Search Results (490)

Entomopathogenic fungi (EPF) are one of the most environmentally friendly ways to control a plethora of chewing insects such as T. pityocampa, G. mellonella, and A. grisella. Bioassay of EPF on these highly damaging pests is considered important in the face of climate change in order to research alternative solutions that are capable of limiting chemical control, the overuse of which increases insects’ resistance to chemical compounds. In this study, the insecticidal virulence of Metarhizium robertsii isolates, retrieved from forest ecosystems, was tested on second-instar larvae of T. pityocampa, G. mellonella, and A. grisella. Bioassays were carried out in the laboratory, where experimental larvae were sprayed with 2 mL of a six-conidial suspension from each isolate. Mortality was recorded for 144 h after exposure. Mean mortality, lethal concentrations, sporulation percentage, and sporulation time were estimated for each isolate. Metarhizium isolates resulted in the highest mortality (89.2% for G. mellonella and 90.2% for A. grisella). Based on the LC₅₀ estimates determined by the concentration–mortality relationships for the tested fungal isolates, we demonstrated significant virulence on larvae of G. mellonella, A. grisella, and T. pityocampa. Our results indicate that entomopathogenic fungi have the potential to become a very useful tool in reducing chemical applications. Full article

Entomopathogenic fungi are among the most promising non-chemical alternatives for the control of many serious phytophagous insect pests, such as moth species. The present research investigates the use of the little-studied entomopathogenic fungus Beauveria varroae as a biocontrol agent against the notorious pests Helicoverpa armigera and Sesamia nonagrioides in laboratory conditions. Conidial suspensions of B. varroae were prepared at 10³-10⁴-10⁵-10⁶-10⁷-10⁸ conidia/mL to assess their insecticidal potential. In this study, we used 100 3rd-instar larvae for each concentration. During the lab bioassays, almost complete mortality of 35–96.6% was recorded for H. armigera larvae and 40–96.6% for S. nonagrioides larvae 10 days after exposure. The lethal effect of the entomopathogen was related to both dose and exposure time of the entomopathogen, with higher concentrations resulting in increased mortality. The survival effect of S. nonagrioides and H. armigera larvae was dependent on the hazard effect of the used dose and the exposure time. These findings indicate that B. varroae has potential as a biocontrol agent. Further research will elucidate this new isolate and optimize application methods in field conditions. Full article

Aging in sexually reproducing organisms is shaped by the declining force of natural selection after reproduction begins. In Drosophila melanogaster, experimental evolution shows that altering the age of reproduction shifts the timing of aging. Using the Drosophila experimental evolution population (DEEP) resource, which includes long- and short- lived populations evolved under distinct reproductive schedules, we investigated how immune defense against Beauveria bassiana changes with age and evolved lifespan. We tested survival post-infection at multiple ages and examined genomic differentiation for immune-related genes. Both population types showed age-related declines in immune defense. Long-lived populations consistently exhibited age-specific defense when both long- and short-lived populations were tested. Genomic comparisons revealed thousands of differentiated loci, yet no enrichment for canonical immune genes or overlap with gene sets from studies of direct selection for immunity. These results suggest that enhanced immune defense can evolve alongside extended lifespan, likely via general physiological robustness rather than traditional immune pathways. A more detailed analysis may reveal that selection for lifespan favors tolerance-based mechanisms that reduce infection damage without triggering immune activation, in contrast to direct selection for resistance. Our findings demonstrate the utility of experimentally evolved populations for dissecting the genetic architecture of aging and immune defense to inform strategies to mitigate age-related costs associated with immune activation. Full article

