Alterations in pest ecology due to climate change can affect crop production. Understanding the rate and period of pest development is essential for predicting population dynamics and determining the optimal timing for pesticide application to ensure stable crop production. In this study, we aimed to develop a mechanical method for determining the developmental periods of rice planthoppers and evaluate the impact of climate change on these periods over a 42-year period. We evaluated interannual variations in the developmental periods of two rice pests, Nilaparvata lugens (Stål) and Sogatella furcifera (Horváth), using light traps to capture data between 1980 and 2022 from 20 areas in Kyushu, Japan, a region of East Asia severely affected by rice planthopper outbreaks. Meteorological data revealed a trend of increasing daily mean temperature (2.2-4.5 × 10-2 °C year-1). A significant correlation was also detected between the length of developmental period and temperature (P < 0.001). For both N. lugens and S. furcifera, a significant trend toward progressively shorter developmental periods was observed over time, even after accounting for differences in the starting dates of development (P < 0.01). These results indicate that for pests, developmental periods have been progressively shortening in response to warming associated with climate change. This study provides important insights for predicting future pest ecology under climate change conditions based on results obtained from rearing experiments conducted in laboratory. © 2026 Society of Chemical Industry.

Phoma stem canker is one of the most economically damaging diseases of oilseed rape, caused by co-existing fungal pathogens Leptosphaeria maculans (Plenodomus lingam) and Leptosphaeria biglobosa (Plenodomus biglobosus). Our previous work showed that timing of their co-inoculation affects their interspecific interactions in vitro, and that L. biglobosa can inhibit the growth of L. maculans if it is inoculated before or up to 1 day after L. maculans. However, the effects of timing of co-inoculation on their interspecific interactions within host plants are not fully understood. The interactions between L. maculans and L. biglobosa were investigated in planta by inoculation with L. maculans first, followed by L. biglobosa sequentially 1, 3 or 5 days later or vice versa, or L. maculans and L. biglobosa co-inoculated simultaneously; controls were inoculation with L. maculans only, L. biglobosa only or sterilised distilled water. The results showed that L. biglobosa can inhibit the growth of L. maculans locally if it is inoculated before or up to 1 day after L. maculans in planta. The results of this study provide evidence that the time L. maculans and L. biglobosa meet and interact on their host significantly affects the interspecific competition and subsequent disease severity. Leptosphaeria biglobosa can deploy multiple interspecific competition strategies against L. maculans to have local and systemic effects on the host to outcompete L. maculans. There is a need to investigate and model the factors affecting the timing of ascospore release and subsequent interactions to develop better control strategies. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The beet armyworm, Spodoptera exigua, is a polyphagous pest with long-distance migration capabilities. It has been a major crop pest in southeastern China since the 1980s, but only emerged as a significant pest in northwestern China (Xinjiang) over the past decade. As a consequence of intensive insecticide use, this pest has developed serious resistance. Although insecticide resistance has been documented in southeastern populations, data on the current resistance status, particularly in Xinjiang populations, remain limited. We evaluated resistance in 13 southeastern populations collected in 2023 and five Xinjiang populations collected in 2024 to four insecticides by comparing their median lethal concentrations (LC50s) with those of the reference WH-S strain. All 18 field populations exhibited high-level resistance to emamectin benzoate (EB; 711- to 8790-fold) and chlorantraniliprole (103- to 1422-fold) relative to a susceptible laboratory strain, whereas resistance to broflanilide and chlorfenapyr was absent or limited. Genotyping identified high frequencies of the CYP9A186 F116V (0.55-1.00) and RyR I4743M/K (0.92-1.00) mutations, which are associated with resistance to EB and chlorantraniliprole, respectively. Resistance magnitudes and resistance-allele frequencies were similar in Xinjiang and southeastern China. Furthermore, resistance to EB and chlorantraniliprole has markedly increased over time (from 2009 to 2024) in southeastern populations. Our results demonstrate widespread, high-level resistance to EB and chlorantraniliprole in S. exigua across China and near-fixation of two major resistance alleles. Although broflanilide and chlorfenapyr currently remain effective alternatives, they should be used judiciously given the ≈10-fold existing variation in susceptibility to both insecticides. Coordinated geographical resistance monitoring and management are needed for S. exigua in China and elsewhere, given its strong migratory and dispersal capabilities. © 2026 Society of Chemical Industry.

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. 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. 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.

