Benzo[a]pyrene (BaP), a potent carcinogen commonly present in foods processed at high temperatures, typically exists at trace levels (μg/L) in complex food matrices such as edible vegetable oils. Traditional BaP detection methods based on chromatographic separation techniques are hindered by issues such as complex sample pretreatment, high instrument costs, and time-consuming procedures, which limit their applicability for rapid screening and on-site testing. This study proposes a rapid, non-destructive method that combines excitation-emission matrix fluorescence (EEMF) spectroscopy with parallel factor analysis (PARAFAC), enabling direct detection of BaP content in edible vegetable oils without the need for sample pretreatment. The method integrates external calibration, PARAFAC and ordinary least squares (OLS) regression to construct an analytical framework. By establishing PARAFAC models for standard solutions of BaP at different concentrations, the linear response range compliant with the Lambert-Beer law was determined to be 1-500 μg/L. Dilution experiments with spiked vegetable oils confirmed that peanut oil, soybean oil, and corn oil samples did not exhibit significant inner filter effects without any pretreatment, indicating that this method is suitable for direct quantitative analysis of BaP in complex matrices. Based on these findings, the method was further applied to detect BaP content in three different types of vegetable oils spiked with the compound. The results showed that the proposed method could effectively distinguish BaP from other natural fluorescent components. By combining relative concentration scores and the established concentration prediction model, the method could achieve precise quantification of BaP concentrations above 10 μg/L in vegetable oils and accurately identify BaP levels above 1 μg/L in peanut oil and corn oil, and above 7.5 μg/L in soybean oil. The method is rapid, convenient, and easy to operate, with high sensitivity and accuracy, making it well suited for on-site BaP screening in diverse real-world scenarios such as quality control in industrial production, regulatory monitoring, and import/export inspection of edible oils. Moreover, the proposed framework offers a generalizable strategy that holds significant reference value and potential for extension to the detection of other highly toxic contaminants in complex oil matrices.

Huanglongbing (HLB), caused by Candidatus Liberibacter asiaticus (CLas) and transmitted by Asian citrus psyllid (ACP), Diaphorina citri, poses a severe threat to global citrus production. In this study, a dual-functional nanopesticide, THX@ZIF-8/PDA, by encapsulating thiamethoxam (THX) within zeolitic imidazolate framework-8 (ZIF-8) followed by polydopamine (PDA) coating was developed, and THX loading capacity was 17.25%. THX@ZIF-8/PDA exhibited pH-responsive release, with cumulative release rates of 99.54%, 65.53%, and 59.14% at pH 5.0, 7.0, and 9.0 after 168 h, respectively. PDA modification reduced surface tension and contact angle on citrus leaves, enhancing foliar adhesion and wash-off resistance. Foliar application of THX@ZIF-8/PDA demonstrated superior toxicity against ACP and extended protection duration compared to commercial THX suspension. Comparative analysis with ZIF-8 controls confirmed that the PDA coating was the primary contributor to ROS scavenging and CLas suppression, while Zn2+ released from ZIF-8 degradation provided additional antimicrobial activity. Confocal microscopy confirmed root-to-leaf translocation of ZIF-8/PDA via the vascular system, and root-applied THX@ZIF-8/PDA enhanced antioxidant enzyme activities while reducing H₂O₂ levels. Transcriptomic analysis revealed significant enrichment in ABC transporter and circadian rhythm pathways. These results demonstrate that THX@ZIF-8/PDA offers a promising integrated strategy for simultaneously suppressing ACP and CLas, advancing sustainable HLB management.

