Studies on the efficacy of some entomopathogenic fungi against sucking pest of rice

Abstract

A field experiment was carried out during the kharif seasons of 2023 to evaluate the effectiveness of various entomopathogenic fungi, including Beauveria bassiana, Metarhizium anisopliae, and Lecanicillium saksnae, applied at a rate of 5 g/l with a concentration of 1x108 CFU. This was compared with a standard treatment using Thiamethoxam 25WG at 0.2 g/l against the brown plant hopper and its natural predators (lady beetles, rove beetles, and spiders). The results clearly indicated that Thiamethoxam 25WG at 0.2 g/l was highly effective against BPH and earhead bug but highly toxic to natural enemies, with a higher grain yield and higher benefit-cost ratio. However, B. bassiana and M. anisopliae at 5 g/l, though found to be ineffective at 5 and after the first spray, had their efficacy against BPH increase with an increase in days after the spray and were found to be at par with Thiamethoxam 25WG 0.2 g/l at 10 days after the second and third sprays.Among the entomopathogens, M. anisopliae and B. bassiana were found to be relatively more effective against BPH relatively less toxic to natural, followed by Lecanicillim saksnae.