Pub Date : 2026-04-01Epub Date: 2025-12-30DOI: 10.1002/ps.70492
Juncheng Wu, Zhengyuan Tao, Jingyi Cao, Wei Hu, Minghao Jiang, Yahui Li, Haiqun Cao, Min Liao, Ning Zhao
Background: Rice flatsedge (Cyperus iria L.) is one of the most troublesome weeds infesting rice fields across China. Bensulfuron-methyl, an acetolactate synthase (ALS)-inhibiting herbicide, has been widely used for the control of Cyperaceae weeds in rice production. However, long-term and extensive use of this herbicide has resulted in the evolution of resistant C. iria populations. In this study, a suspected bensulfuron-methyl-resistant (R) population collected from a rice field that survived field-recommended applications was investigated to elucidate its resistance level and underlying mechanism.
Results: Compared with a susceptible (S) population, the R population exhibited a high level of resistance to bensulfuron-methyl [resistance index (RI) = 12.88] and cross-resistance to metazosulfuron (RI = 11.66), bispyribac-sodium (RI = 9.10) and penoxsulam (RI = 6.35). No mutations were detected in the ALS gene, and ALS expression levels did not differ significantly between the R and S plants. Pretreatment with the cytochrome P450 inhibitor malathion and the glutathione S-transferase inhibitor 4-chloro-7-nitrobenzoxadiazole effectively reversed bensulfuron-methyl resistance in R plants. Liquid chromatography tandem mass spectrometry analysis showed that the R plants metabolized bensulfuron-methyl significantly faster than the S plants. RNA sequenccing analysis revealed remarkable upregulation of CYP97A3 and GSTF1 in the R population, while molecular docking indicated strong binding affinities between both enzymes and bensulfuron-methyl at their active sites.
Pub Date : 2026-04-01Epub Date: 2025-12-29DOI: 10.1002/ps.70489
Jana Niedobová, Michal Skalský, Zdeněk Faltýnek Fric, Jana Ouředníčková
Background: Natural enemies provide essential pest control services, but their decline in agricultural landscapes threatens the sustainability of crop protection. In orchards, integrated pest management (IPM) depends not only on pest surveillance, but also on reliable monitoring of beneficial arthropods. However, practical tools for this purpose remain scarce.
Results: We tested artificial cardboard shelters as a low-cost, non-lethal method for year-round monitoring of natural enemies in temperate apple orchards. Two shelter types (roll and tape) were evaluated at different tree positions and compared with beating samples. Roll shelters, especially when placed on trunks, consistently captured more spiders and other beneficial arthropods than tape shelters. Importantly, the presence of shelters did not reduce the abundance or richness of free-living canopy arthropods. Seasonal dynamics were clearly detected in Voják orchard, where earwigs dominated the 'other beneficial arthropods' group: spiders dominated shelters during winter, whereas earwigs were most abundant in summer.
Pub Date : 2026-04-01Epub Date: 2026-01-02DOI: 10.1002/ps.70494
Wanxiao Jin, Bohan Wang, Yanrui Sun, Xudong Guo, Lifang Wang, Di Meng, Baoliang Pan
Background: Juvenile hormone (JH) has been demonstrated to play pivotal roles in diverse developmental and reproductive processes across insect taxa. Juvenile hormone acid methyltransferase (JHAMT), the terminal enzyme in the JH biosynthetic pathway, serves as the key rate-limiting enzyme. Previous studies on JHAMT have primarily focused on insects, with limited investigation in non-insect arthropods such as arachnids and crustaceans. Notably, JHAMT remains particularly understudied in Acari (ticks and mites). No JHAMT has been reported in Dermanyssus gallinae, a notorious blood-sucking ectoparasite on poultry farms, that causes huge economic losses.
Results: In this study, one DgJHAMT, which contains the conserved S-adenosyl-l-methionine binding motif, was identified for the first time. Multiple alignment and phylogenetic analyses showed that DgJHAMT was grouped together with Acari JHAMTs with high similarities. RNA interference of DgJHAMT significantly suppressed vitellogenin expression, impaired female mite reproduction, caused egg malformations, reduced molting rate in deutonymphs, and increased adult mite sensitivity to pesticides. Furthermore, this protein also exhibited potential as a protective antigen candidate.
