Tuta absoluta is a major invasive pest of Solanaceous crops, largely managed through chemical interventions. Despite its economic importance, the genomic landscape of its detoxification machinery remains poorly understood. We performed a genome-wide identification of 23 GST genes (TabsGSTs) in T. absoluta, characterized by amino acid lengths of 147-289 aa and a predominantly 1- or 5-exon genomic architecture (∼65%). The identification of four tandemly arranged gene clusters highlights potential evolutionary hotspots for insecticide resistance. Phylogenetic analysis categorized these genes into seven subfamilies, with the lineage-specific expansion of the Epsilon class indicating its key role in xenobiotic metabolism. Transcriptional profiling revealed divergent responses to insecticides: chlorantraniliprole exposure (LC50) largely failed to induce TabsGST expression, whereas spinetoram LC50 treatment triggered significant upregulation of TabsGSTe6 and TabsGSTu1. This study elucidates the molecular characteristics and expression dynamics of the GST family in T. absoluta, offering vital molecular targets for resistance monitoring and the design of targeted control measures.

1. The core-periphery paradigm predicts that asymmetric selection along environmental gradients drives divergent adaptation at range margins, influencing range limits and invasion dynamics. However, empirical tests spanning entire latitudinal gradients and mechanistic explanations for the genetic paradox of invasion-rapid adaptation despite limited genetic diversity-remain rare. 2. We conducted a five-year reciprocal transplant common garden experiment on the invasive annual Amaranthus palmeri across its entire invasive range in China (21-49 degrees N). Population fitness was quantified using asymptotic growth rates (As) to test for asymmetric adaptation. We then measured key phenotypic traits and used structural equation modelling (SEM) to identify trait-fitness relationships. Finally, we integrated quantitative genetic (Q(ST)) and neutral genomic (F-ST ) comparisons with gene-level analyses, including genome-wide association studies (GWAS), a genome-wide F-ST scan and expression validation, to elucidate the evolutionary mechanisms underlying adaptation. 3. We detected pronounced latitudinal asymmetry in adaptation. Northern peripheral populations evolved local specialization through genetic shifts towards earlier flowering (2.5-18.9 days) and prolonged flowering duration (5.7-18.2 days), increasing fitness (|ss| > 0.56, p < 0.01). Trait divergence (Q(ST)= 0.41-0.62) greatly exceeded neutral expectations (F-ST= 0.0156), indicating diversifying selection on standing genetic variation. Genomic analyses identified PTM as the top GWAS candidate, a single candidate gene associated with flowering phenology variation, ranking in the top 5% of the genome-wide F-ST distribution and showing signatures of recent selective sweeps, with significantly higher expression in northern peripheral populations. In contrast, southern edge populations exhibited consistent maladaptation, revealing a fundamental asymmetry in range-limiting filters. 4. Synthesis. Climatic extremes at range margins drive rapid genetic adaptation in key phenological traits, facilitating asymmetric range expansion. By linking phenotypic selection, fitness consequences and genomic divergence across spatial scales, our study provides a mechanistic framework for understanding range limits and offers insights for predicting species redistribution and managing biological invasions under climate warming.

Baculoviruses are widely used as biological control agents against lepidopteran pests, yet their effects on host feeding and oviposition behaviour remain poorly understood compared with plant and vertebrate viruses that are known to manipulate vector host choice. Here, using Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) and its host S. exigua as a model, we show that viral infection reconfigures host use through an axis linking olfaction and nutrition. SeMNPV infection of fifth instar larvae shifted feeding preference from carbohydrate-rich to protein-rich host plants, a pattern that was independently confirmed on artificial diets differing only in protein to carbohydrate ratio. Comprehensive analysis of genomic and transcriptomic data allowed us to annotate 66 olfactory receptor (OR) genes, among which SexiOR23 was strongly induced by SeMNPV. RNA interference of SexiOR23 abolished the infection-associated shift toward protein-rich hosts and restored the original preference for carbohydrate-rich diets, demonstrating that SexiOR23 is required for the virus-associated change in nutrient-oriented feeding. Furthermore, infected larvae feeding on high-protein diets exhibited reduced susceptibility and increased resistance to SeMNPV relative to larvae on standard diets, whereas silencing SexiOR23 did not alter viral sensitivity, indicating that this receptor drives behavioural reprogramming rather than immune activation per se. Moreover, the behavioural modification persisted into the adult stage: viruliferous females showed pronounced upregulation of SexiOR23 and switched oviposition preference from carbohydrate-rich to protein-rich host plants. These findings identify a mechanistic link between baculovirus infection, OR gene regulation and nutrient-based host choice, provide a new perspective on the ecological adaptation of noctuid pests, and offer a conceptual framework for refining SeMNPV-based biocontrol using semiochemical-guided strategies for more precise management of S. exigua.

