Characterization of cyantraniliprole resistance in Spodoptera frugiperda: Selection, inheritance pattern, and cross-resistance to other diamide insecticides.

BACKGROUND

Cyantraniliprole, a diamide insecticide, is widely used in Brazil to control sucking and defoliating pests, including the fall armyworm (Spodoptera frugiperda), a major agricultural pest. However, increasing resistance to diamides has raised concerns about the long-term effectiveness of cyantraniliprole. This study aimed to (i) assess the evolution of cyantraniliprole resistance in field populations of S. frugiperda, (ii) investigate cross-resistance to other diamides, and (iii) analyze the role of the I4790K mutation in resistance mechanisms.

RESULTS

A significant decrease in the susceptibility to cyantraniliprole was observed in field populations of S. frugiperda in Brazil, particularly in regions with intensive agricultural systems, such as the Brazilian Cerrado, from 2017 to 2023. A cyantraniliprole-resistant strain of S. frugiperda was selected from a field-collected population in Bahia (BA) using the F screening method. The inheritance of resistance to cyantraniliprole in this strain was autosomal recessive and monogenic, with 3414-fold resistance ratio. High cross-resistance to the diamides flubendiamide, chlorantraniliprole, and cyclaniliprole was also detected. Molecular analysis confirmed the presence of the homozygous I4790K mutation in the ryanodine receptor gene as one of resistance mechanisms of this cyantraniliprole-resistant strain.

CONCLUSION

These findings highlight the decreased susceptibility of field populations of S. frugiperda to cyantraniliprole and the role of the I4790K mutation in accelerating the evolution of resistance to diamide insecticides due to cross-resistance. These results underscore the urgent need for integrated pest management (IPM) strategies, including insecticide rotation and resistance monitoring, to preserve the efficacy of cyantraniliprole and other insecticides. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.