Pest Management Science最新文献

Background: The enhanced capacity for metabolic detoxification is a key adaptive strategy enabling insects to tolerate plant secondary metabolites (PSMs). This adaptation is largely driven by the transcriptional regulation of detoxification genes. Our previous work established the critical involvement of specific detoxification enzymes in xanthotoxin metabolism in Spodoptera litura. In the present study, we aimed to identify and characterize the transcription factors responsible for orchestrating detoxification gene expression.

Results: RNA-sequencing analysis revealed that, alongside transcription factors induced by xanthotoxin, the nuclear receptor hormone receptor-like 51 (HR51) was uniquely and consistently down-regulated in both the midgut and fat body of S. litura. To elucidate the role of HR51 in xanthotoxin detoxification, we generated HR51-knockout mutants using CRISPR/Cas9-mediated gene editing. These mutants displayed markedly enhanced tolerance to xanthotoxin, accompanied by the up-regulation of detoxification genes responsible for its metabolism. Mechanistic studies through dual-luciferase reporter assays coupled with site-directed mutagenesis demonstrated that HR51 suppressed the expression of detoxification genes through binding to the specific cis-acting element within their promoter.

Conclusion: This study uncovers a novel derepression mechanism in which suppression of the transcriptional repressor HR51 alleviates its inhibition on detoxification genes, thereby facilitating S. litura adaptation to xanthotoxin. These findings advance our understanding of insect counter-defense against PSMs and highlight HR51 as a promising molecular target for the development of innovative pest management strategies. © 2026 Society of Chemical Industry.

Background: Herbivore-induced plant volatiles (HIPVs) play multiple roles in mediating plant-arthropod species interactions. Methyl salicylate (MeSA) is a well-known HIPV given its effectiveness in attracting parasitoids and predators and its use in biological control strategies. In addition, non-crop vegetation of field margins are important habitats that harbor natural enemies but may fail to increase biological control. Volatiles like MeSA could synergistically interact with field margin vegetation and increase biological control within crops. The present study examines through a field experiment the effects of MeSA (MeSA-exposed versus control plants) and in-field location (near vegetation margins versus field center) on plant-arthropod interactions to enhance biological control of Brassicaceae pests.

Results: MeSA-exposed cabbage plants tended to have different volatile compositions than control plants, showing a slight proportional increase in 3-pentanol and the absence of hexenal in MeSA-exposed samples. Herbivore abundance was slightly lower in MeSA-exposed compared to control plants, while in-field location did not influence the second trophic level. Natural enemy abundance and parasitism rates were significantly higher in the field margins than in the center, but the opposite pattern was registered for predation. No MeSA effects were detected on third trophic level species.

Conclusion: MeSA altered plant volatile organic compound (VOC) emissions and had a slight effect on herbivores, while natural enemies responded solely to field-margin vegetation. Our study highlights the importance of conserving spontaneous vegetation to support parasitoids and underscore the need to study several functional groups and trophic levels for improving biological control. The use of VOCs, integrated with habitat management strategies, represents a complementary approach to enhance pest control. © 2026 Society of Chemical Industry.

Background: With increasing resistance to traditional fungicides and growing environmental concerns, it is crucial to develop novel succinate dehydrogenase inhibitors to enhance disease management and support sustainable agriculture.

Results: This study systematically designed and synthesized a series of nicotinohydrazides bearing a biphenyl fragment, evaluating their antifungal activity against six plant pathogenic fungi. The results demonstrated that their fungicidal spectrum significantly surpasses boscalid and carbendazim. Utilizing a palladium-catalyzed cross-coupling strategy, combined with diazotization-reduction and dehydration condensation reactions, we successfully synthesized 35 target compounds (F1-F18, G1-G17). Antifungal assays revealed that most compounds exhibited more than 80% inhibition against the tested fungi at a concentration of 20 mg/L, particularly compound F17, which showed a half-maximal effective concentrations value ranging from 0.33 to 2.77 mg/L and achieved an efficacy of 89.94% against Sclerotinia sclerotiorum on canola leaves at a concentration of 200 mg/L. Mechanistic investigations indicated that F17 exerts its antifungal effects through multiple mechanisms, including the inhibition of succinate dehydrogenase, disruption of cell membranes and induction of oxidative damage. Toxicity predictions and cytotoxicity assays assessed the safety of this series of compounds. Density functional theory and molecular electrostatic potential analyses elucidated the reasons for the high activity of F17.

Conclusion: Nicotinohydrazide derivatives exhibit a broader spectrum of antifungal activity than traditional inhibitors, and their multiple mechanisms of action provide a theoretical basis for further structural optimization and the design of novel agrochemicals. © 2026 Society of Chemical Industry.

