Search Results (192)

Endosymbiotic bacteria in insects are known to influence plant–insect interactions by altering host plant physiology. This study reveals that the endosymbiont Wolbachia significantly impairs photosynthesis in cotton plants. Comparative transcriptomic analysis of cotton leaves infested by Wolbachia-infected spider mites (Tt-I) and uninfected spider mites (Tt-UI) identified 1912 differentially expressed genes (DEGs). Photosynthesis was the most adversely affected biological process, with 17 genes downregulated in the photosynthesis pathway (e.g., key genes psbW and PETF), as supported by GO and KEGG enrichment analyses. Gene co-expression network analysis further highlighted core genes involved in photosynthesis disruption and carbon fixation. Physiological assessments showed that Wolbachia infection led to significantly reduced chlorophyll content and elevated reactive oxygen species (ROS) levels, inducing oxidative stress. These findings demonstrate that Wolbachia disrupts cotton photosynthesis through transcriptional repression and ROS-mediated oxidative stress, providing novel insights into plant–insect-symbiont interactions and a theoretical basis for managing mite pests in cotton. Full article

This paper presents the application of ozone for pest control in large-scale systems, with the potential for industrial implementation. The designed ozone generation system is capable of producing an ozone concentration of 550 ppm within 30 min in a controlled chamber. Ozone technology was applied for the control of insect pests in the orchid export industry, both for current use and future applications. A high-concentration ozone generator was designed to operate at temperatures ranging from 30 to 35 degrees Celsius. The total operating time of the system was 90 min, with a power consumption of 2647 watts. Experimental results indicated that the orchids were not adversely affected by the ozone exposure and that no chemical residues remained after treatment. Furthermore, the research evaluated the effectiveness of ozone fumigation against common orchid pests, namely aphids and red spider mites. When exposed to ozone concentrations ranging from 550 to 650 ppm for 60 min, the system achieved a 100% pest elimination rate for both species. These findings suggest that ozone treatment is a promising alternative to chemical pesticides for pest control in the orchid industry. Full article

Spider mites (Oligonychus trichardti) are emerging as a major constraint to Urochloa forage productivity in East Africa; however, knowledge of genotypic variation and tolerance remains limited. Herein, 55 Urochloa genotypes were evaluated under field-infested and non-infested conditions across two seasons using an alpha-lattice design. Agronomic and physiological traits, including plant height (PH), tiller number (TN), the Normalized Difference Vegetation Index (NDVI), total dry weight (TDW), and mite damage indices (visual severity index (VSI) and stress tolerance index (STI)) were assessed. Infestation reduced biomass by 22.4% on average, with reductions of up to 45% in susceptible genotypes. Significant genotypic variation was detected for PH, TN, TDW, and VSI. Heritability estimates under mite infestation were moderate to high for all traits except TDW, suggesting that direct selection of these traits could be effective in breeding programs aimed at improving mite resistance. VSI showed a strong negative correlation with NDVI (r = −0.63), supporting its value as a phenotyping indicator of spider mite response. Additive main effects and multiplicative interaction (AMMI) analysis revealed significant genotype × environment interactions for TDW. The AMMI biplot identified Xaraes, ILRI_13369, and ILRI_14787 as high-yielding and stable genotypes, while the AMMI Stability Value (ASV) and the Weighted Average of Absolute Scores from the Best Linear Unbiased Prediction (WAASB) identified CIAT_16122, CIAT_664, ILRI_14801, ILRI_14787, and ILRI_13266 as the most stable and broadly adapted across environments. STI further highlighted ILRI_13751 (2.71) and ILRI_13531 (2.58) as highly tolerant under stress. Overall, the study reveals substantial exploitable genetic diversity and identifies stable, high-yielding, and mite-tolerant genotypes suitable for breeding to improve Urochloa productivity in East Africa. Full article

