Metarhizium anisopliae, a potential agent for the control of grape phylloxera

This investigation deals with the control effects of the insect pathogenic fungus Metarhizium anisopliae var. anisopliae on Daktulosphaira vitifoliae. In pot experiments, the soil surrounding phylloxera-infected grapes was inoculated with barley colonised with M. anisopliae. After thirty-two days, in eight of ten Metarhizium-applied pots no fresh phylloxera infections could be observed. In two of ten plants, a few fresh nodosities singly occupied with phylloxera or phylloxera eggs could be found. In all untreated plants, fresh nodosities with either single (two of six plants) or multiple (four of six plants) occupation with phylloxera could be observed. M. anisopliae could be re-isolated in a concentration of >1 x 10(3) CFU g(-1) soil dry weight from those pots with phylloxera-infected plants that had been treated with the fungus. The potential role of M. anisopliae in grape phylloxera management is discussed.