Crematogaster sjostedti

One of four ant species (also Crematogaster mimosae, Crematogaster nigriceps, Tetraponera penzigi) that live on Vachellia 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.

Distribution based on Regional Taxon Lists
Afrotropical Region: Kenya, Mozambique, United Republic of Tanzania, Zimbabwe.

Biology
Inhabits swollen thorns of Vachellia drepanolobium, a dominant tree in large expanses of African savanna and acacia woodland. This species and three other ants (Crematogaster mimosae, Crematogaster nigriceps, Tetraponera penzigi) that compete for the hollow thorn nesting sites have been the subject of some of the most intensive ecological research examining interactions between ants, acacias, and other elements, e.g., herbivory and fire, in places where this plant is abundant. Many of these studies have been carried out in Kenya's | Mpala Research Centre and surrounding areas, all of which are part of the expansive Laikipia Plateau.

Crematogaster gerstaeckeri sjostedti is the dominant ant in the largest, oldest trees (>5 m in height). The ants are mutualists with the acacia trees. The trees provide nesting resources (domatia) and can produce extralfloral nectaries. The ants, in turn, protect the tree from herbivory. Rather than using the extrafloral nectaries as a food resource, as some of the other ants that are part of this arboreal community do, C. sjostedti appears to tend scale insects.

Nomenclature

 * . Crematogaster sjostedti Mayr, 1907b: 17 (w.) TANZANIA.
 * Type-material: syntype workers (number not stated).
 * Type-locality: Tanzania (“Deutsch-Ostafrika”): Usambara Mts, nr Tande (Y. Sjöstedt).
 * Type-depository: NHMW (perhaps also in NHRS).
 * Combination in C. (Crematogaster): Wheeler, W.M. 1922a: 844;
 * combination in C. (Acrocoelia): Emery, 1922e: 148.
 * Status as species: Wheeler, W.M. 1922a: 844; Emery, 1922e: 148; Santschi, 1928d: 65.
 * Subspecies of gallicola: Forel, 1913a: 124 (in text); Forel, 1914d: 237; Santschi, 1914b: 94.
 * Subspecies of gerstaeckeri: Santschi, 1930b: 69; Santschi, 1935b: 270; Santschi, 1937a: 55; Santschi, 1937g: 76; Bolton, 1995b: 162; Hita Garcia, et al. 2013: 210.
 * Status as species: Santschi, 1919b: 236; Santschi, 1920b: 15; Wheeler, W.M. 1922a: 844; Emery, 1922e: 148; Santschi, 1928d: 65; Taylor & McGavin, 2020: 13.
 * Distribution: Kenya, Mozambique, Sudan, Tanzania.