Recent advances in microbiome studies have deepened our understanding of endosymbionts and gut-associated microbiota in host biology. Of those, lepidopteran systems in particular harbor a complex and diverse microbiome with various microbial taxa that are stable and transmitted between larval and adult stages, and others that are transient and context-dependent. We highlight key microorganisms—including Bacillus, Lactobacillus, Escherichia coli, Pseudomonas, Rhizobium, Fusarium, Aspergillus, Saccharomyces, Bifidobacterium, and Wolbachia—that play critical roles in microbial ecology, biotechnology, and microbiome studies. The fitness implications of these microbial communities can be variable; some microbes improve host performance, while others neither positively nor negatively impact host fitness, or their impact is undetectable. This review examines the central position played by the gut microbiota in interactions of insects with plants, highlighting the functions of the microbiota in the manipulation of the behavior of herbivorous pests, modulating plant physiology, and regulating higher trophic levels in natural food webs. It also bridges microbiome ecology and applied pest management, emphasizing S. frugiperda as a model for symbiont-based intervention. As gut microbiota are central to the life history of herbivorous pests, we consider how these interactions can be exploited to drive the development of new, environmentally sound biocontrol strategies. Novel biotechnological strategies, including symbiont-based RNA interference (RNAi) and paratransgenesis, represent promising but still immature technologies with major obstacles to overcome in their practical application. However, microbiota-mediated pest control is an attractive strategy to move towards sustainable agriculture. Significantly, the gut microbiota of S. frugiperda is essential for S. frugiperda to adapt to a wide spectrum of host plants and different ecological niches. Studies have revealed that the microbiome of S. frugiperda has a close positive relationship with the fitness and susceptibility to entomopathogenic fungi; therefore, targeting the S. frugiperda microbiome may have good potential for innovative biocontrol strategies in the future. Full article

The Tetranychus urticae Koch (Acari: Tetranychidae) is one of the primary pests affecting buckwheat, and its management has become increasingly critical. Entomopathogenic fungi offer a promising way to solve this problem by providing both pest control and disease resistance, as well as promoting plant growth through endophytic colonization. This study investigated the effects of applying Isaria cateniannulata (Liang) Samson & Hywel-Jones and Beauveria bassiana (Bals.-Criv.) Vuill. on different buckwheat varieties, and analyzed the physiological indices of buckwheat, the population of T. urticae and Euseius nicholsi (Ehara & Lee). Results showed that the optimum concentration for fungal colonization on buckwheat was 1 × 10⁷ spores/mL. The combined application of I. cateniannulata and B. bassiana significantly enhanced buckwheat growth, with root length, plant height, main stem diameter, fresh weight, and dry weight reaching 63.3 mm, 24.1 cm, 2.1 mm, 2.0 g, and 0.1 g, respectively. The highest escape rate of T. urticae was 76.33%. Furthermore, the combined application of mixed fungal suspension and E. nicholsi had the best control effect on T. urticae, with pest suppression exceeding 97.83% and an oviposition as low as 0.25 eggs per female. This study is the first to demonstrate that the joint application of I. cateniannulata and B. bassiana can promote buckwheat growth and, when combined with predatory mites, effectively control T. urticae. These findings provide a theoretical basis for the development of integrated biocontrol strategies combining entomopathogenic fungi and predatory mites. Full article

Entomopathogenic fungi (EPF) are substantial biocontrol agents reducing the populations of economically important pests in numerous crops. Recent findings indicate that their role in agroecosystems is more complex and extends to affecting plant physiology and growth. This study examined the effects of Beauveria bassiana and Isaria fumosorosea, as well as Salicylic acid (SA), on physiological parameters of grapevine (Vitis vinifera cv. Sauvignon Blanc). Additionally, the impact of SA on spore germination and pathogenicity of EPF against larvae of the European grapevine moth (Lobesia botrana) was tested. Foliar application of EPF was found to increase the electron transport rate (ETR) from PSII to PSI, indicating higher photosynthetic activity compared to control plants. EPF also elevated the transpiration rate (E) and stomatal conductance (gs). In contrast, SA treatments decreased E and gs, while the high dose (10 mM) exhibited reduced Fv/Fm value, accompanied by phytotoxic spots on leaves. Spore germination of both fungi was significantly reduced only by the SA concentration of 2 mM, while 0.5 and 1 mM did not affect germination. Combination EPF and SA treatments presented the highest larval mortality of L. botrana (87.5% at 28 °C and 77.5% at 24 °C for B. bassiana and I. fumosorosea, respectively). However, SA reduced larval mycosis in most cases. Overall, the results suggest that EPF and SA can be co-applied and included in vineyard integrated strategies to support grapevine health. Full article

