DOI: 10.36347/sjavs.2017.v04i12.007

Pages: 552-559

The striped stem borer, Chilo suppressalis is one of the most important pests in the rice fields distributed in all rice producing regions of Iran (except for Khuzestan province). Three strains of Beauveria bassiana and Metarhizium anisopliae were evaluated for potential use as bio-control agents against C. suppressalis. Virulence of three isolates were tested based on dose-response mortality bioassays and showed that B. bassiana isolate Mcb18 had the lowest LC 50 values to egg, larva and pupa of 6.64 × 104, 1.78× 103 and 4.94 × 104 conidia mL-1, and with lower LT50 values ranged from 5.22 to 11.90 days, from 5.07 to 11.53 and from 6.09 to 19.08 days for concentrations that resulted in 50% mortality during three weeks for B. bassiana Mcb18, for egg, larva and pupa of C. suppressalis, respectively. Based on these results B. bassiana strain Mcb18 has the highest potential as a bio-control agent for C. suppressalis. However, B. bassiana Mcb18 isolate showed the ability to grow, sporulate and produce mycosis under laboratory conditions, indicating the potential for causing an epizootic in treated rice fields.