Search Results (232)

In June 2023, a larva of grassland caterpillar Gynaephora qinghaiensis naturally infected by an entomopathogenic fungus was collected from an alpine rangeland in Gangcha County, Haibei Tibetan Autonomous Prefecture, Qinghai Province. After laboratory isolation and cultivation, the pathogen was identified as Beauveria bassiana (designated as GC23620) based on morphological characteristics and ITS-rDNA sequence similarity analysis. The larvicidal efficacy of B. bassiana GC23620 against fourth-instar larvae of G. qinghaiensis were assessed using two inoculation methods in laboratory conditions. The infection process and pathogenicity were analyzed by simulation and parameter estimation using the Time–Dose–Mortality (TDM) model. The estimated parameters for the concentration effect of strain GC23620 (β) were 0.56 (leaf dipping method) and 0.30 (insect immersion method), respectively. After treatment with conidial suspensions (1.05 × 10⁵ to 1.05 × 10⁹ conidia/mL), the cumulative corrected mortalities were 72.73–100.00% (leaf dipping method) and 42.42–90.91% (insect immersion method) at 8 days after inoculation (DAI), and the median lethal doses (LD₅₀) decreased to 1.74 × 10³ conidia/mL (leaf dipping method) and 1.85 × 10⁴ conidia/mL (insect immersion method), respectively, during the same post-inoculation period. After inoculation with conidial suspension under a concentration of 1.05 × 10⁶ conidia/mL, the median lethal times (LT₅₀) were 2.40 (leaf dipping method) and 4.51 days (insect immersion method). A control efficacy of 84.27% was obtained for G. qinghaiensis larvae on grassland at 21 days post-treatment after spraying the fermentation solution with a low dose of 1.05 × 10⁵ conidia/mL. In conclusion, B. bassiana strain GC23620 exhibited high pathogenic activity against G. qinghaiensis larvae and has strong potential for the green control of grassland pests. Full article

The management of Culex pipiens (Diptera: Culicidae), key vectors of arboviruses like West Nile virus, necessitates sustainable alternatives to chemical insecticides. This study screened indigenous entomopathogenic fungi (EPF) from forest soils in Achaia, Greece, for their larvicidal efficacy against Cx. pipiens biotype molestus. Fifteen fungal isolates were obtained via insect baiting and identified as Beauveria and Metarhizium species. A comprehensive bioassay at 1 × 10⁸ conidia mL⁻¹ revealed significant variation in pathogenicity after 72 h. Two isolates, Beauveria bassiana (BB) (Hypocreales: Cordycipitaceae) and Metarhizium anisopliae (K3(1)) (Hypocreales: Clavicipitaceae), exhibited the highest virulence among the tested isolates, each causing 60% mortality with a rapid median lethal time (LT₅₀) of ~18.5 h. Survival analysis, Cox modeling, and non-linear kinetic modeling (Gompertz/Richards) classified three distinct virulence clusters: high/rapid, moderate/consistent, and low/delayed. A pathogenicity network analysis and a composite virulence index further validated BB and K3(1) as the most effective candidates. These results demonstrate the high isolate specificity of fungal efficacy and underscore the importance of screening local fungal diversity. The identified high-virulence isolates represent promising, environmentally sound candidates for the development of targeted biopesticides. Future research should focus on formulation for aquatic environments and integration into resistance-resilient integrated vector management programs. Full article

Nematodes in the genus Oscheius (Rhabditidae) have traditionally been regarded as free-living bacteriophagous or necromenic associates of insects. Over the past two decades, however, multiple Oscheius species and isolates have been shown to express facultative pathogenicity toward insects and, in some cases, parasitism of mollusks. This has stimulated interest in Oscheius as a complementary group of biological control agents that may function under conditions limiting classical entomopathogenic nematodes (EPNs) of the genera Steinernema and Heterorhabditis. Here, we synthesize current knowledge on Oscheius taxonomy and diversity, life-history strategies, bacterial associations and virulence mechanisms, evidence for control of insect and mollusk pests, and recent advances in chemo-ecology relevant to host finding. We emphasize that Oscheius represents a continuum of ecological strategies, and we adopt conservative terminology in which “entomopathogenic” is reserved for Oscheius species/isolates that meet operational criteria of insect pathogenicity. Finally, we highlight key barriers to wider implementation—strain variability, bacterial partner instability, non-target and community effects, and production/quality control needs—and propose research priorities for the development of robust, field-reliable Oscheius-based biocontrol. Full article

