Efficacy of entomopathogenic fungi on lesser grain borer, Rhyzopertha dominica infesting paddy in storage

The entomopathogenic fungi, Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii @ 5 gil containing conidial concentration of 2 x 10⁶, 1 X 10⁹ and 2 x 10⁷/g were tested for their efficacy as bag treatment and grain treatment against lesser grain borer, Rhyzopertha dominica. Among the grain treatments, highest mortality was observed with B. bassiana (88.9%) followed on par by M. anisopliae (81.5%), while lowest mortality of 59.3% was recorded with L. lecanii at 15 DAT Among the bag treatments, B. bassiana and M. anisopliae recorded equal mortality of adults (29.6%) whereas L. lecanii recorded least mortality of 22.2% at 15 DAT The grain treatment was found to be superior to bag treatment, but both were significantly superior to control. Among the grain treatments, least progeny of 122.3 was observed with B. bassiana followed by M. anisopliae (130.7), which were atpar at 180 DAT, whereas highest progeny was recorded with L. lecanii (168.7). Among the grain treatments, B. bassiana proved superior with less per cent weight loss of 21.2 followed by M. anisopliae and L. lecanii (24.0 & 27.6%) at 180 DAT. An average of 66.6, 64.3 and 54.0 per cent reduction in progeny and 59.8, 54.5 and 47.8 per cent reduction in weight loss was observed in grain treated with B. bassiana, M. anisopliae and L. lecanii when compared to control.