Chitinases are crucial in the molting process of insects and represent potential targets for the development of RNA interference (RNAi)-based insecticidal strategies. In this study, we identified and characterized 11 chitinase genes (TaChts) in T. absoluta, each harboring at least one GH18 catalytic domain. Phylogenetic analysis placed these proteins into 11 established groups (I-X and h), revealing conserved lineage-specific patterns. Spatiotemporal expression profiling showed that most TaChts peak during key developmental transitions. TaCht1, TaCht2, TaCht3, TaCht5, TaCht6, TaCht7, TaCht10, TaCht-h, and TaIDGF were predominantly expressed in the integument, whereas TaCht8 and TaCht11 showed gut-enriched expression, indicating functional specialization. Stage-tailored RNAi assays demonstrated that silencing TaCht5, TaCht7, TaCht10, and TaIDGF caused pronounced mortality in both larvae and pupae. In larvae, delivery of dsRNA using carbon quantum dots (CQDs) disrupted molting: knockdown of TaCht7, TaCht10, and TaIDGF prevented shedding of the old cuticle, whereas TaCht5 silencing produced severe cuticular shrinkage and blackening. Hematoxylin and eosin staining revealed detachment of epidermal cells from the cuticle, providing cytological evidence of disrupted cuticle-epidermis remodeling. In pupae, microinjection of dsRNA induced cuticular collapse, melanization, and eclosion failure due to persistent adhesion of the pupal case, accompanied by marked reductions in chitinase activity. Together, our findings highlight the critical roles of four key chitinases in endocuticular turnover and metamorphic progression in T. absoluta, offering mechanistic insight into chitin-mediated developmental processes. The identified genes represent strong candidates for RNAi-based, species-specific pest management strategies against this globally significant insect.

Enhancing resistance to piercing-sucking pests while preserving superior agronomic performance remains a key challenge in plant breeding, constrained by the classical "growth-defense trade-off". Lignin, a core component of plant secondary cell walls, acts as a vital physical barrier against pest invasion, yet genetic regulators that simultaneously reinforce lignin-mediated defense and promote plant growth are rarely reported. Here, we cloned MdLac18 (GenBank Accession No.: PV341664), a laccase gene from the aphid-resistant apple cultivar 'Starkrimson', and heterologously expressed it in Nicotiana benthamiana via Agrobacterium-mediated transformation. Transgenic lines exhibited robust resistance to Myzus persicae: corrected aphid mortality reached 43.99% and fecundity decreased by 55.13% at 8 days post-inoculation. Electrical Penetration Graph (EPG) analysis revealed prolonged salivation (E1 wave) and shortened phloem ingestion (E2 wave) in aphids, reflecting impaired stylet penetration. MdLac18 overexpression increased laccase activity by 59.61% and lignin content by 47.40%, with enhanced vascular tissue lignification. GC-MS analysis confirmed a 176% increase in G-type lignin monomers (coniferyl alcohol derivatives), indicating specific promotion of G-type lignin biosynthesis. Notably, unlike typical defense-related genes, MdLac18 conferred dual benefits: transgenic tobacco showed improved agronomic traits (increased plant height, stem diameter at the early vegetative stage (30-60 days after transplantation), biomass, and early flowering). Our findings establish MdLac18 as a rare genetic resource that, by exerting its stress-regulatory function and enhancing plant adaptability to adverse environments, holds the potential to decouple the growth-defense trade-off under controlled suboptimal conditions, thus providing a novel strategy for breeding crops with durable aphid resistance and superior agronomic performance.