Peri-urban ecosystems represent underexplored habitats rich in entomopathogenic fungi (EPF) that can serve as valuable resources for managing insect pests. This study characterized the EPF communities in two peri-urban sites near Patras, Greece (Dasyllio and Elos), during 2018–2019. Soil samples were collected seasonally, and fungi were isolated using insect baiting with Tribolium confusum Jacquelin du Val and Sitophilus zeamais Motsch., a selective method favoring generalist, fast-acting entomopathogens. A total of 814 isolates were recovered. Of a randomly selected subset (n = 177) subjected to molecular identification, 46.9% were characterized as known EPF, while 53.1% were classified as putative EPF based on taxonomic affiliation (ITS sequence similarity ≥ 99%), pending confirmation of pathogenicity. The Dasyllio site yielded more isolates (63.4%) than Elos (36.6%). Seasonal trends strongly influenced EPF occurrence, with infective fungi peaking in spring and summer (p < 0.001), while community diversity remained stable throughout the year, with the highest evenness (Evenness Index = 0.93) observed in autumn. These results highlight peri-urban green spaces as reservoirs of diverse and ecologically stable EPF, suggesting their potential as sources of biocontrol agents for future development and seasonal integration into pest management strategies. Full article

This study evaluated entomopathogenic nematodes (EPNs) isolated from a cacao agroforestry system in the Peruvian Amazon, focusing on their molecular characterization and efficacy against Spodoptera frugiperda (Lepidoptera: Noctuidae) larvae. Thirteen EPN isolates were obtained from 50 soil samples using the Galleria mellonella baiting technique. Mortality assays revealed significant differences among isolates at 24, 48, and 72 h, with isolates 11N-A4 and 8N-B1 being the most virulent, achieving maximum mortalities of 100% and 96.3% at 72 h, respectively. Median lethal time (LT₅₀) values indicated rapid action of these isolates on G. mellonella larvae, with 33.3 h for 11N-A4 and 32.4 h for 8N-B1. Molecular identification using ITS, D2–D3 (LSU), and COI markers confirmed the isolates as Heterorhabditis sp. (11N-A4) and Heterorhabditis amazonensis (8N-B1). In bioassays with S. frugiperda larvae, both EPNs exhibited dose- and time-dependent mortality. H. amazonensis showed rapid action, reaching 100% mortality at the highest dose (60 IJs/larvae) within 48 h, whereas Heterorhabditis sp. displayed a gradual, sustained increase, attaining 91% mortality at 72 h. Median lethal dose (LD₅₀) and LT₅₀ values reflected the efficiency of both isolates, with Heterorhabditis sp. achieving lower LD₅₀ at later stages and shorter LT₅₀ at low-to-intermediate doses. These findings highlight the potential of Heterorhabditis sp. and H. amazonensis as effective biocontrol agents adapted to local conditions and represent the first report of H. amazonensis in Peru. Further studies under field conditions are required to confirm their suitability for incorporation into integrated pest management strategies in the Peruvian Amazon. Full article

Cordyceps militaris is an entomopathogenic fungus traditionally used in Asian ethnomedicine and increasingly investigated for its potential health-promoting properties, including immunomodulatory and anti-inflammatory activities. In recent years, it has gained attention as a dietary supplement with possible applications in sports nutrition. This narrative review summarizes and critically evaluates the current human evidence regarding the ergogenic and post-exercise recovery effects of C. militaris supplementation in healthy individuals. A structured database search was conducted using predefined eligibility criteria, and the methodological quality of included studies was appraised through domain-based risk-of-bias assessment. Five intervention studies published between 2017 and 2024, comprising 321 participants aged 16–35 years, were identified. Supplementation protocols ranged from 1 to 16 weeks, with daily doses of 1–12 g administered either as isolated fungal material or as a part of multi-ingredient formulations. Assessed outcomes included indices of aerobic performance and exercise capacity, such as maximal or peak oxygen uptake (VO₂max/VO₂peak), time to exhaustion, power output, running performance, and maintenance of peripheral oxygen saturation during high-intensity exercise. Several studies also evaluated biochemical markers related to muscle damage and inflammatory responses, including creatine kinase, blood urea nitrogen, and white blood cell counts. Although some studies reported improvements in selected performance and recovery parameters, the findings were inconsistent. The certainty of the evidence is limited by small sample sizes, heterogeneity of participants and exercise protocols, insufficient reporting of randomization, lack of trial registration in most studies, absence of standardized preparations with quantified bioactive constituents, and the use of multi-ingredient supplements. Well-designed randomized controlled trials using chemically characterized preparations and homogeneous athletic populations are required to clarify the efficacy and practical relevance of C. militaris in sports nutrition. Full article

