Crematogaster mimosae

One of four ant species (also Crematogaster gerstaeckeri sjostedti, Crematogaster nigriceps, Tetraponera penzigi) that live on Acacia drepanolobium. This small arboreal ant assemblage, nesting in this dominant Africa savanna tree, have been the subject of intensive research by a large group of ecologists studying species interactions and species co-existence (e.g., Young et al. 1997; Martins 2010).

Distribution
Sharaf et al. (2019): Initially described from Kenya, in the Afrotropics this species is East African in its distribution found in Kenya, Uganda, Somalia, Sudan, and Tanzania (Guénard et al. 2017; Janicki et al. 2017). In the Arabian Peninsula, it was recorded from the KSA, Oman, the UAE and Yemen (Collingwood 1985, Collingwood and Agosti 1996; Borowiec 2014; Sharaf et al. 2018).

Distribution based on Regional Taxon Lists
Afrotropical Region: Kenya, Saudi Arabia, United Arab Emirates, Yemen. Palaearctic Region: Oman.

Biology
C. mimosae depends on the domatia provided by the plant for brood rearing and are never found free living separately from the acacias. Ants patrol all parts of the tree above the ground and directly prey on invertebrates and repel browsing herbivores.

Workers tend phloem-feeding scale insects, presumably imposing a cost on host plants that partly offsets the protection given against mammalian herbivores. Trees occupied by C. mimosae had significantly less browsing by giraffes and black rhino than trees occupied by other ant species (Martins 2010).



Nomenclature

 *  mimosae. Crematogaster mimosae Santschi, 1914b: 87, fig. 11 (w.) KENYA. Menozzi, 1939c: 105 (q.). Combination in C. (Crematogaster): Wheeler, W.M. 1922a: 841; in C. (Acrocoelia): Emery, 1922e: 148; in C. (Crematogaster): Bolton, 1995b: 166. Current subspecies: nominal plus tenuipilis.

Taxonomic Notes
Sharaf et al. (2019): From a taxonomic perspective, this is one of the “easy” cases within the genus in Arabia, thus very straightforwardly identiﬁable.