• Journal of Life Science
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• v.23 no.8
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• pp.1010-1018
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• 2013

The greenhouse whitefly, Bemisia tabaci, is considered one of the most destructive pests of crops. In this study, we aimed to determine the optimal liquid culture conditions in shake flasks for maximal sporulation of Beauveria bassiana M130 using rice bran. The optimal initial pH for the spore production of B. bassiana using extracted rice bran medium was 5.2 and $28^{\circ}C$. The screening in shake flasks of carbon and nitrogen sources resulted in the identification of an optimal medium based on 0.5% $(NH_4)_2SO_4$, with extracted rice bran 8:1. Using this medium, a production level of $2.15{\times}10^9$ spores per ml was obtained after six days from culture inoculation at $28^{\circ}C$ in a rotary shaking incubator at 130 rpm. In addition, the specific activities of extracellular enzymes of chitinase and protease were $4,296{\mu}mol$ and $375{\mu}mol$, respectively. These results suggest that Beauveria bassiana M130 could be a bio-controller for the greenhouse whitefly.

• Korean Journal of Microbiology
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• v.48 no.4
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• pp.284-292
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• 2012

To date, chemical control remains the most common way to reduce beet armyworm (Spodoptera exigua) populations. However, this insect has become more tolerant or resistant to many chemical insecticides and the insect larvae usually hide inside hollow, tube-like leaves of host plant so they were difficult to kill by spraying insecticides. The use of viral and bacterial insecticide to solve these problems has not been successful because of their novel feeding habit. To overcome these problems, in this study, the biological characteristics and virulence of an entomopathogenic fungus isolated from the cadaver of larvae beet armyworm were investigated. Isolated entomopathogenic fungus was identified as Nomeraea rileyi (Farlow) Samson by morphological examinations and genetic identification using sequences of the ITS, ${\beta}$-tubulin gene and EF1-${\alpha}$ regions. This fungus was named as N. rileyi SDSe. Virulence tests against 3rd larvae of beet armyworm were conducted with various conidial suspensions from $1{\times}10^4$ to $10^8$ conidia/ml of N. rileyi SDSe in laboratory conditions. Mortality rate of beet armyworm showed from 20 to 54% and the virulence increased with increasing conidial concentrations. Although N. rileyi SDSe showed low mortality rate against beet armyworm, it is expected that N. rileyi SDSe will be used effectively in the integrated pest management programs against the beet armyworm.

• Asian Journal of Turfgrass Science
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• v.11 no.3
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• pp.185-191
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• 1997

Biological control of turfgrass insect pest Blitopertha orientalis, forest insect pests, Agelastica coerulea, Meganola melancholia, and Glyphodes perspectalis,vegetable insect pests, Plutella xylostella and Agrotis segetum were conducted with entonopathogenic fungus, Metarhizium anisopliae J-22 isolated from black pine forest soil in Cheju province. Mortality of B. orientalis larvae was 53.3% at the rate of 3.4 $\times$ 1O 7 conidia /ml. A. coerulea and M melancholia larvae showed 100% mortalities at 9.6 $\times$ 106 conidia /ml and 2.7 $\times$ 10 7 conidia /ml as well. However, G. perspectalis larvae were not dead even at 4$\times$ 1O 7 conidia /ml. On the other hand, M anisopliae J-22 was effective against P. xylostella larvae showing 100% mortality at 4 $\times$ 10 7 conidia /ml. KEy words:Entomopathogenic fungi, Biological control, Metarhizium anisopliae, Pathogenicity,Blitopertha orientalis, Agelastica coerulea, Meganola melancholia, Glyphodes perspectalis,Plutella xylostella, Agrotis segetum.

• The Korean Journal of Mycology
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• v.37 no.2
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• pp.139-143
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• 2009

Several entomopathogenic fungi have been exploited to be developed into biological control agents in insect pest management. The beet armyworm, Spodoptera exigua, is a serious insect pest infesting various crops, but not effectively controlled by commercial chemical pesticides due to its high insecticide resistance. A fungal isolate was isolated from S. exigua larvae collected from cabbage field in Andong, Korea. The fungus could be cultured in potato dextrose agar. Larvae of S. exigua injected with the cultured conidia showed a potent entomopathogenicity. To identify the fungus isolate, its internal transcribed space (ITS) and surrounding partial 18S/28S regions were sequenced. The ITS sequence was highly matched (99%) to that of Nomuraea rileyi. Morphological characters of its hyphae and conidia were well fit to those of known N. rileyi. This study reports the first record of an entomopathogenic fungus, N. rileyi, in Korea.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.465-469
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• 2016

An entomopathogenic fungus was isolated from the two-spotted spider mite (Tetranychus urticae) in a rearing house, and identified as Neozygites floridana (Entomophthorales: Neozygitaceae). A high infection rate induced by N. floridana could increase the price of the natural enemy. The body color of mites infected by this fungus changed to red or orange and swelling occurred. Fungal conidia were discharged into the webbing produced by the spider mites, making it relatively easy to infect the mites. Primary conidia were pear shaped and capilliconidia almond shaped. The fungus could not be cultured on solid media (PDA, SDAY, or EYSDA), but could possibly be cultured in liquid media (Grace's insect tissue culture medium + 5% fetal bovine serum). Kidney beans were supplied as food for T. urticae; the mite infection rate in a kidney bean canopy was about 36.1%. The density of infected mites was higher on the underside than on the upper side of leaves. Based on the results of this survey, we need to identify methods of fungal control for natural enemy production and biological control agents for T. urticae for effective crop management.

