Biological control of Tetranychus urticae on cucumber by the predatory mite Phytoseiulus persimilisand its compatibility with Beauveria pseudobassiana

Abstract: The two-spotted spider mite, Tetranychus urticae, has become a major pest ofgreenhouse cucumber and several other host plants. Management with chemical pesticides hasbecome difficult due to its resistance to most commercial acaricides. Biological controlrepresents a potential alternative. This study aimed to determine the efficacy of a local strain ofPhytoseiulus persimilis against T. urticae and its compatibility with a local isolate of Beauveriapseudobassiana intended for aphid and whitefly control within an integrated pest management(IPM) program on greenhouse grown cucumber plants. The experiment consisted of threetreatments, 108 spores/ml B. pseudobassiana solution + 1% vegetable oil + P. persimilis,1% vegetable oil + P. persimilis and the untreated control treatment. This study assessedinteractions between these beneficials and demonstrated that the local P. persimilis managedthe spider mite effectively and was compatible with B. pseudobassiana. These results indicatethat they could be combined in an IPM strategy for cucumber arthropod pests.