Search Results (65)

Locusta migratoria manilensis (Meyen) is a highly destructive insect pest worldwide. However, excessive reliance on insecticides has resulted in significant environmental pollution. Biocontrol complexes combine two or more BCAs to address the limitations of individual agents. However, biocontrol complex for locust control has been rarely reported. Here, we propose BioControl 3.0, which integrates Metarhizium anisopliae var. acridum (Driver and Milner) and Carabus smaragdinus (Fischer von Waldheim) for locust control. We evaluated this system through a series of laboratory bioassays and semi-field cage experiments, comparing single-agent applications, sequential combinations (BioControl 2.0), and predator-mediated delivery (BioControl 3.0), and quantified locust mortality and interaction effects between predation and infection We found that M. anisopliae caused >85% mortality of locust nymphs at 1 × 10⁸ conidia/mL (LT₅₀ ≈ 6 days) while exhibiting negligible virulence toward C. smaragdinus. BioControl 2.0 (sequential application) increased mortality compared to single agents. However, this approach revealed a significant negative interaction between predation and infection, which limited the total control efficacy. BioControl 3.0 (predator-vectored fungus) achieved the highest corrected mortality, with predation and infection acting independently and additively (no detectable antagonistic interaction). By leveraging a predatory vector, BioControl 3.0 decouples negative interaction and harnesses dual biotic pressures, offering a cost-effective, environmentally benign alternative to conventional locust control. Our findings provide a blueprint for designing integrated predator-pathogen complexes and optimizing deployment strategies for sustainable management of locust outbreaks. Full article

Paralipsa gularis (Zeller) has become an increasingly destructive pest in both storage and field ecosystems, particularly affecting maize crops across China. As chemical control methods face limitations due to resistance development and environmental concerns, biological control presents a promising alternative. In this study, we isolated and identified a novel strain of Metarhizium sp. from naturally infected P. gularis larvae collected in Yunnan Province, China. Morphological characterization, along with ITS-rDNA and EF-1α-rDNA sequencing, confirmed the fungus as Metarhizium rileyi. The optimal growth medium for this strain was SMAY, and the optimal conditions were 25 °C under continuous light (L:D = 24:0). Laboratory bioassays showed that the strain exhibited high virulence against P. gularis larvae, with cumulative mortality reaching 82% following infestation with 5 × 10⁸ conidia/mL. Biochemical analyses revealed that fungal infection significantly inhibited the activity of the key antioxidant enzyme SOD in the host, while activities of POD, CAT, and detoxification enzymes (P450, CarE, AChE, and GSTs) were significantly increased. These results indicate that immune responses were triggered, and systemic colonization of the host was achieved. Overall, this native M. rileyi strain demonstrates strong potential as an effective biological control agent. Its ability to overcome insect defenses and induce high mortality supports its integration into pest management programs targeting P. gularis. This work advances the understanding of fungal–insect interactions and contributes to sustainable, environmentally safe strategies for managing a pest of economic importance in agricultural ecosystems. Full article

Conidiobolus coronatus (Entomophthorales), a fungal pathogen with a broad insect host range, is a promising candidate for biocontrol applications. We sequenced a C. coronatus strain isolated from a Rhopalomyia sp. cadaver using PacBio long-read sequencing to elucidate the molecular basis of its wide host adaptability. The newly assembled 44.21 Mb genome exhibits high completeness (BUSCO score: 93.45%) and encodes 11,128 protein-coding genes, with 23.1% predicted to mediate pathogen–host interactions. Comparative genomics with the aphid-obligate pathogen C. obscurus revealed significant expansions in gene families associated with host adaptation mechanisms, including host recognition, transcriptional regulation, degradation of host components, detoxification, and immune evasion. Functional annotation highlighted enrichment in cellular component organization and energy metabolism. Pfam annotation identified one hundred twenty-five seven-transmembrane receptors (putative GPCRs), sixty-seven fungus-specific transcription factors, three hundred sixty-one peptidases (one hundred ninety-eight serine proteases and one hundred three metalloproteases), one hundred twenty-seven cytochrome P450 monooxygenases (P450s), thirty-five cysteine-rich secretory proteins, and fifty-five tyrosinases. Additionally, four hundred thirty carbohydrate-active enzymes (CAZymes) across six major modules were characterized. Untargeted metabolomics detected 22 highly expressed terpenoids, consistent with terpenoid biosynthesis gene clusters in the genome. Collectively, these expansions underpin the broad host range of C. coronatus by enabling cross-host signal decoding and gene expression reprogramming, breaching diverse host physicochemical barriers, and expanding its chemical ecological niche. This study provides genomic insights into broad host adaptability in entomopathogenic fungi, facilitating further understanding of pathogen–host interactions. Full article

