Strumigenys biolleyi

Identification
Bolton (2000) - S. biolleyi is the most variable species in the mandibularis complex and was discussed in detail by Brown (1953e). The form of the lamella on the propodeal declivity, seen in profile, is diagnostic of the species: no other has a lobe or tooth at the base of the declivity whilst lacking a more dorsally situated lobe or tooth. One species, Strumigenys hemidisca, has a simple lamella on the declivity that lacks any form of prominence either dorsally or basally. All others have some form of lobe or tooth both dorsally and basally on the declivity, even though these may sometimes be closely approximated and linked by a fairly broad lamella.

This species, like Strumigenys smithii, Strumigenys prospiciens and other members of the mandibularis series, possesses a small but distinct and acute intercalary tooth between the largest teeth of the apical mandibular fork, and two strong spiniform preapical teeth. In size, general proportions and facies, biolleyi closely resembles smithii and prospiciens, but differs from both in the shape of the propodeal lamellae and, less strikingly, in having relatively slightly more slender mandibular shafts. In closely related species, each propodeal lamella forms an upper and a lower tooth or distinct angles separated by an excision or concavity (except in Strumigenys hemidisca). In S. biolleyi, however, the upper (dorsal) of these angles is obsolete, represented by at most a feeble convexity, while the lower angle remains well developed as a salient triangular tooth, acute but with a usually blunt extremity. In the more distantly-related Strumigenys cordovensis, a similar condition occurs as an inconstant variation, but in biolleyi the propodeal form varies only within very narrow limits and appears to be characteristic.

Distribution based on Regional Taxon Lists
Neotropical Region: Belize, Colombia, Costa Rica, Ecuador, Greater Antilles, Guatemala, Honduras, Jamaica, Mexico, Panama.

Nomenclature

 *  biolleyi. Strumigenys biolleyi Forel, 1908b: 43 (w.) COSTA RICA. Brown, 1953f: 103 (q.); Wheeler, G.C. & Wheeler, J. 1960b: 26 (l.). Senior synonym of luctuosa, tridens: Brown, 1953f: 101. See also: Bolton, 2000: 530.
 * tridens. Strumigenys (Strumigenys) tridens Weber, 1934a: 29, fig. 3 (w.) PANAMA. Junior synonym of biolleyi: Brown, 1953f: 101.
 * luctuosa. Strumigenys (Strumigenys) luctuosa Menozzi, 1936c: 81, fig. 1 (w.) COSTA RICA. Junior synonym of biolleyi: Brown, 1953f: 101.

Worker
Bolton (2000) - TL 2.6-3.3, HL 0.62-0.80, HW 0.52-0.66, CI 79-85, ML 0.37-0.52, MI 58-65, SL 0.43-0.60, SI 83-91, PW 0.33-0.42, AL 0.64-0.82 (30 measured).

Characters of mandibularis complex. Proximal preapical tooth located distal of the mandibular midlength. Outer margins of mandibles only weakly convex at full closure. Mesonotum usually without standing hairs, only rarely with a single pair present. Propodeum in profile with an acute lobe or triangular tooth at base of declivity; top of declivity without trace of an angular lobe or tooth. Disc of postpetiole broader than long, sculpture varying from smooth with peripheral weak sculpture to entirely reticulate-punctate, with all intermediate stages. Fine hairs on first gastral tergite usually confined to basal half, sometimes restricted to a single basal transverse row; hairs more extensive in some populations, especially more darkly coloured forms, where they may arise over the entire sclerite. Basigastral costulae usually absent, at most with minute vestiges immediately behind the limbus.

Type Material
Holotype worker, COSTA RICA: La Palma, 1600 m. (P. Biolley) [examined].