Ensuring food security and agricultural biosecurity increasingly depends on the rapid and accurate identification of harmful organisms that threaten crop production. Traditional identification methods rely heavily on expert knowledge, are time-consuming, and often fail in complex multi-species scenarios. To address these limitations, this study establishes a comprehensive image dataset that includes three major categories of agricultural harmful organisms-pests, weeds, and crop diseases-and proposes an enhanced convolutional neural network, DenseNet-CSL (DenseNet with Coordinate Attention, Deep Supervision, and Label Smoothing), developed based on DenseNet121 for efficient multi-class recognition. The dataset comprises 62 pest species, 28 weed species, and 30 major crop diseases, totaling 23,995 images collected under diverse growth stages, ecological conditions, and imaging environments. DenseNet-CSL incorporates three targeted improvements: a Coordinate Attention mechanism to strengthen spatial and channel feature representation, Deep Supervision to accelerate convergence and enhance generalization, and Label Smoothing Loss to regularize the output distribution and reduce overconfidence, which is beneficial under imbalanced and noisy data. Experimental results demonstrate that DenseNet-CSL achieves a precision of 81.3%, a recall of 80.1%, and an F1-score of 80% on the constructed dataset-outperforming DenseNet121, ResNet101, EfficientNetV2, and MobileNetV3-while shortening inference time by 1.36 s and adding only 1.772 MB of additional model parameters. These findings highlight the effectiveness of DenseNet-CSL for multi-class recognition of agricultural pests, weeds, and diseases, and underscore the importance of multi-source, multi-scene datasets for improving model robustness and generalization. The proposed framework provides a viable technical pathway for intelligent diagnosis and monitoring of agricultural harmful organisms, supporting port quarantine and agricultural biosecurity applications.

The South American tomato pinworm, Tuta absoluta (Lepidoptera: Gelechiidae), is a devastating invasive pest of tomato (Solanum lycopersicum). To evaluate candidate female-oriented semiochemicals, we examined the electroantennogram (EAG) activity of ten tomato-associated volatiles selected from previous reports. The compound 1-nonanol was selected as a candidate based on its relatively strong EAG activity and was subsequently assessed for its effects on olfaction, orientation, and oviposition. These findings indicate that 1-nonanol elicits female-biased attraction and stimulates oviposition under laboratory conditions. However, its ecological relevance within natural tomato volatile blends and its field performance require further validation before it can be developed as a female-oriented IPM component.

Invasive species increasingly threaten global biodiversity and agricultural productivity. However, research on invasion processes often lacks historical references and predictive insights. Liriomyza sativae, native to the Americas, is rapidly expanding worldwide. This study integrated the population genetics and ecological niche modeling to investigate its population history, contemporary global spread, and future invasion risks using global mitochondrial COI genes and occurrence records. Adaptive mechanisms to climatic environments during the expansion were also analyzed using single nucleotide polymorphisms (SNPs). The results reveal that the suitable habitats and demography of L. sativae have expanded rapidly since the Last Glacial Maximum (LGM), likely driven by Holocene warming, creating conditions conducive to its contemporary global invasion. Gene migration analysis reveals a long-distance dispersal network, with Mexico serving as a key source of ancestral haplotypes for invasive populations anda major center of global spread. Recent human activities, including trade and cultivation, may have facilitated its migration. Future climate changes are projected to further enhance the ecological suitability of L. sativae, combined with human-mediated dispersal, may facilitate its expansion into higher-latitude regions. Niche comparisons reveal that invasive populations tolerate colder conditions than native populations, with the mean minimum temperature of the coldest month (bio6) being 0.82 degrees C in the invasive range compared to 9.25 degrees C in the native range. Genotype shifts and candidate genes associated with distinct climatic conditions suggest the species' capacity for rapid adaptive evolution during invasion. Under future climate change and globalization, prevention and control efforts should prioritize high-latitude regions and human-mediated dispersal routes.

