Companion planting is a promising strategy to build biodiversity-friendly and productive agroecosystems while reducing reliance on pesticides. The overlooked spatial arrangement of companion plants within fields might be key to improving the success of conservation biological control. We investigated how the spatial arrangements (surrounded cropping, striped cropping and clustered cropping) of the aromatic plant Tagetes erecta (L.) (Asteraceae) within tea plantations affected the abundance, diversity, and evenness of natural enemies and the subsequent impact on pests. Clustered cropping of T. erecta showed the most beneficial effects, including the highest natural enemy abundance and species richness, the lowest pest abundance and species richness. The abundance of natural enemies was, on average, 2.7-fold higher than in clean tillage. An increased Pielou's evenness of pest in T. erecta clustered cropping indicated a balanced pest community. The significant linear relationships between Aphididae/Aphidiidae abundances and predatory/herbivorous mite populations demonstrated that companion plants facilitated pest tracking by natural enemies, regardless of spatial arrangements. Our study shows the importance of the spatial arrangement of aromatic plants within the field to enhance biological pest control and indicates that clustered cropping of aromatic plants allows optimizing pest management in tea plantations.

Harmonia axyridis Pallas is an important predatory insect in biological control. Understanding the relationship between the flight performance and energy metabolism of H. axyridis can optimize its field release strategies and enhance the efficiency of biological control. This study analysed the differences in flight ability, energy metabolic substances and the expression of genes related to these traits under different flight durations between male and female individuals of native H. axyridis using tethered flight assays. Results showed that the pre-flight body weight, reserves of triglycerides and three types of carbohydrates in female individuals were significantly higher than those in males. The long-duration and long-distance flight ability of females was also superior to that of males. In addition, based on gene expression results, it was inferred that in terms of energy metabolism, females primarily consumed glycogen and trehalose for energy during the early flight phase and compensated with minor triglyceride mobilization in the later phase. In contrast, males enhanced trehalose levels through glycolipid conversion to maintain energy supply during the mid-to-late flight phases. At the same time, two trehalase activities and related gene expressions indicated that males may primarily rely on increasing soluble trehalase activity to promote trehalose decomposition, while females may mainly depend on membrane-bound trehalase. In summary, our results indicate that the flight energy metabolism of H. axyridis may follow a 'carbohydrate-first, lipid-subsequent' pattern. Females performed better in long-duration and long-distance flights due to higher initial energy reserves, while males narrowed the later gap through lipid metabolism mobilization. The study not only fills the research gap in the coupling mechanism between flight and metabolism of the H. axyridis but also provides an important theoretical basis for its application and strategy optimization in biological control.

Trichogramma wasps serve as crucial biological control agents against the Asian corn borer (Ostrinia furnacalis). To find hosts within their short life span, the wasps must adjust their host-seeking behaviors via chemical cues such as host sex pheromones. To elucidate the molecular mechanism of host location, we systematically investigated how Trichogramma wasps detect the host's sex pheromone. Behavioral assays in a four-arm olfactometer revealed a pronounced preference of Trichogramma ostriniae for the sex pheromones of O. furnacalis, with significant responsiveness to its key components, (Z)-12-tetradecenyl acetate ((Z)-12:14AC) and (E)-12-tetradecenyl acetate ((E)-12:14AC). Subsequent transcriptomic analysis of female heads exposed to these pheromones identified eight upregulated olfactory receptor (OR) genes. Functional validation via RNAi demonstrated that silencing TostOR9a or TostOR92a significantly reduced the wasps' behavioral response to the sex pheromones, confirming their necessity in host-seeking behavior. Molecular docking simulations indicated strong binding activity, with TostOR9a exhibiting the lowest binding energy for (Z)-12:14AC (-8.68 kcal/mol) and TostOR92a for (E)-12:14AC (-9.50 kcal/mol). Finally, heterologous expression and electroantennogram (EAG) validation in Drosophila melanogaster confirmed that TostOR9a and TostOR92a are sufficient to confer olfactory sensitivity to (Z)-12:14AC and (E)-12:14AC, respectively. This study describes how Trichogramma wasps detect host sex pheromones at the molecular level and can thus provide a theoretical basis for the development of new biological control tools for olfaction.