Background: Tomato chlorosis virus (ToCV) and tomato yellow leaf curl virus (TYLCV) are two important plant viruses. Co-infection of them leads to exacerbated disease symptoms and poses a significant challenge for control. Using nanomaterials to package and deliver double-stranded RNA (dsRNA) for inducing RNA interference (RNAi) has emerged as a promising antiviral strategy in agriculture.

Results: In this study, two established nanomaterials, chitosan quaternary ammonium salt (CQAS) and aminated mesoporous silica nanoparticles (MSN@NH₂), were selected to package dsRNAs targeting the TYLCV C1 gene, the ToCV RNA-dependent RNA polymerase (RdRP) gene, or the ToCV 1a polyprotein gene, forming CQAS/dsRNA and MSN@NH₂/dsRNA nanoparticles, respectively. The results indicated that these nanoparticles enhance the stabilities of dsRNAs. The efficacy of these nanoparticles against ToCV and TYLCV infection was assessed in tobacco cv. K326, Nicotiana benthamiana, and tomato cv. Micro-Tom plants. The results showed that these nanoparticles could significantly reduce viral gene transcription levels, with inhibition rates ranging from 33.5% to 99.5% depending on the nanoparticle formulation, target virus, and host plant. For instance, in N. benthamiana under co-infection, MSN@NH2/dsRNA nanoparticles inhibited TYLCV and ToCV by 99.5% and 79.8%, respectively. These findings demonstrate that both CQAS/dsRNA and MSN@NH2/dsRNA nanoparticles are effective in controlling ToCV and TYLCV single or co-infection in plants.

Conclusion: Both CQAS and MSN@NH₂ effectively package and protect dsRNA from degradation. Our findings further support the notion that the nanoparticle-mediated RNAi is a promising strategy for virus disease management. This approach contributes to global efforts toward sustainable agriculture. © 2026 Society of Chemical Industry.

Background: Managing stored-grain pests requires new strategies to limit economic and health risks. This study analyses the sublethal effects of the natural compound carlina oxide on Prostephanus truncatus, providing new behavioural insights through a multidisciplinary approach. A fully automatic computer vision approach was developed to label two specific insect body parts, enabling the generation of an annotated dataset without manual intervention. This dataset was used to train a convolutional neural network (CNN) for pose estimation. A second dedicated CNN focused on the antennae to investigate neuroethological and sensory variations.

Results: CNN for body parts detection achieved an average precision of 0.78, recall of 0.90, and F1 score of 0.84 on the test dataset. An additional CNN tracked key points for antennal pose estimation. Motor analysis showed that the LC₃₀ of carlina oxide reduced average speed and distance, induced altered exploratory behaviour, and affected thigmotaxis. Statistically significant features were evaluated using machine learning classifiers: random forest, support vector machine, and K-nearest neighbours. The analysis comparing control and treated groups distinguishes LC₃₀ and LC₁₀ from the control group, while SHapley Additive exPlanation (SHAP) analysis explained the features contribution to predictions.

Conclusions: Metrics poorly distinguish individuals in the LC₁₀ and LC₃₀ classes, supporting the employment of lower sublethal concentration for the control of P. truncatus. However, our findings indicate possible neuroethological effects of green pesticides on sensory systems, highlighting the need for an accurate risk assessment to minimize ecosystem impacts and supporting integrated pest management within One-Health and Eco-Health frameworks. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Background: Black spot disease is a significant disease during the growth period of pear trees. The species and pathogenicity of Alternaria fungi causing black spot disease in Anhui Province are still unclear.

Results: In this study, through phylogenetic analysis of multi-gene tandem sequences, pathogens causing pear black spot disease (PBS) in Anhui Province were identified, primarily Alternaria alternata, Alternaria gaisen and Alternaria tenuissima, with A. alternata being the dominant species (41.18%). The single nucleotide polymorphism (SNP) density of Alt a1 was much higher than that of other genes, and the codon bias was affected by both natural selection and mutation. The codon bias and the amino acid ratio of Alt a1 in A. alternata and A. gaisen were highly consistent, and A. tenuissima was quite different from them. The pathogenicity of A. alternata was significantly negatively correlated with the daily mycelia growth rate, dry weight of mycelia and alternariol production, and significantly positively correlated with tenuazonic acid (TeA) and tentoxin production. TeA might be the main virulence factor in the pathogenic process of A. alternata.