The ATP-binding cassette (ABC) transporter superfamily is one of the largest groups of membrane proteins, involved in phase III of the detoxification process and plays important roles in insecticide resistance. In this study, A total of 69 ABC transporter proteins genes was identified based on genome and transcriptome, including 18 ABCA genes, 6 ABCB genes, 11 ABCC genes, 5 ABCD genes, 3 ABCF genes, and 26 ABCG genes in Eriosoma lanigerum. Among the 69 ABC transporters, 15 are classified as full transporters, while 27 are identified as half transporters. Within the ABCA and ABCG subfamilies, there are 14 and 5 proteins, respectively, that possess only the NBD domain and lack the TMD domain, indicating that these proteins do not perform transmembrane functions. Two notable ABC transporters have recently been identified in the ABC transporters of E. lanigerum. ElABCC1 features 4 NBDs and 4 TMDs, whereas ElABCG21 comprises 3 NBDs and 3 TMDs. In this study, the ElABCG2 gene was cloned, revealing that its full-length sequence is 2082 bp and that it belongs to the category of half transporters. Temporal and spatial expression analyses indicate that the expression level of this gene significantly increases during the growth of the instar stages. Furthermore, it is expressed in the head, thorax, and abdomen, with expression levels exhibiting an upward trend. The RNAi technique was employed to specifically knock out the ElABCG2 gene. Subsequently, E. lanigerum were exposed to the median lethal concentrations of imidacloprid and thiamethoxam. The results demonstrated that following the knockout of this gene, the sensitivity of E. lanigerum to imidacloprid increased significantly, while no notable change was observed in their sensitivity to thiamethoxam. This suggests that the ElABCG2 gene may play a crucial role in the detoxification process of E. lanigerum against imidacloprid. However, the specific detoxification mechanism warrants further investigation.

Insect insulin signaling plays a central role in regulating development, metamorphosis, and reproduction, yet its mechanistic functions in the tomato leafminer, Tuta absoluta, a globally significant pest, remain poorly understood. This study aimed to elucidate the role of the serine/threonine kinase Akt (TaAkt) in coordinating metamorphosis and female reproductive processes. The TaAkt gene was cloned and characterized, and its spatiotemporal expression was analyzed across various developmental stages and tissues. RNA interference (RNAi) was employed to knock down TaAkt in late pupae and newly emerged females, followed by assessment of pupal-adult eclosion, chitin metabolism, 20-hydroxyecdysone (20E) titer, ovarian development, juvenile hormone (JH) levels, vitellogenin synthesis, and fecundity. Knockdown of TaAkt significantly reduced 20E titers and downregulated the expression of ecdysone biosynthesis and signaling genes, leading to pupal mortality, defective molting, and reduced chitin content. In adult females, TaAkt silencing impaired ovarian growth, decreased JH levels, suppressed vitellogenin production, and reduced egg number and hatching rates. These findings demonstrate that TaAkt exerts pleiotropic control over both metamorphic and reproductive processes in T. absoluta. The study identifies TaAkt as a promising molecular target for RNAi-based pest management strategies, offering a potential approach to simultaneously suppress survival and reproductive capacity in this economically important pest.

The beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), is an important agricultural pest, and S. exigua multiple nucleopolyhedrovirus (SeMNPV) is a host-specific biological control agent. However, baculovirus efficacy can be limited by host antiviral responses. S. exigua peptidoglycan recognition protein LB (SePGRP-LB) has been identified as an antiviral immune factor, suggesting that its suppression may increase larval susceptibility to SeMNPV. In this study, bacterially produced double-stranded RNA targeting SePGRP-LB (bac-dsPGRP-LB) was orally delivered to larvae to induce RNA interference. Feeding bac-dsPGRP-LB reduced SePGRP-LB transcript levels by 24.0% to 65.7% over 7 d. SePGRP-LB knockdown prolonged fifth-instar larval development, reduced female pupal weight, shortened male adult longevity and the oviposition period, and decreased fecundity by approximately 51%. Life table analysis further showed significant reductions in the intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R0) following bac-dsPGRP-LB treatment. During SeMNPV infection, co-feeding with bac-dsPGRP-LB significantly suppressed SePGRP-LB expression, increased the SeMNPV genomic load, and reduced larval survival compared with the SeMNPV + bac-dsGFP treatment. These findings identify SePGRP-LB as a promising RNAi target for simultaneously reducing S. exigua fitness and enhancing its susceptibility to SeMNPV under laboratory conditions.

Microbial interaction networks are critical determinants of ecosystem stability and function, yet how invasive plants differentially reshape these networks compared to native species remains poorly understood. In this study, we conducted a long-term common garden experiment using three invasive plant species (Ambrosia artemisiifolia, Bidens pilosa, and Flaveria bidentis) and two native species (Chenopodium serotinum and Setaria viridis). By employing 16S rRNA gene sequencing, molecular ecological network analysis, and structural equation modelling (SEM), we characterized and compared the rhizosphere bacterial co-occurrence networks of these species and quantified the pathways linking plant invasion, soil properties, and network structure. Our results demonstrate that invasive plants foster significantly more complex and stable bacterial networks than native plants, evidenced by a higher number of nodes and edges, greater average degree (avgK). Notably, we observed divergent ecological strategies among invasive plants: A. artemisiifolia formed highly modular but vulnerable multi-hub networks, whereas F. bidentis established highly integrated and robust networks, suggesting a complexity-stability trade-off. Furthermore, this enhanced complexity is amplified by an indirect pathway: the superior quality of litter and root exudates from invasive plants increases soil organic matter (SOM) and total nitrogen (TN), which alleviates resource competition among rhizosphere bacteria. Furthermore, SEM revealed that this enhanced complexity is amplified by an indirect pathway: the superior quality of litter and root exudates from invasive plants increases soil organic matter, which in turn promotes network stability while constraining excessive complexity. Our study highlights the importance of investigating microbial co-occurrence networks in soils invaded by plants, as they provide key insights into community stability, functional interactions, and the underlying mechanisms driving ecosystem processes under biological invasion.

The serine/threonine-protein kinase polo plays a crucial role in regulating the cell cycle and mitosis in insects. While the cigarette beetle, Lasioderma serricorne, is a globally distributed pest threatening stored products, the functions of its polo gene remain largely unexplored. This study investigates the polo gene to elucidate its role in the development and reproduction of L. serricorne. The Lspolo gene, which encodes a protein containing a catalytic serine/threonine kinase domain and polo box domains, was identified and cloned. Spatio-temporal expression analyses indicated that Lspolo is predominantly expressed in the ovary, peaking in 5-day-old adult females. RNA interference (RNAi)-mediated knockdown of Lspolo caused significant disruptions in the pupal-adult transition, leading to lethal molting defects and abnormal elytra formation. Lspolo knockdown also significantly reduced the expression of wing development-associated genes. Furthermore, Lspolo silencing resulted in pronounced ovarian abnormalities, including disrupted oocyte maturation, impaired vitellogenesis, and structural anomalies in follicular cells. Additionally, a significant decrease in vitellogenin content and marked downregulation of LsVg and LsVgR gene expression were observed. These cellular and morphological deficits induced a notable decrease in female fecundity, a 6.7-day shorter oviposition period, reduced egg production, and a 34% decrease in offspring hatching rate. Our findings demonstrate that Lspolo plays a crucial role in pupal-adult metamorphosis and oogenesis in L. serricorne, highlighting its potential as a molecular target for RNAi-based pest control strategies.

