Detection of ryanodine receptor target‐site mutations in diamide insecticide‐resistant Spodoptera frugiperda in China. (1st January 2021)

• Record Type: Journal Article
• Authors: Lv, Sheng‐Lan; Shi, Yang; Zhang, Jia‐Cheng; Liang, Pei; Zhang, Lei; Gao, Xi‐Wu
• Is Part Of: Insect science. Volume 28:Number 3(2021)
• Page Start: 639
• Page End: 648
• Publication Date: 2021-01-01
• Subjects: diamide insecticides -- resistance -- resistance risk -- Spodoptera frugiperda; Insects -- Periodicals; Entomology -- Periodicals; 595.705
• DOI: 10.1111/1744-7917.12896
• Languages: English
• ISSNs: 1672-9609

Abstract

Abstract: Spodoptera frugiperda (Lepidoptera: Noctuidae) is a widely distributed pest of corn. Since it invaded China in 2018, it has caused serious damage to local corn production. Chlorantraniliprole, an anthranilic diamide insecticide, has been widely used to control lepidopteran pests. Tetrachloropyramid is a new allosteric modulator insecticide developed based on chlorantraniliprole, so it has a similar mechanism and insecticidal effect. In this study, we investigated resistance levels to chlorantraniliprole and tetrachloropyramid in S. frugiperda from 13 populations in China. Among the populations tested, the relative highest resistance to chlorantraniliprole occurred in the Guangzhou population, and the most susceptible to chlorantraniliprole was found in the Wuhan population. The lethal dosage LD50 value of the Guangzhou population against chlorantraniliprole was 27.8‐fold higher than that of the Wuhan population. Minimal differences were observed among S. frugiperda populations in terms of sensitivity to tetrachloropyramid. Heterozygous mutations at the I4734 site of the ryanodine receptor (RyR) were found, while no mutations were found in the G4891 site. The mutations were detected in only two of the 786 individuals analyzed, one from the Qinzhou population and other from the Anshun population (frequency below 2% in both cases). There were no significant differences in the expression levels of RyR between Guangzhou and Wuhan populations. In summary, our results indicate that: (i) S. frugiperda has low resistance levels to diamide insecticides in China; and (ii) the differences in relative resistance among the 13 populations analyzed are not caused by the mutations in RyR or the expression of RyR . Abstract : The present study indicated the following in over 13 Spodoptera frugiperda populations from 13 provinces in China. (1) The Hubei population exhibited the highest susceptibility to chlorantraniliprole and the Guangdong population had the highest resistance to chlorantraniliprole. (2) No target mutation was found at the G4891 site of the ryanodine receptor ( RyR ). (3) In the Guangxi population, 1.7% of tested individuals had the heterozygous mutation genotype at position I4734 and no homozygous mutation genotype was found. (4) In the Guizhou population, 1.4% of tested individuals had the heterozygous mutation genotype at position I4734 and also no homozygous mutation genotype was found. (5) Messenger RNA (mRNA) expression in Guangdong strains was not significantly different than in the Hubei strain. Overall, this study suggests that the current resistance of S. frugiperda populations in the field in China has nothing to do with the RyR mutation nor the mRNA expression of the RyR gene.