Neopestalotiopsis is one of the three genera within the Pestalotiopsis-like fungi that infect tea plants, causing severe diseases. Carbendazim (MBC) is a broad-spectrum, systemic benzimidazole fungicide widely used to control various phytopathogenic fungi. In this study, a 20% MBC resistance frequency was observed among the Pestalotiopsis-like strains collected from Jiangsu Province, eastern China. The molecular mechanism of this resistance was identified; specifically, amino acid substitutions (E197K, E197A, F199Y) within the ß2-tubulin conferred high-level resistance (RF > 200, MIC ≥ 200 μg/mL) of Neopestalotiopsis clavispora against MBC, which was further confirmed by isogenic replacement experiments. The MBC-resistant strains exhibited no fitness costs in terms of mycelial growth, conidiation and pathogenicity. Furthermore, no cross-resistance was observed with phenamacril, or prochloraz. These findings reveal that the control of Neopestalotiopsis clavispora with MBC faces significant challenges due to the emerging resistance, while alternative fungicides can be integrated into management strategies.
Alternaria alternata causes leaf brown spot disease on tobacco and threatens the yield and quality of tobacco leaf preharvest and postharvest. Prochloraz, one member of demethylation inhibitors has been registered for controlling various pathogens, including A. alternata. Here, we determine the sensitivities of 88 A. alternata isolates to prochloraz using the mycelial growth rate method. Our results indicate that the mean EC50 value for the 66 sensitive isolates is 0.552 ± 0.290 μg/ml and that for the resistant 22 isolates is 2.209 ± 0.643 μg/ml. Compared with the prochloraz-sensitive populations, the prochloraz-resistant populations exhibit no significant differences in mycelial growth, sporulation, spore germination, and pathogenicity. A positive cross-resistance is observed between prochloraz and difenoconazole but not between prochloraz and metconazole or tebuconazole. Sequencing of the complete AaCyp51 gene from A. alternata isolates reveals that the prochloraz-resistant isolates carry a combination of six substitutions at codons 188 (AAC→AAA), 192 (GTC→ATC), 237 (TCG→GCA), 307 (GCT→GGT), 412 (CAC→TAC), and 434 (GAG→GAC), which are not detected in the sensitive isolates. Molecular docking simulations shows that hydrophobic interactions between prochloraz and AaCYP51 are weakened after the six simultaneous substitutions in AaCYP51(N→K, V→I, S→A, A→G, H→Y, and E→D), correlating with a lower binding affinity of prochloraz to the protein. The six-substitution transformants obtained through artificial construction confer prochloraz resistance, with EC50 values of 1.501 μg/ml and 1.671 μg/ml (0.204 μg/ml for parental isolate), while exhibiting no significant fitness penalty (i.e., sporulation, spore germination, and pathogenicity). To our knowledge, this is the first study to report that six simultaneous point mutations in Cyp51 confer resistance to prochloraz.
The insect nervous system represents a primary target for insecticide development. However, the evolutionary conservation of neural targets between insects and mammals, the off-target safety of neurotoxic insecticides has raised growing concerns. Existing studies have primarily focused on single-task applications, such as pesticide toxicity prediction or central nervous system (CNS) drug screening, while integrated frameworks that jointly assess neurotoxic insecticidal potential and human CNS risk remain scarce. In this study, a neurotoxic insecticide classification model (Pest-LGBM) and a CNS drug classification model (CNS-XGB) were developed using neurotoxic/non-neurotoxic insecticide datasets and CNS/non-CNS drug datasets, respectively. Both models exhibited robust classification performance and generalization ability. Pest-LGBM achieved a 100% positive prediction rate on External Test Set 1, whereas CNS-XGB achieved negative prediction rates of 80.0%, 85.0%, and 92.2% on the training, validation, and External Test Set 1, respectively. Furthermore, we established a dual-model prediction framework, termed DualNeuro, which effectively discriminates compounds with high insecticidal potential but low predicted CNS risk from those exhibiting dual-high responses. Systematic structural characterization at both the global molecular level and core scaffold level was performed via chemical space analysis and Murcko scaffold enrichment. Neurotoxic insecticides were primarily enriched in phosphorus/sulfur-containing ester motifs and hydrophobic aromatic structural units, whereas CNS drugs preferentially contained complex fused-ring scaffolds and nitrogen-containing moieties. Overall, this study provides a computational framework to support safety-oriented design of neurotoxic insecticides, non-target risk assessment, and early-stage CNS drug candidate screening.
