Spodoptera frugiperda (S. frugiperda) is an invasive pest that threatens
global crop production and food security and poses a serious threat
to maize production worldwide. Metal–organic framework (MOF)
nanocarriers have great potential for agricultural pest control applications.
The present study successfully prepared the chemical cross-linking
of iron-based metal–organic framework nanoparticles (MIL-101(Fe)-NH2 NPs) with sodium lignosulfonate (SL) as a pH/laccase double
stimuli-responsive pesticide release system. The average particle
size of the prepared chlorfenapyr (CF)-loaded nanoparticles (CF@MIL-101-SL
NPs) was 161.54 nm, and the loading efficiency was 44.52%. Bioactivity
assays showed that CF@MIL-101-SL NPs increased the toxicity of CF
to S. frugiperda and caused the rupture
of the peritrophic membrane and enlargement of the midgut. Data from
16S rRNA gene sequencing showed that CF@MIL-101-SL treatment reduced
the resistance of S. frugiperda to
pesticides and pathogens and affected nutrient and energy availability
by remodeling the intestinal microbiota of S. frugiperda. The dysregulated microbial community interacted with the broken
peritrophic membrane, which exacerbated damage to the host. Nontargeted
metabolomic results showed that ABC transporters may be a potential
mechanism for the enhanced toxicity of CF@MIL-101-SL to S. frugiperda. In summary, the present study provides
effective strategies for toxicological studies of nanopesticides against
insects.