The intensification of agriculture faces dual challenges of enhancing crop productivity while minimizing environmental footprints. Nanotechnology-driven co-delivery systems present a promising avenue to achieve this balance by integrating crop protection and nutrition. To advance sustainable agricultural development, this study developed an enzyme-responsive amino acid-based lignin nanoparticle system (IDC@Leu-DAL) for the synergistic delivery of the insecticide indoxacarb (IDC) and L-leucine (Leu) fertilizer. The nanoparticle was synthesized through the green self-assembly of purified dealkylated lignin (DAL) with Leu, exhibiting a uniform spherical morphology (253.7 nm), high drug loading capacity (48.06%), and excellent stability. The system enables intelligent enzyme-responsive release, significantly improving wettability, adhesion, and anti-leaching capacity on maize leaves. Importantly, it overcomes the poor systemic mobility of conventional IDC, achieving bidirectional transport and targeted accumulation in maize plants. Bioassays against corn borer larvae revealed that IDC@Leu-DAL has superior insecticidal and growth-inhibitory effects over commercial IDC-WDG, due to enhanced midgut damage and apoptosis induction. Simultaneously serving as an efficient nano-fertilizer, it upregulates key nitrogen metabolism enzymes (NR, LAP), promotes photosynthetic carbon assimilation, and activates antioxidant defenses, thereby synergistically improving corn growth, nitrogen use efficiency, and stress tolerance. IDC@Leu-DAL also demonstrates excellent biosafety without affecting seed germination or seedling development. This work offers a novel strategy for developing efficient pesticide-fertilizer integrated carriers, promoting green plant protection and precision agriculture.

Guava (Psidium guajava L.) is a climacteric fruit with limited postharvest storability. This study evaluated the effects of preservation packaging (PP) and conventional packaging (CP) on the postharvest quality of guava (‘Baizhenzhu’) under ambient and low-temperature storage. Fruit quality was assessed by marketable fruit rate, sensory score, weight loss, firmness, total soluble solids, and nutritional traits. Metabolomic analysis was further used to compare treatment-associated metabolic differences. Packaging treatment significantly affected guava quality during storage. Compared with CP, PP better maintained marketable fruit rate, which was 13.3%-56.7% and 30.0%-50.0% higher under ambient and low-temperature conditions, respectively. PP also resulted in 1.85-4.22 times higher sensory scores, lower weight loss, and better retention of firmness and total soluble solids. Metabolomic analysis showed that PP was associated with a more stable metabolic profile, particularly in amino acid-related metabolism, and the relative amino acid content in PP-treated fruit was 1.48-fold that in CP-treated fruit. These results suggest that PP is more effective than CP in maintaining postharvest quality of guava and provide metabolomic insight into packaging-associated quality differences.

Spinosad (Spi) is a promising insecticide with a novel mode of action and favorable environmental safety, but its field efficacy is severely limited by environmental instability, which restricts its preventive application. In this study, spinosad-loaded chitosan-sodium alginate particles (CS-ALG@Spi) were successfully fabricated and systematically characterized. The prepared microspheres exhibited regular morphology, suitable particle size, good dispersion, and satisfactory dilution stability. Compared with free Spi, CS-ALG@Spi showed significantly enhanced UV stability and an obvious acid-responsive release profile. Bioassays indicated that the formulation displayed remarkably improved insecticidal activity against Spodoptera frugiperda. It caused severe structural damage to the larval midgut and increased the activities of antioxidant enzymes. In vitro cytotoxicity assays revealed that the formulation exerted pronounced cytotoxic effects by inducing reactive oxygen species accumulation, eliciting G2/M cell cycle arrest, and decreasing mitochondrial membrane potential. Our study provides a reliable and eco-friendly strategy for the development of efficient pesticide delivery systems.