The two-spotted spider mite, Tetranychus urticae Koch, is a major agricultural pest that causes economic losses in the cultivation of most crops worldwide. Pesticide resistance and the phase-out of many active pesticidal substances have accelerated research into alternative methods for pest management. The effects of light-emitting diodes (LEDs) on plants, as well as their potential use in pest management, have attracted the attention of researchers for the last 25 years. In this study, the repellent effects of UV-A, blue, and red LEDs on T. urticae were investigated using choice tests in laboratory conditions. The lethal effect of red LED light on adult individuals was determined by a no-choice test. Importantly, red LED caused 67.0 ± 4.5% (mean ± SE) mortality in adults in the no-choice test. Second, the UV-A LED clearly had a strong repellent effect on T. urticae in the choice tests. In the “UV-A vs. white LED” and “UV-A vs. darkness” choice tests, the egg-laying percentage in the UV-A part remained below 0.55%. Furthermore, UV-A also had a significant repellent effect on T. urticae larvae. In the choice tests, the larval ratio in the UV-A part was less than 5%. The results of laboratory experiments indicated that red and UV-A LEDs have significant lethal and repellent effects on T. urticae. Comprehensive investigations should be performed in greenhouses using different strategies to optimize how these potential effects can be used in pest management. Full article

The two-spotted spider mite, Tetranychus urticae Koch, is a major arthropod pest that causes substantial economic losses in strawberry and other crops worldwide. Its management often relies on intensive acaricide applications, which may negatively affect human health, the environment, and beneficial organisms. Biological control using predatory mites has been widely adopted under greenhouse conditions, and its success is influenced by several factors, particularly temperature, T. urticae population density, and predator release methods. During the 2023–2024 season, this study evaluated the effects of ambient greenhouse temperature on the population dynamics of T. urticae and on the efficacy of two phytoseiid predators, Phytoseiulus persimilis (Athias-Henriot) and Amblyseius swirskii (Athias-Henriot). The predators were released individually and in combination on strawberry plants. The efficacy of single and combined releases was assessed under three temperature ranges: 25–27 °C, 28–30 °C, and 30–32 °C. The results showed that the mean number of motile T. urticae per plant increased from 21.7 to 95.66, while the mean number per leaf increased from 2.33 to 6.05 during the experimental period. The mean greenhouse temperature ranged from 23.83 °C to 31.88 °C. Temperature was strongly and positively correlated with T. urticae population density, with higher temperatures generally accelerating development and population growth. Both predator species, whether released individually or in combination, significantly reduced T. urticae populations compared with untreated control plants. Amblyseius swirskii demonstrated greater efficacy than P. persimilis at temperatures above 28 °C. However, the combined release consistently achieved the highest level of mite suppression across all temperature ranges. Significantly greater population reduction was observed at approximately 25–26 °C compared with single-species releases, while maximum effectiveness occurred at temperatures above 28 °C. These findings indicate that the combined use of P. persimilis and A. swirskii represents an effective biological control strategy for managing T. urticae in greenhouse-grown strawberries, particularly under elevated and fluctuating temperature conditions. Full article

Hemp (Cannabis sativa L.) is an important crop, yet little is known about how herbivory and soil microbial communities interact to influence plant performance. In this study, two hemp cultivars, BaOx and Cherry Citrus, were grown under identical greenhouse conditions and exposed to naturally occurring background populations of the two-spotted spider mite (Tetranychus urticae). Plant traits were measured, and rhizosphere soil was sampled for 16S rRNA gene sequencing to compare bacterial community composition and diversity between cultivars. Spider mite injury was assessed using a standardized 0–5 visual damage scale commonly applied in integrated pest management studies. Although the cultivars did not differ significantly in growth traits, Cherry Citrus experienced significantly less spider mite damage than BaOx, suggesting greater tolerance or resistance to herbivory under shared conditions. Rhizosphere bacterial communities differed markedly between cultivars despite identical soil and environmental conditions. BaOx rhizospheres were enriched in Actinobacteria, including taxa associated with decomposition and antimicrobial compound production, whereas Cherry Citrus rhizospheres were enriched in Alphaproteobacteria, particularly nitrogen-cycling and root-associated taxa such as Rhizobium and Reyranella. Alpha diversity metrics did not differ between cultivars; however, beta diversity analyses revealed significant cultivar-level separation, particularly in phylogenetic community structure. Because herbivore pressure and microbial communities were not experimentally manipulated, this observational study identifies ecological associations rather than direct causal relationships. Nevertheless, the results demonstrate that hemp cultivar identity is associated with distinct rhizosphere microbiomes and differential susceptibility to spider mite damage. These findings highlight the potential for integrating cultivar selection and microbiome-informed strategies into sustainable pest management programs for hemp. Full article

