Tetramorium rimytyum Bolton

Type location Ghana (Bolton, 1980, illustrated, alitrunk and pedicel, worker). Solely known from the holotype described from his own collection at Mt. Atewa, where he found it on a fallen tree trunk (1.xii.1968) .

Bolton's description (1980) is at .

WORKER - TL 4.8 mm; clypeus with conspicuous median notch. Antennal scrobes absent. Eyes prominent and hemispherical in full-face view. Propodeum with long, narrow spines and conspicuous metapleural lobes. Petiole with fairly long peduncle and domed profile, postpetiole also domed but dome as if falling backwards. All dorsal surfaces with abundant long, fine, acute hairs. Colour uniform dark brown.

According to Bolton, this is of some significance as an intermediate between the aculeatum-group and the more obviously typical Tetramorium types of the setigerum-group. If, as seems the case, the specimen I separated out as Macromischoides species Tą (see below) was determined by Bolton as no more than one of the variants of Tetramorium aculeatum [he lists a finding as "Onipe (B. Taylor)")] then this species, based on a single specimen must be of questionable status.

The photomontage is of the holotype worker, collated from http://www.antweb.org/specimen.do?name=casent0901225.

Tetramorium aculeatum (Mayr), colour variant

Nigeria specimens (as Macromischoides species Tą, Taylor, 1979: 61). WORKER. TL 5.29 mm, HL 0.96, HW 1.12, SL 1.28, PW 0.78
Colour very dark red-brown. Sculpturation rugoreticulate, rugae dominant, on head and alitrunk, longitudinal except on dorsal pronotum, where transversely arcuate, and oblique on the lateral mesonotum. Abundant rather coarse long hairs all over. Mandibles with denticles much reduced except the apical pair. Clypeus with spiculate central area and anteriorly marginate. Frontal carinae of head short and no antennal scrobes. Metanotal groove impressed; propodeum with a pronounced anterior dorsal carina; propodeal spines noticeably curved upwards but relatively short when compared to the common T. aculeatum.
In Nigeria, I collected a single specimen from a vine on a shade tree in a cocoa plot, Onipe 1/1, Plot C, at the Cocoa Research Institute of Nigeria, Idi Ayunre. It is very distinctive in appearance and is larger than the queen of the common T. aculeatum, which was found on neighbouring cocoa trees. Thus, despite Bolton's determination of it as aculeatum (personal communication, 1976), it seems to merit the separate treatment and the drawing. In general the features all fit those described for the larger specimens by Bolton (1980).

With the availability of the Antweb images, it can be seen that my drawing is a very close match to "rimityum", supported by my description.