Succinate dehydrogenase inhibitors (SDHIs) have been widely employed as agricultural fungicides due to their effectiveness and low toxicity. Recently, sulfonyl fluoride (R-OSO2F) has emerged as a promising active moiety in pesticide development. Previously, our team identified aryl sulfonyl fluoride compounds with strong antifungal activity. Expanding on this, we incorporated the sulfonyl fluoride group into the heterocyclic amide scaffold of SDHIs, designing and synthesizing 56 novel aniline-based sulfonyl fluoride derivatives. Their structures were confirmed using 1H NMR, 13C NMR, and high-resolution mass spectrometry (HRMS). Antifungal activity assays showed that compound 4a exhibited the highest inhibitory activity against Rhizoctonia solani (EC50 = 2.89 μg/mL). In bioassays on rice leaves and pot experiments, compound 4a demonstrated 50.75% protective efficacy and 32.43% curative efficacy at 200 μg/mL, comparable to that of commercial SDHI fungicide boscalid. Enzyme inhibition assays confirmed its potent suppression of succinate dehydrogenase (SDH), and molecular docking studies demonstrated binding modes similar to boscalid, with improved binding affinity attributed to the sulfonyl fluoride moiety. We developed a novel sulfonyl fluoride series, identifying 4a as a potent antifungal lead with SDHI-like action. These findings provide valuable insights and new directions for the development of sulfonyl fluorides as next-generation fungicides.

The phyllosphere microbiome is an important component of plant-associated ecosystems, and its structure is susceptible to biotic stress and agricultural interventions. However, the non-target effects of plant-derived pesticides and their nanoformulations on the phyllosphere microbial community remain unclear. By using 16S rRNA amplicon sequencing, we investigated the non-target effects of azadirachtin (Aza) and its nanoformulation (O-carboxymethyl chitosan-loaded azadirachtin, O-cmc-aza) on the phyllosphere microbial community of maize, including Spodoptera frugiperda herbivory stress (Attack) as an additional treatment. The results showed that all three treatments significantly altered the phyllosphere microbial community structure, while the overall microbial diversity indices remained stable. Specifically, the Attack treatment significantly enriched bacterial genera such as Akkermansia and Burkholderia-Caballeronia-Paraburkholderia; the Aza treatment mainly increased the abundance of taxa such as Stenotrophomonas and Herbaspirillum, which have been associated in the literature with plant growth promotion; and the O-cmc-aza treatment specifically enriched microbial groups such as Ralstonia and Sphingomonas, which have been reported to include strains involved in pollutant degradation and nitrogen cycling, while reducing the ACE index but maintaining high community evenness. Our results indicated that azadirachtin and its nanoformulations induced compositional changes in the phyllosphere microbiome, without causing marked decline in microbial diversity. This study provides data support for evaluating plant-derived pesticides and nanoformulations with respect to their non-target effect on phyllosphere microbial communities in green agricultural systems.

IntroductionSoil salinity, characterized by excessive soluble salts in the root zone, affects over 950 million hectares globally and continues to expand due to climate change, seawater intrusion, and unsustainable agricultural practices. High salinity imposes osmotic and ionic stress on plants, disrupting water and nutrient uptake, inducing ion imbalance, and triggering excessive reactive oxygen species (ROS) production, which leads to oxidative damage and impaired plant growth. Nanotechnology is an emerging strategy for enhancing plant stress tolerance, and combining nanomaterials with complementary properties offers a promising approach to improve plant resilience under such conditions.MethodsThis study evaluated the efficacy of cerium-coated triiron tetraoxide (Fe3O4@Ce) nanocomposites (NCs) applied at different concentrations to mitigate salt stress in maize. Seedlings were subjected to 150 mM NaCl and treated with foliar-applied NCs. Growth parameters, photosynthesis, oxidative stress markers, ion homeostasis, and ultrastructural changes were analyzed.Results and DiscussionSalt stress significantly reduced plant growth, biomass, and photosynthetic efficiency while increasing oxidative damage and disrupting cellular ultrastructure. In contrast, NC application enhanced biomass production, chlorophyll content, antioxidant enzyme activities, and osmolyte accumulation, while reducing malondialdehyde (MDA), superoxide (O2•⁻), and hydrogen peroxide (H2O2) levels. The treatment decreased Na+ accumulation and increased K, Ca, and Mg uptake, improving ionic homeostasis and alleviating oxidative stress. Gas exchange parameters and stomatal structure were restored, and ultrastructural analyses confirmed recovery of mesophyll and root cell integrity. These results indicate that Fe3O4@Ce nanocomposites mitigate salt stress through coordinated regulation of antioxidant defense, ion balance, and cellular structure, highlighting their potential as an eco-friendly strategy for enhancing crop resilience.