A central challenge in invasion biology is to determine whether disjunct distributions of invasive species stem from secondary spread from an initial introduction bridgehead or from recurrent, human-mediated introductions. The devastating alien weed Amaranthus palmeri, with its large-scale disjunct distribution across China, provides an ideal system to address this question. We tested the competing hypotheses of bridgehead-mediated expansion (originating from the initial introduction in Beijing, 1985) versus multiple independent introductions. By integrating genetic analyses with stable isotope geolocation, we treated propagules from imported soybean shipments as direct, traceable links to potential source populations. Newly field-collected populations in China harbored significantly higher nucleotide diversity (π=(0.78 ± 0.18) × 10-3) and haplotype diversity (Hd = 0.47 ± 0.04) than both the initial introduced population and the pooled propagules from the primary source, the United States (US). Significant genetic differentiation (FST > 0.20) was observed both among newly field-established populations and between them and the initial introduction. Non-significant neutrality tests, coupled with multimodal mismatch distributions (Raggedness index = 0.0946, P > 0.05), indicated that these populations did not undergo a recent demographic expansion or selection. Genetic diversity and structure correlated with regional soybean import volume (r = 0.59, P < 0.05) but not with environmental distance (Mantel r = 0.24, P > 0.05). Our findings demonstrate that recurrent transcontinental introductions, mediated by global grain trade, are the dominant force shaping the genetic pattern and invasion process. This study provides a framework for reconstructing invasion pathways and highlights the need for proactive, source-targeted biosecurity strategies to manage invasions in the Anthropocene.

Beauveria bassiana and Bacillus thuringiensis are widely utilized entomopathogens for biological control. Insects combat these microbial threats through the activation of innate immune defenses, with antimicrobial peptides (AMPs), particularly defensins, playing pivotal roles. Tuta (Phthorimaea) absoluta (Lepidoptera: Gelechiidae), is a rapidly spreading and highly destructive invasive tomato pest that has developed resistance to conventional insecticides. To enhance the efficacy of entomopathogens targeted by AMPs, we investigated defensin functions in T. absoluta during pathogen challenge. A genome-wide survey identified four defensin genes (tadef1–4), each encoding 76–124 amino acids (228–372bp ORFs). All contained the insect defensin motif (C-X5-16-C-X3-C-X9-10-C-X4-7-CX1-C) and a conserved two-exon structure. Phylogenetic analysis confirmed their membership in the insect defensin family. Post-infection expression profiling showed that tadef1/2 were upregulated by both B. bassiana and B. thuringiensis, while tadef3/4 were suppressed by B. bassiana but induced by B. thuringiensis relative to uninfected controls. Developmental and tissue-specific expression analyses showed that tadef1/2 peaked in early instar larvae, especially midgut. Recombinant tadef1/2 demonstrated antibacterial activity against B. thuringiensis but lacked antifungal effects against B. bassiana. These results establish tadef1/2 as key effectors against Gram-positive bacteria and provide a molecular basis for improving the biocontrol of T. absoluta via immune modulation.

Caspases play critical roles in virus-induced apoptosis. In lepidopteran insects, caspase-4 is a unique effector caspase, but its regulatory cascade and function during baculovirus infection remain unclear. Here, we identified and characterized caspase-4 from Spodoptera exigua (SeCaspase-4). Sequence analysis revealed high similarity to lepidopteran caspase-4 and Drosophila Damm. Enzyme activity and subcellular localization assays confirmed that SeCaspase-4 is an effector caspase that does not translocate to the nucleus and is functionally distinct from SeCaspase-1. Quantitative PCR revealed a sequential activation cascade: SeCaspase-5 activates SeCaspase-4, which in turn activates SeCaspase-1. Mutational analysis demonstrated that the large and small subunits and Cys287 are essential for proapoptotic activity of SeCaspase-4. Recombinant AcMNPV carrying SeCaspase-4 increased viral virulence against S. exigua larvae, presumably by promoting apoptosis in insect cells, despite reducing viral production. These findings clarify the lepidopteran apoptotic pathway and provide insights for engineering baculoviruses with improved insecticidal activity and agricultural application potential.

