Abstract
In August of 1997, fruit bodies of Pleurotus eryngii covered with white mold and showing rot symptoms were found in cultivation houses in Oita Prefecture, Japan. The fungus was isolated from the diseased fruit bodies reproduced by the rotting symptoms of P. eryngii by artificial inoculation and had pathogenicity to another species, i. e., Flammulina velutipes, Hypsizygus marmoreus, P.osteratus and Lentinula edodes. There was no difference in the susceptibility depending on the growth stage of the fruit bodies of P. eryngii. However, severe symptoms did appear on the fruit bodies which were infected in the early primordia formation stage. The causal fungus was indentified as Cladobotryum varium Nees ex Steud. according to it's cultural and morphological characteristics. This is the first report of C.varium infecting P. eryngii. The common name of "Watakabibyo" is proposed for this disease.