Global agriculture and food security are under serious threat from abiotic stresses, including salinity, drought, heavy metals, and extreme temperatures. While industrial development has driven progress, it has also intensified environmental challenges and contributed to declining crop productivity. Tackling these issues demands innovative and sustainable solutions. Nanotechnology has emerged as an effective approach to enhance stress tolerance, improve nutrient use efficiency, and increase crop yield and quality. This review critically examines the expanding role of nanoparticles (NPs) in mitigating abiotic stresses and promoting sustainable agricultural systems. While several studies have investigated the use of NPs in stress mitigation, ongoing research continues to reveal novel mechanisms and applications, highlighting the untapped potential of nanotechnology in plant science. The review discusses the impact of abiotic stress on plant growth and physiology, followed by a detailed analysis of the mechanisms through which NPs confer stress tolerance. Particular attention is given to the interaction of NPs with phytohormones and other growth regulators, as well as their role in the remediation of contaminated soils. Furthermore, the review highlights the dual role of NPs in stress alleviation and environmental remediation, while also considering emerging concerns about their potential ecological and toxicological impacts. Emphasis is placed on the need for risk assessments and effective management strategies. The review also identifies key knowledge gaps and methodological limitations, offering recommendations to guide future research in this emerging field.

Environmental fragility and host immune clearance remain major barriers to the field efficacy of entomopathogenic fungi in agricultural pest management. In this study, we developed a bio-based nanocarrier using self-assembled, castor oil-derived waterborne polyurethane (WPU) to encapsulate Beauveria bassiana conidia. The resulting WPU nanodispersion (∼34.8 nm) formed a stable coating on the conidial surface through interfacial self-assembly. Encapsulation significantly improved conidial germination and fungal development while enhancing tolerance to ultraviolet irradiation, thermal stress, and chemical stress. Maize phylloplane assays showed that the WPU matrix acted as an adhesion-promoting coating, substantially increasing rainfastness and environmental persistence. Functional assays and microscopic observations indicated reduced hemocyte recognition and phagocytic clearance of WPU-coated conidia, suggesting attenuated early immune elimination during infection. Comparative transcriptomic analysis of encapsulated and unencapsulated conidia under basal and UV-stress conditions revealed differential expression of genes associated with DNA repair, antioxidant defense, and cuticle-degrading enzyme activity, indicating stress-related transcriptional changes. Overall, these results suggest that castor oil-based WPU functions both as a protective coating and as a biologically interactive matrix. This study provides mechanistic insight into polymer-mediated enhancement of entomopathogenic fungi and offers a practical framework for developing high-performance, environmentally stable mycoinsecticide formulations.

BACKGROUND: The Paracoccus marginatus (Hemiptera: Pseudococcidae) is a significant pest in papaya cultivation. Its thick, waxy epidermal structure protects it from the penetration of most pesticides, leading to increased pesticide application development and resistance. To find effective additives, we screened out D-limonene and evaluated its effect on the wax layer and bioactivity of P. marginatus.RESULTS: Notably, after 72 h of treatment, lethality rates for Spi, Tol, and Spi + D-lim were 50%, 60%, and 75%, and the median lethal concentrations for P. marginatus were 118.81, 80.192 and 18.264 μg/mL, respectively. After combination of toluene, D-limonene and spirodiclofen, the co-toxicity coefficients (synergistic coefficients) of the two tested mixtures were 1.48 and 4.39, respectively.At 48 h after treatment, the GST activities of P. marginatus treated with D-limonene, spirodiclofen, and spirodiclofen combined with D-limonene were 1.669, 1.463, and 0.837 U/mg, respectively, while the corresponding CarE activities were 0.077, 0.074, and 0.071 U/mg. Our findings indicate that D-lim has substantial synergistic effects with conventional insecticides.CONCLUSIONS: These results indicate that D-lim could dissolve the defensive wax layer of P. marginatus, significantly increase the insecticidal activity and inhibit GST enzymatic activities. The D-Limonene has the potential to become a new green additive for pest control.

