Herbaspirillum seropedicae strain HS09, previously isolated from commercial rice (Oryza sativa) and identified by molecular analysis, has shown biocontrol potential against Burkholderia glumae under greenhouse conditions. However, the molecular mechanisms by which HS09 induces systemic resistance against B. glumae in rice remain poorly understood. In this study, we investigated the molecular basis of plant growth-promoting bacteria-mediated systemic resistance against B. glumae in rice through transcriptomic analysis. Four treatments were evaluated: an untreated control, a treatment inoculated with the endophyte HS09, a treatment inoculated with the pathogen B. glumae, and an inducer treatment consisting of HS09 inoculation followed by B. glumae challenge. For the experiment, 90 seeds were used per treatment and randomly distributed under controlled greenhouse conditions. The results showed that HS09 activates key defense-related signaling pathways, particularly those mediated by jasmonic acid (JAMyb and MYC2) and ethylene (EIN3, EILs, and ERF transcription factors). In addition, Rboh and CaMCML, genes associated with calcium-dependent signaling and the hypersensitive response (HR), were upregulated, indicating the involvement of Ca²⁺-mediated defense activation. Enrichment analyses also revealed induction of the phenylpropanoid biosynthesis pathway, promoting the production of antimicrobial secondary metabolites such as isoflavones. Notably, 404 differentially expressed genes were uniquely identified in the inducer treatment, supporting the role of HS09 in priming multiple molecular pathways involved in pathogen defense. These findings highlight the potential of H. seropedicae HS09 as a sustainable biocontrol agent against B. glumae and support its integration into crop protection programs and policies aimed at reducing dependence on chemical pesticides and promoting environmentally friendly disease management strategies in rice production systems.
The fall armyworm (Spodoptera frugiperda), a highly invasive and destructive pest of maize, poses serious challenges to sustainable crop protection due to its rapid spread and widespread resistance to chemical insecticides. In this study, we evaluated the insecticidal and sublethal effects of two indigenous entomopathogenic bacterial symbionts, Xenorhabdus indica UASD_BidS and Photorhabdus luminescens UASD_KaH, isolated from Steinernema spp. and Heterorhabditis spp., respectively. Molecular identification based on 16 S rRNA sequencing confirmed the taxonomic placement of both isolates. Bioassays against third-instar S. frugiperda larvae revealed strong concentration-dependent mortality, with cell-free supernatants (CFS) consistently outperforming cell suspensions (CS). While both bacteria caused significant lethal effects at higher concentrations, P. luminescens exhibited greater potency, inducing faster mortality and stronger feeding deterrence. At sublethal concentrations, both bacteria significantly reduced larval feeding, larval weight and pupal mass, cuasing severe developmental abnormalities in emerging adults. Notably, extracellular metabolites mediated pronounced growth inhibition and feeding suppression even in the absence of immediate mortality. Comparative analysis demonstrated that P. luminescens exerted stronger sublethal effects than X. indica, particularly on larval growth and pupal development. These findings highlight the critical role of secreted bacterial metabolites in disrupting insect physiology and development. Overall, the study underscores the strong potential of X. indica and P. luminescens, especially their extracellular metabolites, as eco-friendly biocontrol agents for inclusion in integrated management strategies against fall armyworm.
