Green agriculture represents a modern agricultural development model characterized by intrinsic requirements for ecological security, resource conservation, and environmental friendliness. Its core objective is to promote the synergistic advancement of agricultural production, ecological conservation, and industrial sustainability through reliance on sustainable, low-pollution, and high-efficiency technological systems (Liu et al., 2024). However, the long-term and intensive application of chemical pesticides has not only led to increasingly severe pest resistance issues (Rosli et al., 2024) but also posed significant challenges to the quality and safety of agricultural products. Furthermore, the residual presence of pesticides and their dispersal into the environment contribute to considerable ecological risks (Sonkar et al., 2025). The concept of green plant protection, which prioritizes ecological balance and environmental conservation (Song et al., 2020), emphasizes the scientific and rational integration of agricultural control measures without compromising the natural environment, thereby effectively enriching integrated pest management strategies (Chen and Wu, 2024). Therefore, green barrier technologies have gained considerable importance.

Plant-derived repellent and antifeedant dual-functional Barrier technology utilizes plant secondary metabolites as active ingredients (Pavela et al., 2025). By simultaneously modulating pest olfactory and gustatory systems (Akhtar and Isman, 2004), this approach establishes a synergistic "repellent + antifeedant" barrier, demonstrating advantages such as high efficacy, low toxicity, easy degradability, and environmental safety (Li et al., 2005). Previous studies have indicated that active compounds including terpenoids (Smith et al., 2018), phenylpropanoids (Durofil et al., 2021), alkaloids, and flavonoids (Wu et al., 2021; Schnarr et al., 2022) exhibit significant feeding inhibition effects on pests. These effects have been corroborated by field demonstrations in crops such as tomato (Jiao et al., 2024), citrus (Qasim et al., 2024), and maize (Wu, 2020), which reported substantial reductions in pest populations.

The widespread application of Plant-derived repellent and antifeedant dual-functional Barrier technology faces several constraints.Main challenges include the unclear identification of active components and their specific functions, insufficient understanding of the mechanisms of action and non-target ecological risks, inadequate research on formulation and delivery systems, and a lack of systematic knowledge regarding its potential for field application. Therefore, this review systematically summarizes the active components and their functions, mechanisms of action and non-target effects, formulation technologies and delivery systems, as well as the field application potential of plant-derived repellent and antifeedant dual-barrier technology. It aims to provide a theoretical foundation for establishing a novel green management system for farmland pests.

Terpenoids

Terpenoids are among the most representative functional components in Plant-derived repellent and antifeedant dual-functional Barrier technology. Their molecules are based on isoprene (C₅) units as the fundamental building blocks, which polymerize in head-to-tail or tail-to-tail arrangements to form diverse skeletons such as monoterpenes (C₁₀), sesquiterpenes (C₁₅), and diterpenes (C₂₀). This structural plasticity directly underpins their high efficacy and diverse modes of action in interfering with insect behavior. Studies indicate that the structure-activity relationships of terpenoids are primarily governed by the type of functional groups, their substitution positions, and stereochemistry (Xu et al., 2019). Terminal double bonds or epoxy structures in terpenoid molecules are critical for repellent activity. For instance, 8-hydroxy-p-menth-1-ene in citronellal can selectively bind to insect olfactory receptors (ORs), thereby significantly enhancing its biological activity (Xu et al., 2019). Azadirachtin, on the other hand, effectively suppresses feeding behavior by activating cells associated with feeding inhibition in pests, ultimately leading to an antifeedant effect (Li et al., 2005). The endo-conformation of 8-hydroxy-allodihydrocarveyl propionate exhibits significantly higher repellent activity against ants than its racemic form, reducing the repellency threshold by two to threefold. Similarly, the trans-cyclopropane configuration of nopyl acetate demonstrates superior repellent efficacy compared to its cis-isomer (Wang et al., 2009). For terpenoid compounds, achieving a balance between molecular volatility and persistence is crucial. Monoterpenes, characterized by high vapor pressure, enable rapid repellency (Abdelgaleil et al., 2019), whereas sesquiterpenes—with lower volatility and higher molecular weight—are more suitable for incorporation into sustained-release systems such as microcapsules or nanocarriers (Wang et al., 2025).