Terpinolene, a monoterpene volatile, has been demonstrated to exhibit repellent activity against Bemisia tabaci adults. However, molecular basis of B. tabaci identifying and responding to terpinolene was unclear. Chemosensory proteins (CSPs) family is one of the most important member in insect olfaction system which plays a crucial role in hosts selection. Here, we cloned 13 BtabCSP genes in B. tabaci MED and detected transcriptional response to terpinolene. Based on proteins structure prediction, molecular docking, protein expression and fluorescence competition binding assay, BtabCSP1and BtabCSP12 exhibited strong binding affinity to terpinolene. Moreover, RNA interference (RNAi) combined with Y-tube assays showed that silencing BtabCSP1 or BtabCSP12 genes weakened the repellency effect of terpinolene to B. tabaci. Our results not only revealed molecular mechanism of CSPs-mediated repellency of terpinolene against B. tabaci, but also provided a theoretical basis for terpinolene-based repellent for pest management.

Objectively defining an effective choice is crucial for the reliability of results in insect olfactory behavior research. Relying on subjective time thresholds often leads to inconsistent findings, primarily due to the high likelihood of mistaking an accidental intrusion for an effective choice. Our analysis indicated that 29% of preference responses were not consistent among 0 s, 15 s, 30 s, and 60 s, when these thresholds were applied to evaluate the behavioral responses of Trichogramma japonicum Ashmead (Hym.: Trichogrammatidae) to 20 odorants in a four-arm olfactometer. This inconsistency arises because subjective thresholds fail to distinguish between accidental, transient entries and sustained, purposeful choices, leading to false positives or false negatives. To address this issue, we compiled a database of the initial stay duration of T. japonicum in the odor zone, and applied the 5th percentile of its empirical distribution—a widely accepted statistical standard for excluding extreme outliers (i.e., accidental brief entries) in medical and biological research—as the threshold to differentiate between accidental intrusion and effective choice. We then systematically assessed the behavioral responses of T. japonicum to 20 odorants and validated the authenticity of olfactory preferences through oviposition choice experiments. A continuous stay of ≥10 s was determined as an effective choice. Based on this criterion, T. japonicum exhibited significant preference for 0.1 μg/μL α-pinene, 0.01 μg/μL D-limonene and 0.001 μg/μL citral, whereas avoiding 10 μg/μL β-ionone. The results of the oviposition choice experiments showed high consistency with the olfactory behavioral preferences, confirming the reliability of this standard in predicting its actual host selection decisions. Collectively, this study proposes a data-driven protocol for establishing an objective and stable behavioral criterion in insect olfactory behavior research.

Urbanization is widely recognized as a major threat to biodiversity. Flower-visiting insects, especially hymenopterans such as bees, serve as important indicators for biological conservation in large cities due to their crucial role in pollination and ecosystem services. This study analyzed data collected from 2019 to 2022 in Beijing, China, by examining inflorescences of various plant species across different habitats for hymenopteran visitors. Field sampling was conducted at 28 sites over the four-year period. Each sampling event took place on a single day between 09:00 and 17:00 under sunny, calm, and warm conditions. Within a delimited 20 × 20 m plot at each site, a standardized protocol was applied over approximately four hours. The results revealed distinct bee community compositions between urban and ecological conservation zones. In ecological conservation zones, Bombus ignitus was the most abundant bee species, whereas Apis mellifera dominated in urban areas. Generalized Linear Mixed Models (GLMM) showed a significant reduction in wild bee richness in urban zones, with species counts 59.3

Soil contamination by cadmium (Cd) poses an increasing threat to agricultural ecosystems and may disrupt biological pest control mediated by natural enemies. However, the multigenerational effects of Cd stress on parasitoid reproductive strategies and performance, particularly in species with contrasting ovigeny syndromes, remain poorly understood. Here, we compared the short-term (F1) and long-term (F5) effects of host-mediated Cd exposure on the synovigenic Trichogramma cacoeciae and the proovigenic T. dendrolimi. Cadmium exposure did not shift the core oviposition rhythm of either species, demonstrating that ovigeny syndrome represents a canalized life-history trait robust to multigenerational heavy metal stress. For the synovigenic species T. cacoeciae, F1 Cd exposure extended female lifespan and elevated lifetime parasitism, consistent with a hormetic stress response; by contrast, continuous Cd exposure across 5 generations (F5) suppressed early-age oviposition and total reproductive output, reflecting cumulative physiological fitness costs. In contrast, T. dendrolimi showed no significant changes in survival, daily parasitism pattern, emergence rate, or percentage of female progeny under Cd stress, except for a reduction in total parasitism after F5 exposure. These findings demonstrate that synovigenic species exhibit greater plasticity and stage-dependent responses to transgenerational Cd stress, whereas proovigenic species appear more robust. Our results provide empirical evidence for how heavy metal pollution influences parasitoid life-history traits and fitness across generations, and offer practical guidance for selecting resilient biological control agents in Cd-contaminated agricultural landscapes.