Citrus fruits in Tunisia face significant challenges, including fungal diseases, pests, and climate stress, impacting yield and quality. This study is the first that focuses on profiling the fungal secondary metabolites and mycotoxins occurrence in two Tunisian orange varieties, navel and clementine. Therefore, contaminated navel (n = 20), and clementine (n = 20) and intact navel (n = 15), and clementine (n = 15) from 10 orchards in Tunisia were collected. The UPLC-ESI-MS-TOF analysis of the peel and juice of these samples identified 348 fungal secondary metabolites, with predominance of polyketides (55.59
Sugarcane is one of the world’s most important industrial crops. However, its productivity is severely threatened by the crown mealybug (CMB), Phenacoccus saccharifolii, and Pokkah boeng disease caused by a Fusarium species complex, leading to crown rot, leaf drying, substantial economic losses, and significant yield loss. CMB remains difficult to manage due to its hidden feeding habit in the crown region and a thick wax layer that protects it from pesticides and natural enemies, allowing it to persist year-round. This study investigated the morphological, biochemical, and molecular characteristics of P. saccharifolii and its fungal association to better understand its ecological associations and adaptive traits. Microscopic observations revealed that the insect possesses a soft, segmented body with piercing–sucking mouthparts and abundant wax pores that support protection and efficient feeding. Gas Chromatography–Mass Spectrometry (GC–MS) and Fourier Transform Infrared Spectroscopy (FTIR) analyses of the CMB wax showed the presence of hydrocarbons, alcohols, esters, and ketones, which are known in other systems to contribute to waterproofing and antimicrobial defence, although direct functional testing was not performed here. In addition, two Fusarium-derived mycotoxins were detected in trace amounts in the CMB wax matrix, representing, to our knowledge, the first report of these fungal metabolites associated with insect wax and providing biochemical evidence of active fungal interaction. The detection of mycotoxins in the CMB wax matrix was further supported by the isolation of two fungal species, F. verticillioides and F. equiseti, through morphological and molecular analysis. These findings characterize the CMB wax microenvironment as a structural and biochemical interface that can support fungal persistence. They also provide a mechanistic basis for future quantitative tests of how wax traits and fungal associations affect pesticide delivery and biological control efficacy in sugarcane.
The root-lesion nematode Pratylenchus thornei Sher Allen, 1953 is one of the major constraints limiting wheat production and productivity in many wheat-growing regions worldwide. However, information on its occurrence and pathogenicity in Ethiopia remains limited. In this study, root-lesion nematodes extracted from soil and infected root samples collected from wheat fields in the East and West Arsi zones were identified as P. thornei, representing the first report of this species infecting bread wheat in Ethiopia. Species identification was confirmed through morphological examination using light microscopy and molecular characterization based on partial 18 S (SSU) rDNA sequences. Greenhouse pathogenicity assays showed that the wheat varieties Abay and Biqa are suitable hosts, with nematode reproduction factors > 4. These findings provide the first confirmed report of the occurrence and pathogenic potential of P. thornei in Ethiopian wheat production systems and indicate the need for further studies on its distribution, impact, and management.
Lepidopteran pests of the genus Spodoptera, particularly the invasive fall armyworm (Spodoptera frugiperda), threaten global food security, and rising resistance to synthetic insecticides has intensified the need for sustainable biocontrol. Entomopathogenic fungi (EPF) are promising candidates for integrated pest management. We conducted a systematic review of 63 studies and a multilevel mixed-effects meta-analysis of 44 studies (52 experimental arms), using median lethal concentration (LC₅₀) as the primary outcome. The review revealed a shift from localized management of endemic pests (S. litura, S. littoralis) toward a worldwide focus on S. frugiperda, with bioprospecting relying mainly on generalist soil fungi (Beauveria bassiana, Metarhizium anisopliae) and the specialist Metarhizium rileyi. The meta-analysis showed substantial heterogeneity (I² = 96.8
The maize weevil (Sitophilus zeamais Motschulsky, 1885) and the red flour beetle (Tribolium castaneum Herbst, 1797) are among the most economically significant coleopteran pests affecting stored products worldwide. Their infestations result in substantial quantitative and qualitative losses due to grain damage by both larvae and adults. Conventional control strategies rely heavily on chemical insecticides, which pose risks of environmental contamination and contribute to the development of resistant pest populations. As a sustainable alternative, entomopathogenic nematodes (EPN) offer potential for the biological control of insects in cryptic habitats. This study aimed to evaluate the pathogenicity and virulence of eight Brazilian EPN isolates, six from the genus Heterorhabditis and two from Steinernema, against adults of S. zeamais and T. castaneum under laboratory conditions. In addition, S. carpocapsae and H. bacteriophora were included as positive controls. All EPN demonstrated pathogenicity against both pest species, with Steinernema carpocapsae, Steinernema sp. CER21, S. brazilense, and Heterorhabditis amazonensis MC01 showing mortality rates above 25
