THE PRIMARY AND AUXILIARY AMBROSIA FUNGI ISOLATED FROM THE AMBROSIA BEETLES,

An ambrosia fungus and several kinds of yeasts associated with the ambrosia beetles Scolytoplatypus shogun Blandford and Crossotarsus niponicus Blandford were isolated and identified. A specific ambrosia fungus, Am-brosiella sp., was isolated from both the mycetangia and the galleries of S. shogun. Pichia spp. were also isolated from the galleries of the beetles. It is considered that the fungus, Ambrosiella sp., is the primary ambrosia fungus and the Pichia spp. are the auxiliary ambrosia fungi of S. shogun, respectively. Two kinds of yeasts, Endomycopsis platypodis and Torulopsis norvegica. were commonly isolated from both mycetangia and galleries of C. niponicus. These fungi seem to be the primary ambrosia fungi of this beetle. The morphological and physiological characteristics of these isolates were described. The range of the optimum temperature of Ambrosiella sp. was extremely narrow at approximately 23°C. For E. platypodis and T. norvegica, the range of the optimum temperature was relatively wide from 20°C to 30°C