Cadmium (Cd) is a pervasive heavy metal pollutant in agricultural ecosystems, posing toxic threats to crop productivity, food safety, and the efficacy of biological control programs. The Asian corn borer (ACB), Ostrinia furnacalis is a destructive lepidopteran pest of maize in East Asia, while Trichogramma ostriniae serves as the most widely applied egg parasitoid for the sustainable management of this pest in integrated pest management (IPM) programs. However, the cascading effects of sublethal Cd stress transmitted from herbivorous hosts to egg parasitoids remain poorly understood. Here, we investigated the sublethal effects of dietary Cd exposure (5.0 mg/kg) on the development and Cd bioaccumulation of ACB, and subsequently evaluated the parasitism performance of the egg parasitoid T. ostriniae reared on Cd-contaminated host eggs. Results showed that chronic Cd exposure did not significantly affect larval weight, male pupal weight, or female pupal weight of ACB, but significantly increased female adult body weight, indicating stage-specific stimulatory effects. Cd concentrations in larvae, female pupae, and female adults of ACB were markedly elevated following dietary exposure, with the highest Cd loads detected in female pupae (41.23 mg/kg). However, maternal Cd transfer to eggs did not result in a statistically significant increase in egg Cd concentration. Notably, parasitism by T. ostriniae on Cd-contaminated ACB eggs significantly increased the number of eggs parasitized, although offspring emergence rate and female progeny ratio remained unaffected. This study fills the research gap regarding the trophic transfer of Cd between ACB and T. ostriniae, clarifies the complex bottom-up effects of Cd pollution on host–parasitoid interactions, and provides empirical references for the rational deployment of T. ostriniae as a biocontrol agent in Cd-contaminated maize fields.

Arthropod natural enemies-encompassing predators and parasitoids-form the backbone of sustainable agriculture, delivering irreplaceable ecosystem services via biological pest suppression. Driven by global demand for eco-friendly alternatives to synthetic pesticides, research in this domain has grown sharply over the past decade. Here, we report a systematic bibliometric analysis of 6515 Web of Science Core Collection papers focused on arthropod natural enemies in biological control (2016-2025), with the goal of charting the field's intellectual structure. Performance metrics confirmed an initial rapid increase from 2016 to 2019 followed by a plateau and a slight rise in 2025, with the US, China, and Brazil dominating output. Keyword co-occurrence networks pinpointed core themes, including conservation biological control, predatory mites, and integrated pest management (IPM). Temporal trends further revealed a pivot toward applied work on invasive pest systems. Co-citation analysis uncovered six foundational research clusters, while bibliographic coupling of 2021-2025 papers uncovered five active emerging subfields: landscape ecology and habitat manipulation, tri-trophic interaction mechanisms, high-impact invasive pest biocontrol, non-target risk assessment for introduced agents, and fall armyworm integrated management. We synthesize cross-cutting implications and outline future priorities-including AI-enabled rearing systems, functional biodiversity boosting, climate adaptation, and multifunctional landscape tuning. By consolidating historical progress and forward-looking directions, this framework empowers researchers, extension practitioners, and policymakers to scale sustainable pest management worldwide.

Insect natural enemies are central agents in biological-control programs. Their pest-suppression performance depends not only on release strategy, but also on traits shaped by long-term laboratory rearing and selection. Conventional mass-rearing systems usually evaluate insect natural enemies using production-oriented indicators, such as survival, fecundity, emergence rate, sex ratio and production cost. However, continuous mass rearing can drive laboratory adaptation, genetic drift, inbreeding, shifts in host or prey use, and reduced field performance. In this review, we summarize key target traits for insect natural enemy improvement, including production efficiency, host or prey use, parasitism, predation, nonreproductive host killing, stress tolerance, pesticide compatibility, dispersal, retention and field efficacy. We further discuss how recurrent artificial selection, hybridization, population genetics, and genomics approaches can be integrated to improve insect natural enemies while maintaining genetic quality. Finally, we discuss the links among trait screening, selection design, quality control, storage and transport, and field-performance validation in the development and application of selected lines or improved strains. Overall, this review highlights practical directions for developing stable and field-proven natural enemy lines. Beyond agriculture, this perspective may also support ecological design in urban landscapes through natural enemy conservation and reduced pesticide use.