The plant-derived photoactivated fungicide α-Terthienyl (α-T) exerts antimicrobial effects through light-induced reactive oxygen species generation. However, its agricultural application has been constrained by poor targeting capability and low photostability. To address these challenges, we developed a dual-responsive nanoparticle delivery system (α-T NPs) based on a pectin-chitosan polymer network that specifically recognizes the acidic and pectinase-rich microenvironment created by Botrytis cinerea hyphae secretions. Controlled release studies demonstrated that both acidic conditions (pH 5.0) and pectinase exposure substantially promoted α-T release, achieving cumulative release rates of 71.73% and 74.49% respectively over 60 h. The nanoparticle system showed no adverse effects on healthy tomato leaf growth while forming a protective barrier that effectively suppressed fungal infection. Targeted delivery significantly enhanced fungicidal efficacy, with α-T NPs exhibiting an EC₅₀ of 0.419 mg/L compared to 1.943 mg/L for α-T (technical material, TC). Confocal microscopy and quantitative analysis confirmed the enhanced targeting mechanism, revealing substantially stronger fluorescence intensity and higher α-T accumulation specifically on treated fungal hyphae. Additionally, α-T NPs significantly improved photostability, extending the half-life by approximately 1.93-fold under continuous illumination compared to α-T (TC). This work establishes an innovative "pathogen-activated" delivery platform with promising applications in sustainable crop protection.

Plant diseases caused by various pathogenic microorganisms lead to significant economic losses and increasingly threaten global food security. These challenges are exacerbated by the evolution of pathogens and climate change, which increase the frequency and severity of disease outbreaks. Currently, up to 40% of global crop production is lost due to plant pests and diseases. Therefore, developing novel and eco-friendly methods for efficient disease management is essential to prevent disease outbreaks and monitor plant growth. This review is organized to describe nanoparticle-based strategies for efficient disease management and pathogen monitoring, emphasizing their mechanisms of action in controlling plant diseases. We discuss the direct effects of nanoparticles on pathogens to suppress virulence, their advantages over traditional pesticides, and their interaction with plant growth modulators to regulate key signaling pathways. Despite being in its early stages, research into nanoparticle-mediated plant protection shows excellent potential for advancing sustainable agriculture. Nanoparticle-based pesticides exhibit multiple antipathogenic mechanisms, including modulation of secondary metabolites, activation of disease resistance genes, and targeted delivery of agrochemicals. With the further development of technology, nanoparticle-based sensors can perform molecular-level detection of pathogens, facilitating timely interventions and improved disease management. Additionally, research gaps and experimental limitations are discussed to guide future work toward optimizing nanotechnology for plant disease management.

Fluralaner, as a broad-spectrum and highly effective pesticidal molecule, is severely limited from agricultural application due to its high toxicity to honeybees. Herein, novel pro-pesticides were prepared by covalently linking fluralaner to polyethylene glycol and long-chain fatty acids, respectively, and were subsequently self-assembled into regular nano-micelles to reduce the toxicity of fluralaner to honeybees. The results showed that the obtained pro-pesticides self-assembled into nano-micelles without using any adjuvants, and the prepared nano-micelles showed spherical morphology, a low polydispersity index, strong negative charges, good surface activity and excellent maximum retention on hydrophobic leaves because of the amphiphilic structure. The toxicity of fluralaner prodrug molecules coupled with different fragments against Apis mellifera was more than 50 times lower than that of fluralaner. The solubility of compound E1 was increased by 68.4 times and was systemically distributed in all parts of Chinese flowering cabbage (Brassica rapa var. parachinensis; abbreviation: CS) seedlings. Therefore, the self-assembly nanotechnology of this prodrug conjugate is expected to improve the effective utilization rate of pesticides and reduce the toxicity of pesticides to the ecology and environment.