Cucumber mosaic virus (CMV) has seriously affected the yield of crops and caused huge economic losses. By exploring the detection methods of CMV, CMV can be detected more accurately and rapidly. The introduction of screen-printed electrodes (SPE) has greatly promoted the development of photoelectrochemical (PEC) biosensors. Herein, a PEC biosensor based on flexible SPE was developed, to achieve sensitive detection of CMV. This work efficiently regulated the PEC reaction by conducting enzymatic biocatalytic precipitation (BCP) on ZnIn2S4, which is exemplified by a CMV-dependent sandwich immune reaction and subsequent alkaline phosphatase (ALP)-activated BCP response. The developed PEC sensor demonstrates excellent analytical performance in CMV detection, with detection limit of 0.001 ng mL-1. The advantage of this work lies in the introduction of one-time SPE, which acts as a flexible electrode, greatly enhances the speed and sensitivity of detection, and is expected to stimulate further research on wearable flexible electronic sensing.
Fusarium spp. are critical pathogenic fungi threatening the safe production of maize (Zea mays). Their infections not only cause substantial yield losses, but also drive the accumulation of carcinogenic mycotoxins in grains, which severely endangers human and livestock health and restricts the sustainable development of the maize industry. In this study, with biological activity and environmental compatibility as core evaluation indicators, five chemical fungicides and two biogenic fungicides were systematically screened, yielding two synergistic fungicidal formulations: isobavachalcone-tetramycin(Isob+Tet)and isobavachalcone-fludioxonil (Isob+Flu). Synergistic virulence assays confirmed that the two combined formulations exhibited significantly stronger antifungal activity than individual active ingredients. Laboratory assays demonstrated that the two combinations disrupted mycotoxin biosynthetic pathways, achieving inhibition rates of 45.15–49.80% for fumonisin B1 (FB1) and 63.51–66.74% for deoxynivalenol (DON). Field trials showed that the two formulations delivered 55.12% and 57.93% control efficacy against maize ear rot, respectively, and effectively reduced mycotoxin residues in grains by activating maize host defense responses and suppressing fungal efflux pump function. This study establishes a novel dual-effect strategy for the synergistic management of Fusarium diseases and mycotoxin contamination, providing a technical basis for safeguarding postharvest grain safety and supporting sustainable maize production.
Scalable dsRNA production is essential for RNAi-based pest control, yet production yield alone does not determine field efficacy. Environmental degradation, insufficient pest exposure, and pest-specific variation in RNAi responsiveness collectively limit the conversion of produced dsRNA into effective gene silencing—a problem that yield, purity, and cost metrics cannot capture. This review examines major dsRNA production and delivery architectures for insect pest control and proposes a platform–barrier co-design framework that links platform architecture to four interacting functional capacities: production capacity, protective capacity, exposure-route matching, and physiological compatibility. By evaluating platforms according to the barriers they resolve rather than their biological origin or production method, this framework provides a basis for pest-specific platform selection and integrated multi-barrier design. For RNAi-responsive pests, improved dsRNA durability and exposure-route matching are often sufficient. For refractory or variably responsive pests, effective control typically requires integrated designs combining protection, nuclease avoidance, sustained delivery or uptake enhancement. However, some multi-barrier pest systems may remain difficult to control when degradation, poor uptake, and target-tissue inaccessibility occur simultaneously. Next-generation dsRNA biopesticides should therefore be engineered not simply to maximize dsRNA output, but to maximize its conversion into field-effective RNAi activity under pest- and context-specific conditions.