The control of insect pests in stored grains carried out through insecticides that may select resistant populations and generate environmental risks. Secondary plant compounds are alternatives to control insect pests. However, the high volatility has been an obstacle in their practical use. This study develops natural dispersants for the application of Mentha piperita essential oil for the control of Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae). Two types of dispersants were tested: a gypsum-based dispersant prepared with a mixture of gypsum and water molded in aluminum, and a sachet dispersant composed of polyester sachets. The efficiency of the dispersants was assessed by contact, fumigation and repellency tests. For that, unsexed S. zeamais up to 15 days old were used and evaluated after 48 h of experiment assembly. The persistence effects of the essential oil in dispersants were also evaluated. The fumigation test with essential oil in the sachet and gypsum dispersants generated, respectively, LC50 values of 23.78 and 34.32 and LC99 values of 54.27 and 79.28 μL. For the contact test, the sachet dispersant presented sublethal and lethal concentrations of LC50 25.84 and LC99 48.40 μL, respectively. However, only the 26 μL concentration was repellent for both dispersants. The repellent and fumigant effects of the sachet lasted for 15 and 24 days, while These effects observed with gypsum-based dispersants lasted 21 and 30 days, respectively. Both dispersants were considered promising due to their ability to retain and gradually release the bioactive compounds present in Mentha piperita L. essential oil, thereby enhancing fumigant and repellent effects against Sitophilus zeamais Motschulsky, 1855 (Coleoptera: Curculionidae). These results indicate that gypsum is a potential carrier material for improving the residual activity and efficacy of botanical insecticides in stored grain protection systems.
Septoria tritici blotch (STB) of winter wheat continues to be amongst the most economically impactful diseases of winter wheat across Europe. The application of fungicides, particularly the azole fungicides is relied upon as a key management strategy. Unfortunately, the development of azole resistance in Zymoseptoria tritici populations is increasing and poses a significant threat to our future ability to control STB. Overexpression of CYP51 is a contributing factor to this increasing resistance. Caused by a 120 bp in the CYP51 promoter region CYP51 overexpression was first identified in Z. tritici populations over a decade ago. At this time, it was associated with a specific CYP51 haplotype, however in more recent years it has been observed in multiple CYP51 haplotypes, including those highly evolved. In this study we developed a ddPCR to accurately detect the insert in individual isolates and to quantify in field populations. We demonstrate its specificity and sensitivity, and by applying the assay to field population from 2012 onwards we reveal how the Irish Z. tritici population has changed, with high variability in its frequency originally observed in the mid-2010 replaced by a relatively stable frequency at approximately 5
Meloidogyne javanica as a severe soil-borne pathogen, causes great damage to several crops, leading to huge economic losses annually. Bacillus strains produce a broad spectrum of metabolites with different mode of action against Meloidogyne spp. In the current study the volatile organic compounds (VOCs) and non-VOCs of native Bacillus spp. exhibited considerable antagonistic activity against M. javanica infecting cucumber. In vitro assays identified two highly effective isolates including B. cereus Ba2 and B. pumilus ToIr-MA. Their fermentation broths resulted in ≥ 93.6
In Spain, the avocado crop is mainly located in Andalusia. However, there is also great interest in the north of the country as its climate is favourable in terms of the high water demands of this species. In 2021, damage on avocado twigs was observed in a greenhouse located in Carbayín (Principality of Asturias). The damaged tissues were blackish-brown in colour, with cracking and loss of tissue. Two isolates (LPPAF-996 and LPPAF-997) were recovered from twig samples and identified as Colletotrichum gloeosporioides species complex. To more accurately identify the two isolates, a multigene analysis was used that allowed both strains to be assigned to the species C. cigarro. Pathogenicity tests were performed on one-year-old avocado seedlings and the symptoms observed in the field were reproduced. Fungi were recovered from inoculated plants, thereby fulfilling Koch’s postulates. C. cigarro has been described as a pathogen of avocado in New Zealand and Mexico, but to our knowledge, this is the first report of C. cigarro affecting avocado in Spain.