Bacterial diseases pose significant threats to crop production. Natural products offer promising alternatives due to their structural diversity, low toxicity, and reduced resistance potential for controlling plant bacterial diseases. Xanthomonas campestris pv. campestris (Xcc) is the causal agent of black rot disease in cruciferous vegetables, yet effective natural products for managing black rot have not been thoroughly explored. In this study, we isolated γ-mangostin from the pericarp of mangosteen (Garcinia mangostana), which displayed significant activity against the phytopathogen Xcc with an EC50 of 6.48 ± 1.07 μg/mL. We observed that γ-mangostin exhibits strong antibacterial activity, significantly reduces the virulence of Xcc, and provides both protective and curative effects against crucifer black rot. Further mechanistic analysis reveals that γ-mangostin treatment significantly disrupts DNA synthesis, impairs swimming motility, and induces marked alterations in Xcc cell morphology. We demonstrate for the first time that γ-mangostin exerts potent antibacterial activity by compromising cellular integrity and suppressing critical virulence functions in Xcc. These findings provide a molecular foundation for advancing γ-mangostin as a sustainable biocontrol agent against Xcc for the management of crucifer black rot disease. © 2025 Society of Chemical Industry.

4-Hydroxyphenylpyruvate dioxygenase (EC 1.13.11.27, HPPD), as a key enzyme for tyrosine decomposition, is a highly regarded herbicide target. In this work, a series of cyclohexenone derivatives containing a substituted pyrazole group were designed and synthesized by active fragment splicing method for screening new HPPD inhibitors. The bioassay results indicated that some target compounds exhibited noticeable inhibitory activity against Capsella bursa-pastoris (CB), Portulaca oleracea (PO), Echinochloa crus-galli (EC) and Setaria viridis (SV). As an outstanding representative, compound 8n showed excellent inhibitory activity against four tested weeds with the rates more than 90% at 225 active ingredient per hectare (a.i./ha) dosage, especially with a rate more than 90% against CB at 75 a.i./ha dosage, comparable to the control herbicide mesotrione. Compound 8n also demonstrated satisfactory safety for the crops wheat, maize, sorghum and rice. Furthermore, the molecular docking, molecular dynamics (MD) simulations and frontier molecular orbital analysis revealed that compound 8n had strong interaction with the target protein AtHPPD, which could tightly bind with amino acid residues in the active pocket to generate its herbicidal activity. This study suggested that compound 8n could be used as a valuable lead molecular structure for the design of novel HPPD inhibitors, while providing an important foundation for the development of new herbicides. © 2025 Society of Chemical Industry.

Anthracnose, caused by Colletotrichum gloeosporioides sensu lato (Cg), severely impacts strawberry and other crops, primarily infecting foliage via rain or overhead irrigation. Previous reports on strawberry foliar resistance to Cg are partially controversial because of methodological variations and rapid pathogen evolution in agroecosystems. Recent phylogeny analysis using next-generation sequencing enabled re-identification of strawberry pathogenic Cg strains from Eastern China (2007-2023), providing a basis for renewed investigation into host-pathogen interactions. Site-specific inoculation of eight re-identified Cg strains on detached leaves revealed partial strain-host specificity. Analysis of variance differentiated strains in terms of pathogenicity (lesion counts) and virulence (lesion diameter). Nonparametric correlation and linear regression modeling indicated that the inoculation method exerted the strongest influence on disease severity, followed by fungal ecotype and host genotype. Disease severity in a whole-plant assay did not correlate well with that in a detached-leaf assay, but the severity in leaf blade and petiole was closely linked. Screening 32 Fragaria genotypes via whole-plant spray-inoculation with C. fructicola (CGMCC3.17371) identified 'ShenYi' and 'MiaoXiang7#' as resistant as Fragaria vesca 'Hawaii4', which was consistent with field observations. Detached-leaf inoculation is suitable for assessing Cg pathogenicity and virulence. Whole-plant spray-inoculation integrated with an in vitro leaf assay is recommended for host resistance evaluation. This study establishes a foundation for deploying genetic resistance in strawberry breeding programs, and enabling sustainable anthracnose management through targeted cultivar development and screening protocols. © 2025 Society of Chemical Industry.