Phenylpropanoids

Phenylpropanoids represent a class of plant-derived organic compounds characterized by a C6-C3 basic skeleton. Their biosynthesis originates from the amino acids phenylalanine and tyrosine in plants, leading to various subclasses such as simple phenylpropanes, coumarins, lignans, and phenylpropanoic acid derivatives (Ramaroson et al., 2022; Vogt, 2010). The repellent and antifeedant activities of phenylpropanoids are primarily governed by their molecular structural features, with significant structure-activity relationships (SAR) identified (Chang et al., 2007). SAR studies further reveal that the number and spatial distribution of phenolic hydroxyl groups not only determine their antioxidant potential but also directly influence their binding affinity to insect receptors. For example, caffeic acid exhibits a clear inhibitory effect on aphid feeding behavior (Bonache et al., 2018; Chang et al., 2007). Research indicates that phenylpropanoid-rich essential oils from Apiaceae plants—including parsley oil, cumin oil, ligustilide, and cuminaldehyde,which generally demonstrate both repellent and antifeedant effects. Moreover, parsley oil, cumin oil, and cuminaldehyde exhibit notable acetylcholinesterase inhibitory potential, with particularly significant in vitro activity (Rosa et al., 2020). Piperonyl compounds, specifically the methylenedioxyphenyl group, represent another important active moiety widely present in various lignans and simple phenylpropanes, playing a critical role in their pest antifeedant activity (Harmatha and Dinan, 2003).

Alkaloids and Flavonoids

Alkaloids and flavonoids represent two major classes of crucial secondary metabolites produced by plants during long-term evolution. Their core skeletons consist of a nitrogen-containing C₆-C₃ unit (alkaloids) and a C₆-C₃-C₆ structure (flavonoids), respectively. Through structural variations such as substituent type, ring system rigidity, and hydrogen bond donor-acceptor distribution, these compounds can interfere at multiple physiological levels in insects—including olfactory recognition, gustatory perception, and neural signal transduction—thereby exhibiting synergistic repellent and antifeedant effects (Chowański et al., 2016; Pereira et al., 2024). In Solanaceae plants, mechanical damage caused by pest feeding rapidly induces the synthesis and accumulation of bitter-tasting alkaloids such as α-solanine and α-chaconine in potatoes, reducing palatability to deter further herbivory. Previous studies have confirmed that nicotine and capsaicin, derived from non-host plants, significantly inhibit feeding behavior in exposed insects (Chowański et al., 2016). Research dentified a specifically expressed carboxylesterase Ha006a in Helicoverpa armigera that enhances insecticide resistanceby (Kaur et al. ,2024). Additionally, both isoquinoline alkaloids and piperine were found to elicit strong antifeedant responses, with piperine also exhibiting inhibitory activity against cytochrome P450, effectively blocking Ha006a activity. Research demonstrated that quinine and quinidine effectively activate bitter-sensing neurons in pests, thereby achieving dual regulation of feeding behavior through repellency and antifeedancy(Sparks et al. ,2016). The structural diversity of flavonoids and their wide range of biological activities are attributed to chemical modifications such as methoxylation and glycosylation on their molecular scaffolds (Schnarr et al., 2022). Structure-activity relationship studies reveal that the antifeedant activity of flavonoid skeletons is regulated by multiple structural features. Specifically, hydroxylation at positions C5 and C7 on the A-ring and C3′ and C4′ on the B-ring, along with the carbonyl group at C4, are critical for enhancing activity. Against Spodoptera litura, activity depends more heavily on the C6 or C7 position of the A-ring. Furthermore, the respective positive and negative charge distributions at C3 and C5 may form the electrostatic basis for their pest antifeedant effects (Schnarr et al., 2022). Research confirmed that artificial diets treated with flavonoids such as naringenin, quercetin, and kaempferol inhibited feeding and retarded growth in S. litura larvae, and further revealed significant suppression of enzyme activities including serine protease, trypsin, and esterase in larvae fed flavonoid-treated diets(Su et al. ,2018).

