Strumigenys petiolata

One of the most successful and widely distributed Strumigenys of the Afrotropical region, petiolata nests in rotten wood, under the bark of more recently fallen timber, in log mould, or sometimes directly into the soil. The workers forage singly in the topsoil, leaf litter or in rot tunnels in wood.

Identification
A member of the rufobrunea complex in the Strumigenys arnoldi-group.

Bolton (1983) - As I have not been able to find the types of petiolata my interpretation of this name and its application to this common species must remain somewhat shadowed with doubt. The interpretation is based on Bernard's insufficient original description and figure and supplemented by the notes in Brown's (1954) revision.

Distribution based on Regional Taxon Lists
Afrotropical Region: Angola, Cameroun, Central African Republic, Gabon, Ghana, Guinea, Ivory Coast, Kenya, Nigeria, Sudan, Uganda.

Nomenclature

 *  petiolata. Strumigenys petiolata Bernard, 1953b: 254, fig. 14 (w.) GUINEA. Junior synonym of rufobrunea: Brown, 1954k: 17. Revived from synonymy: Bolton, 1983: 384. See also: Bolton, 2000: 603.

Worker
Bolton (1983) - TL 2.0-2.5, HL 0.54-0.68, HW 0.40-0.53, CI 75-83, ML 0.24-0.32, MI 44-50, SL 0.28-0.36, SI 64-72, PW 0.25-0.32, AL 0.50-0.64 (38 measured).

Mandibles in full-face view with the outer margins shallowly convex, the blades feebly bowed outwards. Apical fork of each mandible consisting of a pair of spiniform teeth, without intercalary teeth or denticles. Preapical armament of each mandibular blade of 2 teeth, the proximal spiniform and the longest in each case. Right distal preapical tooth usually larger than the left. Upper scrobe margins shallowly sinuate in full-face view and bordered by a narrow rim or flange throughout their length. Eyes visible in full-face view, their maximum diameter equal to or greater than the maximum width of the scape. Preocular notch present and strongly developed, the anterior portion of the eye detached from the side of the head. Preocular notch continued onto ventral surface of head as a transverse groove which is narrower than the maximum diameter of the eye and which usually has quite sharply defined margins. Antennal scapes not or only extremely shallowly bent basally, broadest at about the midlength and their leading edges equipped with a row of apically curved narrowly spoon-shaped hairs which are slightly smaller than those on the upper scrobe margins. Cephalic ground-pilosity of minute inconspicuous spatulate to spoon-shaped hairs which are closely applied to the surface. Upper scrobe margins with a row of anteriorly curved large spoon-shaped hairs. Dorsum of head with 6 standing hairs which are arranged in a transverse posterior row of 4 close to the occipital margin and a more anteriorly situated pair. Head finely and usually very sharply reticulate-punctate but in some samples the sculpture is less intensely developed, the punctures not so sharply incised. Pronotal humeri lacking flagellate or any other kind of outstanding hair. Mesonotum with a single pair of stout standing hairs. Ground-pilosity of alitrunk of minute hairs similar to those on the cephalic dorsum. Posterior half of mesonotum sharply depressed behind the level of the standing hairs. Metanotal groove represented by a line across the dorsum but not or only very feebly impressed. Propodeal teeth triangular and subtended by an infradental lamella on each side. Sides of alitrunk with the pleurae smooth except for peripheral punctulae which are best developed dorsolaterally. Sides of propodeum above and behind the spiracle punctulate. Sides of pronotum varying from smooth to very weakly striolate, sometimes also with vestigial punctures. Pronotal dorsum usually finely longitudinally striolate or costulate, often with fine superficial punctures between the longitudinal sculpture. Frequently the costulae or striae are poorly defined and the punctures more conspicuous, and in some samples dense punctures constitute the principal component. Dorsal alitrunk behind pronotum densely reticulate-punctate. Petiole node punctate dorsally, the postpetiole often with some fine longitudinal striolae but these are very variable in development and frequently are absent. Petiole with a narrow ventral spongiform strip whose depth is less than half the depth of the peduncle at its midlength. Sides of petiole node with a small triangular appendage. Ventral spongiform lobe of postpetiole usually marginally larger than the lateral lobe in profile. Petiole, postpetiole and gaster with standing hairs. Colour often uniform, varying in shade from yellow to dark brown or even blackish brown; sometimes with the gaster considerably darker in colour than the head and alitrunk.

Type Material
Syntype workers, GUINEA: Mt Nimba, 700 m, in termitary in forest (Villiers) (not found in ; presumed lost).