Effects of commercial beneficial fungi and a plant strengthener on the two-spotted spider mite Tetranychus urticae

Abstract: The two-spotted spider mite Tetranychus urticae is a polyphagous phytophagous mite with a worldwide distribution, and a serious pest in tomato and several other crops. Besides chemical treatments, predatory mite releases represent an effective biological control method. However, predatory mites are not effective in all crops. Other biological control agents such as beneficial microorganisms, as well as plant strengtheners known to confer resistance against plant pests and pathogens may prove to be alternative biological solutions for controlling spider mites. Here, we assessed this hypothesis by recording the effects of two endophytic and an entomopathogenic fungi as well as one plant strengthener on the performance of T. urticae. We found that all products significantly affected spider mites. Our results highlight the potential of these products in herbivore suppression in addition to plant disease control.