Stag beetles are saproxylic insects, essential for decomposing rotten wood and maintaining the carbon cycle. Their gut bacteria contribute significantly to nutrient digestion and energy acquisition, making them crucial for understanding host-microbe interactions. Despite the fungivorous behavior of stag beetle larvae, research on how diet influences gut bacterial diversity remains scarce. Therefore, this study was conducted to compare the diversity and metabolic functions of gut bacteria in Dorcus hopei larvae fed on fungus (Pleurotus geesteranus) and rotten wood diets using high-throughput sequencing technology. Significant differences (p < 0.05) were observed in gut bacterial community composition between two diets, highlighting diet as a key factor shaping bacterial diversity. Additionally, gut bacterial communities varied across larval developmental stages (p < 0.05), indicating the influence of host age. Dominant bacterial phyla included Firmicutes, Bacteroidetes, and Proteobacteria. Bacteroidetes were more abundant in rotten-wood-fed larvae (7.61%) than fungus-fed larvae (0.15%), while Proteobacteria were more abundant in fungus-fed larvae. Functional analysis revealed that rotten-wood-fed larvae were primarily related to carbohydrate and amino acid metabolism, whereas fungus-fed larvae exhibited enhanced membrane transport function. This study enhances the understanding of gut bacterial diversity and functions in stag beetles, providing a theoretical foundation for their conservation and sustainable utilization. Full article

Bananas, one of the most widely consumed tropical fruits in the world, are susceptible to attack by the anthracnose fungus Colletotrichum musae during the post-harvest period. Currently, fungus control is generally based on the use of chemical products, often applied a few days before harvest, which could lead to a risk of residues in the fruit, thus creating a high demand for fresh and organic fruits. Therefore, essential oils present an emerging alternative for the treatment of anthracnose. Here, we evaluated the chemical composition and potential of Morinda citrifolia essential oil as a preventive and curative measure to control C. musae in bananas, also considering the quality of the fruit. In addition, computational docking analysis was conducted to predict potential molecular interactions between octanoic and butanoic acids and the enzyme Tyrosine tRNA, as a potential target for the M. citrifolia essential oil fungicide actions. We also evaluated the essential oil’s safety for beneficial organisms such as the fungus Trichoderma asperellum and the ladybugs Eriopis connexa Germar and Coleomegilla maculata DeGeer. Initially, in vitro growth inhibition tests were performed with doses of 10.0, 30.0, and 50.0 µL/mL of M. citrifolia essential oil, as well as an assessment of the phytotoxic effects on the fruit. Subsequently, using non-phytotoxic doses, we evaluated the effect of the essential oil as a preventive and curative measure against anthracnose and its impact on fruit quality. Our results showed that octanoic, butanoic, and hexanoic acids were the major compounds in M. citrifolia essential oil, inhibiting the growth of C. musae by interacting with the Tyrosine tRNA enzyme of C. musae. The non-phytotoxic dose on the fruit was 10 µL/mL of noni essential oil, which reduced C. musae growth by 30% when applied preventively and by approximately 25% when applied as a curative measure. This significantly reduced the Area Under the Disease Progress Curve without affecting the fruit weight, although there was a slight reduction in °Brix. The growth of non-target organisms, such as T. asperellum and the insect predators Co. maculata and E. connexa, was not affected. Collectively, our findings suggest that M. citrifolia essential oil is a promising alternative for the prevention and control of anthracnose in banana fruit caused by C. musae, without adversely affecting its organoleptic characteristics or non-target organisms. Full article