Cadmium (Cd) pollution disrupts plant-insect tri-trophic interactions in agroecosystems, yet the mechanisms remain poorly understood. In this study, we systematically investigated the effects of Cd exposure (1.0 mg/L) on the tomato (Solanum lycopersicum)-western flower thrips (Frankliniella occidentalis)-minute pirate bugs (Orius sauteri) system by integrating analyses of tomato photosynthetic physiology, untargeted metabolomics, and the fitness, behavior and Cd accumulation of the two insect species. Cd accumulated abundantly in tomato leaves (115.67 mg kg⁻¹), inhibited photosynthetic efficiency, and significantly enriched flavone, flavonol and monoterpenoid biosynthesis. Cd-stressed tomato plants significantly decreased the survival rate of F. occidentalis nymphs and adults, with a 17.0%-31.0% reduction at 72 h post-exposure. For the natural enemy O. sauteri, Cd stress reduced its predation rate on F. occidentalis by 14.1% (24 h) and 24.3% (48 h), and decreased its oviposition by 46.4%, while no significant effects were observed on adult survival or egg hatching rate. The leaf-to-thrips bio-concentration factor was only 0.0074, while the thrips-to-predator transfer ratio reached 0.16 due to differential excretion and detoxification capacity across trophic levels. Orius sauteri exhibited no olfactory or spatial preference between Cd-treated and control leaves, but its predation rate decreased by 32.6% when feeding on Cd-exposed thrips. Trophic Cd accumulation induced sublethal physiological stress in predators, restraining their predatory activity independent of plant avoidance behavior. This study demonstrates that Cd-induced tomato metabolic reprogramming initiates multi-layer adverse effects across three trophic levels, providing quantitative evidence for evaluating ecological risks of Cd contamination in vegetable IPM systems.

Monolepta hieroglyphica (Motschulsky) (Coleoptera; Chrysomelidae) is a major agricultural pest affecting maize crops in northern and northwestern China. RNA interference (RNAi) technology offers a strategy for sustainable pest control by targeting and silencing specific genes, reducing reliance on chemical pesticides. In this study, we investigated four genes from M. hieroglyphica genome: V-type ATPase subunit A (MhVATP-A), coat protein complexes I (I' subunit (MhCOPI-(I'), cytochrome P450 reductase (MhCPR) and tyrosine decarboxylase (MhTDC) as potential RNAi targets for RNAi-mediated pest control. Through dsRNA injections in adult, we successfully achieved gene silencing in M. hieroglyphica, resulting in significantly reduced expression levels of the target genes. Silencing of MhVATP-A and MhCOPI-(I' resulted in a marked increase in mortality (60-80%), suggesting that these genes play critical roles in essential physiological functions, such as cellular PH regulation and vesicular transport. In contrast, MhCPR suppression resulted in moderate mortality (30%), indicating that while it influences detoxification processes, it may be less effective as a primary target for pest control. MhTDC silencing, involved in nervous system regulation, had no significant impact on adult insect survival, possibly due to compensatory physiological mechanisms. Overall, our findings demonstrate the potential of RNAi technology to target essential genes in M. hieroglyphica, leading to significant insect mortality. The results highlight MhVATP-A and MhCOPI-(I' as promising targets for RNAi-based transgenic maize, offering a species-specific approach for sustainable pest management in maize production. Further investigation is required to assess the effectiveness of RNAi across different development stages and environmental conditions.

Functional plants play a pivotal role in plant protection by bolstering the populations of pests’ natural enemies. When utilized as companion plants, they serve as crucial components in conservation biological control. A systematic analysis of the ecological functions of candidate companion plant species is of utmost importance for effectively attracting and sustaining natural enemies, thereby promoting biological control strategies. In this study, we comprehensively examined the impact of Cosmos bipinnata (Asteraceae) on the olfactory behavior, lifespan, and survival of Harmonia axyridis, and evaluated its function in maintaining field populations and pest control capabilities. Compared to the absence of companion plants, C. bipinnata leaves at the vegetative stage significantly attracted H. axyridis females in Y-tube olfactometer assays, while both females and males significantly avoided C. bipinnata during the flowering stage. Additionally, females lived significantly longer when offered 5 ​C. bipinnata flowers daily compared to those with no food source. Moreover, providing C. bipinnata flowers in addition to aphids (in deprivation or ad libitum) also significantly increased egg production of H. axyridis. Furthermore, in greenhouse pepper production, the introduction of C. bipinnata increased the colonization rate of H. axyridis released in the early stages, thus achieving effective pest control in the short term. In the long term, incorporating C. bipinnata helped sustain multiple developmental stages of H. axyridis populations, accelerating pest suppression and enhancing pepper yield throughout the entire production cycle.