Cordyceps cicadae, a medicinal and edible entomopathogenic fungus, has been widely used in traditional Chinese medicine for treating various ailments. This study aimed to validate its ethnopharmacological uses by investigating bioactive constituents and their antithrombotic and antioxidant activities. Through various chromatographic separations, one unreported flavonoid; quercetin-3-O-β-D-methylglucopyranoside (1); three known flavonoids (2–4); and one new dicarboxylic acid derivative, cicadae acid (5), were isolated from C. cicadae. Their chemical structures were elucidated by a comprehensive spectroscopic analysis (1D/2D NMR and HRESIMS), electronic circular dichroism (ECD) calculations, a DP4+ probability analysis, and the modified Mosher method. All compounds exhibited significant antithrombotic effects at a concentration of 20 μM in a zebrafish model. Compounds 1–4 exhibited potent antioxidant activity in the DPPH radical scavenging assay, with IC₅₀ values ranging from 12.81 ± 3.42 to 20.16 ± 2.64 μM. These findings provide scientific evidence supporting the traditional application of C. cicadae, identifying specific flavonoids and dicarboxylic acids as potential therapeutic agents for thrombosis and oxidative stress-related disorders. Full article

The genus Isaria is a group of abundant and widely distributed entomopathogenic fungi that plays an important role in the history of traditional Chinese medicine. Entomopathogenic fungi with medicinal value were collected from the field, and optimal temperature and growth media compositions were investigated to establish a theoretical foundation for the future development of these strains. A strain of Isaria cateniobliqua, designated ICF, was isolated from soil in the Hualongshan National Nature Reserve in southern Shaanxi. The optimal cultivation temperature and nutrient solution were screened, and the effects of subcultivation on mycelium production, metabolite production, and hydroxyl radical scavenging activity of strain ICF were investigated. The optimal growth temperature for strain ICF was determined to be 21 °C, with the ideal culture medium consisting of glucose and tussah silkworm pupa powder supplemented with KH₂PO₄ and MgSO₄. Mycelium production and cordycepin content peaked in the fourth generation (G4), whereas peak metabolite production and cordycepic acid production occurred in the fifth generation (G5). Polysaccharide content was highest in the first generation (G1), and hydroxyl radical scavenging activity was optimal in G4. Exploring the optimal culture conditions of the strain provides a theoretical basis for its development, utilization, and industrial production for medicinal applications. Full article

The two-spotted spider mite, Tetranychus urticae Koch, is a major agricultural pest whose control is increasingly constrained by resistance to synthetic acaricides. This study evaluated the long-term field efficacy of three commercial entomopathogenic fungal (EPF) biopesticides—Velifer^® (Beauveria bassiana), Metab^® (B. bassiana + Metarhizium anisopliae), and Botanigard^® (B. bassiana)—against larval and protonymph stages of T. urticae on two host plants, Italian cypress (Cupressus sempervirens) and sweet orange (Citrus sinensis). Two foliar applications were conducted during the 2023 growing season (25 May and 25 July), and mite populations were monitored for 140 days after the final application. A randomized complete block design was used, and efficacy was calculated using the Henderson–Tilton formula. All EPF treatments significantly reduced mite populations compared with the untreated control throughout the monitoring period. Velifer consistently achieved the highest suppression of larval populations, particularly on C. sinensis, with efficacy comparable to the chemical standard. Botanigard showed more gradual but sustained population reduction over time, whereas Metab exhibited lower but stable efficacy in all cases. Treatment performance was strongly influenced by host plant species and mite developmental stage, with larvae consistently more susceptible than protonymphs. On C. sinensis, Velifer achieved the highest larval suppression (84.6%), comparable to the chemical standard abamectin, while Botanigard and Velifer were most effective on C. sempervirens. Survival analysis confirmed isolate- and host-dependent differences in hazard effects over time. These results demonstrate that EPF-based products can provide sustained, long-term suppression of T. urticae under field conditions, supporting their integration into integrated pest management programs. Full article