Berberine is a quaternary ammonium alkaloid natural product containing an isoquinoline skeleton. It has broad-spectrum pharmacological activity and plays a key leading compound role in the development of new drugs. Inspired by natural berberine analogues, 51 novel berberine derivatives were designed and synthesized through structural modification, and their bactericidal activities against plantpathogenic bacteria were evaluated. The results showed that compounds A6, A9, B2, B4, H, G1, and K with berberine parent structure showed excellent antibacterial activity. Interestingly, compared with natural berberine analogues, the H series of compounds showed the strongest antibacterial activity, and their minimum inhibitory concentration (MIC) values against Xoo, Xac, and Rs were less than 50 μg mL-1. Among them, compounds H5 and H6 exhibited the strongest antibacterial activity, and the MIC values for Xoo and Rs were 6.25 μg mL-1. The preliminary mechanism showed that compound H6 could inhibit the formation of biofilm, inhibit the production of exopolysaccharides, increase the level of reactive oxygen species, destroy the normal morphology of cells, and had low toxicity to plants. In vivo experiments show that the protective efficacies of compound H6 and thiodiazole copper at 800 μg mL-1 were 34.10% and 24.08%, respectively, and the curative efficacies were 26.91% and 23.98%, respectively. These results indicate that the in vivo protective effect of H6 was better than that of the positive drug thiodiazole copper. Compound H6 is expected to be a new type of broad-spectrum bactericide for exhibiting excellent bactericidal activities, which is worthy of further investigation. © 2026 Society of Chemical Industry.

The Hoplia spectabilis (Coleoptera: Scarabaeidae) is a major pest threatening local shrubs in the plateau ecosystems of western China. However, little information is available on its chemical ecology. In this study, we aimed to identify host-plant volatiles used for host location by Hoplia spectabilis adults that are specialized to feed upon host plant foliage, and to further develop effective attractants for pest management. Field observations revealed that the beetles exhibited a strong feeding preference for Hippophae neurocarpa over Potentilla fruticosa and Myricaria germanica. Electroantennography (EAG) assays confirmed that both female and male beetles responded strongly to hexane extracts of host plant foliage. By using gas chromatography coupled with electroantennographic detection (GC-EAD) followed by GC-mass spectrometry, we identified 22 electrophysiologically active compounds, with (Z)-hex-3-en-1-ol and nonanal dominating the volatile profile of Hippophae neurocarpa (52.4%). A binary blend B of (Z)-hex-3-en-1-ol and nonanal was the most effective attractant, outperforming multi-component blend M consisting of the 11 EAD-active components shared by the three host plants. Volatilization kinetics demonstrated significantly higher release rates of (Z)-hex-3-en-1-ol and nonanal from blend B than from blend M, interpreting higher captures of beetles by blend B. These findings revealed that a binary blend of (Z)-hex-3-en-1-ol and nonanal is a highly effective attractant for Hoplia spectabilis with promising applications in monitoring, mass trapping and integrated pest management programmes. © 2026 Society of Chemical Industry.

When plants are attacked by herbivores, they release a distinct blend of herbivore-induced plant volatiles (HIPVs) that prime or induce defence in neighbouring plants, enhancing defensive capabilities. Although HIPVs mediate tritrophic interactions, the temporal dynamics of aphid-induced volatile effects remain insufficiently explored. Our hypothesis was that HIPVs emitted by aphid-infested plants could affect neighbouring plants, leading to reduced aphid performance and greater attraction of natural enemies. Using a controlled unidirectional airflow system, receiver potato plants (Solanum tuberosum) underwent 48 h of exposure to volatiles released by either aphid-infested or uninfested conspecifics. Bioassays with Myzus persicae and its natural enemies (Harmonia axyridis, Aphidius gifuensis) were conducted at two time points: during the period immediately following exposure (time point 1: 0-48 h post exposure) and during a subsequent period (time point 2: 48-96 h post exposure). At time point 1, aphid survival and neonate production significantly decreased on HIPV-exposed plants versus controls, although settlement was unaffected. Both natural enemies exhibited significant attraction to HIPV-exposed plants. Volatile analysis of the receiver plants after the exposure period revealed significantly elevated total emissions, with seven individual compounds showing higher levels. At time point 2, insect responses showed no significant differences. However, the volatile profile shifted: some compounds elevated at time point 1 were not sustained, although a distinct set of six compounds remained significantly elevated. Brief exposure to aphid-induced HIPVs triggers rapid, transient induction of indirect defences in neighbouring plants. This creates a time-limited window immediately after exposure (0-48 h post exposure) during which aphid performance is reduced and attraction of natural enemies is enhanced, aligning with a difference in volatile profile compared with that observed 48 h later (48-96 h post exposure). Our findings highlight the ecological relevance of volatile-mediated plant communication and its potential for temporally precise defence induction in neighbouring plants. © 2026 Society of Chemical Industry.