• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.2
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• pp.229-234
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• 2004

Six entomopathogenic fungus isolates, Beauveria bassiana J57A, Nomuraea rileyi J125A, Paecilomyces farinosus J3A, Paecilomyces fumosoroseus J50A, Metarhizium anisopliae J88, Aspergilius sp. J64A, causing muscardine disease and aspergillosis in the silkworm, Bombyx mori were investigated for their cultural and morphological characteristics (on PDA culture media within 14 days at $24^{\circ}C$). The results showed that they differ each other from the features of cultural characteristics (colony elevation, colony color, colony growth rate) or morphological characteristics (conidiogenous cell structure, phialides, conidia size and shape). Among cultural characteristics, colony color is the easiest recognizable character between isolates. The morphological characteristics of each fungal isolate correspond to the descriptions of current system of classification.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.2
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• pp.119-123
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• 2005

Benomyl-resistant mutants of entomopathogenic fungus, Metarhizium anisopliae were isolated and their physiological characteristics were investigated. These militants were obtained spontaneously or by UV irradiation in benomyl-treated media. Four spontaneous (S-2, S-11, S-18, S-19) and four UV-induced (UV-4, UV-5, UV-19, UV-24) mutants, which grow stably and normally were selected. No significant differences in conidia or hyphal shape, conidia viability, mycelial biomass, or virulent to the diamondback moth were observed between the wild type and their mutants. But differently from the mycelial growth of other benomyl-resistant mutants which was slower than that of the wild type on a modified Czapek-Dox, SDAY, $4\%$ chitin, or $1\%$ skim milk medium, that in the spontaneous mutants, S-18 and S-19, did not show any difference from the wild type. Especially, S-18 and S-19 grew well at benomyl concentrations up to 50 times or higher than that which inhibits wild type proliferation. These results suggested that S-18 and S-19 could potentially be used with the fungicide, benomyl.

• International Journal of Industrial Entomology and Biomaterials
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• v.36 no.1
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• pp.1-9
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• 2018

The purpose of this study was to determine the best method for minimizing the occurrence of Metarhizium anisopliae infection of Protaetia brevitarsis seluensis during mass breeding on agricultural farms. There is a high demand for the use of P. b. seluensis larvae in animal feed and as food for humans. However, mass breeding results in the entomopathogenic fungal (usually M. anisopliae) infection of P. b. seluensis. A mixture of microorganisms (Bacillus subtilis, Lactobacillus plantarum, and Saccharomyces cerevisiae) delayed fungal infection by M. anisopliae, which infected fewer P. b. seluensis when the microorganism mixture was added to sawdust as feed for P. b. seluensis. When sawdust with the effective microorganisms (EM) was given to P. b. seluensis for 30 d, their mortality rate was approximately 35 % less than that of the control group, which was fed sawdust without the EM. In addition, the growth of M. anisopliae on agar media spread with each bacterium as inhibited by up to 80 % more than those spread with 4 % sodium hypochlorite, which is a harmless fungal inhibitor generally used in agricultural farms for disinfection.

• Mycobiology
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• v.42 no.4
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• pp.385-390
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• 2014

The beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) is difficult to control using chemical insecticides because of the development of insecticide resistance. Several pest control agents are used to control the beet armyworm. Entomopathogenic fungi are one of the candidates for eco-friendly pest control instead of chemical control agents. In this study, among various entomopathogenic fungal strains isolated from soil two isolates were selected as high virulence pathogens against larva of beet armyworm. Control efficacy of fungal conidia was influenced by conidia concentration, temperature, and relative humidity (RH). The isolates Metarhizium anisopliae FT83 showed 100% cumulative mortality against second instar larvae of S. exigua 3 days after treatment at $1{\times}10^7$ conidia/mL and Paecilomyces fumosoroseus FG340 caused 100% mortality 6 days after treatment at $1{\times}10^4$ conidia/mL. Both M. anisopliae FT83 and P. fumosoroseus FG340 effectively controlled the moth at $20{\sim}30^{\circ}C$. M. anisopliae FT83 was significantly affected mortality by RH: mortality was 86.7% at 85% RH and 13.4% at 45% RH. P. fumosoroseus FG340 showed high mortality as 90% at 45% RH and 100% at 75% RH 6 days after conidia treatments. These results suggest that P. fumosoroseus FG340 and M. anisopliae FT83 have high potential to develop as a biocontrol agent against the beet armyworm.

• Mycobiology
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• v.48 no.2
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• pp.139-147
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• 2020

Root-feeding Scarabaeidae, particularly white grubs are considered among the most harmful coleopteran insect pests in turfgrass. In this work, sixteen entomopathogenic fungal species were assayed against flower chafer beetle, Protaetia brevitarsis (Coleoptera: Scarabaeidae) and Metarhizium anisopliae JEF-314 showed high virulence. The control ability of the isolate JEF-314 has been in detail tested for a model insect flower chafer beetle. Further analyses showed insect stage-dependent virulence where the fungal virulence was the highest against smaller instar larvae. Additionally, we confirmed that millet-based solid cultured granule was effective against the soil-dwelling larval stage. The isolate also showed a similar ability for a representative pest (Popillia spp.) in laboratory conditions. Our results clearly suggest a high potential of M. anisopliae JEF-314 to control the flower chafer beetle, possibly resulting in controlling of root-feeding white grubs in turfgrass. Based on the insect life cycle and susceptibility to the fungus, late spring and summer time would be the optimum time to apply JEF-314 granules for an effective control. Further characterization of the efficacy of the fungus under field conditions against the Scarabaeidae beetles might provide an efficient tool to control this beetle in an environment-friendly way.

