Monomorium inquietum

Yode et al. (2020) found this species foraging arboreally in the West Lamto Scientific Reserve, central Côte d’Ivoire.

Identification
Bolton (1987) - A member of the M. boerorum complex in the M. monomorium species group. Known only from two syntypes collected in Zaire, this small species is conspicuous by its combination of uniformly dark colour, small eyes, and clypeal structure. The form of the eye is the same in only five other species occurring in sub-Saharan Africa. Of these Monomorium sryetum has only a single pair of hairs on the dorsal alitrunk and Monomorium floricola has much longer scapes (SI 86-94). The remaining three, Monomorium trake, Monomorium rotundatum and Monomorium shilohense, are mostly or entirely yellow in colour, and the last named has relatively large eyes (0.23-0.24 x HW). Comparative measurements of the six species are given under rotundatum.

Distribution based on Regional Taxon Lists
Afrotropical Region: Democratic Republic of Congo.

Nomenclature

 * . Monomorium inquietum Santschi, 1926b: 233, fig. 3D (w.) DEMOCRATIC REPUBLIC OF CONGO.
 * Type-material: syntype workers (number not stated).
 * Type-locality: Democratic Republic of Congo (“Congo belge”): Haut Uelé, Moto, 1920 (L. Burgeon).
 * Type-depositories: MRAC, NHMB.
 * Status as species: Ettershank, 1966: 89; Bolton, 1987: 394 (redescription); Bolton, 1995b: 263.
 * Distribution: Democratic Republic of Congo.

Worker
Bolton (1987) - TL 1.7-1.8, HL 0.45-0.46, HW 0.38, CI 83, SL 0.29-0.30, SI 76-79, PW 0.21-0.22, AL 0.46-0.47 (2 measured).

Anterior clypeal margin without a differentiated prominent median section with discrete anterior and lateral borders; instead the anterior clypeal margin broadly and quite evenly convex between the inner points of the mandibular insertions. Clypeal longitudinal carinae vestigial to absent. Eyes small, 0.16 x HW and with 4-5 ommatidia in the longest row. Eyes consisting of an outer ring of ommatidia which encloses a single short longitudinal ommatidial row. With the head in full-face view the eyes conspicuously far in front of the midlength of the sides, and the scapes, when laid straight back from their insertions, very obviously failing to reach the occipital border. SI < 80. Occipital margin very broad, evenly shallowly concave across its width. Sides of head shallowly convex. Dorsal outline of promesonotum shallowly convex and low, only slightly higher than the propodeum. Mesonotum sloping evenly to the feebly impressed metanotal groove, without a posterior section which is suddenly downcurved or more steeply sloping than the remainder. Propodeum with a small spiracular orifice, the dorsal outline of the propodeum convex in profile, the dorsum rounding broadly and evenly into the declivity. Petiole node in profile low and broadly subconical, narrowly rounded above. Subpetiolar process a low keel, semitranslucent. Postpetiole low and very rounded in profile, the size of the postpetiole only slightly less than that of the petiole. Standing hairs sparsely present on all dorsal surfaces, the promesonotum with 4 pairs, the propodeum with a single pair. Except for hair-pits and short cross-ribs at the metanotal groove, the entire body is unsculptured and smooth. Colour uniform glossy brown, the gaster slightly darker in shade than the head and alitrunk.

Type Material
Bolton (1987) - Syntype workers Zaire: Haut Uele, Moto, 1920 (L. Burgeon) [examined].

References based on Global Ant Biodiversity Informatics

 * Bolton B. 1987. A review of the Solenopsis genus-group and revision of Afrotropical Monomorium Mayr (Hymenoptera: Formicidae). Bulletin of the British Museum (Natural History). Entomology 54: 263-452.