Plant-mediated Silica nanoparticle exposure disrupts reproduction, development, and population performance of Spodoptera frugiperda

Spodoptera frugiperda is a major invasive pest that threatens global maize production due to its aggressive feeding behaviour. Silica nanoparticles (SiNPs) are extensively used as fertilizers and delivery carriers for pesticides, yet their direct impacts on insects feeding on SiNPs-treated leaves remain poorly understood. Here, we integrated life-table, enzymatic, transcriptomic analyses and phenotypic observations to examine the biological responses of S. frugiperda fed SiNPs-treated maize. Life table analysis showed pronounced demographic suppression in the SiNPs-treated group, with preadult survival falling to 0.48 compared with 0.96 in the control and a longer total pre-oviposition period of 37.36 days compared with 31.15 days. Several larval instars lasted three to four times longer. Reproduction was reduced, with fecundity dropping to 54.01 eggs per female compared with 91.89 in the control, the oviposition period shortening to 3.18 days compared with 8.55 in the control, and only 11 reproductive females emerging compared with 20 in the control. Enzymatic assays revealed elevated detoxification and stress responses, particularly increased carboxylesterase (CarE) activity with moderate induction of cytochrome P450 monooxygenase (P450), glutathione S-transferase (GST), and acetylcholinesterase (AChE). Transcriptomic profiling identified extensive differential expression, including up-regulation of chorion peroxidase, vitellogenin, ecdysone oxidase-like, fatty acyl-CoA reductase, and juvenile hormone epoxide hydrolase, and downregulation of odorant receptor 4-like, fatty acyl-CoA hydrolase, and fatty acyl-CoA reductase. These molecular disruptions corresponded to impaired demographic performance, indicating that SiNPs induce multi-level physiological stress, suppress hormonal and reproductive pathways, and reduce population growth. Our findings demonstrate that SiNPs adversely affect development and reproduction in S. frugiperda , supporting their potential as eco-friendly components of integrated pest management programs. • SiNPs were applied to maize foliage for managing Spodoptera frugiperda . • SiNPs reduced larval survival, development, and adult fecundity. • SiNP exposure disrupted AChE, GST, CarE, and CYP450 enzyme activities. • Reproductive transcriptomes showed SiNP-induced gene dysregulation. • Multi-level data demonstrate SiNPs as a promising eco-friendly S. frugiperda control tool.