The efficacy of two selected Metarhizium rileyi Mexican isolates (T9-21 and L8-22) against Spodoptera frugiperda was evaluated under greenhouse conditions. To this end, a suspension (1 × 10⁸ conidia/mL) of these isolates was sprayed on maize plants previously infested with six second-instar larvae. No significant differences were observed between the survival curves of the T9-21 and L8-22 isolates. Cadaver sporulation was significantly higher, and the lethal time was significantly lower with the T9-21 isolate compared with those of the L8-22 isolate (97% and 8 days vs. 70% and 10 days, respectively). Based on these results, a small-scale field trial on maize was performed to evaluate the degree of pest control achieved by the T9-21 isolate and compare it with the insecticide spinetoram, applied at a rate of 1 × 10¹³ conidia/ha and 75 mL/ha, respectively. No significant differences were observed in the proportion of larval mortality between the T9-21 isolate (0.49) and spinetoram (0.72). However, spinetoram significantly reduced natural enemies and phytophagous insect populations compared with the fungus and the control. In conclusion, M. rileyi T9-21 isolate could be a promising alternative for the control of S. frugiperda larvae. Full article

Urochloa ruziziensis (R. Germ. and C.M. Evrard) Crins (synonym Brachiaria ruziziensis) Poales: Poaceae) pastures are often attacked by spittlebugs, compromising their biomass for livestock usage. A sustainable control method involves the use of entomopathogenic fungi. Therefore, the objective of this study was to evaluate the efficacy of controlling Mahanarva spectabilis Distant, 1909 (Hemiptera: Cercopidae), in greenhouse and field conditions via endophytic entomopathogenic fungi. In the greenhouse, the mortality of nymphs and adults was 100%, and more than 53% of the nymphs and 59% of the adults that fed on plants inoculated with Fusarium multiceps and Metarhizium anisopliae presented with these fungi in their cadavers. In the field, more than 45% of the insect cadavers that had fed on plants grown from fungus-treated seeds were found to contain the fungi. F. multiceps was found to be endophytic in more than 60% of the plants up to 90 days after seed treatment, and M. anisopliae was found in more than 70% of the plants up to 120 days after treatment. The damage scores of the control plants, both in the greenhouse and in the field, were greater than those of the plants inoculated with the fungi. F. multiceps and M. anisopliae in the endophytic pathway of U. ruziziensis are therefore efficient at controlling spittlebugs. Full article

Bradysia difformis Frey (Diptera: Sciaridae) is a fungus gnat that poses a significant threat to greenhouse cultures, and is attracted to soils devoid of peat. Fungal strains from the German Collection of Microorganisms and Cell Culture (DSMZ), such as Beauveria bassiana, Metarhizium flavoviride, Mucor hiemalis, and Niesslia tinuis, as well as Serendipita indica, were screened for entomopathogenic activity against B. difformis and their capacity to colonize Petunia hybrida cv. “Mitchell” and Ocimum basilicum plants. The survival rates of Bradysia difformis (three instar larvae) treated with Metarhizium flavoviride were 45.33% at 14 days following inoculation with 1 × 10⁶ spores/mL of each fungal strain, when compared to others. We concluded that the fungal strain M. flavoviride could serve as an entomopathogenic fungus with the highest virulence against B. difformis larvae. Although M. flavoviride did not show a beneficial effect as an endophyte, interestingly, the strain Niesslia tinuis exhibited plant growth benefits in Petunia hybrida cv. “Mitchell” by enhancing its shoot length up to 13.18 ± 0.72 cm, whereas the control treatment had a shoot length up to 10.68 ± 0.39. Enzymatic assays confirmed the ability of M. flavoviride to produce cuticle-degrading enzymes such as chitinase and protease. Together, these findings highlight the potential of EMPF—particularly M. flavoviride—as a sustainable biocontrol tool well-suited for peat-free horticultural systems, offering an eco-friendly alternative to chemical insecticides where fungus gnat pressure is typically high. Full article

