Polyrhachis latharis

The type was collected from primary forest in a fogging sample. From its collection records it appears to be totally arboreal and is confined to densely forested regions.

Identification
Rigato (2016) - Among alexisi group species it is distinctive for its somewhat trapezoidal elongate head, whose sides are faintly concave in front of the eyes, quadrispinose petiole, and marginate pronotum and propodeum. Lateral propodeal margins run much closer to each other than the actual propodeal width.

Bolton (1973) - The nearest relative of latharis within the group appears to be Polyrhachis limitis, from which it is separated by the different development of the margination of the propodeum and other, more minor dissimilarities.

Distribution based on Regional Taxon Lists
Afrotropical Region: Congo, Ghana.

Nomenclature

 *  latharis. Polyrhachis latharis Bolton, 1973b: 348, figs. 49, 60 (w.q.) GHANA.

Worker
Holotype. TL 6.5, HL 1.45, HW 1.19, CI 82, SL 1.59, SI 133, PW 1.37, MTL 1.52.

Mandibles with five teeth. Anterior margin of clypeus projecting medially as a shallow, rectangular lobe, the corners of which are minutely dentate. Between these small teeth is a notch flanked by two denticles. Head broadest posteriorly, the sides converging in front. Sides of head convex behind level of eyes, weakly concave in front. Eyes convex, set well up on the sides of the head close to the frontal carinae and not breaking the outline of the sides in full-face view. Alitrunk antero-posteriorly compressed and expanded laterally, giving a swollen and foreshortened appearance in dorsal view. Pronotum armed with a pair of short spines, marginate for about half its length and with the dorsal surface strongly convex. Mesonotum not marginate, separated from the pronotum by the promesonotal suture which is represented by a break in the sculpturation. Propodeum unarmed, marginate laterally and with a weak transverse ridge separating the dorsum from the declivity. Metanotal groove represented only by a faint scoring across the sculpturation of the dorstim. In dorsal view the sides of the propodeum are expanded so that the total width of the segment is noticeably greater than the width between the lateral marginations. Declivity of propodeum very deep, shallowly concave. Scale large in proportion to alitrunk, equipped with four short spines. The dorsal pair are directed upwards, outwards and backwards, and the length of each spine is less than half the length separating them along the dorsal edge of the scale. The lateral pair of spines are smaller than the dorsals, and are dentiform. Anterior face of first gastral segment strongly concave.

Erect hairs absent from all dorsal surfaces of head, alitrunk and gaster. A very sparse, short pubescence present on all surfaces, difficult to see at low magnifications.

Clypeus, declivity of propodeum and gaster finery reticulate. Head and dorsal surfaces of alitrunk longitudinally striate-rugose, the rugae less regular on the pronotum and tending to a disorganised rugoreticulum laterally. Mesonotal rugae diverging posteriorly. Sides of pronotum and mesopleuron reticulate-rugose; sides of propodeum striate-rugose as the dorsum. Colour black, with the antenna! funiculi yellow-brown.

Paratype workers as holotype, but with the following range of dimensions: TL 6.5-7.0, HL1.40-1.46, HW 1.19-1.26, CI 82-90, SL 1.55-1.63, SI 124-133, PW 1.37-1.40, MTL 1.45-1.53 (3 measured). Paratype females as workers, with the usual modifications in the structure of the alitrunk found in this caste.

Rigato (2016) - HL 1.34, HW 1.15, CI 86, SL 1.50, SI 130, FW 0.36, FI 31, PW 1.28, WL 1.83, HTL 1.48.

Type Material
Holotype worker, GHANA: Eastern Region, Mount Atewa, by pyrethrum knockdown, sample A5/7, r2.vii.I969 (D. Leston).

Paratypes. 3 workers, 2 queens, same data as holotype, from pyrethrum knock-down samples A4/4 (queen), A5/5 (queen), A5/7, A6/6 and A6/7 (BMNH) (UG).