SPORE GERMINATION AND HYPHAL GROWTH OF BEAUVERIA SP ON INSECT LIPIDS

The effect of cuticular lipids of Ostrinia nubilalis (Hubner) and Melo lontha melolontha (L.) spore germination and hyphal growth of entomopa thogenous fungi was examined. A Beauveria bassiana strain virulent to O. nubilalis and a Beauveria brogniartii strain virulent to ill. melol ontha were used. The epicuticular lipid-extract of the host insect did not alter the growth of the corresponding virulent strain measured bo th as spore germination or hyphal growth. However, the cuticular penta ne-extract of M. melolontha inhibited both the hyphal growth and spore germination of the nonpathogenic strain of B. bassiana. The hyphal in hibition was caused mostly by the unsaturated hydrocarbon fraction. Me thanol-extracts of both insects inhibited hyphal growth and spore germ ination of the 2 virulent and nonvirulent strains. Exposure to O. nubi lalis lipid extract most strongly inhibited hyphal growth of both stra ins.