Monomorium tanysum

Nothing is known about the biology of .

Identification
Bolton (1987) - A member of the M. malatu complex in the M. monomorium species group. The Ghanaian tanysum is related most closely to the Tanzanian Monomorium disoriente, the two sharing a very similar outline shape of alitrunk. In tanysum, however, the ventral process of the petiole is shorter and deeper and the postpetiole node higher and narrower than is indicated in disoriente. Apart from this the eyes are distinctly larger in disoriente (0.24 x HW) and the scapes relatively longer (SI 92). M. tanysum and disoriente together are closest to Monomorium dolatu, a form with only 11-segmented antennae. Overall appearance is very similar in all three but dolatu has a more strongly tapered petiole node which is very narrowly rounded above, and approaches the distinctly cuneate node form of Monomorium affabile and Monomorium malatu. M. dolatu is yellow in colour and has the eyes somewhat further forward on the side than either tanysum or disoriente. In affabile and malatu the propodeum is reticulate-punctate everywhere, a condition not present in any of the foregoing species.

Distribution based on Regional Taxon Lists
Afrotropical Region: Ghana.

Nomenclature

 *  tanysum. Monomorium tanysum Bolton, 1987: 416 (w.) GHANA.

Worker
Holotype. TL 1.5, HL 0.42, HW 0.34, CI 81, SL 0.30, SI 88, PW 0.22, AL 0.46.

Clypeal carinae sharply developed and conspicuous, widely separated and subparallel posteriorly, feebly divergent anteriorly. Space between the clypeal carinae flat to shallowly transversely concave. Anterior c1ypeal margin transverse between the apices of the carinae. Anterior and lateral margins of prominent median portion of clypeus separated by blunt obtuse angles, without denticles or projecting acute angles. Clypeal carinae meeting anterior margin medially of the obtuse angles separating the anterior and lateral margins, each carina paralleled externally by a weak rugule which runs back from the angle to the antennal socket. Maximum diameter of eye 0.18 x HW and with 6 ommatidia in the longest row. In full-face view the eyes just in front of the midlength of the sides. Antennal scapes, when laid straight back from their insertions, failing to reach the occipital margin. Sides of head weakly convex in full-face view, slightly convergent both in front of and behind the eyes. Occipital margin with a short shallow median indentation. Head in profile distinctly biconvex, deepest at about the midlength. Promesonotum a low domed convexity in profile, highest at its midlength and distinctly on a much higher level than the propodeum. Metanotal groove shallowly impressed but broad, traversed by strong cross-ribs dorsally; laterally the cross-ribs are less distinct and become confused with the strong mesopleural sculpture. Propodeal spiracle small, the propodeal dorsum highest immediately behind the metanotal groove. Posterior to this the outline is almost flat in profile and sloping at about 45° until it rounds into the very short declivity through a blunt angle. In dorsal view the posterior half of the propodeum is almost flat transversely. Petiole in profile with a short anterior peduncle which is subtended by a short but deep anteroventral process. Petiole node high and subconical, narrowly rounded above. Postpetiole lower than petiole, more bluntly rounded above and with its anterior face nearly vertical, distinctly steeper than the posterior face. All dorsal surfaces of head and body with standing hairs, the promesonotum with 5 pairs. Unsculptured except for hair-pits, metanotal cross-ribs and reticulate-punctation on the mesopleuron. Colour brown, the gaster darker than the alitrunk and almost blackish brown.

Paratype. TL 1.6, HL 0.42, HW 0.38, CI 83, SL 0.30, SI 86, PW 0.22, AL 0.46.

As holotype but maximum diameter of eye 0.17 x HW and the anterior margin of the prominent median section of the clypeus shallowly concave.

Type Material
Holotype worker, Ghana: Mampong, 17.xi. 1969 (P. Room). Paratype, 1 worker with same data as holotype (BMNH).

References based on Global Ant Biodiversity Informatics

 * Belshaw R., and B. Bolton. 1994. A survey of the leaf litter ant fauna in Ghana, West Africa (Hymenoptera: Formicidae). Journal of Hymenoptera Research 3: 5-16.
 * Belshaw R., and B. Bolton. 1994. A survey of the leaf litter ant fauna in Ghana, West Africa (Hymenoptera: Formicidae). Journal of Hymenoptera Research. 3: 5-16.
 * Stephens S. S., P. B. Bosu, and M. R. Wager. 2016. Effect of overstory tree species diversity and composition on ground foraging ants (Hymenoptera: Formicidae) in timber plantations in Ghana. International Journal of Biodiversity Science, Ecosystem Services & management 12(1-2): 96-107.