Carbon nanotubes (CNTs) show strong potential for improving crop productivity and stress resilience, but their direct effects on agricultural pests require careful evaluation. Here, we assessed single-walled CNTs (SWCNTs) on the spider mite Tetranychus turkestani (Acari: Tetranychidae) using an age-stage, two-sex life table. Leaf disks treated with SWCNTs (0.004, 0.04, 0.2, 0.4 mg/mL) were used to measure development, survival, and reproduction. SWCNT exposure significantly prolonged pre-adult development and reduced female fecundity in a concentration-dependent manner. Population parameters (r, λ) declined significantly in treated groups, while mean generation time (T) increased with concentration. At 0.4 mg/mL, fecundity dropped to 40.57 ± 2.42 offspring per female and population projection was lowest. Overall, SWCNTs inhibited mite development and reproduction in a concentration-dependent manner, providing a demographic basis for ecological risk assessment and suggesting potential utility as a tool or carrier system for integrated spider mite management. Full article

In complex agricultural production environments, small-target pests—characterized by tiny scales, strong background confusion, and close dependence on environmental conditions—pose major challenges to precise monitoring and green pest control. To facilitate the transition from experience-driven to data-driven pest management, a multi-scale vision–sensor collaborative recognition method is proposed for field and protected agriculture scenarios to improve the accuracy and stability of small-target pest recognition under complex conditions. The method jointly models multi-scale visual representations and pest ecological mechanisms: a multi-scale visual feature module enhances fine-grained texture and morphological cues of small targets in deep networks, alleviating feature sparsity and scale mismatch, while environmental sensor data, including temperature, humidity, and illumination, are introduced as priors to modulate visual features and explicitly incorporate ecological constraints into the discrimination process. Stable multimodal fusion and pest category prediction are then achieved through a vision–sensor collaborative discrimination module. Experiments on a multimodal dataset collected from real farmland and greenhouse environments in Linhe District, Bayannur City, Inner Mongolia, demonstrate that the proposed method achieves approximately 93.1% accuracy, 92.0% precision, 91.2% recall, and a 91.6% $F_1$-score on the test set, significantly outperforming traditional machine learning approaches, single-scale deep learning models, and multi-scale vision baselines without environmental priors. Category-level evaluations show balanced performance across multiple small-target pests, including aphids, thrips, whiteflies, leafhoppers, spider mites, and leaf beetles, while ablation studies confirm the critical contributions of multi-scale visual modeling, environmental prior modulation, and vision–sensor collaborative discrimination. Full article

Tetranychus merganser Boudreaux (Acari: Tetranychidae) is a significant pest of papaya (Carica papaya L.) crops. The behavior of female spider mites is altered by interaction with males. However, the cost of this interaction between male and female T. merganser has not been studied. This study aimed to determine the effect of mating on the survival, longevity, and daily oviposition of female T. merganser on five plant species. By comparing virgin and mated females, we tested the hypothesis that mating with a male affects female behavior, leading to greater survival and daily oviposition in virgin females than in mated females. The survival over the entire adult lifespan of mated females was lower than that of virgin females. The mean number of eggs laid by mated females was also lower compared to virgin females. Additionally, mated females initiated oviposition earlier than virgin females, which may suggest male-induced stress or harassment. Full article

Banker plants are non-crop plants that sustain populations of biological control agents prior to pest outbreaks, offering a preventive strategy within integrated pest management (IPM). Their benefits have primarily been attributed to top-down regulation via natural enemy-mediated pest suppression; however, their potential bottom-up effects remain largely unexplored. Here, we show that airborne cues emitted from banker plants infested with the zoophytophagous mirid bug Nesidiocoris tenuis altered the performance of the two-spotted spider mite Tetranychus urticae on neighboring tomato plants Solanum lycopersicum. Exposure to airborne cues from infested sesame Sesamum indicum significantly reduced mite fecundity, whereas those from tomato and spider flower Cleome hassleriana had no detectable effect, indicating that the induction of crop resistance is dependent on banker plant species. Moreover, T. urticae infestation of banker plants consistently suppressed mite oviposition on neighboring tomato plants across all banker plant species tested. These findings suggest that banker plants can exert previously unrecognized bottom-up effects by modulating crop resistance-related responses through airborne cues. Therefore, selecting banker plant species that emit effective airborne cues may strengthen crop protection and stabilize biological control performance in sustainable IPM strategies. Full article

