The pyrroline-derived alkaloid N-(2-methyl-3-oxodec-8-enoyl)-2-pyrroline (MOEP, 1) is a potential pesticide that remains to be structurally diversified for target screening and biosynthesis studies. Bioactivity-guided investigation of the marine-derived fungus Penicillium citrinum SCSIO DF147 yielded five classes of pyrroline-derived alkaloids (1-15), including five new compounds (2-4, 14, and 15). These compounds were first evaluated for chitinase (OfChtII and OfChi-h) inhibition, revealing that both the 3-pyrroline ring and the Δ8',9' double bond are key functional groups. Pesticidal and fungicidal evaluation highlighted compound 1, which outperformed the positive control diflubenzuron against the lepidopteran pest Plutella xylostella, causing 100% larval mortality after 5 days of feeding at 5 mM. The biosynthetic gene cluster (pasA-D) for 1 was identified and characterized. The cytochrome P450 PasB was shown to catalyze the final tailoring step, transforming intermediate 8 into the 3-pyrroline functional group in 1 via dehydroxymethylation and dehydrogenation. These findings provide insights for developing new chitinase-targeting pesticides.

Drought and arbuscular mycorrhizal fungi act as counteracting drivers of maize metabolites that differentially affect three Lepidopteran pests

Gut microbes modulate Helicoverpa armigera immunity and affect its susceptibility to microbial pathogens.

Polyphenols play key roles in plants' resistance to biotic and abiotic stresses. However, in fruits, these compounds are often antinutritive and unattractive to seed dispersers. How plants balance these competing requirements is critical to their survival. Here, we report that phlorizin (P2G), the predominant polyphenol in apples (Malus spp.), and phloretin-2'-O-xyloglucoside (P2XG), the xylosylated product of P2G, show different accumulation patterns in apple fruits. The addition of P2G to the diet of quails, zebra finches, and budgerigars reduced feeding, while the addition of P2XG did not. P2G treatment also lowered the blood sugar concentrations and significantly reduced egg weight in quail, consistent with its ability to inhibit glucose transport mediated by sodium-glucose transporters. Two glycoside-specific glycosyltransferase genes, PGGT1.1 and 1.2, which catalyze the conversion of P2G to P2XG, were identified and shown to be specifically expressed in apple fruits. Transgenic apple plants overexpressing PGGT1 in leaves produced more P2XG, but less P2G. Consequently, these plants became more susceptible to lepidopteran pests and to spider mites. Our results show that the differential expression of glycosyltransferases in apple provides a mechanism to regulate polyphenol metabolism in different tissues to balance the requirements for plant-seed dispersal and plant-pest interactions.

Isocycloseram is a novel isoxazoline insecticide targeting the γ-aminobutyric acid (GABA)-gated chloride channel (GABAR). It exhibits high efficacy against Lepidopteran pests like Plutella xylostella but is safe to natural enemies. However, the risk of isocycloseram resistance in P. xylostella and the mechanisms underlying its selective action between P. xylostella and its natural enemy, Arma chinensis, remain unknown. In this study, the resistance risk of P. xylostella to isocycloseram was assessed. After 16 generation selections, P. xylotella developed 32.0-fold resistance with a realized heritability (h2) of 0.452. The isocycloseram resistant strain also showed 4.4-fold cross-resistance to abamectin but remained susceptible to endosulfan, broflanilide, cyproflanilide, and chlorantraniliprole. Furthermore, isocycloseram was found to be highly toxic to P. xylostella but safe to A. chinensis. The specific activities of esterases, glutathione S-transferases, and cytochrome P450 O-demethylation enzymes in A. chinensis were significantly higher than those in P. xylostella when induced by isocycloseram. In addition, molecular docking demonstrated that isocycloseram binds more strongly to PxGABAR (-9.44 kcal mol-1) than to AcGABAR (-8.06 kcal mol-1). Plutella xylostella has a high risk of developing resistance to isocycloseram. The elevated activity of detoxification enzymes in A. chinensis and reduced binding affinity of AcGABAR to isocycloseram may contribute to the selective toxicity of isocycloseram between P. xylostella and A. chinensis. These findings lay a foundation for the scientific application of isocycloseram in pest control and natural enemy conservation. © 2026 Society of Chemical Industry.