Chemical control using synthetic insecticides is the most widely used method for controlling the fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) in Sub-Saharan Africa (SSA). However, the application of insecticides is not a long-term or sustainable solution. Biological control is an important pillar of integrated pest management, and entomopathogenic fungi (EPFs) are becoming increasingly important as biocontrol agents. However, no EPF biopesticides have been registered in South Africa for the control of S. frugiperda. Few studies have been conducted on the efficacy of commercial formulations of biopesticides against all S. frugiperda life stages. The objective of this study was, therefore, to assess the potential of two Beauveria bassiana (Balsamo-Crivelli) Vuillemin (Hypocreales: Clavicipitaceae) and two Metarhizium anisopliae (Metschnikoff) Sorokin (Hypocreales: Clavicipitaceae) based commercial biopesticides registered in South Africa against other pests, for their efficacy against S. frugiperda. The effects of these EPF formulations were evaluated on larval and prepupal mortality, moth emergence, fecundity, and longevity of the emerged moths. The results indicated that S. frugiperda second- and sixth-instar larvae were not susceptible to the biopesticides. Moth emergence, fecundity, and longevity were not significantly affected. However, prepupae were susceptible to both Metarhizium formulations, with Metarhizium anisopliae ICIPE 78 resulting in the highest mortality (56.7%). This biopesticide holds potential for the management of S. frugiperda when applied to the soil for the control of pupating larvae. Full article

Malaria remains a public health issue across the world. Different methods have been analyzed to achieve this disease’s elimination, such as the vector control of Anopheles spp. Control strategies include the use of different classes of insecticides, although the accelerated evolution of vectors resistant to them makes the development of alternative control methods necessary. Therefore, entomopathogenic fungi have been considered to be promising biopesticides, given that they are safe for human beings and the environment. This study aimed to evaluate the entomopathogenic activity of fungi collected in the Amazon Rainforest against adult female Anopheles aquasalis mosquitoes. Females were exposed to four different species of fungi and observed daily to evaluate their survival rate. Also, fungi species’ behavior was analyzed through scanning electron microscopy (SEM). Those exposed to Trichoderma harzianum and Penicillium citrinum had their survival rate reduced. SEM confirmed the development of fungi on the mosquitoes after 48 h. The findings suggest that the entomopathogenic potential of the fungi used in this study should be considered, given the reduction in the survival rate of Anopheles aquasalis mosquitoes. Full article

Entomopathogenic fungi are a group of fungi that infect and kill insects to obtain nutrients, thereby contributing to the natural regulation of insect populations. In recent years, they have been increasingly utilized as biological control agents, particularly in response to the rising prevalence of pesticide-resistant pests in agricultural systems. Representative examples include Beauveria bassiana and Metarhizium anisopliae, which are regarded as natural enemies of pests in agroecosystems. Since the first report of Korean oak wilt disease in 2004, the disease has continuously spread across the country and causes severe damage to deciduous oak species, especially Quercus mongolica. Although many efforts have been made to effectively control the disease, including chemical treatments, the control efficacy was shown to be low, and given the environmental side effects arising from the use of insecticides, there has been a demand for alternative control strategies. Integrated Pest Management in forests promotes ecological sustainability by reducing chemical pesticide use, conserving biodiversity, and enhancing long-term forest health. In this study, to mitigate issues with disease management strategies, assessments were made on three entomopathogenic fungi, B. bassiana, M. anisopliae, and Purpureocillium lilacinum, as potential biological control agents against oak wilt disease and its insect vector, Platypus koryoensis. In this regard, we investigated the insecticidal efficacy and LT₅₀ of each entomopathogenic fungus, and the results showed that all three entomopathogenic fungal strains exhibited fast insecticidal effects against the insect vector, P. koryoensis, with M. anisopliae showing the fastest action, recording a lethal time to 50% mortality (LT₅₀) of 58.7 h. The spores of M. anisopliae were found to be sensitive to high temperatures, while demonstrating a relatively high germination rate under UV exposure and strong initial germination ability at low temperatures. Full article