Pub Date : 2026-04-01Epub Date: 2026-01-02DOI: 10.1002/ps.70464
Xiaoyuan Wang, Jingqiao Zhao, Huigai Sun, Donglai Ma, Lin Pei, Pei He, Zhengpu Rong, Ye Zhang, Yuguang Zheng, Xiaowei Han
Background: Monocropping poses a significant challenge in the sustainable cultivation of many medicinal plants, including Glehnia littoralis F. Schmidt ex Miq. G. littoralis, known for its culinary and medicinal properties, faces cultivation challenges due to continuous cropping, largely because of autoallelopathy. Phenolic compounds, specifically dibutyl phthalate (DBP) and 2,4-di-tert-butylphenol (2,4-DTBP), from G. littoralis cropped soil, significantly inhibit its seed germination and growth. This study examines the effects of these compounds on seed germination, focusing on phenotypic changes, gene expression, and spatial metabolic profiles. This research investigates the impact of DBP and 2,4-DTBP on G. littoralis seed germination through phenotypic analysis, transcriptomic profiling of gene expression, and spatial metabolic profiling using metabolomics techniques.
Results: Results demonstrate significant inhibition of seed germination. Gene expression analysis indicates disrupted plant hormone signal pathways, which impede normal seed development. Metabolic profiling reveals impaired metabolic processes, altered hormone levels, and abnormal amino acid accumulation, contributing to germination inhibition.
Pub Date : 2026-04-01Epub Date: 2026-01-07DOI: 10.1002/ps.70499
Yuan-Sen Liang, Yi-Fei Sun, Ying-Min Wang, Kun-Yu Yang, Hao Li, Luis Carlos Ramos Aguila, Hao-Sen Li, Hong Pang
Background: Solanaceous plants synthesize the alkaloid alpha-solanine as a chemical defense against herbivorous insects. The plant feeder ladybird Henosepilachna vigintioctopunctata (Coleoptera: Coccinellidae), specialized on solanaceous hosts, causes significant economic losses to solanaceous crops such as potato, tomato and eggplant through its voracious feeding activity. However, little is known about the underlying adaptive mechanisms that enable Henosepilachna vigintioctopunctata to neutralize this plant toxin.
Results: Here, through transcriptome analysis and quantitative polymerase chain reaction (qPCR) validation, we identified a beta-glucosidase gene, HvBgla1, that is significantly up-regulated in response to alpha-solanine ingestion, with particularly high expression observed in midgut tissues. RNA interference (RNAi) mediated silencing of HvBgla1 reduced alpha-solanine degradation, leading to toxin accumulation in the midgut and hindgut. This was accompanied by a decrease in the degradation product solanidine in the midgut, and a reduction in the body weight of newly emerged adults from RNAi-treated larvae. Additionally, phylogenetic analysis revealed that HvBgla1 originated from a lineage-specific duplication clade exclusive to the tribe Epilachnini.
Pub Date : 2026-04-01Epub Date: 2026-01-02DOI: 10.1002/ps.70493
Ephantus J Muturi, Mathew A Neidmann, Victor P Ribeiro, Erica J Goett, Jose L Ramirez, Kumudini M Meepagala
Background: Caterpillars of moths and butterflies represent some of the most destructive agricultural pests and have become increasingly resistant to synthetic chemical insecticides. Manuka essential oil is known to be a potent alternative to synthetic insecticides, but its potential to control caterpillar pests remains underexplored. We evaluated the toxicity of manuka essential oil and its components against third-instar larvae of Trichoplusia ni and Chrysodeixis includens. We also evaluated their potential phytotoxic effects against cabbage, soybean, and corn.
Results: Manuka essential oil and one of its four fractions (fraction 2) were toxic to the two lepidopteran pests with fraction 2 being more toxic than the whole essential oil. Gas chromatography-mass spectrometry analysis revealed leptospermone, isoleptospermone, and flavesone to be the major components of fraction 2. Flavesone and manuka essential oil had similar toxicity to both caterpillar species, whereas leptospermone, isoleptospermone and grandiflorone, a triketone of manuka leaves, were more toxic to both caterpillar species than the whole essential oil. The median lethal dose (LD50) values (μg/larva) for manuka essential oil, fraction 2, leptospermone, isoleptospermone, flavesone, and grandiflorone against T. ni were 50, 25, 20, 20, 45 and 18, respectively and 42, 32, 28, 20, 41, and 14, respectively against C. includens. Manuka essential oil and its constituents were phytotoxic to cabbage, soybean, and corn, with cabbage and corn being the most and the least affected plants, respectively.
