Monomorium guineense

Known from rainforest and primary forest leaf-litter samples.

Identification
Bolton (1987) - Because of its relatively broad and narrow nodes guineense was first described in Epixenus, a spurious generic name which covered a loose assemblage of salomonis-group species linked by their development of apterous or ergatoid females and a tendency in some of their females to possess relatively broad narrow nodes. This was obviously the criterion uppermost in Bernard's mind when he assigned guineense to Epixenus, but it is now plain that guineense is not closely related to any salomonis-group species.

Separated from Monomorium invidium by the characters noted in the description. The third West African species of this group, Monomorium jacksoni, is quickly separated from guineense as the former has the propodeum very strongly sculptured, as well as having petiole and postpetiole nodes which are broader than in guineense.

Distribution based on Regional Taxon Lists
Afrotropical Region: Cameroun, Guinea.

Nomenclature

 *  guineense. Epixenus guineensis Bernard, 1953b: 238, fig. 10 (w.) GUINEA. Combination in Monomorium: Brown & Wilson, 1957b: 245. See also: Bolton, 1987: 426.

Worker
Bolton (1987) - TL 2.3, HL 0.56, HW 0.48, CI 86, SL 0.38-0.39, SI 79-81, PW 0.35-0.36, AL 0.62 (2 measured).

As the more common and more widely distributed Monomorium invidium but with smaller eyes, the maximum diameter 0.13 x HW and with 4 ommatidia in the longest row. The head and alitrunk are unsculptured everywhere except for faint hair-pits, and the propodeal dorsum lacks the faint transverse rugulae usually seen in invidium. In profile the propodeal dorsum meets the declivity in a pair of prominent but obtuse angles and the body colour is uniform dark brown. The nodes of the petiole and postpetiole are much more strongly antero-posteriorly compressed and scale-like than in any other member of the group, the nodes in profile being high narrow and very narrowly rounded dorsally. The postpetiole is slightly narrower than the petiole in profile. In dorsal view both nodes are broad, the dorsal surfaces very short from front to back and the postpetiole only fractionally thicker than the petiole.

Type Material
Bolton (1987) - Syntype workers, Guinea: Mont To, ravin 1, st. B2.41, foret, 21.2 (Lamotte) [examined].