Barnyardgrass is a global threat to food security, yet its control relies heavily on herbicides like quinclorac with low utilization, leading to environmental toxicity. Developing precision delivery systems to maximize efficacy remains a critical challenge. Herein, we engineered a nanocarrier via the pH-driven synergistic co-assembly of WPI and SPI (whey and soybean protein isolate). The optimized nanocarrier (SPI/WPI 8:2) efficiently encapsulated quinclorac (SWQC), exhibiting robust stability, superior foliar adhesion, and sustained release. Notably, SWQC demonstrated enhanced herbicidal activity at one-third of the active ingredient dosage of conventional formulations. Mechanistic investigations revealed that SWQC treatment intensified oxidative stress by significantly upregulating ethylene biosynthesis genes (ACS and ACO) and elevating ABA levels, and further suppressed key metabolic pathways (e.g., TCA cycle and amino acid metabolism), leading to weed mortality. Furthermore, SWQC exhibited excellent biosafety toward non-target organisms, including rice, soil microbes, and tadpoles. This work establishes a dual-protein co-assembly strategy for functional herbicide delivery and advances the structure-property-function understanding of food-derived biomacromolecular nanoparticles.
Weeds threaten crop production, and while essential for control, they commonly cause crop damage. Herbicide safeners safeguard crops by selectively enhancing their detoxification pathways, without affecting herbicide efficacy. However, the rational design of safeners still remains a significant challenge. This review focuses on three core strategies for developing novel safeners: (i) structure-guided design, including the structural optimization of commercial and natural safeners; (ii) mechanism-driven design through integrated multi-omics and detoxification pathway analysis; (iii) enabling efficient delivery via advanced smart delivery systems. By integrating recent progress, this review proposes a strategic framework for developing effective, environmentally friendly safeners for current and future herbicides.
Currently, the control of phytopathogenic fungi faces challenges arising from chemical resistance and biosafety concerns. Triazole fungicides (TFs), as ergosterol biosynthesis inhibitors, possess broad-spectrum and high-efficacy characteristics. However, their single target site has led to increasing field resistance, highlighting the urgent need to discover molecular targets with novel mechanisms of action. Although P-type ATPases drive fungal pathogenicity, their potential as pesticide targets remains unexplored. Here, we identified MoAPT5 as a potential target protein commonly recognized by multiple TFs and elucidated its interaction mechanism. Using Magnaporthe oryzae (M. oryzae) as a model, in vivo experiments revealed that knockout of MoAPT5 inhibited mycelial growth and reduced the sensitivity of M. oryzae to TFs, whereas complementation restored both growth and sensitivity. Further pathogenicity assays showed that the ΔMoapt5 mutant exhibited reduced conidial production, abnormal conidial morphology, delayed germ tube elongation, and decreased pathogenicity on rice leaves, as well as markedly reduced sensitivity to the protective and curative effects of TFs. In vitro binding assays demonstrated that TFs exhibited strong affinity for MoAPT5 and inhibited its ATPase activity by approximately 50%. Molecular docking and dynamics simulations further revealed that TFs bind primarily to a hydrophobic pocket formed by transmembrane helices TM2, TM4, TM5, and TM6 of MoAPT5, with the complex remaining conformationally stable. These findings provide new insights into the multi-target mechanism of TFs and offer a potential target for overcoming existing resistance issues and developing novel fungicides.
