Monomorium

Collingwood, C. A., Pohl, F., Güsten, R., Wranik, W., van Harten, A., 2004, The ants (Insecta: Hymenoptera: Formicidae) of the Socotra Archipelago, Fauna of Arabia 20, pp. 473-495 : 484-485

Monomorium sp. prope qarahe Collingwood & Agosti, 1996

Specimens examined: Yemen, Socotra Island: 2 ☿☿, Diksam, camp , 12°31N 53°57E, 26-27.X.2000, A. van Harten, HLMD-Hym-2086 , NHCY .

Measurements and indices: AL 0.48 mm, HL 0.45 mm, HW 0.31 mm, SL 0.26 mm, CI 69, SI 84.

Description: Mandibles unsculptured with three teeth, antennae 12-segmented with enlarged apical club. Clypeus with concave front margin, occiput mildly concave, eyes small (diameter 0.22 times the HW). Alitrunk with distinct metanotal groove, petiole with somewhat flattened dorsum, a ventral bulge and a long anterior peduncle. Vertex with four hairs, pronotum with two dorsal hairs. Colour brownish yellow, shining with reduced sculpture.

Remarks: Only two specimens were available of this Monomorium species of the M. monomorium-group sensu Bolton (1987). As M. baushare , it could be accommodated in the vaguely defined M. boerorum-complex, but unlike the previous species it has 12-segmented antennae. There may be relations also to the species of the M. mediocre -complex of the M. salomonis -group which grade into the M. monomorium-group. A worker very similar to the two treated here was taken by A. van Harten and A. Sallam in a Malaise trap at Lahj near Aden (Yemen). Apparently these specimens are not referable to any species described from Africa or Arabia. Monomorium qarahe Collingwood & Agosti, 1996 from the Asir Mountains in Saudi Arabia, also known from only two workers, appears to be most similar but is somewhat larger.

The samples available are altogether insufficient for definite appraisal at the present time, therefore this species is omitted from Table 1 and the discussion of zoogeographic affinities of the ants of Socotra.