Pilze aus Pilzgärten von <i>Atta insularis</i> in Kuba

Abstract

Abstract Only one fungus species develops in the fungus gardens of the leaf‐cutting ant Atta insularis in Cuba under the influence of the ants. This species equals the fungus described by MÖLLER and forms the characteristic ‘kohlrabi bodies’ composed of bromatia. The supposed perfect fructification ‘Rozites’ gongylophora MÖLLER, was not found. With regard of the very rare appearance of that basidiomycete and of the dubious generic position of it, the bromatia‐forming mycelium is described under the new name Attamyces bromatificus (Mycelia sterilia ). In pure culture, Attamyces bromatificus does not form reproductive structures. In nature, probably, propagation of this fungus depends almost on the activity of the leaf‐cutting ants. Therefore, the fungus must be considered as a specialized ectosymbiont Attamyces bromatificus forms bromatia also in pure culture. Consequently, bromatia are not formed as a reaction to direct influence (by bite of by moistening with saliva) of ants If the ants are eliminated from the fungus garden, in unsterile conditions, Attamyces bromatificus succumbs rapidly to the competition of unspecific soil fungi. Among others, a rapidly growing imperfect fungus, which represents a new genus and species described as Phialocladus zsoltii , develops frequently within 2–3 days; it corresponds to the ‘strong conidial form of Rozites gongylophora’ illustrated by MÖLLER and others. Simultaneously with the substitution of Attamyce by contaminants, the pH of the fungus substrate ascends from 5 to 6–8.