Disruption of reproduction is an important pest control tactics for management of high-fecundity pests like Helicoverpa armigera (Hübner). In this study, we investigated the role of the testis-biased miR-252a-5p in regulating gonad development and reproduction. Through a combination of bioinformatics prediction, dual luciferase reporter assays, functional injections (agomir, antagomir, and siRNA), and phenotypic evaluations, we identified OVOL as a key target gene of miR-252a-5p. We found that miR-252a-5p negatively regulates OVOL expression. Injection of miR-252a-5p agomir or OVOL siRNA into newly emerged females delayed egg maturation and reduced hatching rates. In contrast, inhibiting miR-252a-5p or knocking down OVOL in larval stages did not affect testis development or fertility. These results demonstrate that miR-252a-5p specifically targets OVOL to modulate ovarian development and reproductive success in H. armigera. Both miR-252a-5p and OVOL represent promising targets for reproduction-based control of this and other lepidopteran pests.

The Vip3 protein family from Bacillus thuringiensis shows great potential for controlling lepidopteran pests. However, the natural insecticidal activity of the Vip3C subfamily, such as Vip3Ca, is often limited, restricting its application. This study aims to enhance the insecticidal activity of Vip3Ca through modifications targeting processing and receptor binding. Five Vip3Ca protease cleavage site mutants were constructed, using the protease cleavage sites between domains I and II of Vip3Aa as a reference. Four of these mutants exhibited significantly increased processing in Spodoptera frugiperda midgut protease extracts and enhanced insecticidal activity against S. frugiperda larvae. Three selected cleavage site mutants also showed increased insecticidal activity against the larvae of Helicoverpa armigera, Spodoptera litura, and Spodoptera exigua. Furthermore, substitution of residues G302, N390, or Q468 with lysine improved the binding affinity of Vip3Ca to S. frugiperda brush border membrane vesicles by 1.52- to 1.96-fold, and increased its toxicity against multiple lepidopteran pests. The combined mutants, Vip3CaQ198VKK/G302K and Vip3CaQ198VKK/N390K, also showed significantly higher insecticidal activity than Vip3Ca. The insecticidal activity of the combined mutants against larvae of S. frugiperda, H. armigera, S. litura, S. exigua, and Ostrinia furnacalis increased by up to 5.23-, 4.06-, 3.65-, 6.00-, and 12.30-fold, respectively. This study demonstrates that improving both processing and receptor binding affinity is an effective strategy for enhancing the insecticidal activity of Vip3Ca. The successful engineering of Vip3Ca mutants with significantly improved potency provides valuable insights for the functional optimization of other members within the Vip3 protein family. © 2026 Society of Chemical Industry.

Carposina sasakii Matsumura is a significant lepidopteran pest in the Carposinidae family, inflicting substantial damage on stone and pome fruit trees such as jujube, peach, and apple. Using MaxEnt, we assessed the worldwide climatic suitability for C. sasakii and its key environmental drivers, evaluating how climate change impacts dispersal risks. Integrating global occurrence records with 37 environmental variables, the model (AUC = 0.982) quantitatively identifies July precipitation (prec7), minimum average temperatures in April and August (tmin4 and tmin8, respectively), and maximum average temperature in May (tmax5) as critical distribution determinants. Among these, prec7 exhibits the highest contribution (threshold approximately 370 mm). The current suitable habitat spans 10.39 × 102 km2, concentrated predominantly in East Asia's temperate monsoon zone (eastern China, the Korean Peninsula, and Japan) and southern North America. Under future climate scenarios, the high-emission pathway (SSP585) will reduce highly suitable areas, while moderately suitable zones expand coastward. In contrast, SSP370 projects a significant, albeit phased, habitat increase with a 19.61% growth rate. Precipitation regimes and extreme temperatures jointly regulate niche differentiation in C. sasakii, whose range shifts toward Southeast Asia and suboptimal regions in Europe and America, underscoring cascading climate change effects. These findings provide a scientific basis for transnational monitoring, early warning systems, and regional ecological governance.

