A new fungus with dual biocontrol capabilities: reducing the numbers of phytophagous mites and powdery mildew disease damage

Abstract The fungus Meira geulakonigii Boekhout, Scorzetti, Gerson & Sztejnberg (Basidiomycota: Ustilaginomycetes) was assayed against three species of phytophagous mites and against cucumber powdery mildew, Sphaerotheca fusca (Fr.) Blumer. The corrected mortality of the citrus rust mite, Phyllocoptruta oleivora (Ashmead), came to almost 100%, whereas that of the citrus red mite, Panonychus citri McGregor, and that of the carmine spider mite, Tetranychus cinnabarinus (Boisduval), was around 80%. The coverage of cucumber leaves by the powdery mildew was significantly lower on detached cotyledons and on growing plant foliage sprayed with Meira geulakonigii and cucumber fruit yield was significantly higher. These leaves also carried fewer carmine spider mites. The novelty of these results and their practical application are discussed.