Herbicide resistance threatens sustainable weed control and demands new design strategies beyond conventional single-target chemistries. Protoporphyrinogen oxidase (PPO) and solanesyl diphosphate synthase (SPS) are two essential enzymes linked to chlorophyll biosynthesis and plastoquinone production, respectively, making them attractive targets for combinatorial intervention in plants. Here, we report the structure-guided development of a dual-target PPO/SPS inhibitor from the herbicide scaffold aclonifen. Among the synthesized analogs, compound 3q retained potent inhibition of AtSPS1 while exhibiting a ∼60-fold improvement in NtPPO inhibition relative to aclonifen. Differential scanning fluorimetry supported direct engagement of both targets by 3q. A co-crystal structure of the SPS-3q complex revealed binding at the dimer interface and stabilization through π-π interactions with Phe211, whereas molecular dynamics simulation and mutational analysis supported the binding mode of 3q in PPO. In planta, 3q strongly inhibited primary root growth, triggered reactive oxygen species accumulation, and caused characteristic bleaching and burning-curling phenotypes. Notably, 3q remained active against an R128G PPO-resistant Amaranthus retroflexus biotype under greenhouse conditions. Together, these results establish 3q as a dual-target herbicide and provide a proof-of-concept that simultaneous inhibition of PPO and SPS can be exploited to overcome resistance and expand herbicide design strategies.
In this study, a nanobiopesticide based on mesoporous silica was prepared as a support for the Bacillus thuringiensis Cry3Aa protein. The selected support material was UVM-7 silica, which has been demonstrated to possess high accessibility due to its hierarchical bimodal porosity. The functionalisation of the silica with Ce as a heteroelement was achieved through incorporation using the atrane method, resulting in a final molar ratio of Si/Ce = 16. The modified support material exhibited a high BET surface area (747 cm3/g) and pore volume (1.02 cm3/g). Ce, which generates CeO2-type nanodomains detected by RAMAN, has a dual role: to increase the local isoelectric point to promote interaction with the Cry3Aa protein and to protect the latter from UV radiation. The nanoencapsulation of the protein does not result in alterations to the organisation and morphology of the support, and is achieved through electrostatic interactions. The efficacy of the material as a biopesticide has been substantiated through experimental testing on the potato pest Leptinotarsa decemlineata (Colorado potato beetle, CPB). It has been observed that materials containing cerium (Ce) have the capacity to retain a greater amount of protein and to provide protection against the degradation of the Cry3Aa protein caused by UV radiation. Consequently, these nanobiopesticides have been demonstrated to result in elevated mortality rates (50 ± 7%).
Microfluidic technology has emerged as a powerful enabling platform in agrochemical science, offering precise manipulation of minute fluid volumes coupled with enhanced mass and heat transfer efficiency, significantly reduced reagent consumption, and high degrees of system integration. This review systematically summarizes recent advances in the application of microfluidics to pesticide science, organized around three core domains: (i) continuous-flow synthesis, (ii) nanopesticide preparation, and (iii) on-chip detection of pesticide residues. In continuous-flow synthesis, microreactors facilitate safer, more controllable, and scalable production of herbicides, fungicides, and insecticides, particularly for hazardous transformations such as nitration, diazotization, and catalytic hydrogenation, achieving superior reaction selectivity and reproducibility. In nanopesticide engineering, microfluidic platforms offer exceptional control over particle size, size distribution, and structural uniformity; this translates into markedly improved colloidal stability, programmable release kinetics, and enhanced biocompatibility relative to conventional bulk-phase methods. For pesticide residue analysis, lab-on-a-chip systems integrated with electrochemical, surface-enhanced Raman scattering (SERS), paper-based, 3D-printed, or smartphone-readout modules enable rapid, on-site, and sensitive detection of multiple pesticide classes at trace levels. By bridging synthetic chemistry, formulation engineering, and analytical detection, microfluidics establishes a robust, scalable, and environmentally responsive technological foundation for next-generation crop protection. This review highlights the critical role of microfluidics in addressing safety, environmental, and efficiency challenges in pesticide development, while also outlining promising pathways toward intelligent, green, and digitally enabled agrochemicals.