Microcapsules and Sustained-Release Technology

Plant-derived repellent and antifeedant active ingredients often face challenges in field applications, such as high volatility, rapid photodegradation, and insufficient persistence, which severely restrict the stability of their control efficacy. The inadequate field stability of these bioactive components leads to rapid loss due to volatilization and photolysis after application, compromising sustained pest management and limiting their practical use in agricultural systems (Jyotsna et al., 2024). To address these stability and persistence bottlenecks, microencapsulation-sustained release technology based on natural polymeric materials has emerged as an effective solution. This technology encapsulates active ingredients and controls their release, effectively shielding them from environmental factors. Microcapsule systems constructed using natural polymers such as chitosan (CS) and sodium alginate (SA) as wall materials have shown great potential as functional pesticide formulations due to their wide availability, high environmental compatibility, biodegradability, and safety toward non-target organisms. These systems significantly enhance the field stability of plant-derived repellent and antifeedant ingredients and prolong their control duration (Meng et al., 2023; Paques et al., 2014). Microencapsulation is a technology that encapsulates solid, liquid, or gaseous active substances within a polymeric shell, forming a micron-scale core–shell structure that functions as a reservoir system with controlled release properties (Nguyen et al., 2020). In agricultural applications, this technology is particularly suitable for encapsulating easily degradable plant-derived active ingredients. Microcapsule systems based on natural polysaccharides such as chitosan and sodium alginate are favored mainly due to their excellent biocompatibility, controllable biodegradability, and abundant raw material sources (Huang et al., 2024). In practice, chitosan, with its superior film-forming ability, forms stable wall materials through techniques such as ionotropic gelation and emulsion crosslinking. Sodium alginate, on the other hand, leverages its ion-responsive characteristics to efficiently encapsulate hydrophobic active components after crosslinking with calcium ions, thereby significantly enhancing the efficacy of the bioactive ingredients (Fujita et al., 2004; Wani et al., 2023). The release of encapsulated pharmaceutical or pesticidal active ingredients from microcapsules can be triggered by environmental stimuli such as pH, humidity, and enzymatic activity, enabling on-demand release and prolonged action. This environmentally responsive release mechanism helps improve the utilization efficiency of active ingredients in the field and enhances the stability of control effects (Meng et al., 2023; Wani et al., 2023). Building on existing microcapsule systems, the incorporation of rigid polysaccharide nanoparticles such as cellulose nanocrystals can enhance the mechanical integrity and anti-permeability of the capsule wall. This significantly improves shielding against environmental stressors such as UV radiation and moisture, providing an effective strategy to mitigate issues related to photosensitivity and high volatility in plant-derived repellent and antifeedant formulations (Wani et al., 2023).

Nanoemulsions

As a cutting-edge technology in agricultural science, nanotechnology is driving innovation and transformation in strategies for plant disease and pest control, offering novel pathways to overcome the limitations of conventional pesticides in terms of utilization efficiency, residue, and resistance (Kumar et al., 2015). Nanoemulsion technology provides an innovative approach to improve the application performance of plant-derived repellent active ingredients. By constructing nanoscale droplet delivery systems, it significantly enhances the solubility and dispersion stability of active components, thereby improving their bioavailability and persistence. Compared to traditional pesticide formulations and delivery systems, nanoemulsions exhibit notable advantages in foliar deposition, rainfastness, and controlled release, helping to reduce environmental dispersion and improve targeting efficiency (Xiong et al., 2025; Gupta et al., 2024). In the development of pesticide nanoemulsions, the oil-in-water (O/W) structure has become the predominant design. This formulation demonstrates excellent loading capacity for lipophilic active ingredients due to its hydrophobic core. Its stability primarily stems from the oriented distribution of hydrophobic groups of active molecules at the oil-water interface. This arrangement not only enhances the compactness of the interfacial film but also significantly improves the drug loading efficiency and long-term stability of the system by increasing electrostatic repulsion between droplet surfaces (Mustafa and Hussein, 2020). The choice of surfactants plays a decisive role in the stability of nanoemulsions during their construction. The hydrophilic-lipophilic balance (HLB) value and ionic sensitivity have been identified as two core selection criteria, directly influencing the interfacial behavior and long-term stability of the droplets (Feng et al., 2018; Gupta et al., 2024). In the production of nanoemulsions containing natural repellents, the type of surfactant is crucial for stability. Currently, non-ionic surfactants are the most widely used, primarily maintaining droplet dispersion through steric hindrance effects. They are less susceptible to interference from environmental ionic strength, resulting in higher system stability. In contrast, although ionic surfactants can introduce a net charge at the oil-water interface and prevent droplet aggregation through electrostatic repulsion, their stability is more sensitive to electrolyte concentration in the environment and may, under specific conditions, lead to droplet flocculation or accelerated sedimentation (Gupta et al., 2024). Emulsion systems constructed based on nanotechnology possess excellent kinetic stability, effectively inhibiting droplet aggregation and Ostwald ripening. This maintains a uniform dispersion state throughout storage and application, not only facilitating direct dilution during field operations but also promoting even distribution of the formulation within the crop canopy. This effectively avoids risks of phytotoxicity and control gaps caused by uneven local concentration (Malik et al., 2019).

