USE OF INDIGENOUS ISOLATES OF METARHIZIUM, ISARIA AND BEAUVERIA AS POTENTIAL BIO-CONTROL AGENTS AGAINST Sitophilus oryzae UNDER LABORATORY CONDITIONS.

Entomopathogenic fungi (EPF) are suggested as a new class of alternates followed by Synthetic chemical control of the insect pests .Virulence of seven EPF isolates, four strains of Metarhizium {(Qin-08, Qin-13, Qin-18 and ME-38 (LT-178)}, two of Isaria {ME-33 (ILT-01), Yulin-5 (IYL-01)} and one of Beauveria bassiana (Qin-21) were assessed against the adults of Sitophilus oryzae under laboratory conditions, firstly at single conidial concentration (1x10⁸ ml^-1) by immersion and the food mix methods. Qin-21, ME-33 and Qin-18 caused significantly highest mortality of S.oryzae at immersion methods (100, 100 and 98%), followed by food mix method to 100, 84.16 and 91.66% respectively. Yulin-5 was the least effective, showing significantly the lowest mortality at food mixed (32.49%) and immersion methods (40.20%) respectively. Hence, the immersion method was found to be most effective, resulting the higher mortality rate of S. oryzae in comparison to food mix method, in all tested fungal isolates. Secondly, we screened out the most effective isolates for multiple dose comparison i.e., 1x10⁴ to 1x10⁷ conidia ml^-1 by immersion method only. The isolate ME-33 resulted in 100% mortality of the pest at higher conidial dose as compared to Qin-21 and Qin-18 which showing 80 and 64.64% mortality respectively. The LT₅₀ was observed to be 3.63, 4.17 and 8.58 days in ME-33, Qin-21 and Qin-18, respectively at the highest conidial concentration (1x10⁷ml^-1). ME-33 isolate with the highest mortality and lowest LT₅₀ at conidial concentration 1x10⁷ ml^-1 proved to be most effective for the control of S. oryzae. So these fungal islotes could be a better alternative for the management of S. oryzae. [ABSTRACT FROM AUTHOR]