Study on the efficacy of some entomogenous fungi against brown plant hopper, Nilaparvata lugens Stal in irrigated rice

Abstract

A field trial was conducted for three consecutive kharif seasons of 2010, 2011 and 2012 to study the efficacy of certain entomopathogenic fungi viz., Beauveria bassiana, Metarhizium anisopliae, Verticilium lecani @ 5 g/l having 1×108 CFU along with standard check - Acephate 75% SP @ 1.5 g/l against brown plant hopper, Nilaparvata lugen Stal and predators (mirid bugs and spiders). The results clearly indicated that Acephate 75 SP @ 1.5g/l was highly effective against BPH, but highly toxic to predators with higher grain yield and higher benefit cost ratio. However, B. bassiana, and M. anisopliae @ 5 g/l though found to be ineffective at 5 days after first spray, their efficacy against BPH increased with increase in days after spray and found to be at par with Acephate at 10 days after second spray. Among the entomopathogens, B. bassiana, and M. anisopliae were found to be relatively more effective against BPH and relatively less toxic to predators, followed by V. lecani. © 376.