Delivery Systems

Although microencapsulation and nanoemulsion technologies have made considerable progress in improving the stability and sustained-release properties of botanical pesticides, further enhancing their field efficacy hinges on the development of more sophisticated and intelligent novel delivery systems. These advanced systems are crucial to overcome current bottlenecks related to inadequate environmental adaptability and insufficient longevity of efficacy in complex field conditions (Zhao et al., 2018). An ideal delivery system should not only ensure the stability of active ingredients in complex environments but also enable precise control over release kinetics and targeted transport. This dual capability significantly enhances bioavailability while minimizing the risk of environmental residue (Kah et al., 2018). With the deep integration of materials science and nanotechnology, the research focus has gradually shifted from traditional nanocarriers to stimuli-responsive systems possessing more intelligent characteristics (Shi et al., 2026). Stimuli-responsive systems can trigger the precise release of active ingredients at specific sites on plant surfaces or within plant tissues in response to dynamic changes in environmental signals such as pH, temperature, light, specific enzyme activity, or redox potential. This enables temporally precise and on-demand regulation of the pesticide application process (Kumar et al., 2019; Gupta et al., 2024). These intelligent carriers enable precise, environmentally triggered release of compounds: including temperature-sensitive systems that initiate release under heat stress, light-responsive carriers activated by specific wavelengths, and multi-responsive systems designed to leverage combined triggers for synergistic control (Meng et al., 2023; Wani et al., 2023). This intelligent release mechanism effectively enhances the deposition efficiency and action precision of pesticides at target sites, significantly reduces drift loss to non-target areas, and minimizes final residue accumulation in agricultural products (Shi et al., 2026).

Vegetable Crops

In intensive protected vegetable production systems, the stable warm and humid environment provides continuous habitat and breeding conditions for pests, leading to a significant increase in the number of generations per year and pronounced generational overlap. The prevalence of concealed feeding behaviors, such as boring and leaf-mining, further complicates pest identification and control. The long-term overreliance on chemical pesticides has induced widespread multi-drug resistance in pest populations, resulting in declining field efficacy of many conventional insecticides. Confronted with this situation, continuing to rely solely on chemical control strategies can no longer achieve the synergistic goals of effective pest suppression and agricultural ecological security (Lamichhane et al., 2015; Mallott et al., 2019). Behavioral manipulation strategies based on plant-derived natural active ingredients offer a new green pathway for the integrated management of vegetable pests. By interfering with crucial pest behaviors such as olfactory recognition, feeding choice, and oviposition site selection, these strategies enable effective regulation of pest population dynamics. Sourced from nature, easily degradable, and exhibiting minimal impact on non-target organisms, these plant-based ingredients contribute to building a green pest management technology system with high ecological safety and control efficacy (Li et al., 2025). The whiteflies is a major pest threatening the safe production of vegetables. Its propensity to develop resistance to various commonly used insecticides has increasingly challenged field control. Consequently, utilizing plant-derived repellents for green management has emerged as a potential alternative strategy. Research on tomato pest management further confirmed that nicotine-based botanical pesticides exhibit significant repellent activity against whiteflies, alongside direct toxic effects on some individuals, thereby achieving effective population regulation through a dual mechanism of "repellence and antifeedance(Kishore and Sarkar ,2021) ." A study also demonstrated that applying patchouli essential oil in greenhouse tomato cultivation induced significant repellent effects against whiteflies( Lee et al.,2019). The active components, ocimene and carvacrol, reduced pest populations by 26% and 33%, respectively, confirming the control potential and environmental adaptability of plant volatiles in practical applications. Therefore, behavioral intervention using plant-derived repellents can reduce dependency on chemical insecticides to a certain extent, providing a sustainable and effective green management pathway for integrated whitefly control in vegetable production systems.

