Acacia-ant symbiosis is the interaction between myrmecophilousVachellia trees (ant acacias) and ants that nest on them (acacia ants). Obligate acacia ants dwell in the gall-like domatia within the swolen stipularspines of African or Central American ant acacia species, and they also take the food (nectar or Beltian bodies) offered by the tree. Some of them protect ant acacias from herbivores in return, hence mutualism; the others provide inadequate protection or none at all, hence weaker or non-mutualism. Facultative (non-obligate) acacia ants often nest on stems instead of in gall-like domatia, and tend to be non-mutualistic.[1][2][3]
Some swollen-spine acacias in Central America are less dependent on acacia-ant mutualism and often unocuppied by obligate acacia ants without being significantly damaged by herbivores, e.g. V. cookii, V. globulifera, and V. ruddiae.[5]
^Lebrun, Jean-Pierre; Stork, Adélaïde L. (2008). Tropical African Flowering Plants: Ecology and Distribution. Vol. 3. Genève: Conservatoire et jardin botaniques de la Ville de Genéve. ISBN978-2-8277-0114-8.