A Preliminary Study on Controlling Chilo suppressalis in Rice Fields Using Precision Timing and Insecticide Combinations

Chilo suppressalis (Walker) is one of the most important rice pests worldwide, posing a significant challenge to effective control. To develop a precision-timed, eco-friendly management strategy, overwintering population investigation and dynamic monitoring of C. suppressalis populations were conducted in the Meishan region of Sichuan, China, from 2023 to 2024. The optimal timing for insecticide application was estimated, followed by field trials evaluating the efficacy of different insecticides. Results demonstrated that the peak emergence of first-generation adults typically occurred in early July (under the environmental conditions of the Meishan region), with the ambient humidity below 75% and temperature around 29°C. Pesticide efficacy trials show that insecticide combinations exhibited superior control. Notably, a combined treatment of emamectin benzoate·methoxyfenozide + chlorantraniliprole achieved the highest control efficacy (90.05%) and a corresponding yield of 12,491.55 kg/ha. All tested treatments were determined to be safe for rice growth. Furthermore, this optimized strategy resulted in notable economic benefits, including a 50% reduction in pesticide usage and cost savings of 4796.15 CNY compared to conventional practices. This study provides valuable insights into sustainable rice production and pest management and, for the first time, proposes a precision application time window based on intelligent monitoring.