A comprehensive assessment of insecticide resistance mutations in source and immigrant populations of the diamondback moth Plutella xylostella (L.)

Abstract

BACKGROUND The diamondback moth (DBM) Plutella xylostella has developed resistance to almost all insecticides used to control it. Populations of DBM in temperate regions mainly migrate from annual breeding areas. However, the distribution pattern of insecticide resistance of DBM within the context of long‐distance migration remains unclear. RESULTS In this study, we examined the frequency of 14 resistance mutations for 52 populations of DBM collected in 2010, 2011, 2017 and 2018 across China using a high‐throughput KASP genotyping method. Mutations L1041F and T929I conferring pyrethroid resistance, and mutations G4946E and E1338D conferring chlorantraniliprole resistance were near fixation in most populations, whereas resistant alleles of F1020S, M918I, A309V and F1845Y were uncommon or absent in most populations. Resistance allele frequencies were relatively stable among different years, although the frequency of two mutations decreased. Principal component analysis based on resistant allele frequencies separated a southern population as an outlier, whereas the immigrants clustered with other populations, congruent with the migration pattern of northern immigrants coming from the Sichuan area of southwestern China. Most resistant mutations deviated from Hardy–Weinberg equilibrium due to a lower than expected frequency of heterozygotes. The deviation index of heterozygosity for resistant alleles was significantly higher than the index obtained from single nucleotide polymorphisms across the genome. These findings suggest heterogeneous selection pressures on resistant mutations. CONCLUSION Our results provide a picture of resistant mutation patterns in DBM shaped by insecticide usage and migration of this pest, and highlight the widespread distribution of resistance alleles in DBM. © 2022 Society of Chemical Industry.

A high‐throughput KASP assay provides insights into the evolution of multiple resistant mutations in populations of the two‐spotted spider mite Tetranychus urticae across China

“…In our study, KASP genotyping can be performed in 384‐well plates, including 4–8 populations (46/94 individuals per population), giving it much higher throughput than the other methods. Our study showed that KASP is a potential method for high throughput detection of resistant mutations, following our use of this approach in a different context 39,40 …”

“…Our study showed that KASP is a potential method for high throughput detection of resistant mutations, following our use of this approach in a different context. 39,40 However, the two forward primers for the KASP assay need to stop at the mutation site, reducing the flexibility of the primer design. Thus, the KASP assay might be limited for some resistant mutations.…”

“…36 This method has been used in molecular breeding, 36,37 species identification, 38 and more recently for detecting resistant mutations. 39,40 It provides an ideal approach for high throughput genotyping resistant mutations in the TSSM.…”

“…KASP technology delivers extremely high levels of assay accuracy with accuracy > 99.8% based on independent assessment 36 . This method has been used in molecular breeding, 36,37 species identification, 38 and more recently for detecting resistant mutations 39,40 . It provides an ideal approach for high throughput genotyping resistant mutations in the TSSM.…”

Metabolic Resistance of Sogatella furcifera (Hemiptera: Delphacidae) toward Pymetrozine Involves the Overexpression of CYP6FJ3

“…Previous studies showed that in 2017 and 2018, S. furcifera from the test field populations in Sichuan were at a susceptible or low level of resistance toward pymetrozine; ,, however, our results found that the resistance of some field populations reached a high level of resistance, and the levels of resistance increased rapidly. This is due to the migratory nature of the pest, where its resistance is determined not only by the local practices of insecticide usage and rice varieties in the new area but also by the historical patterns of insecticide usage and resistance in the source population. − Consequently, field populations within the same rice area exhibit significant variations in their resistance to insecticides from year to year. In particular, there has been a notable issue with pymetrozine resistance, not only in Sichuan but also in other regions of China.…”