Spodoptera cosmioides (Walker) (Lepidoptera: Noctuidae), the “black armyworm”, is a native species of theAmericas, where it has been recorded approximately from latitude 10° north to 35° south, excluding Chile. It is a polyphagous species and a secondary pest of soybean and cotton crops. Because this species is not a target of Bt soybeans and cottons crops, it is one of the most abundant species of Lepidoptera attacking this technology in different regions and, thus, has the potential to cause yield losses. Its development is faster and its survival is greater when it feeds on soybeans and cotton than on other crops. Furthermore, thermal requirement models indicate that expected climate change conditions could trigger a significant southward latitudinal expansion toward temperate production zones. In this review, an update of its biology, morphology, identification, host plants and current control and pest management tools are presented. Because the occurrence of S. cosmioides has increased and caused damage to soybean crops no specific control methods have been developed yet. This review aims at increasingawarenessabout this pest and helping develop specific management strategies.
Almond anthracnose, caused by Colletotrichum species, is one of the main barriers to production because of the limited effectiveness of preventive and curative treatments. This study evaluated in vitro the susceptibility of Colletotrichum godetiae, C. acutatum and C. gloeosporioides to seven fungicides, including biopesticides, natural mineral substances and synthetic organic compounds. Mycelial growth inhibition and conidial germination were assessed, and EC50 values were estimated using dose–response models. Bacillus amyloliquefaciens D747 showed a complete and consistent inhibition of mycelial growth and conidial germination in all isolates, indicating high potential as a biocontrol agent. Among synthetic organic fungicides, captan and dithianon showed stable, dose-dependent inhibition with low EC50 values. Fluazinam showed high efficacy against C. godetiae and C. gloeosporioides, but variable efficacy against conidial germination, suggesting limitations in preventive control. Difenoconazole showed inconsistent results, especially against C. acutatum, suggesting a possible reduction in sensitivity during model fitting. Sulphur and aqueous extract from the germinated seeds of sweet Lupinus albus, on the other hand, showed limited antifungal activity. These results, although requiring validation in field studies, show that the effectiveness of fungicides depends on the active substance and the target species and underline the need for specific management strategies. Integration of biological agents and chemical fungicides with multiple sites of action, combined with rotation of modes of action, is necessary to improve disease control and reduce the risk of resistance.
The aim of this study is to investigate whether the activation of plant defense systems and the type of defense compounds depends on the population or threat of microorganisms when plants are simultaneously challenged by different pathogens or by non-pathogenic organisms or a combination of both in different population ratios. This study focuses on root-knot nematodes and Fusarium vascular wilt, along with the non-pathogenic bacterium Bacillus subtilis, applied in various combinations to tomato plants. The results show that in addition to reducing the pathogenicity indices of nematodes and fungi by Bacillus subtilis as a biocontrol agent and also the disease synergy between the two pathogens, plant defense responses are also induced with different quantity and quality. Chitinase enzyme activity is significantly increased in response to the fungal pathogen compared to the nematode, while protease activity is significantly higher against the RK-nematode. When the plant is simultaneously attacked by two pathogens or by a pathogen and a non-pathogen, the activation of defense responses appear to be dictated by the intensity of signaling from the organism with the larger population. Notably, RK-nematodes demonstrate a pronounced ability to suppress the plant’s defense mechanisms. However, certain compounds, such as hydrogen peroxide, as well as specific defense enzymes like phenylalanine ammonia lyase, exhibit varying degrees of response to these suppressive effects. This study underscores the complexity of plant-pathogen interactions and highlights the significance of pathogen population dynamics in shaping plant defense strategies.
Plant biostimulants are increasingly applied in agriculture to enhance crop performance and contribute to more sustainable production systems. Their adoption by farmers depends largely on product availability, regulatory accessibility, and demonstrated efficacy under field conditions. Under EU Regulation (EU) 2019/1009, plant biostimulants are defined as products that improve nutrient use efficiency, tolerance to abiotic stress, or crop quality traits, explicitly excluding direct plant protection claims. This paper reviews the current definition of plant biostimulants, outlines the development of the EU legal framework, and summarizes the requirements for market placement within the European Union. Particular attention is given to the coexistence of two regulatory pathways: the harmonized EU framework applicable since June 2022 and pre-existing national regulatory systems. Their respective advantages and limitations are critically assessed in relation to different market strategies. The biostimulants are known to influence plant physiology through multiple mechanisms and their effect may not always be clear when it comes to the distinction between biostimulation and plant protection. The harmonized EU procedure offers obvious advantages for manufacturers targeting multi-country markets and developing innovative products, whereas national pathways may remain more suitable for companies operating in localized markets with established distribution networks. Overall, this analysis highlights a conceptual and regulatory gap between the legally defined functions of biostimulants and their scientifically recognized multifunctionality, with implications for future policy development and product innovation.