Fruit Crops

In intensive fruit tree cultivation systems, the dense canopy and complex spatial distribution of branches and leaves significantly hinder the effective deposition and uniform coverage of pesticide droplets, posing a major constraint to chemical control efficacy. Traditional high-volume hydraulic spraying often results in substantial droplet drift and poor deposition uniformity within and across the canopy, leading to low actual pesticide utilization and suboptimal control outcomes (Hong et al., 2018). Within the current development of plant protection technologies, the control strategy leveraging the dual repellent and antifeedant functions of plant-derived active ingredients has matured considerably. By integrating sustained-release carriers and nano-delivery systems, a targeted and long-lasting ecological pest management system has been constructed (Malik et al., 2019). This technological framework combines the spatially precise release characteristics of slow-release formulations with the high permeability and strong adhesion of nanoemulsions. It maintains stable control efficacy while significantly reducing chemical pesticide application, providing a systematic technical solution for advancing the green and sustainable management of fruit tree pests.

The Asian citrus psyllid (Diaphorina citri) is one of the most damaging pests in citrus production. Both adults and nymphs harm tree growth by sucking sap from young shoots. Furthermore, as the natural vector of Citrus Huanglongbing (HLB), it facilitates the rapid spread of this devastating disease, posing a severe threat to the citrus industry (Grafton-Cardwell et al., 2013). Research confirmed that guava leaf volatiles exert significant behavioral regulatory effects on adult citrus psyllids(Zaka et al. ,2010). In olfactory preference tests, the number of adult psyllids decreased by 36.62% and 52.70% after 12 h and 24 h of exposure to the volatiles, respectively, demonstrating a clear time-dependent repellent characteristic. In a complex odor environment containing both guava leaf volatiles and citrus leaf odor, the repellent effect was significantly enhanced compared to single components. Olfactory behavioral choice assays showed that psyllids selected the arm with citrus leaf odor at rates of 38.75% and 33.75%, while the selection rates for the arm with guava leaf volatiles were only 17.50% and 13.75%, indicating that these volatiles effectively interfere with the pest's host-locating behavior. The findings suggest that active components in guava leaves may synergize with citrus volatiles, thereby enhancing the comprehensive behavioral disruption of the Asian citrus psyllid.

Integrating plant-derived repellent substances with novel delivery systems such as nanoemulsions can effectively address issues associated with traditional spraying methods, including severe droplet drift, poor deposition uniformity within the canopy, and unstable repellent effects. This integration offers a technically promising pathway for the integrated green management of fruit tree pests.

Other Crops

In intensive agricultural production systems, the unique canopy structure, micro-ecological environment, and intensive management practices place higher demands on the compatibility and effectiveness of pest and disease control technologies compared to traditional cultivation methods. In field cropping systems such as rice and wheat rotation, the dense canopy formed during the mid to late growth stages significantly impedes the effective penetration and uniform deposition of pesticide droplets. Traditional high-volume spraying technology not only results in substantial drift loss and inadequate coverage in the middle and lower canopy layers but also contributes to severe agricultural non-point source pollution (Xue et al., 2021; Hilz and Vermeer, 2013). Consequently, the threat posed by invasive alien pests has become increasingly prominent, with the fall armyworm (Spodoptera frugiperda) emerging as a significant new risk to crop production security. Native to tropical and subtropical regions of the Americas, the fall armyworm is characterized by its wide host range, high reproductive capacity, and rapid dispersal. Having spread to multiple major maize-producing regions domestically, it has caused substantial yield losses in maize and other crops (Palli et al., 2023; Abd-Elnabi et al., 2025). In field trials evaluating turmeric rhizome extract (TRE), neem leaf ash solution (NLAS), and neem bark extract (NBE) against the fall armyworm in maize, the NBE treatment resulted in the lowest larval population count at 33 days after sowing (Sogra et al., 2023).Integrating plant-derived active ingredients, such as neem bark extract, with conventional application technologies can significantly enhance field control efficacy against the fall armyworm. Furthermore, combining these botanical active ingredients with advanced delivery systems has been confirmed to substantially improve control effectiveness against field crop pests. This approach also effectively addresses the issue of chemical resistance developed by the fall armyworm, providing crucial technical support for sustainable agricultural pest management (Sogra et al., 2023; Wu, 2020).