The search for sustainable pest management alternatives has intensified due to the risks of chemical pesticides. Entomopathogenic fungi and plant extracts, rich in insecticidal secondary metabolites, are among the most promising approaches. Integrating these agents can enhance complementary mechanisms and reduce environmental impact. This study evaluated the insecticidal potential of fungi produced by submerged fermentation (Beauveria bassiana, Metarhizium anisopliae, Trichoderma asperelloides, Isaria javanica, and Cordyceps fumosorosea) applied alone and combined with Trichilia claussenii extract against Euschistus heros and Spodoptera frugiperda. Fermentation showed good fungal adaptation and high sporulation, especially B. bassiana (8.33 × 10⁸ spores mL⁻¹) and T. asperelloides (9.42 × 10⁷ spores mL⁻¹). Adding the plant extract increased colony-forming units, notably for M. anisopliae (7.40 × 10⁷ CFU mL⁻¹) and B. bassiana (1.55 × 10⁸ CFU mL⁻¹). In bioassays, cell suspensions were more effective than isolated metabolites, reaching 97.8% mortality for E. heros and 91.5% for S. frugiperda with B. bassiana plus extract. These results indicate that combining entomopathogenic fungi with T. claussenii extract is a promising strategy for developing efficient and sustainable biopesticides, contributing directly to integrated pest management practices with reduced environmental impact. Full article

Tuta absoluta (Meyrick) is a globally invasive lepidopteran pest that has developed resistance to multiple classes of chemical insecticides, posing major challenges for the sustainable production of Solanaceae crops. In this study, we investigated the physiological and molecular responses of T. absoluta larvae to infection by the entomopathogenic bacterium Serratia marcescens (Bizio) strain Tapa21, which was isolated from naturally infected larvae and characterized through phenotypic, molecular, and phylogenetic analyses. Laboratory bioassays demonstrated dose- and time-dependent mortality of T. absoluta larvae, with mortality reaching nearly 80% at the highest Tapa21 concentration at 120 h post-infection (hpi), with a median lethal concentration (LC₅₀) of Optical Density (OD)₆₀₀ = 0.52 and a median lethal time (LT₅₀) of 5.2 d. RNA-Seq was performed, revealing 493 differentially expressed genes (DEGs), including 304 up-regulated and 189 down-regulated transcripts. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses indicated activation of detoxification-related enzymes, lysosome- and immune-associated pathways, and metabolic reprogramming, suggesting coordinated defense responses. A subset of genes, randomly selected across expression levels, was validated by RT-qPCR, corroborating the transcriptomic results. These results delineate the molecular mechanisms by which T. absoluta reshapes its physiological state during bacterial challenge and provide insight into how entomopathogenic strain Tapa21 disrupts host homeostasis. Such a mechanistic understanding could potentially contribute to sustainable and integrated pest management (IPM) strategies. Full article

Invertebrate iridescent viruses (IIVs, family Iridoviridae) are icosahedral double-stranded DNA viruses that infect a wide range of invertebrates, particularly in humid and aquatic environments. During field trials in Chiapas, southern Mexico, larvae of the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae), displayed an unexpected lavender iridescence, leading to the discovery of novel IIV isolates from this major agricultural pest. Restriction endonuclease analysis revealed evident diversity among isolates from individual infected larvae. Although one field experiment yielded inconclusive results, a second experiment revealed a positive association between IIV disease and SfMNPV infection, compared to a negative association with the prevalence of parasitoids, and no association with entomopathogenic nematodes (probably Hexamermis sp.). These findings require further investigation to determine the distinct ecological routes through which the virus may transmit across host species. IIV infection of S. frugiperda was also identified in Veracruz State, Mexico, and northern Argentina, revealing a previously unrecognized geographic and host range for these viruses. The genomic and evolutionary features of the three isolates from S. frugiperda were compared with those of two other lepidopteran isolates from Helicoverpa zea (IIV30C obtained from CSIRO) and Anticarsia gemmatalis (AgIIV). Genome sizes ranged between 196.1 and 205.4 kbp (~28% GC content), with several large inversions, and were rich in tandem repeats. The average amino acid identity of the complete genomes and phylogenetic analyses of 26 core gene sequences placed all five isolates within the genus Chloriridovirus, closely related to IIV22 and IV22a isolated from blackflies (Diptera) in Wales and a previously sequenced isolate of IIV30 from the USA. We conclude that these lepidopterans are all infected by closely related strains of the virus species Chloriridovirus simulium1 across their native geographical range. These findings highlight the unexpected ecological breadth and evolutionary adaptability of IIVs. Full article

