DIVERSITY AND EVOLUTION OF THE FUNGICULTURE IN FUNGUS-GROWING ANTS (FORMICIDAE: MYRMICINAE: ATTINI)

Abstract

The fungiculture of ants belonging to the Attini tribe (Formicidae: Myrmicinae) is categorized into five systems with distinctive characteristics. The most advanced system is that of ``leaf-cutting higher Attini,{''} followed by ``non-leaf-cutting higher Attini.{''} Both cultivate clades of the species Leucoagaricus gongylophorus (M \& ouml;ller) (Basidiomycota: Agaricales: Agaricaceae). Subsequent systems, known as ``minor fungiculture,{''} ``yeast fungiculture,{''} and ``coral-type fungus fungiculture,{''} are less advanced. In all cases, except for coral fungi, leucocoprinaceous fungi closely related to L. gongylophorus and free-living fungi are cultivated. However, these systems vary in the level of specialization between fungi and their symbiotic ants. Cultivars of higher Attini are obligate symbionts, meaning the cultivated fungus will scarcely survive outside of mutualism, while fungi cultivated in lower fungicultures are facultative symbionts. Cultivars in the coral-type fungus fungiculture system belong to three species of the genus Myrmecopterula (Agaricales: Pterulaceae), which are entirely different from leucocoprinaceous fungi. The characteristics of each fungiculture system vary based on the phylogeny of ants and their cultivars. Understanding the diversity of fungi cultivated by Attini ants and the complexity of their fungiculture systems will elucidate one of the most successful coevolutionary processes between ants and fungi in evolutionary history. This review was aimed to discuss the current knowledge on the fungiculture developed by Attini ants, as well as the level of specialization between cultivated fungi and their relationship with the chronological coevolution of Attini.