Entomopathogenic fungi are used to produce raw materials by applying solid culture technology using grains. But there are various problems such as low production efficiency and cross-contamination. Solvum Co., Ltd. conducted research on liquid culture technology to develop a method that can overcome these shortcomings of solid culture technology. We conducted research and development on using Beauveria bassiana 331R to observe the culture according to the seed inoculation amount in a 30 L fermenter, it was carried out at 1.0 % (v/v) and 10.0 % (v/v). Although there was a difference of 1 day, 1.0 %(v/v) seed inoculation was observed to be more than twice that, and active blastospores and yield were observed at over 95.0 %. As a results, it was determined that cost and efficient production would be possible during the culture process in mass production. Based on these experiments, a 300 L fermenter was cultured with 1.0 % (v/v) seed inoculation, resulting in a yield of 1.24E+09 CFU/mL on the 6th day of cultivation. As a result of freeze-drying using the final culture medium, it was confirmed that the production yield was improved by 113.0 % compared to the control.

Cryptotympana atrata belongs to the family Cicadidae, has long been recognized as a damaging plant-sucking pest, and is distributed in East Asian countries. In addition, their cries cause direct harm to us through noise pollution and also reported twig damage in the forest environments. In this study, we isolated strains of the entomopathogenic fungus Metarhizium that occurred from C. atrata collected this year. Here, we provide the morphological character and molecular phylogenetic relationship of this species. This is the first record of the entomopathogenic fungus Metarhizium viridulum isolated from C. atrata in Korea and provides a candidate strain with potential use for biological agents.

An outbreak of stick insects, Ramulus mikado, as forest pests in South Korea has become a topic of concern. While other countries have reported these insects being severely affected by the entomopathogenic fungus Metarhizium spp., comprehensive research in South Korea remains limited on this topic. In our two-year investigation, we investigated the infection rate and mortality of R. mikado caused by Metarhizium anisopliae. In 2022, specimens were collected from Cheonggyesan, and in 2023 from Geumamsan. Although no infections were confirmed in the specimens collected in June of both years. Beginning in July, mortality and infection rates were greatly increased. In conclusion, the summer monsoon appears to create hot and humid conditions in the forest, contributing to reduced survival rates for these insects due to infection by M. anisopliae.

Metarhizium anisopliae (녹강균)는 흰점박이꽃무지에게 질병을 일으키는 곤충 병원성 곰팡이 중 하나이다. 이러한 곰팡이의 병원성은 환경 조건에 의해 영향을 받는다. 녹강균에 대한 흰점박이꽃무지 유충의 민감성을 알기 위해 온도(20℃, 25℃, 30℃), 상대습도 (RH 40%, 50%, 60%, 70%), 톱밥 수분함량 (40%, 50%, 60%)이 다른 사육 조건에서 유충의 치사율을 확인하였다. 녹강균을 처리한 흰점박이꽃무지 유충의 치사율은 온도에 따라 차이가 나타나지 않았으나, 낮은 상대습도 (RH 40%)와 톱밥 수분함량 (40%)에서 유충의 치사율이 높았다. 녹강균에 대한 1령, 2령, 3령 유충의 치사율은 1령에서 가장 높게 나타났다.

Trialeurodes vaporariorum is an important greenhouse pest worldwide. We compared the efficacy of a new strain of Beauveria bassiana (ARP14) with a commercialized one (GHA) against 2nd instar and 4th instar of T. vaporarioum. Those nymphs were exposed to the fungus in a concentration of 1×108 conidia/mL by leaf dipping method. There was no difference in mycosis rates at any observation time between the two strains in both 2nd (100.0%) and 4th instar (100.0%). Lethal median time (LT50) wasn't different between the two strains in both 2nd and 4th instar. In conclusion, the new B. bassiana strain (ARP14) would be a good candidate of mycoinsecticide for whitefly management.

Biological control has emerged due to the side effects of chemical control such as residual and toxicity. One of the biological controls is entomopathogenic fungi. The entomopathogenic fungus used in this study was first detected in the insectary. The fungus was identified as Lecanicillium sp. based on the sequences of the ITS1 and 2 regions. Lecanicillium sp. infects aphids, scale insects and whiteflies, especially Myzus persicae and Aphis gossypii. In this study, we characterized the fungal phenotype, growth condition, and pathogenicity against green peach aphid. Mycelial growth of Lecanicillium sp. was 12.79±0.46 mm diameter during 7days on potato dextrose agar at 25℃. In addition, the fungus was able to annihilate 100% green peach aphids, after 8days of inoculation. Ultimately, this study would be provide new information on Lecanicillium sp. and suggest the potential utilization of this fungus as a biological control agent.

Destruxins (Dtxs) are insecticidal cyclic hexadepsipeptides produced by the entomopathogenic fungus Metarhizium anisopliae. Media composition for dtxs production was optimized with industrial grade media. Glycerol and casein peptone were selected as a carbon source and a nitrogen source, respectively. Dtxs production varied with C/N ratios. High yields of dtxs were observed at C/N ratios ranging 0.3 to 1.5, with concentrations mostly higher than 800 mg/L. Low yields were caused by high C/N ratio ranging from 3.0 to 8.0, resulting in less than 500 mg/L. The highest yield of Dtxs was obtained with 2% glycerol and 3% casein peptone, showing 192.2 mg/L of dtx A, 911.1 mg/L of dtx B, and 113.3 mg/L of dtx E, respectively. These results indicated that dtxs production is highly influenced by C/N ratio, especially the content of nitrogen source.

Bemisia tabaci (Gennadius) is an important polyphagous pest and transmits plant pathogenic virus to numerous agriculture crops. We compared the efficacy of Beauveria bassiana ARP14 strain with commercialized GHA strain against 2nd instar and 4th instar of B. tabaci. The nymphs were exposed in 1×108 conidia/mL by dipping method. There was no difference in mycosis rate between the two strains in both 2nd and 4th instar. After 72 h, mycosis rate of 2nd instar was 100.0% in B. bassiana ARP14 strain followed by 97.4% in B. bassiana GHA strain. In 4th instar, B. bassiana ARP14 strain caused 100.0% while B. bassiana GHA strain caused 93.3%.