Susceptibility of Spodoptera frugiperda to novel insecticides and detection of known target-site mutations following invasion of Taiwan
Journal
Journal of Asia-Pacific Entomology
Journal Volume
29
Journal Issue
3
ISSN
1226-8615
Date Issued
2026-09
Author(s)
Abstract
The fall armyworm, Spodoptera frugiperda, is a lepidopteran pest which rapidly spread from the Americas to Africa and Asia, and invaded Taiwan via mainland China in 2019. To establish baseline susceptibility data for this invasive pest, eggs and larvae were collected from five regions in Taiwan (Kinmen, Hualien, Yunlin, Chiayi, and Tainan) and tested against six insecticides: spinetoram (IRAC Group 5), novaluron (Group 15), methoxyfenozide (Group 18), chlorantraniliprole (Group 28), cyantraniliprole (Group 28), and a chlorantraniliprole/thiamethoxam mixture (Group 28 + Group 4 A). A susceptible reference strain was established using samples collected from Yunlin and Pingtung, which were reared without insecticide exposure. Collected fall armyworms showed the highest LC50 sensitivity to spinetoram, followed by chlorantraniliprole, cyantraniliprole, and novaluron, and the lowest sensitivity to the chlorantraniliprole/thiamethoxam mixture. We conducted point mutation screening targeting three resistance-associated genes: acetylcholinesterase (AChE), voltage-gated sodium channel (VGSC), and ryanodine receptor (RyR). Only the AChE F290V mutation was consistently detected among our five locations, with frequencies exceeding 50%. No VGSC or RyR mutations were found. Further screening of survivors exposed to high insecticide concentrations confirmed F290V frequency at 60%, suggesting low-frequency mutation resistance in VGSC and RyR loci in the fall armyworm. Transcriptomic sequencing of F1 larvae (2019), FN larvae (2020), and a susceptible strain (Susp) revealed differentially expressed metabolic enzyme genes potentially linked to resistance. These findings provide essential data for managing fall armyworms in Taiwan and offer a foundation for future study on resistance mechanisms in invasive pest populations. © 2026 Korean Society of Applied Entomology. Published by Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Subjects
Fall armyworm
Metabolic enzyme genes
Susceptibility
Target-site mutation
Transcriptome
Publisher
Elsevier BV
Description
Article number 102584
Type
journal article