Banana (Musa spp.) is an economically important crop whose relevance is steadily increasing in greenhouse-based production systems. This study aimed to determine pest and natural enemy species, and pest population densities in greenhouse banana fields in the Western Mediterranean Region of Türkiye. Periodic studies were conducted every 15 days in 2.4 hectares for two consecutive years (2022–2023), while nonperiodic studies covered 128.9 hectares. Species were collected through visual inspection, sticky traps, and plant sampling. Seventeen pest species from four orders and eight families were recorded: Frankliniella intonsa (Trybom 1895), Thrips hawaiiensis (Morgan), Thrips tabaci Lindeman Hercinothrips femoralis (Reuter), Pentalonia nigronervosa Coquerel, Rhopalosiphum maidis (Fitch), Brachycaudus helichrysi (Kaltenbach), Tetranychus turkestani Ugarov & Nycolsky, Tetranychus urticae Koch, Spodoptera littoralis (Boisduval), Bemisia tabaci (Gennadius), Aleyrodes sp., Planococcus citri (Risso), Dysmicoccus brevipes (Cockerell), Ceroplastes rusci (L.), Coccus hesperidum L., and Chrysomphalus aonidum (L.). Twenty-two natural enemies from six orders and thirteen families were identified. This study also provides the first Turkish records of parasitoid Coccophagus shillongensis Hayat and Singh from C. hesperidum and Encarsia aurantii (Howard) from C. aonidum. The data showed that spider mites were the most abundant pests, while phytoseiid mites were their most abundant natural enemies. This study represents an important contribution to the scarce literature on insect and mite fauna associated with banana greenhouses in the Western Mediterranean Region. The findings are expected to contribute to the development of effective and sustainable pest management strategies for greenhouse banana production. Full article

Cotton spider mites pose a significant threat to cotton production, while traditional manual investigation and blanket pesticide application are inefficient for precision pest management in large-scale cotton fields. To address this challenge, this study developed an integrated UAV multispectral remote sensing system for spider mite monitoring and precision spraying. Multispectral imagery was acquired from cotton fields in Shaya County, Xinjiang using UAV-mounted cameras, and vegetation indices including RDVI, MSAVI, SAVI, and OSAVI were selected through feature optimization. Comparative evaluation of three machine learning models (Logistic Regression, Random Forest, and Support Vector Machine) and two deep learning models (1D-CNN and MobileNetV2) was conducted. Considering classification performance and computational efficiency for real-time UAV deployment, Random Forest was identified as optimal, achieving 85.47% accuracy, an 85.24% F1-score, and an AUC of 0.912. The model generated centimeter-level spatial distribution maps for precise spray zone delineation. An improved NSGA-III multi-objective path optimization algorithm was proposed, incorporating PCA-based heuristic initialization, differential evolution operators, and co-evolutionary dual population strategies to optimize deadheading distance, energy consumption, operation time, turning frequency, and load balancing. Ablation study validated the effectiveness of each component, with the fully improved algorithm reducing IGD by 59.94% and increasing HV by 5.90% compared to standard NSGA-III. Field validation showed 98.5% coverage of infested areas with only 3.6% path repetition, effectively minimizing pesticide waste and phytotoxicity risks. This study established a complete technical pipeline from monitoring to application, providing a valuable reference for precision pest control in large-scale cotton production systems. The framework demonstrated robust performance across multiple field sites, though its generalization is currently limited to one geographic region and growth stage. Future work will extend its application to additional cotton varieties, growth stages, and geographic regions. Full article

