Molecular surveillance of resistance mutations in invasive populations of Spodoptera frugiperda in Europe, for evidence-based pest control.

BACKGROUND

The invasive fall armyworm (Spodoptera frugiperda, FAW), a highly destructive pest affecting more than 350 plant species, has recently invaded Europe raising urgent management concerns. Insecticide resistance profiling is essential to support evidence-based pest control strategies. In this study, we analyzed target-site insecticide resistance mutations in FAW populations from Greece to inform pest control strategies. In addition, DNA barcoding through cytochrome oxidase subunit 1 (COI) gene sequencing was used to trace the pest's geographic origin and potential invasion pathways.

RESULTS

All Spodoptera frugiperda specimens in Greece were identified as the rice strain, exhibiting two almost balanced haplotypes (Haplotype 1: 58.6%; Haplotype 2: 41.4%), suggesting a likely origin from a single, genetically diverse source population. Resistance-associated mutations were identified in the ABCC2 gene (A > G single-nucleotide polymorphism (SNP); up to 80.9%) and the Ace-1 gene (F290V: up to 37.5%; A201S: up to 3.85%), conferring resistance to Bacillus thuringiensis (Bt) and organophosphates/carbamates, respectively. By contrast, no resistance-associated mutations were detected for other key insecticides (diamides, pyrethroids, oxadiazines, spinosyns, and avermectins), suggesting their current efficacy in Greece.

CONCLUSION

This study provides a critical baseline for monitoring insecticide resistance in invasive FAW populations in Europe, supporting the development of sustainable integrated pest management strategies in line with the European Union Green Deal. Continuous monitoring with molecular diagnostics, alongside complementary bioassays, is recommended to mitigate the impact of FAW on European agriculture. © 2025 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.