Strumigenys hensekta

Known from litter samples from a range of wet forest habitats.

Identification
Bolton (2000) - The only member of the hensekta complex in the Strumigenys emarginata  group.Characters of hensekta-complex. Anterior clypeal margin transverse. Maximum diameter of eye less than maximum width of scape. Base of first gastral tergite without an indented depressed median area. First gastral tergite in dorsal view with suture line between limbus and sclerite proper transverse. Dorsum of head with numerous standing simple hairs from about highest point of vertex to occipital margin. Pronotal humerus with a laterally projecting stout hair. Dorsal alitrunk with standing hairs on both pronotum and mesonotum, and first gastral tergite with numerous standing hairs. Pleurae and side of propodeum mostly or entirely reticulate-punctate.

Bolton (1983) - Apart from slight variation in intensity of punctate sculpture on the alitrunk the main variation is only that 6-7 pairs of hairs may be present on the dorsal alitrunk and that the outermost pair of hairs on the anterior clypeal margin (at the corners) may be relatively small, so that the anterior margin may have 3-4 medially curved pairs of hairs.

Within the emarginata-group hensekta is quickly diagnosed by its transverse anterior clypeal margin and characteristic pilosity as described above. It apppears closest related to Strumigenys truncatidens but the two are separated as follows in the worker.

Distribution based on Regional Taxon Lists
Afrotropical Region: Angola, Cameroun, Democratic Republic of Congo, Gabon, Ghana, Ivory Coast, Kenya, Uganda.

Nomenclature

 *  hensekta. Smithistruma hensekta Bolton, 1983: 293, fig. 12 (w.) GHANA. Combination in Pyramica: Bolton, 1999: 1673; in Strumigenys: Baroni Urbani & De Andrade, 2007: 121. See also: Bolton, 2000: 303.

Worker
Holotype. TL 2.1, HL 0.60, HW 0.41, CI 68, ML 0.10, MI 17, SL 0.24, SI 59, PW 0.25, AL 0.58.

Mandibles with 5 relatively large teeth following the basal lamella (concealed by the clypeus), distal to which are 2 slightly smaller teeth followed by 4 minute denticles and a small apical tooth. Anterior clypeal margin transverse, equipped with 3 pairs of medially curved flattened hairs of which the outermost pair is the largest, forming a transition to the long anteriorly curved spatulate hairs which form a continuous fringe along the lateral clypeal margins. Sides of clypeus feebly convergent anteriorly. With the head in full-face view the sides with numerous straight to slightly curved freely projecting stout hairs which are feebly clavate. Dorsum of clypeus and cephalic dorsum from posterior clypeal margin to highest point of vertex with numerous short scale-like hairs which are curved anteriorly. Scale-like hairs absent from highest point of vertex back to the occipital margin, replaced by numerous distinctly longer erect to suberect hairs which are simple to feebly clavate and mostly slightly curved anteriorly. This broad band of simple hairs occupies the dorsum from the vertex to the occiput and the surfaces of the occipital lobes. Flagellate hairs absent. Antennal scapes curved and broadened at about the basal third, the leading edge of the scape with a freely projecting row of long stout hairs. Maximum diameter of eye 0·15 x HW. Cephalic dorsum reticulatepunctate everywhere, with a rough granular appearance. Clypeal dorsum less strongly sculptured than remainder of head. Pronotum not sharply marginate laterally, lacking a median longitudinal ridge or carina dorsally and without flagellate hairs at the humeri. Metanotal groove absent but posterior half of mesonotum very shallowly concave. Propodeal teeth long and narrow, slightly upcurved along their length. Infradental lamellae vestigial. Flagellate hairs absent but pronotal humeri each with a laterally projecting stout hair which is feebly clavate. Dorsal alitrunk with 6 pairs of elongate stout erect hairs which are simple to feebly clavate, and similar hairs are numerous on the petiole, postpetiole and first gastral tergite but tending to be curved posteriorly on the pedicel segments; without other pilosity. Sides of alitrunk densely punctate. Dorsal alitrunk densely punctate, the punctures slightly smaller and more widely spaced on the pronotum than on the mesonotum or propodeum. Dorsum of petiole finely punctate; disc of postpetiole unsculptured and glassy smooth. First gastral tergite unsculptured except for the sharply defined row of basigastral costulae. Spongiform appendages of pedicel segments strongly developed in profile. In dorsal view the petiole node with a spongiform strip along the posterior margin, the spongiform material also extending down the posterolateral surfaces of the node. Anterior postpetiolar margin transverse to exceptionally feebly concave, with a narrow spongiform strip; the posterior margin with a much broader spongiform band which is broadest posterolaterally and narrowed medially. In dorsal view the lateral spongiform tissue of the post petiole can be seen projecting beyond the outline of the disc. Base of first gastral tergite with a transverse spongiform band which is overlapped by that on the posterior margin of the postpetiole. Colour uniform dull yellow.