Pear psylla (Cacopsylla chinensis), a major pear tree pest widely distributed in China, is increasingly affecting the productivity of orchards. This species exhibits seasonal polyphenism with two distinct forms, namely, a summer form and a winter form. Through topically applying Beauveria bassiana conidial suspensions to the abdominal cuticle of C. chinensis, we demonstrated that the entomopathogenic fungus B. bassiana exhibits significant yet phenotypically divergent virulence against these two forms. Using PacBio SMRT sequencing and Illumina RNA-seq, we analyzed transcriptomic changes post-infection, revealing form-specific immune responses, with 18,232 and 5027 differentially expressed genes identified in summer- and winter-form pear psylla, respectively, and a total of 3715 DEGs shared between the two seasonal phenotypes. In summer-form individuals, B. bassiana infection disrupted oxidative phosphorylation and downregulated immune recognition genes, cellular immune-related genes, and signaling genes, along with the upregulation of the immune inhibitor serpin, indicating immunosuppression. Conversely, in winter-form individuals, immune-related genes and glycolytic rate-limiting enzymes were upregulated after infection, suggesting that the winter-form immune system normally responds to B. bassiana infection and supports efficient defense through metabolic reprogramming to fuel energy-demanding defenses. These findings advance our understanding of C. chinensis/B. bassiana interactions, providing a basis for elucidating immune regulation in seasonally polymorphic insects. The results also inform strategies to optimize B. bassiana-based biocontrol, contributing to sustainable pear psylla management. Full article

Amylostereum areolatum (Chaillet ex Fr.) Boidin (Russulales: Amylostereaceae) is a symbiotic fungus of Sirex noctilio Fabricius that has ecological significance. Terpenoids are key mediators in fungal–insect interactions, yet the biosynthetic mechanisms of terpenoids in this species remain unclear. Under nutritional conditions that mimic natural growth, A. areolatum was sampled during the lag phase (day 7), exponential phase (day 14), and stationary phase (day 21). Metabolome (solid-phase microextraction (SPME) combined with gas chromatography–mass spectrometry (GC-MS) and liquid chromatography–mass spectrometry (LC-MS)) and transcriptome (Illumina NovaSeq) profiles were integrated to investigate terpenoid–gene correlations. This analysis identified 103 terpenoids in A. areolatum, substantially expanding the known repertoire of terpenoid compounds in this species. Total terpenoid abundance progressively increased across three developmental stages, with triterpenoids and sesquiterpenoids demonstrating the highest diversity and abundance levels. Transcriptomic profiling (61.66 Gb clean data) revealed 26 terpenoid biosynthesis-associated genes, establishing a comprehensive transcriptional framework for fungal terpenoid metabolism. Among 11 differentially expressed genes (DEGs) (|log2Fold Change| ≥ 1, adjusted p < 0.05), HMGS1, HMGR2, and AaTPS1-3 emerged as key regulators potentially governing terpenoid biosynthesis. These findings provide foundational insights into the molecular mechanisms underlying terpenoid production in A. areolatum and related basidiomycetes. Full article

Bemisia tabaci is a major agricultural pest that affects both greenhouse and field crops by feeding on plant sap, which impairs plant growth, and by secreting honeydew, promotes sooty mold growth that further reduces photosynthesis. Additionally, these insects are vectors for viruses such as the cucurbit chlorotic yellows virus (CCYV), which causes significant damage to cucurbit crops. Traditional chemical pesticide treatments have limitations, including the development of resistance, harm to non-target organisms, and environmental contamination. Traditional chemical pesticides have limitations when it comes to controlling plants infested by CCYV and whitefly. However, the underlying reasons for these limitations remain unclear, as does the impact of entomopathogenic fungi on whitefly responses. This study explores the potential of using biological control agents, specifically Beauveria bassiana and Purpureocillium lilacinum, to manage whitefly populations and control CCYV transmission. Laboratory experiments were conducted to evaluate the pathogenicity of these fungi on non/viruliferous whitefly. The results indicated that both fungi effectively reduced whitefly populations, with B. bassiana showing particularly strong adverse effects. Whiteflies infected with CCYV exhibited a higher LC₅₀ to B. bassiana and P. lilacinum. Furthermore, bio-pesticides significantly altered the bacterial microbiome dynamics of the whitefly. Interestingly, CCYV increased the susceptibility of whiteflies to entomopathogenic fungus. The findings suggest that these biocontrol agents offer a sustainable alternative to chemical pesticides. Our study unraveled a new horizon for the multiple interaction theories among bio-pesticides–insects–symbionts–viruses. Full article

