Toxicity of different insecticides against rice stem borer

Results of field experiments conducted to evaluate the effect of five different groups of insecticides viz., anthranilic diamides (chlorantraniliprole, flubendiamide), nereistoxin analog (cartap hydrochloride), phenylpyrazole (fipronil), synthetic pyrethroid (bifenthrin) and organophosphate (chlorpyriphos) against rice stem borers are reported. Of the different insecticides chlorantraniliprole 18.5 SC proved better for the control of borers in both the field trials. Among the different insecticidal groups tested, anthranilic diamide group was found effective. Chlorantraniliprole 18.5 SC at 0.3 mLL⁻¹ recorded 2.17 and 5.41 per cent dead heart and 1.96 and 1.81 per cent white ear in the field trials I and II, respectively whereas the untreated check showed 15.40 and 34.12 per cent dead heart and white ear in field trial I and 34.12 and 26.36 per cent dead heart and white ear in field trial II. This treatment exhibited 85.91 and 94.26 and 78.26 and 93.13 per cent reduction of dead heart and white ear respectively in the field trials I and II over untreated check. The treatment gave the maximum yield of 6.42 and 5.08 tonnes ha⁻¹ in field trial I and II, respectively and has therefore been identified as an efficacious insecticide in integrated pest management of stem borers in rice.