Field Evaluation of Entomopathogenic Fungi and Bacteria for the Control of Two-Spotted Spider Mite (Tetranychus urticae Koch) on Eggplant

The two-spotted spider mite, Tetranychus urticae Koch, is a highly destructive eggplant pest and cause of yield and quality loss. The misuse of broad-spectrum acaricides has led to the development of resistance, environmental and human health risks, necessitating the development of sustainable alternatives. The current research evaluated the field efficacy of entomopathogenic fungi (Trichoderma harzianum, Beauveria bassiana, and a mixture of both) and entomopathogenic bacteria (Bacillus thuringiensis, Pseudomonas putida, and their mixture) against T. urticae on eggplant. Mite infestations were monitored after 1, 3, 5, and 10 days after spray treatment. In the treatment, T. harzianum registered the highest and most reliable suppression (86.064–77.33 % in the 1st spray and 81.38–63.074% in the 2nd spray), followed by the mixture of fungi and B. thuringiensis, B. bassiana and P. putida were moderately active, while the bacterial mix was least active. Apart from the control of pests, all the microbial treatments elevated chlorophyll content and microelement accumulation in eggplant tissues. These findings indicate that entomopathogenic fungi, in this case T. harzianum, are a safe, environmentally friendly alternative to integrated management of T. urticae in eggplant production systems.