Some Pseudococcidae species interact with Coffea arabica’s roots and are associated with basidiomycete fungi. The fungal mycelium envelops the roots, which hinders their water and nutrient absorption. Combined with the feeding activity of the insects, this results in chlorosis, defoliation, and even plant death. Despite the significance of these interactions, they remain under-studied. To investigate the relationship between sporocarps found at the base of coffee trees, the cysts covering their roots, and the mealybug insects within them, samples of these three organisms—sporocarps, cysts, and mealybugs—were collected from 27 coffee plants across three farms in the departments of Norte de Santander and Quindío, Colombia. Fungi and cysts were identified by sequencing a nuclear gene region of the 28S large ribosomal subunit (28S rDNA) using the primers LSU200-F and LSU481-R. Fungal identification was further confirmed through classical taxonomy. Mealybugs were identified by sequencing a region of the mitochondrial gene Cytochrome C oxidase subunit I (COI) with CIF-CIR primers, corroborated through classical taxonomy. This study identified four fungal species associated with four species of Pseudococcidae. The fungus Phlebopus beniensis was associated with the mealybugs Pseudococcus elisae, Dysmicoccus neobrevipes, D. brevipes, and Pseudococcus nr. sociabilis. Phlebopus portentosus was linked to D. neobrevipes, while Xerophorus olivascens and Boletinellus rompelii were associated with other Pseudococcidae species. Additionally, the fungus Pseudolaccaria pachyphylla was found in coffee plants harboring mealybugs. These findings confirm the existence of specific associations between fungal species and mealybug insects that affect coffee plants. Full article

The entomopathogenic fungus (EPF) Metarhizium acridum is a typical filamentous fungus and has been used to control migratory locusts (Locusta migratoria manilensis). This study examines the impact of the Zn(II)2Cys6 transcription factor, MaAzaR, in the virulence of M. acridum. Disruption of MaAzaR (ΔMaAzaR) diminished the fungus’s ability to penetrate the insect cuticle, thereby decreasing its virulence. The median lethal time (LT₅₀) for the ΔMaAzaR strain increased by approximately 1.5 d compared to the wild-type (WT) strain when topically inoculated, simulating natural infection conditions. ΔMaAzaR compromises the formation, turgor pressure, and secretion of extracellular hydrolytic enzymes in appressoria. However, the growth ability of ΔMaAzaR within the hemolymph is not impaired; in fact, it grows better than the WT strain. Moreover, RNA-sequencing (RNA-Seq) analysis of ΔMaAzaR and WT strains grown for 20 h on locust hindwings revealed 87 upregulated and 37 downregulated differentially expressed genes (DEGs) in the mutant strain. Pathogen–host interaction database (PHI) analysis showed that about 40% of the total DEGs were associated with virulence, suggesting that MaAzaR is a crucial transcription factor that directly regulates the expression of downstream genes. This study identifies a new transcription factor involved in EPF cuticle penetration, providing theoretical support and genetic resources for the developing highly virulent strains. Full article

