Abstract
Three pathogenic fungi were isolated from the dead larvae of Mimela costata HOPE. Two isolates were identified as Beauveria tenella (DELACR.) SIEM. and B. bassiana (BALS.) VUILL., respectively. The larvae of Anomala cuprea HOPE, Heptophylla picea MOTSCH., and Maladera castanea ARROW were infected experimentally by dipping them in the liquid media containing conidia of B. tenella and of B. bassiana, and by contacting them with the pupal cadavers of Bombyx mori L. which had been infected with these fungi. The third isolate was closely related to Synnematium jonesii SPEARE, but it differed from SPEARE'S original description of S. jonesii in having short phialides and very small oblong conidia. This is the first record of these fungi on scarabaeid larvae in Japan. B. tenella appeared to be the major factor causing the decline of the high population density of M. costata.
