Biological Control of Tomato Leafminer Moth, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) Using Entomopathogen ic Fungi and Bacteri

Tuta absoluta (Meyrick) is one of the most important pests of tomato crops in Iran. In this study, the pathogenecity of the entomopathogenic fungi, Beauveria bassiana isolate Iran 1395C and Metarhizium asisopliae isolate Iran 1018C and a commercial formulation of Bacillus thuringiensis was evaluated against 2nd instar larvae of this pest. The experiments were performed by leaf dipping bioassay method at 25 ± 1°C and 70 ± 5% R.H. under laboratory conditions. The results showed that B. bassiana alone and in combination with M. anisopliae, caused more than 80% mortality in T. absoluta larvae seven days after treatment. The lowest LT50, 35.84 and 28.25 h, was observed in these two treatments, respectively. The mortality rate for B. thuringiensis was about 65%, seven days after treatment. There was no significant difference between mortality caused by B. tharingiensis and B. bassiana. However, M. asisopliae isolate Iran 1018C showed significantly lower effect than B. bassiana Iran 1395C and B. thuringiensis against T. absoluta larvae.