The fall armyworm (Spodoptera frugiperda (J.E. Smith, 1797)) is a damaging pest of maize that causes significant agricultural losses in its native habitat in the Americas and in newly invaded regions worldwide. Reliance on chemical pesticides for their control can lead to environmental problems and may impair sustainable crop production, underscoring the need for ecologically suitable alternatives. This research assessed the individual and combined effects of silicon (Si) supplementation and the egg parasitoid Trichogramma pretiosum on fall armyworm performance, parasitism, and maize development under field conditions. Silicon was applied as sodium silicate at 800 and 1200 ppm via foliar spray and soil drenching, either alone or in combination with T. pretiosum. The combination of 1200 ppm silicon and T. pretiosum produced the greatest effects, reducing egg hatching from 94 to 48
Cypress trees (Cupressaceae) are commonly planted in European urban landscapes but frequently affected by fungal diseases. In this study, we investigated fungal pathogens associated with Thuja occidentalis L. and Chamaecyparis species at different sites in Hungary. Fusarium isolates, tentatively identified through sequencing of the nuclear ribosomal internal transcribed spacer (ITS), were obtained from browning, necrotic tissues. For species-level resolution, monoconidial cultures were produced, and multilocus phylogenetic analysis was performed using partial translation elongation factor 1-α (TEF), RNA polymerase II largest (RPB1), and second-largest (RPB2-1 and RPB2-2) subunits. Seven Fusarium species representing six species complexes were identified: F. clavus, which was the most frequently isolated species; F. verticillioides; F. sambucinum; F. culmorum; F. inflexum; F. negundinis; and F. celtidicola. To our knowledge, this study is the first to report these Fusarium taxa from Thuja occidentalis and Chamaecyparis sp. trees. Our findings expand the current knowledge on host range of several Fusarium taxa and contribute to a more comprehensive understanding of the diversity of Fusarium species associated with ornamental conifers.
Food loss caused by postharvest insect infestations is a major challenge to global food security, resulting in significant economic losses and wastage of agricultural resources. Conventional methods for detecting stored grain insect pests, such as visual inspection and trap-based monitoring, are often labor- intensive, destructive, and insufficiently sensitive to detect early-stage infestations, and still, there is a lack in comparing the effectiveness of different imaging technologies and their integration with advanced artificial intelligence and real-time monitoring systems for practical grain storage applications. Therefore, the objective of this to review the applications of hyperspectral imaging, X-ray imaging, and thermal imaging for detecting damage in stored grain insect pests, and to examine the recent advances in deep learning techniques for pest segmentation and classification. This study was based on a comprehensive review related to imaging-based pest detection technologies, focusing on their operational principles, detection performance, advantages, limitations, and integration with Internet of Things (IoT)-based systems. The findings reveal that imaging technologies combined with deep learning approaches significantly enhance the speed, accuracy, and non-invasive detection of stored grain insect pests compared with conventional methods. In Hyperspectral imaging showed high sensitivity in detecting internal grain damage, X-ray imaging proved effective for identifying hidden infestations, and thermal imaging demonstrated strong potential for rapid monitoring applications. Further, IoT integration enables real-time, automated, and scalable pest monitoring in grain storage facilities. This review provides the advancement of intelligent pest detection systems and highlights the policy-related implications for improving food safety, minimizing postharvest losses, enhancing storage management practices, and supporting sustainable agricultural supply chain development.
The current alarming trends in global climate development are increasingly threatening agriculture. Extreme weather events, such as prolonged drought and heat waves, put crops under greater stress and alter the occurrence and severity of plant diseases. This article reflects on exemplary Fusarium–drought interaction experiments in barley, providing insights on how researchers can support breeding for disease resistance under future, more unfavourable environmental conditions.