Insecticide overuse in agriculture raises significant concerns, particularly in rice cultivation, where pest management heavily relies on chemical control. Major pests, such as rice leaf folders, are frequently targeted, leading to increased insecticide applications and subsequent selection pressure, fostering resistance development. Resistance in rice leaf folder, Cnaphalocrocis medinalis to diamide and organophosphate groups of insecticides has already been reported. However, despite the widespread use of synthetic pyrethroids, particularly lambda-cyhalothrin, in Kerala, India, data on resistance levels and underlying mechanisms remain sparse. This study bridges this gap by assessing the susceptibility of field populations of C. medinalis to lambda-cyhalothrin and investigating the key biochemical mechanisms driving resistance. Resistance ratios (RR) across populations were alarmingly high, ranging from 170.73- to 763.66-fold, indicating significant resistance. Biochemical assays revealed elevated detoxification enzyme activity, including CarE (1.11-1.63 times), GST (2.33-2.97 times), and Cyt P450 (1.52-2.49 times). Synergism assays confirmed metabolic resistance mechanisms, with increased CarE activity contributing to resistance in the PKD population, elevated Cyt P450 activity in the KUD and ONT populations, and multiple detoxification enzymes involved in resistance in the TCR population. This marks the first documented evidence of field-evolved resistance to lambda-cyhalothrin in C. medinalis globally. The outcomes highlight serious implications, as high resistance levels may prompt more frequent and higher doses of insecticide applications, increasing the risk of unintentional environmental contamination, particularly in aquatic ecosystems. Moreover, evidence from other lepidopteran pests suggests that chronic exposure to broad-spectrum insecticides may enhance preadaptive detoxification pathways, perpetuating a pesticide treadmill and accelerating resistance evolution. Given these findings, the study emphasizes the urgent need for resistance monitoring and integrated resistance management strategies to sustain rice productivity while mitigating ecological risks and preserving the long-term efficacy of available insecticides.

Lambda-cyhalothrin (λ-cyhalothrin) is a broad-spectrum pyrethroid against lepidopteran pests, yet its efficacy is increasingly threatened by insect resistance. Although CYP6AE48 overexpression has been implicated in λ-cyhalothrin detoxification in Spodoptera litura, the regulatory mechanism remains unclear. Here, CRISPR/Cas9-generated CYP6AE48 knockout increased larval susceptibility to λ-cyhalothrin, confirming its essential role in detoxification. λ-Cyhalothrin exposure triggered the expression of several transcription factors, including CncC, MafK, EcR, USP, AhR, and ARNT. Their knockdown suppressed CYP6AE48 expression, thereby compromising larval tolerance. Dual-luciferase reporter assay demonstrated that these transcription factors regulated CYP6AE48 transcription by binding to the specific cis-acting elements. Moreover, protein kinases AKT, ERK, JNK, and RSK2 were implicated as upstream regulators, orchestrating transcription factor expression and subsequent CYP6AE48-mediated detoxification. These findings reveal a multilayered regulatory circuitry that activates CYP6AE48 expression to facilitate λ-cyhalothrin detoxification, providing novel insights into the evolutionary adaptation of detoxification mechanisms and highlighting potential molecular targets for future pest management strategies.

ABSTRACT Trichogramma are tiny wasps commonly used in augmentative biocontrol against many Lepidopteran pests. We designed a specific experimental setup to study their olfactory preferences related to egg‐laying behavior. This Y‐shaped olfactometer was coupled with an image‐recognition model, trained with artificial intelligence, to automatically count the number of parasitized eggs. A Bayesian inference pipeline was developed to analyze the data and estimate the attraction or repulsion elicited by the tested odors. We used Trichogramma cordubensis as a model species to validate the new experimental setup, and we demonstrated that T. cordubensis females were attracted to honey and to the sexual pheromone of a potential host ( Mythimna unipuncta ), while they were repelled by vinegar or peppermint essential oil. Overall, this new experimental device will be useful for studying Trichogramma behavioral responses to odors.