Ambrosia beetles, known for their symbiotic relationship with fungi cultivated within the tissues of host trees, have become significant pests, particularly when they serve as vectors for pathogenic fungi such as Raffaelea lauricola. Given the regulatory and environmental constraints for chemical application as a tool for their control, entomopathogenic fungi (EPF) represent a promising pest management alternative. This review presents an overview of bioassays assessing the pathogenicity and virulence of EPF against ambrosia beetles. Most studies have been performed in vivo (artificial diet) under laboratory conditions, focusing on exotic species and testing EPF genera such as Beauveria, Metarhizium, Isaria, and Purpureocillium. However, variations in inoculation methods, environmental conditions, and fungal formulations, have led to diverse results. In addition, the complex biology of these insects, particularly their dependence on symbiotic fungi, represents significant methodological challenges. Field trials (in situ bioassays) are still scarce, and there is a need to move toward standardized protocols and more objective experimental models that consider not only insects’ behavior but also ecological factors. Bridging this gap is essential for successfully implementing EPF-based strategies to assess ambrosia beetles’ biocontrol. Full article

The use of entomopathogenic fungi (EPF), such as Cordyceps javanica, to reduce insect pest populations is gaining traction since it is an environmentally safe approach that can control many pests at different life stages. Here, we focus on the histopathology of the coffee berry borer, Hypothenemus hampei, infected by C. javanica. Morphological observation revealed that C. javanica conidia germinated within 12 h following inoculation according to light microscopic and ultrastructural levels. The fungus thoroughly penetrated the fat body and muscular tissue between 84 and 120 h post-inoculation. Transmission electron microscopy (TEM) confirmed the hyphal invasion of the cuticle at 12 h post-inoculation, with progressive tissue disruption and organelle degeneration, especially mitochondria and rough endoplasmic reticulum in adipocytes. All organelles were completely degenerated at 96 h post-inoculation. There was evidence of a connection between C. javanica activity and the coffee berry borer that might cause histopathological changes in the host defense against the pathogen, pointing to increased mortality and potential control of coffee berry borer in natural populations. Additionally, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) confirmed that apoptotic cells were slightly increased in the adipose tissue and integument of the coffee berry borer. The ability of C. javanica to fatally infect the coffee berry borer suggests that it could be deployed as a biological control agent in the field. Full article

The striped flea beetle (SFB), Phyllotreta striolata, is a significant pest of cruciferous crops. Entomopathogenic fungi (EPF) hold great promise for the integrated pest management (IPM) of the SFB. However, the lack of understanding of the different interactions between the SFB and EPF restricts the development of mycoinsecticides. This study aims to elucidate the interaction performance of the SFB with three EPF—Beauveria bassiana BbPs01 (Bb), Metarhizium robertsii MrCb01 (Mr), and Cordyceps javanica IjH6102 (Cj). The bioassay results indicated that the virulences of EPF to the SFB adults were recorded as Bb > Mr > Cj. Then, the EPF with distinct infection pathways were observed, in which Bb penetrated the SFB cuticle via germ-tubes and appressoria, Mr typically invaded using appressoria, while Cj employed germ-tubes. Moreover, the SFB with different symptoms following infection by the EPF species were recorded. Bb primarily caused SFB adults to lose their appetite, become sluggish, and die rapidly. In contrast, SFB adults infected with Mr often experienced shivering, uncoordinated movement, and slower death. Cj-infected larvae frequently displayed dendrite-like melanization originating from the spiracles, while infected adults exhibited weak shivering and slow death, which seems similar to Mr. Our findings provide novel insights into the interactions between EPF and insects and offer valuable materials for enhancing the application of mycoinsecticides in the control of the SFB. Full article