Pyrazole-4-carboxylates are versatile precursors for diverse bioactive molecules, yet direct regioselective synthesis remains challenging. Condensations of unsymmetrical 1,3-dicarbonyls afford regioisomeric mixtures, while diazo-based strategies involve toxic and potentially explosive intermediates. Both routes typically require elevated temperatures and environmentally burdensome organic solvents. To develop an eco-friendly, highly regioselective protocol for synthesizing ethyl 1,5-disubstituted-1H-pyrazole-4-carboxylates and to elucidate the cyclization mechanism through density functional theory (DFT) calculations. A series of 4-substituted 2-ethoxymethylidene-1,3- diketones were cyclized with mono-substituted hydrazines (alkyl, aryl, heterocyclic) under optimal conditions. Regioselectivity was determined by HPLC and confirmed by X-ray crystallography. DFT calculations were performed at the M06-2X/6-311++G (d, p) level. Antifungal activity was assessed by mycelial growth inhibition against eight phytopathogens and anticancer activity was evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay against cell lines (A549, PC-3, and K562). The cyclization afforded 1,5-disubstituted products with excellent regioselectivity (regioisomeric ratio (rr) of 3a:3a' up to 98:2) and good isolated yields (70-89%). Scale-up under solvent-free conditions (50 mmol scale) gave 80% yield under aqueous or solvent-free conditions at 25 °C for 20 min. DFT revealed a stepwise [3 + 2] pathway with a rate-determining barrier of 17.54 kcal mol−1, wherein preferential C2–N1 bond formation is driven by the higher electrophilicity of C2 (Pk+ = 0.0031) and avoidance of CF3⋯N electrostatic repulsion. Compounds T1, T5, and T6 exhibited significant antifungal activity (inhibition rates >80% against multiple pathogens, surpassing boscalid), while T4 and T6 showed potent anticancer activity (IC50 = 4.7 ± 0.5 μM and 4.9 ± 1.1 μM against PC-3, respectively). This green protocol provides a practical, scalable route to regio-defined pyrazole-4-carboxylates and positions the 1,5-disubstituted scaffold as a versatile platform for agrochemical and drug discovery.
Carbon dots (CDs) possessing reactive oxygen species (ROS) scavenging activity have emerged as promising agents for enhancing plant tolerance to salt stress. However, their potential in saline-alkali soils has received limited attention. Furthermore, although metal-doped CDs have been explored, the comparative efficacy of chemically modified versus physically mixed metal-CD formulations remains unclear. Herein, we demonstrate that lysine-derived carbon dots (LysCDs) physically combined with calcium ions (Ca2++LysCDs) confer superior benefits to soybean under saline-alkali stress compared with chemically conjugated Ca2+/LysCDs. Despite comparable ROS-scavenging capacities in vitro, the two formulations differed markedly in surface charge: Ca2++LysCDs exhibited a negative zeta potential, whereas Ca2+/LysCDs showed near-neutral surface charge. This difference in surface charge likely modulates root uptake efficiency, thereby affecting intracellular ROS clearance and the activation of downstream signaling cascades governing ion homeostasis and antioxidant defense. In addition, Ca2++LysCDs amendment more effectively improved the rhizosphere soil environment, as reflected by increased activities of urease and dehydrogenase and the selective enrichment of plant growth-promoting rhizobacteria. Collectively, these findings offer a framework for the rational development of CD-based soil amendments tailored to improve crop resilience in saline-alkali environments.
To explore the potential of utilizing renewable bioresources as sustainable alternatives to fossil-derived chemicals in green pesticide development, N-acetylglucosamine (NAG), the monomer of chitin, was employed as a starting scaffold for structural design, synthesis, and bioactivity evaluation. An efficient room-temperature synthetic route was developed, successfully yielding a series of novel thiourea glycoside conjugates. In vitro screening identified glycoside 3m as the most potent candidate against Fusarium oxysporum, achieving an inhibition rate of 94.4% at 200 μg/mL. Morphological and ultrastructural analyses via SEM and TEM showed that while glycoside 3m induced notable surface distortions in mycelia, the cell wall and membrane remained intact. Further untargeted metabolomics studies suggested that glycoside 3m primarily suppresses fungal growth by perturbing mitochondrial energy metabolic pathways, including glycolysis and the tricarboxylic acid cycle. Capitalizing on this bioenergetic vulnerability, a synergistic formulation combining glycoside 3m with hydrogen peroxide (H2O2) was evaluated. The co-application of 100 μg/mL glycoside 3m with 0.3‰ H2O2 achieved a 100.0% inhibition rate in vitro and a 52.9% protective efficacy in vivo. Overall, this study demonstrates the feasibility of developing high-efficiency fungicides from renewable marine biomass, offering a promising and sustainable approach for the management of agricultural pathogenic fungi.