The fungus Trichoderma is widely regarded as the most common fungal biocontrol agent for plant health management. More than 25 Trichoderma species have been extensively studied and have demonstrated significant potential in inhibiting not only phytopathogen growth but also insect pest infestations. In addition to their use as biopesticides, there is increasing evidence that several Trichoderma species can function as fungal endophytes by colonizing the tissues of specific plants. This colonization enhances a plant’s growth and improves its tolerance to abiotic and biotic stresses. In recent decades, there has been a proliferation of literature on the role of Trichoderma endophytes in crop protection. Although the mechanisms underlying plant–fungal endophyte interactions are not yet fully understood, several studies have suggested their potential application in agriculture, particularly in the mitigation of plant pests and diseases. This review focuses on the diversity of Trichoderma endophytic strains and their potential use in controlling specific diseases and pests of crop plants. Trichoderma endophytes are considered a potential solution to reduce production costs and environmental impact by decreasing reliance on agrochemicals. Full article

Beauveria bassiana is an entomopathogenic fungus that parasitizes and kills insects. The role of volatile organic compounds (VOCs) emitted by B. bassiana acting as semiochemicals during its interaction with lepidopterans is poorly explored. Here, we studied the effect of VOCs from B. bassiana and 3-methylbutanol (as a single compound) on the feeding behavior of L2 larvae of Spodoptera frugiperda in sorghum plants. Additionally, we assessed whether fungal VOCs induce chemical modifications in the plants that affect larval food preferences. Metabolomic profiling of plant tissues was performed by mass spectrometry and bioassays in a dual-choice olfactometer. The results showed that the larval feeding behavior was affected by the B. bassiana strain AI2, showing that the insect response is strain-specific. Furthermore, 80 µg of 3-methylbutanol affected the number of bites. The larval feeding choice was dependent on the background context. Fragment spectra and a matching precursor ion mass of 165.882 m/z enabled the putative identification of 4-coumaric acid in sorghum leaves exposed to fungal VOCs, which may be associated with larval deterrent responses. These results provide valuable insights into the bipartite interaction of B. bassiana with lepidopterans through VOC emission, with the plant as a mediator of the interaction. Full article

Both parasitoids and entomopathogenic fungi are becoming increasingly crucial for managing pest populations. Therefore, it is essential to carefully consider the potential impact of entomopathogenic fungi on parasitoids due to their widespread pathogenicity and the possible overlap between these biological control tools during field applications. However, despite their importance, little research has been conducted on the pathogenicity of entomopathogenic fungi on parasitoids. In our study, we aimed to address this knowledge gap by investigating the interaction between the well-known entomopathogenic fungus Beauveria bassiana, and the pupal endoparasitoid Pteromalus puparum. Our results demonstrated that the presence of B. bassiana significantly affected the survival rates of P. puparum under laboratory conditions. The pathogenicity of B. bassiana on P. puparum was dose- and time-dependent, as determined via through surface spraying or oral ingestion. RNA-Seq analysis revealed that the immune system plays a primary and crucial role in defending against B. bassiana. Notably, several upregulated differentially expressed genes (DEGs) involved in the Toll and IMD pathways, which are key components of the insect immune system, and antimicrobial peptides were rapidly induced during both the early and late stages of infection. In contrast, a majority of genes involved in the activation of prophenoloxidase and antioxidant mechanisms were downregulated. Additionally, we identified downregulated DEGs related to cuticle formation, olfactory mechanisms, and detoxification processes. In summary, our study provides valuable insights into the interactions between P. puparum and B. bassiana, shedding light on the changes in gene expression during fungal infection. These findings have significant implications for the development of more effective and sustainable strategies for pest management in agriculture. Full article