Over the last few decades, the frequency of outbreaks of Ips acuminatus has rapidly increased in Latvia. These beetles are commonly associated with blue-stain fungi, which increase tree mortality and decrease the timber quality of affected trees. The aims of this study were: (i) to identify fungi associated with I. acuminatus in Latvia and (ii) to determine the influence of different factors (such as locality, month of beetle capture, beetle sex) on the diversity of associated fungi. From a total of 590 analysed I. acuminatus beetles, 564 resulted in fungal growth and yielded 1247 fungal isolates, representing 36 fungal taxa. Among the fungi isolated, the most common were Akanthomyces muscarius, followed by Penicillium spp., Mucor spp., Cladosporium cladosporioides, Leptographium cucullatum, Ophiostoma minus, and Graphilbum acuminatum. No significant differences in fungal diversity between different locations and between male and female I. acuminatus were observed. However, significant seasonal differences were observed between months in which I. acuminatus beetles were captured and fungal communities isolated from them. More research is needed on the potential of the entomopathogenic fungi isolated in this study for the biological control of I. acuminatus. Also, the pathogenicity of isolated Ophiostomatoid fungi and their ability to cause blue-stain in Pinus sylvestris timber could be further evaluated. Full article

The emerald ash borer (EAB; Agrilus planipennis Fairmaire) is a deadly pest of ash trees (Fraxinus spp.) in North America. Chemical and biological control methods are already in use against EAB, but additional integrated pest management (IPM) strategies are needed to reduce EAB populations in remote, northerly forests on the edge of the infestation front, such as those in northern Minnesota, USA. One entomopathogenic fungus (EPF) isolate, Beauveria bassiana (Bals.-Criv) Vuill. CFL-A, deployed in autodissemination devices (ADDs) has previously shown promise in reducing EAB population growth. Additionally, EPF has been found to be associated with EAB in Minnesota. This study assessed the suitability of ten Minnesota-indigenous, and one commercial, EPF strains for potential use in ADDs targeting EAB adults. Fungal isolates spanned five genera, including Beauveria, Purpureocillium, Metarhizium, Clonostachys, and Samsoniella. Of those tested, Beauveria pseudobassiana S.A. Rehner and Humber EAB 16.8, Beauveria bassiana GHA, Metarhizium sp. Meta, and Purpureocillium sp. EAB 59-16-2 consistently reduced the mean survival time (MST) and probability of survival over time for EAB adults dropped into an EPF-containing ADD in the laboratory. Furthermore, these fungi were readily recovered from surface-sterilized EAB cadavers. Future ADD field trials using these isolates are warranted to validate their ability to reduce EAB population growth. Full article

Most organisms are associated with microorganisms, which influence their behavior during their life cycles. Fungi are no exception; they interact with plants, viruses, and bacteria in various environments, forming complex communities. These associations can occur externally around the mycelia and internally within the hyphae. Fungi can harbor bacteria, mycoviruses, and other fungi within their hyphae. Some endobacteria (EB) have been shown to alter fungal host function, development, and interactions with other organisms. Most fungi that host endobacteria (EB) are plant-associated. Although members of the genus Metarhizium are among the most abundant fungi isolated from soils, their associated EB have not been sufficiently studied. Endobacteria were recently detected in M. bibiondarum and M. anisopliae; however, the biological roles of these bacteria in the different Metarhizium life cycles remain unknown. In this study, Metarhizium strains were isolated from the rhizosphere and Phyllophaga spp. Bacillus subtilis was identified as an endobacterium, and its influence on the physiology of Metarhizium and entomopathogenic capacity was studied. Our analysis revealed that EB have a negative impact on the virulence of Metarhizium against Galleria mellonella and Tenebrio molitor. Full article