Genome-wide diamide resistant linked mutation survey in Spodoptera exigua (Lepidoptera: Noctuidae)

Beet armyworm, Spodoptera exigua is lepidopteran pest that polyphagous and agricultural destructive worldwide, To control S. exigua, diamide such as chlorantraniliprole have been widely used for more than a decade. However, high level of diamide resistance have been reported last five years in Korea. To elucidate the mechanism of resistance to diamide, two factors were identified: metabolic factors and increased insensitivity to diamide insecticide based on mutations. Metabolic factor was evaluated using the synergists test and RNAseq, and it was confirmed that some of specific cytochrome P450 such as CYP9A40 is involved in the development of resistance. As a result of confirming the mutation in the target site, Ryanodine receptor (RyR), only I4790M mutation was found in the field population as well as extremely high level of diamide resistant strain. However, it does not appear to be involved in the development of high resistance. Because I4790M mutation was found even in old samples which collected before diamide commercialized in Korea (2008). Therefore, after constructing the Korean reference genome data set (ASM1567961v1), in total 19 individual consensus genome sets generated to identified diamide resistant related mutations and/or InDels. These results will be discussed.