Anthropogenic disturbance of tropical humid forests leads to habitat loss, biodiversity decline, landscape fragmentation, altered nutrient cycling and carbon sequestration, soil erosion, pest/pathogen outbreaks, among others. Nevertheless, the impact of these alterations in multitrophic interactions, including host–pathogen and vector–pathogen dynamics, is still not well understood in wild plants. This study aimed to provide insights into the main drivers for the incidence of herbivory and plant pathogen damage, specifically, into how vegetation traits at the local and landscape scale modulate such interactions. For this purpose, in the tropical forest of Calakmul (Campeche, Mexico), we characterised the foliar damage caused by herbivores and pathogens in woody vegetation of 13 sampling sites representing a gradient of forest disturbance and fragmentation in an anthropogenic landscape from well preserved to highly disturbed and fragmented areas. We also evaluated how the incidence of such damage was modulated by the vegetation and landscape attributes. We found that the incidence of damage caused by larger, mobile, generalist herbivores, was more sensitive to changes in landscape configuration, while the incidence of damage caused by small and specialised herbivores with low dispersal capacity was more influenced by vegetation and landscape composition. In relation to pathogen symptoms, the herbivore-induced foliar damage seems to be the main factor related to their incidence, indicating the enormous importance of herbivorous insects in the modulation of disease dynamics across tropical vegetation, as they could be acting as vectors and/or facilitating the entry of pathogens by breaking the foliar tissue and the plant defensive barriers. The incidence of pathogen damage also responded to vegetation structure and landscape configuration; the incidence of anthracnose, black spot, and chlorosis, for example, were favoured in sites surrounded by smaller patches and a higher edge density, as well as those with a greater aggregation of semi-evergreen forest patches. Fungal pathogens were shown to be an important cause of foliar damage for many woody species. Our results indicate that an increasing transformation and fragmentation of the tropical forest of southern Mexico could reduce the degree of specialisation in plant–herbivore interactions and enhance the proliferation of generalist herbivores (chewers and scrapers) and of mobile leaf suckers, and consequently, the proliferation of some symptoms associated with fungal pathogens such as fungus black spots and anthracnose. The symptoms associated with viral and bacterial diseases and to nutrient deficiency, such as chlorosis, could also increase in the vegetation in fragmented landscapes with important consequences in the health and productivity of wild and cultivated plant species. This is a pioneering study evaluating the effect of disturbances on multitrophic interactions, offering key insights on the main drivers of the changes in herbivory interactions and incidence of plant pathogens in tropical forests. Full article

Spodoptera frugiperda (Lepidoptera: Noctuidae) is a migratory agricultural pest that is devastating on a global scale. Beauveria bassiana is a filamentous entomopathogenic fungus that has a strong pathogenic effect on Lepidoptera pests but little is known about the microbial community in the host gut and the dominant populations in fungus-infected insects. B. bassiana AJS91881 was isolated and identified from the infected larvae of Spodoptera litura. The virulence of AJS91881 to the eggs, larvae, pupae and adults of S. frugiperda was measured. Moreover, the gut microbial community diversity of healthy and fungus-infected insects was analyzed. Our results showed that after treatment with B. bassiana AJS91881, the egg hatching rate, larval survival rate and adult lifespan of the insects were significantly reduced, and the pupae rigor rate was significantly increased compared to that of the control group. Additionally, the gut microbial community was reconstructed after B. bassiana infection. At the phylum and genus level, the relative abundance of the Proteobacteria and Serratia increased significantly in the B. bassiana treatment group. The KEGG function prediction results showed that fungal infection affected insect gut metabolism, environmental information processing, genetic information processing, organism systems and cellular processes. Fungal infection was closely related to the metabolism of various substances in the insect gut. Serratia marcescens was the bacterium with the highest relative abundance after infection by B. bassiana; intestinal bacteria S. marcescens inhibited the infection of insect fungi B. bassiana against the S. frugiperda. The presence of gut bacteria also significantly reduced the virulence of the fungi against the insects when compared to the group with the larvae fed antibiotics that were infected with fungal suspension (Germfree, GF) and healthy larvae that were infected with fungal suspension prepared with an antibiotic solution (+antibiotic). In conclusion, the reconstruction of the insect intestinal bacterial community is an indispensable link for understanding the pathogenicity of B. bassiana against S. frugiperda. Most importantly, in the later stage of fungal infection, the increased abundance of S. marcescens in the insect intestine inhibited the virulence of B. bassiana to some extent. The findings aid in understanding changes in the gut microbiota during the early stages of entomopathogenic fungal infection of insects and the involvement of insect gut microbes in host defense mediated by pathogenic fungal infection. This study is also conducive to understanding the interaction between entomopathogenic fungi, hosts and gut microbes, and provides a new idea for the joint use of entomopathogenic fungi and gut bacteria to control pests. Full article