Evaluation of the Efficacy of Novel Insecticides against the Rice Gundhi Bug, Leptocorisa acuta (Thun.) in the Eastern Region of Uttar Pradesh, India

The field investigation was carried out to study the evaluation of certain insecticides against rice gundhi bug. The experiment was conducted in a Randomized Block Design with three replications and eight treatments on Rice var. ‘NDR-2065’. It was observed that all treated plots were significantly gave better results over Control (Water Spray). However, among all the treatments minimum bug population was recorded in Thiamethoxam 25 g a.i./ha (0.52 nymphs/adults/hill) treated plots compared to other treatments followed by Fipronil 50 g a.i./ha (0.69 nymphs/adults/hill). Pymetrozine 100 g a.i./ha (0.74 nymphs/adults/hill) was the next best treatment which was at par with Acetameprid 20 g a.i./ha (0.83 nymphs/adults/hill). Azadirachitin 50 g a.i./ha (1.38 nymphs/adults/hill) was least effective treatment but significantly superior to control. Maximum reduction of bug population was observed in Thiamethoxam 25 g a.i./ha (82.6%) followed by Fipronil 50 g a.i./ha, Pymetrozine 100 g a.i./ha and Acetameprid 20 g a.i./ha, having 77.1, 75.3 and 72.3 per cent population reduction. Minimum pest population with the highest grain yield of rice (34.43 q/ha) recorded in treatment T3- Thiamethoxam 25 g a.i./ha followed by Fipronil 50 g a.i./ha recorded 33.27 q/ha yield. Maximum net return was recorded from Thiamethoxam 25 g a.i./ha (Rs. 13433). The benefit cost ratio of different insecticides revealed that Thiamethoxam 25 ga.i./ha (1:14.8) was the most economical treatment followed by Fipronil 50 g a.i./ha (1:4.7) and Acetamaprid 20 g a.i./ha (1:3.4).