Many microbial agents, such as Bacillus amyloliquefaciens, have been reported to promote the growth of plant roots, which may enhance the uptake of systemic pesticides by plant roots. Through experimental methods, such as microscopic observation and HPLC (High Performance Liquid Chromatography) detection, the colonization behavior of B. amyloliquefaciens HN11 in sweet potato rhizosphere and its effects on sweet potato growth and fosthiazate uptake were studied. The results show that B. amyloliquefaciens HN11 could effectively colonize the rhizosphere of sweet potatoes and significantly promote the growth of sweet potato roots, leading to increase the yield of sweet potatoes. Moreover, the colonization of B. amyloliquefaciens HN11 promoted the absorption of fosthiazate by sweet potato roots under drip irrigation. The control efficiency against root knot nematodes of sweet potato also improved under this management approach. In summary, drip application of fosthiazate to sweet potato roots inoculated with B. amyloliquefaciens HN11 revealed a new approach to insecticide application. This method could improve the effective utilization rate of fosthiazate and the control efficiency of root knot nematodes, help farmers increase production and income, be environmentally friendly and meet the requirements of sustainable development. This study provides new references for the application direction of microbial agents.

BACKGROUND:Soybean (Glycine max L. Merrill), a vital source of edible oil and protein, ranks seventh in global agricultural production, yet its productivity is significantly hindered by potential toxic metal/liods (PTM) stress. Arsenic (As), a highly toxic soil contaminant, poses substantial risks to both plants and humans, even at trace concentrations, particularly in China. RESULTS:This research endeavor delves into the combined effect of arsenate (AsV), a common form of As in soil, and nano-selenium (nSe), on the transcriptional regulation of key genes and the modulation of signaling and metabolic cascades in young soybean seedlings. Our findings indicate that nSe mitigates AsV toxicity by modulating hormonal signaling cascades, particularly the phenylalanine and salicylic acid pathways, thereby augmenting antioxidant defenses and mitigating the damaging effects of reactive oxygen species (ROS) on soybean roots. CONCLUSION:This study offers valuable insights into the molecular mechanisms underlying metalloid tolerance in soybean, opening avenues for the development of strategies to bolster As resistance in contaminated soils. Nevertheless, further investigation is imperative to elucidate the intricate interplay of hormonal signaling in soybean roots during nSe supplementation under As stress conditions.

A series of cyclic sulfonamides were synthesized through sulfur(VI) fluoride exchange (SuFEx) reactions as potential pesticide candidates. Among the 30 synthesized derivatives, bioassay screening revealed pronounced insecticidal activity against Plutella xylostella, with compound G30 demonstrating optimal efficacy (LC50 = 39.86 mg/L). Furthermore, antifungal evaluation against six plant pathogenic fungi via the mycelial growth rate method identified six compounds (G11, G16, G17, G19, G23, and G25) with exceptional activity against Rhizoctonia solani, exhibiting EC50 values ranging from 5.99 to 17.54 mg/L. Notably, compound G11 (EC50 = 5.99 mg/L) displayed remarkable preventive (79.20%) and curative (90.73%) efficacy against R. solani on rice plants at 400 mg/L. Although these values were marginally lower than those of the commercial fungicide thiabendazole, the results highlight the therapeutic potential of this compound. This study provides new perspectives for developing cyclic sulfonamides as innovative lead structures in agrochemical discovery, demonstrating dual pesticidal and antifungal functionalities worthy of further optimization.

