Pantnagar Journal of Research

Abstract

The brown planthopper (Nilaparvata lugens, BPH) is a major pest of rice that causes significant yield loss, while the mirid bug (Cyrtorhinus lividipennis, MB) serves as an important natural enemy of BPH by feeding on its eggs and nymphs. A field study was conducted during Kharif 2023 and 2024 at the Norman E. Borlaug Crop Research Centre, G. B. Pant University of Agriculture and Technology, Pantnagar, to assess the population dynamics of BPH and MB in relation to weather parameters. Weekly observations were recorded from 10 days after transplanting (DAT) till harvest on rice variety Pant Dhan 12. In 2023, BPH appeared in the 35th standard week with a population of 1.8/hill and reached a peak of 20.8/hill during the 41st week. MB appeared in the 36th week (0.2/hill) and peaked at 6.9/hill in the 40th week. In 2024, BPH was first recorded in the 32nd week (1.2/hill) and reached the highest population of 20.5/hill during the 37th week, while MB first appeared in the 33rd week (0.2/hill) and peaked at 6.8/hill in the 38th week. Multiple linear regression analysis showed that 87.6% and 97.2% of the variation in Brown Planthopper population in 2023 and 2024, respectively, could be predicted using weather parameters. This indicates the strong predictive power of the developed regression models for forecasting BPH populations.