Acta Entomologica Sinica ›› 2024, Vol. 67 ›› Issue (4): 477-489.doi: 10.16380/j.kcxb.2024.04.004

• RESEARCH PAPERS • Previous Articles     Next Articles

Analysis of the reduced pesticide use and enhanced effectiveness in controlling rice pests through transplanting insecticide-pretreated rice seedlings

WEI Qi1, ZHANG Ming2, ZHU Xu-Hui1, HE Jia-Chun1, LIU Lian-Meng1, LAI Feng-Xiang1, WANG Wei-Xia1, WAN Pin-Jun1, LIU Long-Sheng2, FU Qiang1,*   

  1.  (1. State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Hangzhou 311401, China; 2. Hengyang Academy of Agricultural Sciences, Hengyang 421101, China)
  • Online:2024-04-20 Published:2024-05-24

Abstract: 【Aim】 Taking the novel, highly effective, and long-lasting insecticides triflumezopyrim and tetraniliprole as examples, this study aims to investigate the practical significance of reduced pesticide use and enhanced effectiveness in controlling rice pests through transplanting insecticide-pretreated rice seedlings. 【Methods】 Laboratory simulation experiments involving transplanting insecticide-pretreated rice seedlings were conducted to assess the toxicity and duration of efficacy of triflumezopyrim (active ingredient, a.i.) exposure to rice seedlings at the doses of 1.95, 5.85 and 9.75 mg a.i./m2 against the adults or nymphs of the brown planthopper, Nilaparvata lugens, and the white-backed planthopper, Sogatella furcifera, respectively. Field experiments for transplanting high-dose insecticide-pretreated rice seedlings were carried out to evaluate their control efficacy against the rice stem borer, Chilo suppressalis, and rice planthoppers, as well as the impact of different modes of pesticide application on the population dynamics of parasitic wasps in paddy fields, in Hangzhou, Zhejiang Province, and Hengyang, Hunan Province, respectively, for early-, mid-, and late-season rice crops. 【Results】 In the laboratory, transplanting rice seedlings pretreated with 5.85 and 9.75 mg a.i./m2 of triflumezopyrim caused exceeding 75% corrected mortality rates in N. lugens adult females and the 3rd instar nymphs at 35 d after transplanting (DAT). The corrected mortality rate of S. furcifera adult females exceeded 80% when transplanting rice seedlings exposed to 5.85 mg a.i./m2 of triflumezopyrim at 28 DAT. For controlling C. suppressalis in early-season rice, the applications of tetraniliprole at the doses of 12.75 and 25.50 mg a.i./m2 resulted in a corrected control efficacy of over 85% at 35 DAT. The comprehensive analysis of the field experiment results in both mid- and late-season rice in Hangzhou and Hengyang revealed that transplanting rice seedlings exposed to 5.85 mg a.i./m2 of triflumezopyrim and 25.50 mg a.i./m2 of tetraniliprole could reduce pesticide applications once or twice and the usage of effective pesticide ingredients by over 98%. Moreover, this practice of pesticide application method maintained control efficacy comparable to conventional spraying, resulting in an increase in the total number of parasitic wasp species by 29.0%-49.7% and their total number of individuals by 61.2%-69.3%, respectively. 【Conclusion】The application of highly effective and long-lasting insecticides to rice seedlings before transplanting could reduce the frequency and quantity of pesticide use during the early stage of rice cultivation, thus yielding favorable economic and ecological benefits. This study offered valuable guidelines to promote environmentally friendly management of rice diseases and pests through the application of transplanting pesticide-pretreated rice seedlings.

Key words: Transplanting insecticide-pretreated rice seedlings, rice pest, triflumezopyrim, tetraniliprole, reduction of pesticide application, conservation of natural enemies