Eleven fungal isolates belonging to Beauveria bassiana (Balsamo-Crivelli) Vuillemin Metarhizium anisopliae (Metschinikoff) Sorokin, Lecanicillium lecanii (Zimmerman) Zare and Gams and Metarhizium flavoviride Gams and Rozsypal var minus with different host origins were assayed for their pathogenicity against the tomato thrips, Thrips tabaci Lindeman. The tomato thrips were found susceptible to all the examined isolates of entomopathogenic fungi. The fungal isolate Bb111 of B. bassiana was found highly virulent to T. tabaci with an LC50 of 1.6 × 105 spores/mL as evidenced by its non overlapping fiducial limits to other isolates. Mycosis on T. tabaci by Bb111 isolate had

fast lethal effect after treatment with conidial suspensions at the concentration of 108conidia/mL. The values of the median lethal time required for 50% mortality (LT50) of the respective isolate was 104.91 h. The rest of the tested isolates showed higher LC50 and LT50 values, indicating the intermediate or low virulence to T. tabaci. The results of the present investigation revealed that the Bb111 could be further exploited on a field scale against T. tabaci.