Background:The reactivation of neurodevelopmental programs in cancer highlights parallel biological processes that occur in both normal development and brain tumors. Achieving a deeper understanding of how dysregulated developmental factors play a role in the progression of brain tumors is therefore crucial for identifying potential targets for therapeutic interventions. Single-cell RNA-sequencing (scRNA-Seq) provides an opportunity to understand how developmental programs are dysregulated and reinitiated in brain tumors at single-cell resolution. The aim of this study is to identify the developmental origins of brain tumors using scRNA-Seq data. Methods:Here, we introduce COORS (Cell Of ORigin like CellS), a computational tool trained on developmental human brain single-cell datasets that annotates "developmental-like" cell states in brain tumors. COORS leverages cell type-specific multilayer perceptron models and incorporates a developmental cell type tree that reflects hierarchical relationships and models cell type probabilities. Results:Applying COORS to various brain cancer datasets, including medulloblastoma (MB), glioma, and diffuse midline glioma (DMG), we identified developmental-like cells that represent putative cells of origin in these tumors. Our method provides both cell of origin classification and cell age regression, offering insights into the developmental cell types of tumor subgroups. COORS identified outer radial glia developmental cells within IDHWT glioma cells whereas oligodendrocyte precursor cells (OPCs) and neuronal-like cells in IDHMut. Interestingly, IDHMut subgroup cells that map to OPC show bimodal distributions that are both early and late weeks in development. Furthermore, COORS offers a valuable resource by providing novel markers linked to developmental states within MB, glioma, and DMG tumor subgroups. Conclusions:Our work adds to our cumulative understanding of brain tumor heterogeneity and helps pave the way for tailored treatment strategies.

Monolepta hieroglyphica, in view of its wide-ranging host and highly polyphagous characteristics, has become an important agricultural pest in East and Southeast Asian countries. To better understand its biology and develop control strategies, we present a high-quality chromosome-level genome assembly of M. hieroglyphica, with contig N50 of 18.62 Mb and scaffold N50 of 241.916 Mb. Using 156x Hi-C data, we anchored a total length of 2,313 Mb (91.9% of the genome) to nine chromosomes. We predicted 46,561 genes using an integrated approach. The completeness of the final reported genome and proteome were assessed by BUSCO and show high values of 99.4% and 95.2%, respectively. The high-quality chromosome-level genome assembly of M. hieroglyphica will be a useful molecular resource for the communities of both beetle and crop protection.

Combined use of eco-friendly insecticides with natural enemies is increasingly being used in pest management. In this study, the combination of eco-friendly insecticides and Orius nagaii (Yasunaga) (Hemiptera: Anthocoridae), an important predator of the thrips, in controlling Dendrothrips minowai (Priesner) (Thysanoptera: Thripidae), a major tea pest, was evaluated in both laboratories and tea plantations. Five commercial insecticides were first screened the toxicity to D. minowai, and their safety to O. nagaii. The results showed mineral oil and Metarhizium anisopliae CQMa421 were toxic against D. minowai, while diafenthiuron, mineral oil and M. anisopliae CQMa421 were relatively safe for O. nagaii. Sublethal bioassay on eggs, nymphs, and adults of O. nagaii showed that mineral oil exposure minimized hatching rate among the 5 insecticides. The adverse effects of diafenthiuron and M. anisopliae CQMa421 on the development and reproduction of O. nagaii were inferior to those of spinetoram and indoxacarb. Both spinetoram and indoxacarb displayed significant acute and sublethal effects on O. nagaii. Field trials unveiled that the combined use of O. nagaii and diafenthiuron was an effective and lasting pest control strategy against D. minowai. The results contribute to an improved D. minowai management coordinated eco-friendly insecticide with natural enemy insects.