Paratypes. TL 2.0-2.1, HL 0.58-0.60, HW 0.39-0.41, CI 67-68, ML 0.10-0.11, MI 17-18, SL 0.24-0.25, SI 59-63, PW 0.24-0·26, AL 0.58-0.60 (4 measured).

As holotype but in two workers the mandibles are open and the basal lamella is visible as a broad-based high triangle which tapers strongly to a narrow truncated apex; there is no diastema between the basal lamella and the basalmost tooth of the principal row.

Bolton (2000) - TL 2.0-2.2, HL 0.56-0.60, HW 0.37-0.41, CI 66-69, ML 0.10-0.12, MI 17-18, SL 0.24-0.25, SI 59-65, PW 0.24-0.26, AL 0.58-0.61 (15 measured).

Type Material
Holotype worker, Ghana: Mampong, 9.ii.I970 (P. Room). Paratypes. 4 workers with same data as holotype (BMNH; ; ).

References based on Global Ant Biodiversity Informatics

 * Belshaw R., and B. Bolton. 1994. A survey of the leaf litter ant fauna in Ghana, West Africa (Hymenoptera: Formicidae). Journal of Hymenoptera Research 3: 5-16.
 * Belshaw R., and B. Bolton. 1994. A survey of the leaf litter ant fauna in Ghana, West Africa (Hymenoptera: Formicidae). Journal of Hymenoptera Research. 3: 5-16.
 * Bolton B. 1983. The Afrotropical dacetine ants (Formicidae). Bulletin of the British Museum (Natural History). Entomology 46: 267-416.
 * Bolton, B. 2000. The Ant Tribe Dacetini. Memoirs of the American Entomological Institute 65
 * CSIRO Collection
 * Garcia F.H., Wiesel E. and Fischer G. 2013.The Ants of Kenya (Hymenoptera: Formicidae)Faunal Overview, First Species Checklist, Bibliography, Accounts for All Genera, and Discussion on Taxonomy and Zoogeography. Journal of East African Natural History, 101(2): 127-222
 * IZIKO South Africa Museum Collection
 * Kone M., S. Konate, K. Yeo, P. K. Kouassi, and K. E. Linsenmair. 2012. Changes in ant communities along an age gradient of cocoa cultivation in the Oumé region, central Côte dIvoire. Entomological Science 15: 324339.
 * Ross S. R. P. J., F. Hita Garcia, G. Fischer, and M. K. Peters. 2018. Selective logging intensity in an East African rain forest predicts reductions in ant diversity. Biotropica 1-11.
 * Yeo K., T. Delsinne, S. Komate, L. L. Alonso, D. Aidara, and C. Peeters. 2016. Diversity and distribution of ant assemblages above and below ground in a West African forest–savannah mosaic (Lamto, Cote d’Ivoire). Insectes Sociaux DOI 10.1007/s00040-016-0527-6