumigenys abdita (Brown, 1953a:90) and a Mississippi worker had been misidentified as Strumigenys bunki. The confusion of this species with abdita was almost certainly based on observation of the striking clypeal pilosity which both possess, and the fact that both had been found at the same locality (Catawba Beach). However, abdita belongs to the pulchella-group and has only 4 strong principal basal teeth on the mandible. Confusion with bunki, which belongs in the same group as hyalina, probably depended upon the presence of a mandibular diastema, but the diastema in bunki is short (less than length of basal tooth), whereas in hyalina it is definitely longer (greater than length of basal tooth). Also, bunki lacks apicoscrobal and mesonotal flagellate hairs, features that are immediately obvious in hyalina.

Apart from the long-diastemate, small-toothed mandible and distribution of flagellate hairs, the most striking feature of hyalina is its clypeal pilosity, not duplicated anywhere else in the group. The closest relative of hyalina yet found is certainly Strumigenys chiricahua, known from a single specimen from Arizona. This shares the long mandibular diastema but has a very different dental array. This, plus the other key characters and those noted above under the discussion of chiricahua, will differentiate the two species.

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



Nomenclature

 *  hyalina. Pyramica hyalina Bolton, 2000: 128 (w.q.) U.S.A. Combination in Strumigenys: Baroni Urbani & De Andrade, 2007: 121

Worker
Holotype. TL 2.0, HL 0.55, HW 0.39, CI 71, ML 0.09, MI 16, SL 0.30, SI 77, PW 0.26, AL 0.52. Fully closed mandible with a distinct basal gap that is longer than the basal tooth. Teeth of principal basal row small and narrow, the first (basal) tooth two times longer than the second; tooth 3 equal in length to 1 or slightly longer; tooth 4 shorter than 3 (about same length as tooth 2); tooth 5 longer than 4. Anterior clypeal margin transverse or very shallowly convex. Dorsum of clypeus with numerous very broadly spatulate or spoon-shaped hairs which are strongly curved and in full-face view appear scale-like; they are translucent at high magnification. Lateral clypeal margins with a fringe of anteriorly curved hairs that are very broadly spatulate or spoon-shaped and very conspicuous. Ground-pilosity of head immediately behind clypeus the same shape and almost as broad as that on clypeus, but more posteriorly on the vertex the hairs become finer, longer, narrower and much more erect. Apicoscrobal hair very long and extremely finely flagellate. Cephalic dorsum with at least one pair of flagellate or looped hairs, located close to the occipital margin. Pronotal humeri each with an extremely long fine flagellate hair; pronotal dorsum and mesonotum each with a pair of long fine flagellate hairs. One or 2 flagellate hairs project from dorsal (outer) surface of hind tibia and basitarsus.

Paratypes. TL 1.9-2.0, HL 0.52-0.54, HW 0.37-0.38, CI 70-71, ML 0.09, MI 16-17, SL 0.28-0.30, SI 76-77, PW 0.23-0.25, AL 0.50-0.52 (3 measured). One paratype has a minute adventitious denticle proximal of the first (basal) tooth).

Type Material
Holotype worker, U.S.A.: Ohio, Catawba Beach, 18.viii.1938, no. 171 (M.E. Amstutz) (holotype is top worker on a pin of 3).

Paratypes. 3 workers and 1 queen (2 workers are middle and bottom specimens on same pin as holotype) with same data as holotype; 1 worker, Ohio, Catawba Beach, 18.viii.1935 (M. Talbot); 1 worker Mississippi, Oktibbeha Co., Noxubee Ref., 21.vii.1981, berlese litter, hardwood forest (R.L. Brown) (MCZ,, ).