EXTENT OF DAMAGE OF RICE BUG (Leptocorisa Acuta) AND ITS CONTROL WITH INSECTICIDES

Abstract
The rice bug, Leptocorisa acuta is one of the major and destructive pests of rice. The experiments were conducted to study on the extent of damage of rice bug, Leptocorisa acuta and to determine the efficacy of five insecticides. The experiments were laid out in a Randomized Complete Block Design (RCBD) with three replications of each treatment. From the study it was found that the infestation rate was in linear progress and the hill infestation was 5.42 to 13.75%, panicle infestation was 27.27 to 54.55%, grain infestation was 4.70 to 7.58% and partial grain infestation was 1.82 to 2.58% respectively. After using different treatments, it was found that the maximum percent of infestation was observed in control and minimum was in Malathion 57 EC treated plot. The maximum no. of grain per panicle was observed in case of Malathion 57 EC (206.4), whereas the minimum was observed in Control (172.6) plot. Malathion and Neem oil showed similar effect when yield was compared while the minimum yield was observed in control treatment. The efficacy of insecticides was ranked as Malathion 57 EC > Azadiractin 2% > Chlorpyrifos 20 EC > Voliam flexi 300 SC > Imidacloprid 17.8 SL. The efficacy of all insecticides on the infestation of rice at different time intervals indicate that all the toxicity of all the products decreases with the progress of time after application. It can be recommended that Malathion 57 EC was most effective chemical in controlling rice bug.