This review synthesizes the research progress in plant-derived repellent and antifeedant dual-barrier technology, encompassing the entire system from the screening of active ingredients and elucidation of mechanisms of action to the development of formulations and field application. Studies have demonstrated that plant-derived active substances, represented by terpenoids, phenylpropanoids, alkaloids, and flavonoids, can effectively establish a dual behavioral barrier of "repellence and antifeedance" by specifically modulating insect olfactory and gustatory receptors, thereby significantly impeding pest damage (Qian et al., 2024). The innovation and application of novel delivery systems, such as microcapsules, nanoemulsions, and biodegradable fiber films, provide crucial technological support for overcoming bottlenecks like poor stability and short persistence of plant-derived active ingredients (Meng et al., 2023; Paques et al., 2014; Xiong et al., 2025). In the integrated pest management of crops like tomato and citrus, this technology has achieved control levels comparable to conventional chemical pesticides while demonstrating favorable non-target organism safety (Zhao et al., 2022).

At the theoretical level, this study elucidates the regulatory mechanisms of plant-derived active ingredients on pest behavior from multiple perspectives, deepening the understanding of the synergistic work via the "olfactory-gustatory" dual pathways (Simmonds, 2001; Weiss et al., 2011). At the practical level, plant-derived repellent and antifeedant dual-barrier technology provides a feasible green technological pathway to collaboratively address industry challenges such as increasing pest resistance, high dependency on chemical pesticides, and significant environmental pollution risks, holding positive implications for advancing agricultural sustainability and ensuring agricultural product quality and safety.

However, the large-scale adoption of this technology still faces a series of practical challenges. The supply of plant-derived active components is insufficient, and their large-scale preparation is constrained by both the stability of raw material supply and the energy costs of purification processes. In the realm of formulation development, existing delivery systems still encounter bottlenecks such as high production costs and insufficient intelligent responsive release capability in complex field environments (Xiong et al., 2025; Wang et al., 2022). Genetic diversity in target receptors within field pest populations can lead to differences in individual sensitivity, necessitating the integration of omics analyses, electrophysiological techniques, and field observation data to build a precise resistance risk assessment system (Koul, 2024).

Future research should focus on three core directions. First, applying synthetic biology and plant factory technologies to establish efficient biosynthetic pathways for crucial active ingredients, achieving their low-cost, large-scale, and sustainable production. Second, developing intelligent delivery systems with continuous production capabilities, integrating artificial intelligence and Internet of Things technologies to construct a framework for real-time pest/disease monitoring and environment-responsive precise release. Third, establishing a comprehensive policy framework including residue limit standards, organic certification protocols, carbon footprint accounting, and traceability mechanisms to provide systematic institutional support for the large-scale promotion and application of the technology. Therefore, by integrating multidisciplinary technological systems and advanced delivery systems, plant-derived repellent and antifeedant dual-barrier technology demonstrates broad application prospects in the field of green crop protection. This technology not only provides a viable path for reducing chemical pesticide use but also offers crucial technological support for driving the green transformation of agriculture.

This review systematically elaborates on the development of plant-derived repellent and antifeedant dual-barrier technology, covering advancements from active ingredient screening and mechanism elucidation to formulation innovation and field application. Studies have demonstrated that plant-derived active compounds including terpenoids, phenylpropanoids, alkaloids, and flavonoids can specifically target insect olfactory and gustatory receptors, establishing an effective dual behavioral barrier that integrates repellency with antifeedant activity. Through the introduction of novel delivery systems such as microcapsules and nanoemulsions, the stability and persistence of these active ingredients have been significantly improved. Field applications in a variety of crops, including tomato, citrus, and maize, have shown control efficacy comparable to that of conventional chemical pesticides, while also exhibiting excellent environmental compatibility and non-target organism safety. Although challenges remain in scaling up the production of active ingredients, controlling formulation costs, and enhancing field-level intelligent responsiveness, the future integration of cutting-edge technologies—such as synthetic biology, smart materials, and digital agriculture—is expected to enable the establishment of a highly efficient and cost-effective green pest management system.