• KSBB Journal
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• v.14 no.3
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• pp.365-370
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• 1999

To optimize the culture conditions for Beauveria bassiana 726, the effects of culture medium, pH, and temperature on mycelium and spore production were investigated. The optimum temperature and pH for the cultivation of B. bassiana 726 were 28 $^{\circ}C$ and 5.0, respectively. The optimized medium was composed of 1.0~2.0% total sugar from molasses, 0.5% corn steep liquor and 0.05% KH$_2$PO$_4$. In the cultivation of B. bassiana 726 with the optimum medium, the specific growth rate and substrate utilization were well-fitted with the proposed kinetic model in the shake flask and stirred tank reactor. When the fed-batch cultivation using carbon suorce, nitrogen source, and mineral salt as a feeding medium was compared with batch cultivation in stirred tank reactor, mycelium (12.7 g/L) and spore production (5.4$\times$$10^8/mL$) were enhanced up to 110% and 85%, respectively.

• Korean Journal of Organic Agriculture
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• v.31 no.4
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• pp.427-439
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• 2023

The silverleaf whitefly, Bemisia tabaci, is a major pest distributing worldwide damaging over 900 host plant species, and is highly resistant to chemical pesti- cides. Due to the high pesticide resistance of whitefly, there is a need for alternatives to chemical control. Entomopathogenic fungi are candidates for biological pesticide that can overcome the resistance problem of chemical pesticide. Therefore, in this study, we tested pathogenicity of the entomopathogenic fungi to select high insec- ticidal activity against whitefly. As a result, IPBL-C (Cordyceps fumosorosea) and IPBL-F (Metarhizium pinghaense) isolates showed high insecticidal activity against whitefly. Additionally, as a result of culturing the selected isolates on spent coffee grounds medium, the conidia of IPBL-F produced on coffee grounds medium showed five times higher heat stability after heat treatment at 45℃ for one hour than conidia produced on PDA medium.

• The Korean Journal of Mycology
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• v.46 no.4
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• pp.479-490
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• 2018

Red pepper is seriously damaged by thrips (Thrips palmi) and anthracnose caused by Colletotrichum acutatum throughout its development. Because of biotic constraints, producers often depend on chemicals that are expensive and have adverse effects on the environment, operator, and beneficial insects. In addition, resistance is developed because of the repeated use of chemicals. In recent decades, the use of microorganisms in crop protection has become a credible alternative because it is eco-friendly. In this study, we aimed to select isolates with insecticidal and fungicidal activities against the pathogens that cause anthracnose and thrips. We treated T. palmi adults and juveniles with 13 strains of entomopathogenic fungi (isolated from the soil by using the insect-bait method), and 6 strains showed excellent insecticidal activity (70-100%) 5 days after the treatment. The selected isolates were cultured with C. acutatum to screen for the strain with excellent anti-fungal activities, among which an isolate FT333 showed more than 95% control efficacy against C. acutatum in vitro. The isolate was identified as Isaria javanica through its morphological characteristics and phylogenetic analysis of the ITS and ${\beta}-tubulin$ nucleotide sequences. The Isaria javanica FT333 isolate could be used effectively for dual bio-control of thrips and anthracnose during red pepper cultivation.

• The Korean Journal of Mycology
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• v.27 no.1 s.88
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• pp.63-65
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• 1999

Conidiobolus obscurus and C. thromboides (Zygomycetes: Entomophthorales), aphid-attacking fungi, were found on the Dactynotus species (Homoptera: Aphididae) in June 1998 for the first time in Korea. They produce globose primary conidia typical to the genus Conidiobolus but their dimensions are clearly distinguished. Conidiobolus thromboides produces rhizoids and conidiophores with cylindrical constriction at their apices but C. obscurus does not form rhizoids or constricted conidiophores. Resting spores were not found in our specimens of both species, but their vegetative structures observed readily allowed identification.

• Asian Journal of Turfgrass Science
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• v.18 no.4
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• pp.221-229
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• 2004

Biological control of lepidopterous insect pests, Agrotis segetum, Artogeia rapae, Mamestra brassicae, Plutella xylostella, Spodoptera exigua, and S. litura with entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae isolated from Gyeongbuk province were investigated. Mean lethal concentration ($LC_50$) values of B. bassiana and M. anisopliae against $2\cdot3rd$ instar of A. segetum larvae were $1.2\times10^7\;conidia/m\ell$ and $5.2\times10^6\;conidia/m\ell$, respectively. $LC_50$ values of B. bassiana and M. anisopliae against $2\cdot3rd$ instar of A, rapae larvae were $1.2\times10^7\;conidia/m\ell$ and $5.2\times10^6\;conidia/m\ell$, respectively. $LC_50$ values of B. bassiana and M. anisopliae against $2\cdot3rd$ instar of M. brassicae and P. xylostella, larvae were $1.5\times10^6\;conidia/m\ell$, $9.7\times10^5\;conidia/m\ell$, $3.0\times10^6\;conidia/m\ell$ and $1.4\times10^6\;conidia/m\ell$, respectively. $LC_50$ values of B. bassiana and M. anisopliae against $2\cdot3rd$ instar of S. exigua, and S. litura larvae were $6.3\times10^6 \;conidia/m\ell$, $2.6\times10^6\;conidia/m\ell$, $1.6\times10^7\;conidia/m\ell$ and $3.4\times10^6\;conidia/m\ell$ respectively.