A high-quality chromosome-level genome assembly for the agricultural pest Mythimna separata

The oriental armyworm, Mythimna separata, poses a persistent challenge to agricultural pest management due to its strong migratory abilities and polyphagous feeding behavior. In this study, we present a chromosome-level genome assembly using Illumina, PacBio HiFi, and Hi-C sequencing technologies. The final assembly spans 714.5 Mb with a scaffold N50 of 22.7 Mb and a GC content of 38.8%. A total of 32 chromosomes were successfully anchored, including the Z and W sex chromosomes. BUSCO analysis indicated a genome completeness of 98.6%, and 19,879 protein-coding genes were predicted. The W chromosome, measuring 30.55 Mb with a repeat content of 68.34%, harbors 824 protein-coding genes. Furthermore, a PCR-based method confirmed W-linked sequences for female-specific sex detection via the ZW system. This enhanced genome assembly provides a valuable resource for evolutionary research on M. separata and facilitates the development of sex-regulated pest control strategies.