Strumigenys dotaja

Identification
A member of the Strumigenys lujae-group.

Bolton (1983) - The presence of very long fine flagellate hairs on the mesonotum as well as on the pronotum immediately distinguishes dotaja from all other species as in those the mesonotum has one or more pairs of stout hairs which are thickened or clavate apically. The species Strumigenys lujae, Strumigenys serrula, Strumigenys concolor and Strumigenys maynei are also distinguished from dotaja by their possession of conspicuous pronotal sculpture, and Strumigenys maynei, Strumigenys sulumana and Strumigenys geoterra lack cephalic flagellate hairs. From Strumigenys ludovici samples in which the enlarged basal series of mandibular denticles is not very strongly developed dotaja differs in having the pleurae and propodeal dorsum smooth, as well as by having simple cephalic, petiolar, postpetiolar and gastral pilosity, all of which are clavate in ludovici. Strumigenys simoni, the closest relative of dotaja, is separated as follows.

A single worker of simoni from Burundi (in MCZ) with very reduced sculpture is responsible for the qualifying ‘at least’ and ‘very rarely’ in the sculpture characters listed above. In this specimen the sculpture is more reduced than is usual in simoni and it is more like dotaja in this respect than any other sample examined. However, even in this individual the pilosity characters are absolutely those of simoni.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Democratic Republic of Congo, Gabon.

Nomenclature

 *  dotaja. Serrastruma dotaja Bolton, 1983: 339, figs. 35, 38 (w.) CAMEROUN. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 119. See also: Bolton, 2000: 313.

Description
Holotype. TL 23, HL 0.53, HW 0.42, CI 79, ML 0.22, MI 42, SL 0.36, SI 86, PW 0.32, AL 0.62.

Mandibular denticles small even and regular, without a basal series of 4-8 enlarged denticles; only the basalmost denticle enlarged. Upper scrobe margins narrow and petering out posteriorly, not composed of a broad continuous lamellate granular flange; equipped just behind the level of the eye with an extremely long flagellate hair which basally projects laterally from the margin. Clypeus smooth on the disc, with appressed small spatulate hairs, the anteriormost row of spatulate hairs situated on the false margin of the clypeus and freely projecting forwards over the mandibular bases. Ground-pilosity of head to highest point of vertex consisting only of sparse narrow inconspicuous hairs which are decumbent to appressed and directed anteriorly. Dorsum of head behind highest point of vertex with similar but slightly longer ground-pilosity and also with two pairs of anteriorly curved long simple hairs, one pair situated just behind the highest point and the other latero-occipitally. Dorsum and sides of head densely and strongly reticulate-punctate everywhere. Pronotum marginate anteriorly but laterally the sides of the alitrunk separated from the dorsum only by smoothly rounded blunt angles. In profile the pronotum and anterior part of the mesonotum forming an even shallow convexity, the posterior part of the mesonotum sloping down to the shallowly impressed metanotal groove. Propodeal dorsum curving down posteriorly to the bases of the strong propodeal teeth which are elevated and slightly upcurved. Infradental lamellae present down the depth of the propodeal declivity, its width equal to or slightly greater than the diameter of the propodeal spiracle. Sides of alitrunk glassy smooth, devoid of sculpture. Dorsal surfaces of pronotum, anterior mesonotum and propodeum glassy smooth. Posterior (sloping) portion of mesonotum smooth centrally but with some weak lateral punctulae and posteriorly with some irregular sculpture just in front of the metanotal groove. Propodeal declivity reticulate-punctate between the bases of the teeth. Pronotum and mesonotum each equipped with a pair of extremely long fine flagellate hairs, each hair arising from a small papilla. Dorsum of promesonotum otherwise only with very sparse short ground-pilosity which is subdecumbent. With the pedicel segments in profile the spongiform appendages well developed. Ventral petiolar process spongiform posteriorly but more solid and opaque anteriorly. Ventral and lateral spongiform lobes of postpetiole about equal in size, lateral appendage of petiole node smaller. In dorsal view both petiole and postpetiole smooth and very shiny, the former with a distinct spongiform strip running across the posterior face. Disc of postpetiole transversely roughly oval in dorsal view, the anterior face with a narrow transverse lamellate strip, the sides bordered with spongiform material which becomes broader posteriorly, and the posterior margin bordered with a broad spongiform strip the posterior margin of which is shallowly concave medially. Extreme base of first gastral tergite lamellate spongiform, with a continuous band of short basigastral costulae which do not run further back than the pair of long gastral hairs; remainder of tergite glassy smooth. Petiole and postpetiole each with a single pair of stout simple posteriorly curved long hairs. First gastral tergite with a single pair of simple hairs which are situated close to the base of the sclerite. Colour jet black, glossy behind the head, the appendages brown.

Paratypes. TL 2.3-2.5, HL 0.50-0.54, HW 0.41-0.43, CI 78-82, ML 0.20-0.23, MI 38-43, SL 0.34-0.37, SI 81-88, PW 0.31-0.34, AL 0.60-0.66 (20 measured).

As holotype but specimens from Gabon are slightly lighter in colour, blackish brown with somewhat lighter pedicel segments.

Type Material
Holotype worker, Cameroun: Nkoemvon, 16.iii.1980 (D. Jackson). Paratypes. Cameroun: 12 workers with same data as holotype; 3 workers with same data but 2S.xi.1980, N52. Gabon: 11 workers, Plateau d'Ipassa, 6, IPA CI9 (J. A. Barra); 1 worker with same data but IVIS, IPA 8 (BMNH; ; ).