Evaluation of the insecticidal activity of the spider-venom peptides Dc1a and Ta1a against economically important lepidopteran pests.

Cyproflanilide, a novel meta-diamide insecticide, overcomes multiple insecticide resistance in Cnaphalocrocis medinalis: Evidence from comparative toxicity assays and genome-edited Drosophila.

Genomic and toxicity analysis of Lepidopteran toxic novel Bacillus thuringiensis strain T407.

ABSTRACTSoybean yield is often reduced by pest attacks. Among these, Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae) stands out as one of the most important defoliating pests of soybean. Therefore, the development of new bioinsecticides targeting Lepidopteran pests is an urgent need. Protease inhibitors (PIs) have emerged as promising molecules in this context. In this study, we designed four peptides (TGPCK, TGPCR, AVIMK, and AVIMR) inspired by the reactive center loops of BPTI and SKTI to assess their potential as competitive inhibitors of trypsin‐like proteases in A. gemmatalis. In silico and kinetic analyses revealed that peptide binding affinity was influenced by specific chemical interactions, with pi‐sigma bonds correlating with higher affinity for AVIMK, while alkyl/pi‐alkyl and C‐H bonds were associated with lower affinity for AVIMR and TGPCK. Key residues (His57, Asp102, Ser195, Asp189, S195, and G197) played a crucial role in ligand binding. Enzyme inhibition assays confirmed that all peptides acted as competitive inhibitors of A. gemmatalis trypsin‐glen proteases, with TGPCK displaying the highest efficacy. These findings highlight BPTI‐derived peptides as potential candidates for future pest management strategies. Further studies should evaluate their effects when applied to plants, considering possible metabolic interactions and phytotoxicity.

Sublethal effects of flufenoxuron on Spodoptera mauritia Bosid. (Lepidoptera: Noctuidae) testicular biochemical profiling and Spermatogenic alterations.

Genetically engineered crops that produce insecticidal proteins from Bacillus thuringiensis (Bt) have many benefits and are used globally to manage key insect pests, including Helicoverpa zea (Lepidoptera: Noctuidae), a major pest of crops in the Americas. However, pests of at least 11 species, including H. zea, have evolved resistance to Bt crops, diminishing their effectiveness and benefits. For H. zea in the United States, practical resistance to Bt corn and cotton producing crystalline (Cry) Bt proteins is widespread and early warning of resistance to the vegetative insecticidal protein Vip3Aa has been reported. Thus, a better understanding of the genetic basis of resistance to Vip3Aa is needed to monitor, manage and counter resistance. In some strains of lepidopteran pests, resistance to Vip3Aa is associated with disruptive mutations in the chitin synthase 2 (CHS2) gene but this association had not been investigated previously in H. zea. Here, we show that mutations introduced by CRISPR/Cas9 editing of the CHS2 gene can cause resistance to Vip3A in H. zea. Disruptive mutations in CHS2 facilitated the creation of strain CHS2-KO that had 29 000-fold resistance to Vip3Aa relative to its unedited parental susceptible strain. Resistance to Vip3Aa in CHS2-KO was autosomal, recessive, and did not cause cross-resistance to Cry1Ac or Cry2Ab. Results of this study indicate that CHS2 plays an important role in Vip3Aa intoxication in H. zea. It will be important to determine if mutations in CHS2 contribute to field-evolved resistance to Vip3Aa in H. zea and other pests. © 2025 Society of Chemical Industry. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Differential roles of ABCC2, ABCC3, and cadherin in mediating Cry1Ac toxicity in Spodoptera exigua.

Induced Bowman-Birk trypsin inhibitor TaBBTI-1 in wheat during poor-host interactions with aphids confers broad-spectrum resistance to insect herbivores.

Structure-oriented molecular extension strategies unlock C-glycoside insecticides targeting OfChtII and OfHex1.