Original paper
Sublethal effects of thiamethoxam on Encarsia formosa: intergenerational impacts and insights from transcriptomic analysis
Wang, Ke; He, Yanyan; Zhang, Yan; Dong, Rui; Hu, Shouyin; Yang, Zezhong; Guo, Zhaojiang; Zhang, Youjun; Xie, Wen; Wang, Shaoli
Entomologia Generalis Volume 45 Number 1 (2025), p. 275 - 284
published: Feb 26, 2025
published online: Feb 18, 2025
manuscript accepted: Jan 14, 2025
final revised version received: Dec 13, 2024
manuscript revision requested: Sep 12, 2024
manuscript received: Sep 9, 2024
DOI: 10.1127/entomologia/2025/3007
ArtNo. ESP146004501023, Price: 29.00 €
Abstract
Pesticides are extensively applied in agriculture to suppress pests, but their potential side effects on nontarget species cannot be ignored. Thiamethoxam is applied to control sweet potato whitefly, Bemisia tabaci, a global agricultural pest, thereby affecting the endoparasitoid Encarsia formosa. We studied the parasitism rate and transgenerational effects of thiamethoxam on E. formosa and analyzed important genes in E. formosa upon exposure to thiamethoxam at different concentrations. The thiamethoxam at LC10 and LC25 concentrations affected the performance of E. formosa, reducing survival rate and decreasing parasitism efficiency on B. tabaci nymphs. The F1 generation of E. formosa experienced negative effects, including prolonged egg-pupal and pupal-adult development periods, reduced overall lifespan and decreased fecundity, after thiamethoxam exposure. In addition, the demographic parameters, including the intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R 0), were reduced by the insecticide. Transcriptome analysis based on the various comparison groups revealed 236 shared differentially expressed genes (DEGs), with 13 up-regulated and 223 down-regulated in both thiamethoxam treatment groups. Among the DEGs, the expressions of development and reproduction related genes including Vg and JHBP were down-regulated in parental generation of E. formosa after exposure to thiamethoxam. Different expression levels were also observed in cytochrome P450 genes in thiamethoxam-treated groups (vs. control). We demonstrated negative impacts of thiamethoxam on E. formosa, and highlighted the need to optimize pesticide use in Integrated Pest Management (IPM) to protect natural enemies.
Keywords
neonicotinoid • whitefly • risk assessment • pest management • gene expression