Conclusion: This study presents novel ideas for classifying Alternaria fungi and provides a theoretical basis for establishing prevention and control technologies for PBS control and toxin reduction. © 2026 Society of Chemical Industry.

Background: Accurate characterization of spray droplet size distribution is critical for optimizing pesticide application from unmanned aerial spraying systems (UASSs), as it governs deposition efficiency and off-target drift. However, conventional methods like water-sensitive paper (WSP) are prone to inaccuracies from droplet spread and coalescence, while in-flight laser diffraction is impractical for field-wide measurements under turbulent downwash conditions. This study developed and validated an image-processing-based liquid immersion method using silicone oil as the collection medium. A custom test apparatus was used to collect droplets from a UASS, and high-resolution images were analyzed to determine droplet size distributions. The method's performance was compared against WSP and photographic paper (PP) and validated against a laboratory-standard laser diffraction instrument.

Results: Across five nominal droplet-size settings, SO-based Dv50 estimates showed a clear empirical association with laser diffraction and exhibited lower variability than WSP and PP. Droplet-size uniformity across the spray-width transect was higher for SO (CV 10-12%) than for WSP (16-22%) and PP (22-32%). In high-deposition regions where paper-based collectors tended to show inflated droplet sizes due to overlap/oversaturation, the SO method provided more consistent estimates.

Conclusion: The proposed SO liquid-immersion workflow offers a practical, cost-effective, and field-deployable option for characterizing UASS spray quality under realistic downwash airflow. This capability can support evidence-based optimization of nozzle settings and flight parameters to improve targeting performance while mitigating off-target drift. © 2026 Society of Chemical Industry.

Introduction: Rhopalosiphum padi (L.) is a major vector of barley yellow dwarf virus (BYDV), one of the most economically damaging viral diseases of cereals, including wheat. Although host resistance to BYDV or to aphids individually has been exploited, less is known about how aphid resistance performs against viruliferous vectors. We recently identified a winter genotype (G1) exhibiting strong aphid resistance through antixenosis and antibiosis. Here, we test whether this resistance remains effective against BYDV-vectoring aphids and how it compares with BYDV resistance.

Results: We evaluated G1 alongside four wheat cultivars with contrasting aphid and BYDV resistance traits, including the BYDV-resistant cultivar RGT Wolverine and the fully susceptible RGT Illustrious. Seedling settlement assays showed that antixenosis in G1 remained effective against R. padi carrying BYDV-PAV. Electrical penetration graph recordings revealed restricted phloem access and reduced salivation of viruliferous aphids on G1, consistent with lower virus transmission efficiency. Quantitative reverse transcription polymerase chain reaction showed a threefold reduction in BYDV gene expression in inoculated leaves of G1 compared with RGT Wolverine and RGT Illustrious. By contrast, RGT Wolverine exhibited high initial transmission but reduced systemic infection, consistent with resistance acting on suppression of viral replication and/or movement. Aphid rearing host genotype altered subsequent aphid host-selection behaviour, indicating vector conditioning with consequences for virus spread.

Conclusion: Aphid resistance in G1 significantly reduced BYDV transmission, whereas Bdv2-mediated resistance in RGT Wolverine limited systemic infection. These complementary resistance mechanisms highlight the value of combining aphid- and virus-targeted traits to improve durable BYDV management in wheat. © 2026 Society of Chemical Industry.

Background: In this study, a previously optimized pneumatic spray delivery (PSD)-based solid set canopy delivery system (SSCDS) was compared with an airblast sprayer (grower control [GC]) for the delivery of fungicides in the management of powdery mildew (Erysiphe necator) in vineyards. For 2023 and 2024 growing seasons, spray coverage was quantified for each application date and treatment. Visual disease severity on clusters and leaves was assessed five times per season. The accumulated area under the disease progression curve (AUDPC) was developed from these ratings.

Results: Over two seasons, spray coverage for PSD-SSCDS treatment ranged from 16.7% to 32.7%, whereas GC achieved coverage between 39.9% and 62.9%. The average difference in maximum cluster and foliar disease severity between GC and PSD-SSCDS was 5.5% and 14.2%, respectively.

Conclusions: Despite lower spray coverage in PSD-SSCDS, the accumulated AUDPC for cluster disease severity was similar to GC treatments in both growing seasons. However, foliar disease severity differed significantly, with GC showing less disease than PSD-SSCDS. These study findings indicate that optimal emitter selection is crucial for achieving enhanced spray performance and effective disease control using the PSD-SSCDS technology in vineyards. Both fungicide spray treatments effectively protected clusters from powdery mildew, indicating PSD-SSCDS as an emergent alternative spray technology. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.