Strumigenys chiricahua

This species is known from two collections and possibly a third. The holotype worker was collected in a Berlesate sample of concentrated leaf litter from an oak woodland, and a colony of more than 20 workers was extracted from a rotten root in a juniper woodland. Both validated collections were made in August at or near the Southwestern Research Station in the Chiricahua Mountains in Arizona. A third possible specimen is an alate queen tentatively identified from images. This specimen was collected by Gary Alpert in a Malaise trap 16 km southeast of Flagstaff in Walnut Canyon National Monument, Coconino County, in the bottom of a ravine (BugGuide 2020a) (Booher, 2021).

Identification
Bolton (2000) - A member of the Strumigenys rostrata-group. P. chiricahua has a much longer diastema than is usual in this group, matched only by Strumigenys hyalina. The keyed characters of dentition, clypeal pilosity and length of basigastral costulae will easily separate the two.

Apart from these characters chiricahua has a relatively long hind tibia, ca 0.72 X HW as opposed to 0.67 X HW in hyalina, and the two have the clypeus somewhat different in shape. In full-face view the lateral margins of the clypeus in chiricahua are more or less straight and are quite evenly divergent posteriorly; the maximum width across the clypeus is ca 1.80 X the width across the outer margins of the fully closed mandibles at the point where they intersect the anterior clypeal margin. In hyalina, on the other hand, the lateral clypeal margins are very obviously convex and the maximum width across the clypeus is ca 2.20 X the width across the outer margins of the fully closed mandibles at the point where they intersect the anterior clypeal margin.

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

Nomenclature

 *  chiricahua. Smithistruma chiricahua Ward, 1988: 119, fig. 8 (w.) U.S.A. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 117. See also: Bolton, 2000: 127.

Worker
Bolton (2000) - TL 2.1, HL 0.55, HW 0.39, CI 71, ML 0.10, MI 18, SL 0.31, SI 79, PW 0.24, AL 0.57. Fully closed mandibles with a distinct basal gap; length of diastema greater than length of basal tooth. Five principal teeth in the basal row, tooth 1 (basal) distinctly shorter than 2; tooth 2 fractionally shorter than 3 (which is the longest tooth); 4 and 5 subequal, shorter than 2 or 3. Anterior clypeal margin broadly shallowly and evenly convex. Dorsum of clypeus conspicuously clothed with short spatulate hairs. Apicoscrobal hair short-flagellate (may be broken). Cephalic dorsum apparently without flagellate hairs close to the occipital margin, but these may have been abraded. Pronotal humeral hair long, fine and flagellate; pronotal dorsum and mesonotum each with a pair of fine standing hairs. One or 2 flagellate hairs project from dorsal (outer) surface of hind tibia and basitarsus.

Type Material
Bolton (2000) - Holotype worker, U.S.A.: Arizona, Cochise Co., Chiricahua Mts, Southwestern Research Station, 4.viii.1958, No. 175 (L. M. Smith & R. O. Schuster) [examined].

References based on Global Ant Biodiversity Informatics

 * Cover S. P., and R. A. Johnson. 20011. Checklist of Arizona Ants. Downloaded on January 7th at http://www.asu.edu/clas/sirgtools/AZants-2011%20updatev2.pdf
 * Ward, P. S. 1988. Mesic Elemets in the Western Nearctic Ant Fauna: Taxonomic and Bilogical Notes on Amblyopone, Proceratium, and Smithistruma (Hymenoptera: Formicidae) Journal of the Kansas Entomological Society. 61:102-124