Lepidopteran pests are a major driver of global maize yield losses and have evolved substantial resistance to many conventional insecticides. Current management practices lack new active ingredients that are both broadly effective and safe for pollinators. Here, we report a new class of pyrido[1,2-a]pyrimidinone mesoionic derivatives designed via an oxygen-to-sulfur bioisosteric substitution strategy. Laboratory bioassays identified J2 as an optimal analogue with excellent and broad-spectrum insecticidal activity against Spodoptera frugiperda, Chilo suppressalis, Ostrinia furnacalis, and Plutella xylostella, exhibiting efficacy comparable to the commercial standard dicloromezotiaz. Notably, J2 showed low acute honeybee toxicity, with contact and oral LD50 values of 16.478 and 16.858 μg a.i./bee, respectively, which were markedly higher than those of triflumezopyrim and dicloromezotiaz. Preliminary mechanistic studies using enzyme activities, ELISA, RT-qPCR, RNAi, and molecular docking suggest that J2 likely binds to the orthosteric site at the interface of the nAChR α1/β2 subunit in fall armyworm, disrupting neuronal homeostasis and leading to insect mortality. This study provides a promising and safe lead for the sustainable management of lepidopteran pests.
This highlight discusses the study by Yang et al. (Cell, 2026), which reveals an unexpected function of strigolactone (SL) signaling in rice antiviral immunity. This work shows that SL signaling promotes antiviral RNA interference (RNAi) through the ONAC131-MID1-RDR1/RDR6 pathway. Rice grassy stunt virus (RGSV) suppresses this defense through viral protein P3, which targets SL receptor DWARF14 (D14) at its DWARF3 (D3)-binding interface and stabilizes repressor D53, thereby attenuating RDR1/RDR6 expression and virus-derived small interfering RNA amplification. Structural and genetic analyses identify D102 of D14 as a critical determinant of the P3-D14 interaction but not of SL perception. Precise base editing of D102N generates transgene-free rice lines with enhanced RGSV resistance while maintaining normal growth and yield. This work establishes phytohormone receptors as editable targets for crop protection and provides a promising strategy for engineering durable antiviral resistance in rice.
Eugenol displays intrinsic acaricidal activity against both plant mites and parasitic mites, yet its further development as a commercial agrochemical acaricide is restricted by suboptimal bioactivity and non-negligible cytotoxicity. To overcome these limitations, we targeted mitochondrial complex I to perform rational structural modification based on the eugenol skeleton. Thirty-two novel eugenol derivatives were rationally designed, synthesized, and comprehensively assessed for in vitro and in vivo acaricidal efficacy against two critical livestock ectoparasitic mites. Preliminary bioactivity screening singled out compound Eug-32 as the optimal lead molecule with remarkably enhanced acaricidal potency and target selectivity. Mechanistic investigations revealed that Eug-32 serves as a high-affinity inhibitor of mitochondrial complex I via direct interaction with the MTND2 subunit, which interrupts electron transport and suppresses NADH oxidation. Such inhibitory effect triggers the depletion of the key cofactor NAD+, reduces the catalytic efficiency of rate-limiting enzymes in the tricarboxylic acid cycle, and severely impairs parasite energy supply. Meanwhile, impaired respiratory chain function induces massive reactive oxygen species accumulation, triggering abnormal mitochondrial fission and overactivated mitophagy, which together disrupt mitochondrial homeostasis and ultimately cause irreversible damage to mite cellular structure and physiological function. Importantly, Eug-32 exhibits favorable species-selective toxicity: it barely interferes with host mitochondrial activity and presents a favorable toxicological safety profile free of genotoxic risks. This work identifies Eug-32 as a safe, non-genotoxic acaricidal lead capable of perturbing mitochondrial quality control through specific complex I inhibition. Follow-up research evaluating its bioactivity against major agricultural phytophagous mites is ongoing to broaden its application prospects in crop pest management.
