Toxicity of diet-incorporated silica nanoparticles on the invasive fall armyworm, spodoptera frugiperda (lepidoptera: noctuidae): life table and population projection analysis.

Abstract

Fall armyworm (FAW) is a major invasive pest causing significant damage to maize and other cereal crops, necessitating the development of sustainable management strategies. This study evaluated the toxicological and demographic effects of diet-incorporated silica nanoparticles (SiNPs) on FAW under laboratory conditions. SiNPs were incorporated into an artificial diet at concentrations of 100-500 ppm, along with an untreated control, and assessed for their effects on survival, development, reproduction, and population growth using age-stage, two-sex life table analysis. Larval mortality increased with concentration, reaching 85.77% at 500 ppm, with LC₅₀ and LC₉₀ values of 239.23 and 1438.61 ppm, respectively. SiNPs exposure significantly prolonged larval (18.60-24.59 days) and pupal (6.42-8.33 days) durations, while reducing pupal weight (male: 186.04-163.39 mg; female: 222.79-210.46 mg), adult longevity (8.62-7.26 days), female spawning (90.13% to 64.05%), and mating rate (92.81% to 66.13%), whereas mating frequency remained unaffected. Life table parameters showed declines in intrinsic rate of increase (0.158-0.064 day⁻¹), finite rate of increase (1.17-1.06 day⁻¹), and net reproductive rate (149.79-14.10 offspring per individual), along with increased mean generation time (31.67-41.16 days). These results demonstrate that dietary exposure to SiNPs adversely affects the growth, survival, and reproductive performance of FAW, leading to reduced population growth potential. Overall, the study provides clear evidence that SiNPs can suppress FAW populations under controlled conditions and highlights their potential as an eco-friendly component of integrated pest management, although further field-level validation is required.