BACKGROUND:Plant growth and development benefit from the contribution of plant growth-promoting rhizobacteria (PGPR), which have a positive effect on plants by breaking down organic matter and synthesizing growth hormones. In addition, PGPR can stimulate plants to produce secondary metabolites, thereby enhancing its defense against pathogens and pests. To study the effects of Bacillus amyloliquefaciens 8421 (HN11) on the promotion and induction of defense against pests in cowpea, the effects and mechanisms were determined on the basis of phenotypic traits and changes in the levels of defense enzymes and phytohormones in cowpea after application of HN11. RESULTS:The results showed that HN11 effectively colonized the cowpea root system, and at 15 days, 107 CFU mL-1 HN11 significantly improved cowpea agronomic traits and root morphology, especially promoting an increase in nodule weight (47.6%). Furthermore, when challenged by Spodoptera litura larvae, plants inoculated with HN11 exhibited significantly less damage and displayed a greater ability to recover their growth. It was found that HN11 treatment increased both defense enzyme activities and phytohormone levels in cowpea. Notably, HN11 indirectly affected the induced defense against S. litura by promoting plant growth and enhancing tolerance. CONCLUSIONS:This study opens up new avenues for biological control using PGPR, which is of far-reaching significance for enhancing crop yields, reducing chemical pesticide dependence, and preserving the ecological environment. © 2025 Society of Chemical Industry.

Asian citrus psyllid (ACP), Diaphorina citri (Hemiptera: Liviidae), is one of the most devastating pests in citrus orchards due to its role in transmitting Huanglongbing (HLB). Currently, chemical control remains the most effective strategy for ACP management. Mineral oils are commonly used as insecticides or adjuvants in integrated pest management (IPM) practices. To extend the product life of synthetic pesticides, we evaluated the toxicity of chlorpyrifos (CPF), thiamethoxam (THX), or pyriproxyfen (PPF) mixed with mineral oil Lvying (LY) against ACP nymphs under different weather conditions. Individual application of CPF, THX, and PPF effectively controlled against ACP nymphs under no rain conditions, with mortality rates varying from 20 to 100% during 1–5 d after treatment. The addition of LY at 1.0% or 0.5% rates to CPF, THX, and PPF significantly enhanced their control efficacy, achieving sustained mortality rates from 60 to 100% during the same period. Light rain had less impact on the control efficacy of these insecticide mixtures compared to individual insecticides. However, cumulative rainfall above 20 mm significantly reduced the control efficacy of individual insecticides and their mixtures. The addition of LY decreased both surface tension and contact angle of THX solution on citrus leaves, thereby enhancing the solution’s wetting and increasing THX deposition. Moreover, the rainfastness of THX was improved after adding LY, leading to a greater retention on the leaves. LY at a rate of 1.0% exhibited excellent efficacy against ACP nymphs, and observations using scanning electron microscopy (SEM) showed that LY altered ACP mouthpart morphology and blocked spiracles, likely contributing to its insecticidal effects. This study revealed that mineral oils can serve as both insecticides to combine with synthetic pesticides for enhancing toxicity against ACP and as adjuvants to facilitate the deposition and rainfastness of synthetic pesticides on leaves, which could be recommended for sustainable ACP management in citrus orchards.

The growth of different grafted guava was different as affected by grafting on different rootstock varieties, which also influenced the damage degree of Spodoptera litura larvae. The co-regulation of the pest gut by rhizosphere microorganisms and root exudates may contribute to this differential damage. In this study, the microorganisms of soil, plants, S. litura larvae and root exudates of guava grafted on different rootstock varieties were analysed and compared. The activities of superoxide dismutase, peroxidase and catalase in the midgut of S. litura larvae feeding on heterograft leaves of guava (where rootstock and scion are of the different variety) were significantly higher than those in the midgut of S. litura larvae feeding on homograft leaves of guava (where rootstock and scion are of the same variety), and glutathione s-transferase activity showed an opposite result. Enterococcus spp. and Escherichia spp. were the two bacterial genera with the greatest difference in abundance in the midgut of S. litura larvae and exhibited a negative correlation with each other. The root system of guava influenced the root structure, soil nutrients and the population structure and diversity of rhizosphere microorganisms by regulating the type and amount of root exudates. Root exudates also influenced the physiological and biochemical status of S. litura larvae by regulating the rhizosphere microorganisms driving the tritrophic interaction of plant-microbes-insects. Based on our results and the observed differences in pest occurrence among different grafted plants, improving varieties through grafting may become an effective strategy to reduce the impact of insect pests on guava.