Insect reproduction serves as a primary target for insecticide development and resistance management in insects. Ovarian development, a key determinant of insect reproduction, is tightly regulated through complex signaling pathways. Here we reported that AKT-E93 signaling pathway governing ovarian development and oogenesis in Nilaparvata lugens via two key genes Epidermal Growth Factor Receptor (Egfr) and cuticular protein gene Cpr83. Silencing Akt inhibited ovarian development and oocyte budding at the later nymph stage. Phosphoproteome analyses identified 20 transcription factors (TFs) with a lost site phosphorylation after Akt silencing, among which E93 was found essential for oocyte budding. E93 is abundantly distributed in follicular cells, and silencing E93 produced a comparable phenotype as Akt RNAi. Silencing Akt and E93 down-regulated expression of Egfr and three cuticular protein genes (Cpr33, Cpr83 and Cpr95), but only silencing Egfr and Cpr83 led to an obvious suppression of ovarian development. Specifically, silencing Egfr mainly inhibited ovarian development, while silencing Cpr83 led to failure of oogenesis. AKT was identified as modulators of E93 through phosphorylation at serine 530 (S530). These kinases phosphorylated E93 to obtain three patterns in regulating Egfr and Cpr83 expression, suppressing, enhancing and maintaining. These findings reveal a novel mechanism in insects that AKT regulates ovarian development via phosphorylation of E93 at S530 site, which subsequently modulates Egfr and Cpr83 expression. As a node of reproduction regulation, the proteins involved in ovarian development would be targets to develop reproduction suppressants in insects.
The fall armyworm (Spodoptera frugiperda), a highly migratory and polyphagous invasive pest, poses a severe threat to global food security and has rapidly emerged as one of the most destructive agricultural pests in China since its invasion, where it has been officially designated as a Class I Crop Pest owing to its substantial economic impact on maize and other crops. Emamectin benzoate (EB), an insecticide widely used for S. frugiperda control, is constrained by poor water solubility, weak foliar retention, and environmental instability, resulting in suboptimal field efficacy and inefficient pesticide utilization, thereby leading to excessive pesticide inputs, environmental contamination, and the rapid evolution of resistance. Nanodelivery systems represent a promising strategy for improving pesticide stability, plant-surface adhesion, and bioavailability, enabling enhanced pest control with reduced chemical inputs. Here, we developed a hydrophilic–lipophilic diblock polymer (HLDP)-enabled delivery system for the encapsulation and delivery of EB. Isothermal titration calorimetry and Fourier transform infrared spectroscopy revealed that the interaction between HLDP and EB was driven primarily by electrostatic interactions, with hydrogen bonding serving as a secondary force. After encapsulation within HLDP, the particle size of EB decreased from 7687.05 to 152.24 nm, while the contact angle decreased by 30.2° on glass slides and 48.8° on maize leaves, accompanied by a 1.95-fold increase in foliar retention and significantly improved thermal storage stability. Moreover, stomach toxicity against S. frugiperda was markedly enhanced, with a 3.94-fold reduction in LC50 from 4.020 μg/L for EB to 1.021 μg/L for EB@HLDP, and a maximum increase of 38.33% in larval mortality. Transcriptome analysis demonstrated that the complexation with HLDP enhanced the insecticidal activity of EB by potentiating neurotoxicity, suppressing detoxification capacity, inducing lethal proteotoxic stress, and depleting energy reserves. The qRT-PCR and biological validation analyses further corroborated these findings. At field application concentrations, EB@HLDP exhibited favorable biosafety toward maize seed germination and seedling growth. Our study establishes an efficient strategy for reducing pesticide application rates while improving control efficacy against S. frugiperda, highlighting the potential of nanocarrier-based pesticide delivery for sustainable pest management.