Conclusion: These findings demonstrate that manuka essential oil and its components are promising biopesticides, but improved delivery systems are needed to reduce phytotoxicity. Published 2026. This article is a U.S. Government work and is in the public domain in the USA.
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Pub Date : 2026-04-01Epub Date: 2026-01-02DOI: 10.1002/ps.70466
Ana Luiza Caldatto, Gilberto Dinis Cozzer, Heloise Restello Remus, Raquel de Brito, Monica Santin Zanatta Schindler, Cássia Alves Lima-Rezende, Jacir Dal Magro, Renan de Souza Rezende
Background: Urban leaf litter accumulating in water-filled containers may function as either a resource or a stressor for Aedes aegypti larvae, yet the chemical and botanical drivers of these contrasting effects remain poorly understood. We combined untargeted metabolite profiling with factorial life-history bioassays to examine how leachates from two dominant street trees, Tipuana tipu and Handroanthus heptaphyllus, influence mosquito life story. First-instar larvae were exposed to 25%, 50% or 100% leachate aged 7 or 14 days.
Results: The T. tipu leachates were defined by persistent oxalic acid (cyclohexyl hexyl ester) and condensed tannins over 14 days of decay, whereas H. heptaphyllus rapidly lost most phenolics within the first week, shifting to profiles dominated by short-chain alkenes. At 25% dilution, T. tipu reduced mortality to 7% and produced adults with greater wing lengths than controls. However, mortality was >90% in the 50% and 100% T. tipu treatments, independent of leachate age. By contrast, H. heptaphyllus never produced mortality > 16% across all concentration-age combinations. Adult body size responded nonlinearly, with 100% T. tipu aged 14 days generated the smallest adults, whereas the largest adults emerged from 25% T. tipu.
Background: Oak borers in the genus Coraebus, including the bark- and the wood-boring beetles C. florentinus and C. undatus, are major pests of the cork oak tree Quercus suber, and when their population densities are high, effective forest protection measures become critical. The endophagous behaviour of Coraebus species and the limited understanding of their biology, hamper the development of timely and effective management strategies.
Results: The novel strain UNISS22 of the entomopathogenic fungus Beauveria bassiana, isolated from the forest ecosystem, demonstrated strong insecticidal potential against the model coleopteran Tenebrio molitor and the two target Coraebus species, achieving up to 100% mortality in both larvae and adults, with efficacy shown to be concentration-dependent. Beauveria bassiana UNISS22 was found to exhibit endophytic behaviour in Quercus plants and to possess a distinctive ability to produce increased fungal biomass. Genomic analyses revealed a set of genes encoding proteins related to the insecticidal potential, including genes involved in adhesion to the host (adhesins and hydrophobins), in penetration and infection (chitinases, proteases and subtilases), and in the synthesis of bioactive secondary metabolites. Gene sequence analyses revealed a significant level of divergence in strain UNISS22, supporting the presence of distinct biological properties and functional potential compared with other B. bassiana strains.
Background: With the increasing use of pesticides, concerns regarding food safety have intensified. In response, the government of South Korea implemented the Positive List System (PLS) in 2019 to strengthen pesticide residue regulations. Thistle (Cirsium spp.) and olive (Olea europaea) are classified as minor crops, with limited registered pesticides and established maximum residue limits (MRLs). This study examined the residue and metabolic characteristics of the insecticide sulfoxaflor in these crops, followed by a risk assessment.
Results: Initial residue levels averaged 14.23 mg kg-1 g-1 in thistle and 2.54 mg kg-1 g-1 in olive. These differences were attributed to variations in morphological characteristics affecting pesticide adhesion. Metabolite analysis revealed that sulfoxaflor undergoes distinct degradation pathways in each crop, with X11719474 being a primary metabolite in thistle, but not in olive. The estimated half-life of sulfoxaflor was 4.1 days in thistle and 14.7 days in olive. Under the maximum exposure scenario (day of application, 99th percentile consumption), the hazard index (HI) for thistle consumed as a tea was 1.203, indicating a potential risk. However, all harvest groups exhibited HI values below 0.5 after 3 days, suggesting a lower risk level. By contrast, the HI for olive remained below 0.01 even on the day of pesticide application, indicating minimal risk.