Strumigenys crassicornis

Identification
Bolton (2000) - A widely distributed but easily recognised member of the crassicornis-complex. It is the only species of the complex that has not been recorded from Central America. Different series show slight variation in pilosity and sculpture but the diagnostic characters of sublobate scape, spatulate cephalic ground-pilosity, lack of an apicoscrobal hair and obviously swollen postpetiole are always apparent.

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina, Brazil, Guyana, Paraguay, Trinidad and Tobago, Venezuela.

Nomenclature

 *  crassicornis. Strumigenys crassicornis Mayr, 1887: 577 (w.) BRAZIL. Brown, 1959b: 12 (q.). Combination in Neostruma: Brown, 1948e: 111; in Pyramica: Bolton, 1999: 1672; in Strumigenys: Baroni Urbani & De Andrade, 2007: 117. See also: Bolton, 2000: 181.

Worker
Bolton (2000) - TL 2.0-2.3, HL 0.48-0.57, HW 0.37-0.42, CI 72-77, ML 0.16-0.20, MI 30-37, SL 0.22-0.28, SI 60-70, PW 0.23-0.28, AL 0.47-0.56 (20 measured).

Characters of crassicornis-complex. Masticatory margin of mandible with 3 - 5 denticles between apicodorsal tooth and submedian tooth, with 2 - 4 denticles proximal of the submedian tooth. Apex of mandible with 3 - 4 min ute intercalary denticles between apicodorsal and apicoventral teeth. In dorsal view scape shaft narrow or very narrow basally, then the leading edge is abruptly expanded and almost lobate at the subbasal angle, the shaft distinctly widest at this point. Apicoscrobal hair absent. Pair of standing hairs on cephalic dorsum close to occipital margin may be only weakly differentiated from the conspicuous spatulate ground-pilosity. Pronotal humeral hair often absent but a short filiform humeral hair may be present. Postpetiole in profile markedly swollen and subglobular, its ventral spongiform lobe minute to absent. Lateral spongiform lobe of postpetiole reduced to a narrow marginal lamella, sometimes vestigial. First gastral tergite often reticulate but sometimes entirely smooth except for the basigastral costulae; intermediate sculpture patterns are known.

Type Material
Syntype workers, BRAZIL: Santa Catarina (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.