Strumigenys alberti

A widely-distributed common species.

Identification
This widely distributed and common species is immediately diagnosed by its unique dentition, figured by Brown (1953), which includes a basal lamella of the mandible followed by a long, flat topped second lamella that extends to the middle of masticatory margin (described more fully in the alberti-group diagnosis). The second lamella on the masticatory margin of the mandible may have resulted from elongation of the basal lamella, or from the fusion and modification of some basal teeth. Support for the latter is provided by the fact that alberti has a lower dental count (two) than any other species in the group, and by the presence of a small notch between the genuine basal lamella and this secondary structure. Whatever its origin the second lamella is plainly visible and extends through about half the exposed length of the apical margin in full-face view with the mandibles fully closed. Distal of the second lamella alberti has alternating longer acute triangular teeth and lower broadly rounded teeth. A similar alternation of teeth occurs in nigrescens, though the latter lacks the long secondary lamella just discussed. The mandibles in alberti are relatively the longest in the group, MI 27 - 33, as opposed to MI 15 - 24 in the remaining species (Bolton (2000).

Distribution
Known from Mexico to Central America and south to Ecuador, Peru and Brazil in South America; also numerous islands in the Lesser Antilles.

This taxon was described from Antilles.

Biology
Biological data accompanying six of the series indicate that the nests are established by preference in rotten logs either in forest or in partial clearings (Brown 1953).

More generally (for species within the genus),

Nomenclature

 *  alberti. Strumigenys alberti Forel, 1893g: 380 (w.q.) ANTILLES. Brown, 1953g: 95 (q.); Wheeler, G.C. & Wheeler, J. 1960b: 27 (l.). Combination in S. (Cephaloxys): Emery, 1924d: 325; in Smithistruma: Brown, 1953g: 93; in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 115. Senior synonym of guianensis, intermedia: Brown, 1953g: 94. See also: Bolton, 2000: 154.
 * intermedia. Strumigenys alberti var. intermedia Wheeler, W.M. 1913d: 242 (w.) DOMINICA. Combination in S. (Cephaloxys): Emery, 1924d: 325. Junior synonym of alberti: Brown, 1953g: 94.
 * guianensis. Strumigenys (Cephaloxys) alberti subsp. guianensis Weber, 1934a: 50 (w.) GUYANA. Combination in Smithistruma: Brown, 1948e: 106. Junior synonym of alberti: Brown, 1953g: 94.

Worker
Bolton (2000) - TL 2.2 - 2.6, HL 0.52 - 0.61, HW 0.42 - 0.48, CI 76 - 81, ML 0.15 - 0.17, MI 27 - 33, SL 0.29 - 0.32, SI 66 - 70, PW 0.29 - 0.35, AL 0.62 - 0.70 (25 measured). Mandibular dentition unique, described in alberti-group diagnosis and in identification section above. Apicoscrobal hair flagellate, long and fine, sometimes looped. Eye with 4 - 5 ommatidia in longest row. Side of pronotum usually mostly or entirely punctate or reticulate-punctate but sometimes with a smooth patch posterolaterally, of varying extent. Promesonotum with a median longitudinal carina that extends most or all of its length. Dorsal alitrunk usually entirely reticulate-punctate but sculpture may be less sharply defined on pronotum than elsewhere and rarely may be almost effaced anteriorly on each side of the median carina. Petiole node in dorsal view broader than long, the lateral spongiform lobes in this view small and more or less restricted to the posterolateral angles, not extending the length of the side of the node and not strongly projecting laterally.

Queen
Brown (1953) - TL 2.95. 3. 11, HL 0.60.0.65, WL 0.8 1 .0.85, CI 80·83, MI 28·30. Eight females from widely different parts of the range were measured. Among these, there was slight variation in color, size, proportions and length of propodeal teeth.

Differing from the worker in the usual full sexual attributes. Head more broadly and shallowly excised behind. Mandibles about 9/10 the length of the clypeus. Mesonotum with median carinula very weak or absent, except on scutellum, where it is strong and complete, posteriorly helping to form a small but distinctly jutting point. Petiolar node seen from above twice as broad as long, the anterior border straight and transverse. Propodeal teeth much shorter, blunter and farther apart than in the worker. Venation of the forewing in a specimen from Campinas, Brazil : R + Sc, stigma, and 2r sharply defined and weakly pigmented ; Rsfl, M + Mfl, CuA and Rsf5 present, but poorly defined and weakly pigmented; Mf4 indicated as a groove; basal stub of Rs + M present. Body color varying from light to vary dark ferrugineous, gaster often darker; color in general usually darker than in workers of the same colony.

Male
Brown (1953) - Volsella as figured. Remainder of male body not described because of a lack of suitable specimens.

Type Material
Bolton (2000): Syntype workers and queen, ANTILLES IS: St Vincent I., Fitz-Hugh Valley, 500 ft, 4.xi. ; forest near Châteaubelais, 1000 ft, ll.x.; Petit Bordelle Valley, 1500 ft, 13.xi. (queen); Petit Bordelle Valley, 1600 ft, 13.xi.; Glen, branch of Richmond River, 1200 ft (all coll. H. H. Smith) [examined].

Strumigenys alberti var. intermedia W. M. Wheeler, 1913b: 242. Holotype and paratype workers, DOMINICA: Long Ditton, near Roseau (Crampton, Lutz & Miner) [examined].

Strumigenys (Cephaloxys) alberti subsp. guianensis Weber, 1934a: 50. Syntype workers, GUIANA: Kartabo, 19.vii.1920 (W.M. Wheeler) [examined].

Additional References

 * Baroni Urbani, C. & De Andrade, M.L. 2007. The ant tribe Dacetini: limits and constituent genera, with descriptions of new species. Annali del Museo Civico di Storia Naturale “G. Doria” 99: 1-191.


 * Brown, W.L.Jr. 1953. Revisionary studies in the ant tribe Dacetini. American Midland Naturalist 50: 1 - 1 37.