BACKGROUND:Genes in the CYP4G subfamily are essential for the final steps of cuticular hydrocarbon (CHC) biosynthesis, which influences insect metamorphic development, desiccation tolerance, and insecticide penetration. However, the functional roles and regulatory mechanisms of CYP4G genes in Lasioderma serricorne, a major stored-product pest, remain poorly understood. RESULTS:In this study, we identified the CYP4G249 gene in L. serricorne, exhibiting conserved CYP4G structural features. RNA interference (RNAi)-mediated knockdown of CYP4G249 significantly reduced CHC content, impaired larval molting, decreased body weight, and increased desiccation susceptibility. Histological analysis revealed thinning of the newly formed epidermis, while scanning electron microscopy showed cuticular wrinkling and spiracle collapse in dsCYP4G249-treated larvae. Silencing CYP4G249 also enhanced larval mortality following exposure to ethyl formate and methyl isothiocyanate. At the post-transcriptional level, Lse-novel_mir63 was shown to target the coding region of CYP4G249, and administration of Lse-novel_mir63 mimics suppressed CYP4G249 expression, recapitulating the RNAi phenotypes. Overexpression of Lse-novel_mir63 further increased larval susceptibility to fumigants. CONCLUSIONS:These results demonstrate that Lse-novel_mir63 regulates CYP4G249 expression, controlling CHC biosynthesis, larval metamorphosis, and fumigant tolerance in L. serricorne. The CYP4G249-Lse-novel_mir63 axis represents a promising molecular target for RNAi- or miRNA-based pest management strategies, potentially enhancing fumigant efficacy while disrupting insect development. © 2026 Society of Chemical Industry.

The greenhouse whitefly, Trialeurodes vaporariorum Westwood (Hemiptera: Aleyrodidae), is a globally invasive pest that affects both horticultural and agricultural systems, causing substantial economic losses. However, comprehensive studies on its invasion genetics and associated symbiotic landscape in China are lacking. In this study, we analyzed the genetic diversity based on the mitochondrial cytochrome c oxidase subunit I (COI) gene and examined the infection patterns of six key secondary endosymbionts in 1702 individuals from 73 populations across 18 provinces in China. Phylogenetic analysis incorporating global sequences revealed that Chinese populations are comprised of ten haplotypes. Genetic diversity was extremely low, with haplotype H1 being overwhelmingly dominant (97.60% of individuals) and shared with global invasive lineages. Endosymbiont screening showed a high prevalence of Arsenophonus (78.56%) and Hamiltonella (44.98%), with frequent co-infections. These results suggest that the widespread invasion of T. vaporariorum in China likely originated from a limited number of founder individuals, resulting in a significant genetic bottleneck. The invasion success appears to be associated with a "genotype-symbiotype complex"-the dominant H1 maternal lineage combined with a beneficial symbiotic toolkit. These findings provide insights into the invasion dynamics of this pest and implications for targeted control strategies.

RNA interference (RNAi) has emerged as a promising method for pest control. While RNA interference shows promise for pest control, its environmental risk assessment remains essential. Tuta absoluta is a significant invasive pest posing a serious threat to the tomato industry in China, and the study is targeted at the pest. We evaluated two chitin synthase genes (Chs1, Chs2) and a β-1,3-glucanase gene (Beita) as RNAi targets in T. absoluta, with particular emphasis on ecological safety. DsRNA exposure induced significant larval mortality (53-69%), phenotypic abnormalities, and midgut disruption. Most importantly, comprehensive environmental safety assessment confirmed no homologous genes in humans or key nontarget organisms (Nesidiocoris tenuis, Harmonia axyridis, Trichogramma exiguum, Episyrphus balteatus), and critically, no adverse effects on their survival, pollination, predation, or parasitism capacities. This study identifies three effective RNAi targets and provides substantial evidence for the environmental safety of these dsRNAs, supporting their sustainable application in T. absoluta management.