Tagetes patula is a widely cultivated ornamental plant and a natural source of bioactive compounds. This study evaluated the effects of cultivation–substrate systems on growth, flowering, lutein and zeaxanthin accumulation, substrate microbiological properties, and pest and disease occurrence in three T. patula cultivars (‘Csemő’, ‘Robusta kénsárga’, and ‘Orion’) grown under two greenhouse (peat-based substrate and hydroponics) and three field conditions (peat-based and two peat-free substrates). Greenhouse hydroponics markedly enhanced vegetative growth, resulting in the highest plant height, stem diameter, and shoot biomass, whereas peat-based greenhouse substrates produced the lowest vegetative performance. Flowering responses were more moderate and largely cultivar-dependent: peat-based field conditions supported the highest inflorescence numbers, cv. ‘Orion’ produced the greatest inflorescence biomass, and cv. ‘Robuszta kénsárga’ showed the strongest flowering intensity in peat-based systems. Cultivar ‘Csemő’ consistently accumulated the highest lutein and zeaxanthin concentrations among cultivars. Substrate moisture and microbial activity differed substantially among systems, with peat-free substrates frequently exhibiting elevated enzymatic activity. No fungal diseases were detected; thrips occurred only in greenhouse systems, and spider mites were restricted to cv. ‘Orion’ under hydroponic conditions. Overall, hydroponic and peat-free systems enhanced vegetative growth and microbial activity, whereas flowering and carotenoid accumulation were primarily cultivar-specific, as further supported by correlation analysis and PCA. These findings demonstrate that sustainable peat alternatives and hydroponic systems can effectively support high-quality T. patula production and carotenoid yield. Full article

Species sharing the same trophic level can interact not only through competition for resources but also through intraguild predation (IGP). Therefore, an important step toward implementing successful multiple predator releases in biological control strategies requires resolving how predators respond to the presence of heterogeneous competitors. This study examined the compatibility of two predatory mites, N. californicus and P. persimilis, which are both widely employed to suppress two-spotted spider mite populations in greenhouses and open fields. The experiments quantified the frequency and intensity of IGP across different developmental stages of these species on bean leaves, considering scenarios both with and without their shared prey being present. Additionally, a Y-tube olfactometer was employed to assess whether either predator avoided prey patches previously occupied by other heterospecifics, thereby providing insights into potential chemical cues that influence predator behavior. The results revealed that adult females of both predatory mite species predominantly targeted heterospecific eggs and larvae, whereas adults were largely avoided. In the absence of shared prey, N. californicus attacked 83% of the P. persimilis larvae and 37% of the eggs, whereas P. persimilis consumed 67% of the N. californicus eggs. The presence of shared prey reduced IGP risk by approximately 60%. Olfactometer assays revealed no significant avoidance of plants inhabited by heterospecifics at densities of 20 or 40 adults; both predators were similarly attracted to herbivore-induced volatiles. Generalized linear models indicated that host plant experience had a significant influence on the foraging response of N. californicus, whereas the effects of the feeding state weakened over time. Understanding predator foraging plasticity and responsiveness to chemical cues can help optimize biological control strategies in complex agroecosystems. Full article

The increasing resistance of agricultural pests to conventional pesticides necessitates the development of alternative biological control strategies. This study evaluated the acaricidal potential of two Photorhabdus luminescens strains (0805-P2R and the newly isolated 2103-RUVI) against the spider mite Tetranychus truncatus. Culture conditions were optimized using a Taguchi L9(3⁴) design to maximize growth, protease activity, and acaricidal efficacy. The optimized medium for strain 2103-RUVI achieved 90% mortality against T. truncatus at 72 h, compared to 83% for strain 0805-P2R under equivalent conditions. Genomic analysis identified putative phosphoporin PhoE genes exclusively in 2103-RUVI, which may contribute to its enhanced virulence, although this association remains correlative and requires functional validation. Histopathological observations confirmed severe tissue disruption in treated mites. Comparative analysis demonstrated complex, strain-specific relationships among bacterial growth, enzyme activity, and acaricidal effects. These results highlight the potential of the P. luminescens strain 2103-RUVI as an effective biocontrol agent, providing insights for its application in sustainable integrated pest management programs. Full article