• Journal of Microbiology and Biotechnology
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• v.22 no.7
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• pp.889-893
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• 2012

Appressorium is a specialized infection structure of filamentous pathogenic fungi and plays an important role in establishing a pathogenic relationship with the host. The Egh16/Egh16H family members are involved in appressorium formation and pathogenesis in pathogenic filamentous fungi. In this study, a homolog of Egh16H, Magas1, was identified from an entomopathogenic fungus, Metarhizium acridum. The Magas1 protein shared a number of conserved motifs with other Egh16/Egh16H family members and specifically expressed during the appressorium development period. Magas1-EGFP fusion expression showed that Magas1 protein was not localized inside the cell. Deletion of the Magas1 gene had no impact on vegetative growth, conidiation and appressorium formation, but resulted in a decreased mortality of host insect when topically inoculated. However, the mortality was not significant between the Magas1 deletion mutant and wild-type treatment when the cuticle was bypassed by injecting conidia directly into the hemocoel. Our results suggested that Magas1 may influence virulence by affecting the penetration of the insects' cuticle.

• Korean Journal of Organic Agriculture
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• v.31 no.1
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• pp.95-106
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• 2023

Entomopathogenic fungi are one of the microorganisms distributed worldwide, and they inhabit not only insects but also soils of various regions such as agricultural land and forest areas. In this study, entomopathogenic fungi distributed in the soil of forest areas in Korea were isolated using the insect-baiting method, and the relationship between the distribution and diversity of entomopathogenic fungi and the physical/chemical characteristics of the soil was analyzed. The soils were collected from five forest areas in Korea, and a total of 42 entomopathogenic fungal isolates were isolated from the collected soils. Among them, Beauveria bassiana (42.9%) and Metarhizium anisopliae (45.2%) were mainly isolated. In particular, it was confirmed that the distribution of M. anisopliae varies depending on the total nitrogen (g/kg) and organic matter content (%) of the soil. The soils in forest areas in Korea have a low pH of 4-5. Among all isolates, >50% of entomopathogenic fungi were isolated from silt loam. This study suggests that it will be helpful in understanding the relationship between the distribution and diversity of entomopathogenic fungi and the physical and chemical characteristics of soil.

• Korean Journal of Ecology and Environment
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• v.53 no.4
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• pp.374-379
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• 2020

The white-spotted flower chafer (Protaetia brevitarsis) larva is one of the insects widely-used for edible and medicinal purposes in Eastern Asia. As a result of increasing demand for P. brevitarsis, massrearing systems in domestic farms have become necessary. However, the mass-rearing of larvae under confined rearing conditions could provide conditions unsuitable for preventing entomopathogenic diseases. Metarhizium anisopliae is the strongest fatal entomopathogenic fungus against P. brevitarsis. For inhibition of M. anisopliae, we used a Rhus verniciflua Stokes extract that has antifungal components. We investigated the inhibitory effect of the R. verniciflua extract at 1%, 5%, and 10% concentrations. The results showed that a 1% R. verniciflua extract added to sawdust produced a significantly low P. brevitarsis mortality rate. Moreover, extract-treated groups were heavier and had a shorter larval period than those of the untreated group. Consequently, we suggest that using an R. verniciflua extract can reduce the P. brevitarsis fatality rate from entomopathogenic fungi (e.g. M. anisopliae), resulting in more effective mass-rearing systems for P. brevitarsis.

• Journal of Korean Society of Forest Science
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• v.112 no.1
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• pp.117-125
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• 2023

Outbreaks of Ramulus mikado (Insecta: Phasmatodea: Phasmatidae) in the hilly areas of Mt. Bongsan, Mt. Cheonggye, and elsewhere in Seoul and Gyeonggi occurred from 2020 to 2021, causing serious defoliation. We evaluated the insecticidal effects of six eco-friendly organic materials and the insect-pathogenic fungus Metarhizium anisopliae against R. mikado. The fungus was isolated from naturally dead bodies of R. mikado in forest ecosystems. The results revealed that three eco-friendly organic materials containing azadirachtin or geraniol as active ingredients showed high mortality in the range of 85.2%-100%, which were rates similar to that of the chemical insecticide fenitrothion emulsifiable concentrate. All R. mikado adults that were sprayed with a conidial suspension of M. anisopliae at different concentrations were killed within a few days. In conclusion, three eco-friendly organic materials and M. anisopliae could be good alternatives to chemical insecticides.

• Journal of Microbiology and Biotechnology
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• v.27 no.11
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• pp.1897-1906
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• 2017

Swainsonine (SW) is the principal toxic ingredient of locoweed plants that causes locoism characterized by a disorder of the nervous system. It has also received widespread attention in the medical field for its beneficial anticancer and antitumor activities. Endophytic fungi, Alternaria sect. Undifilum oxytropis isolated from locoweeds, the plant pathogen Slafractonia leguminicola, and the insect pathogen Metarhizium anisopliae, produce swainsonine. Acquired SW by biofermentation has a certain foreground and research value. This paper mainly summarizes the local and foreign literature published thus far on the swainsonine biosynthesis pathway, and speculates on the possible regulatory enzymes involved in the synthesis pathway within these three fungi in order to provide a new reference for research on swainsonine biosynthesis by endophytic fungi.