Melon thrips, Thrips palmi Karny (Thysanoptera: Thripidae) is a worldwide polyphagous pest. The management of this pest have mainly relied on chemical agents. However, the overuse is harmful to the environment and results in insects resistance. Therefore, alternative eco-friendly control methods that have different mode of action, such as biological control, are necessary to overcome the current issue. In this study, we isolated entomopathogenic fungi from Korean soil, and characterized them via morphological and molecular techniques and pathogenicity assay against Tenebrio molitor larvae. The isolated fungi were screened for virulence against T. palmi under laboratory conditions and the results were used to establish a thrips-pathogenic fungal library. The highly virulent isolates were selected and further characterized for optimum culture conditions and application as biopesticide in the field.

The global biopesticide market was estimated to become about 4% of the total crop protection market in 2015, mainly due to variability of their efficacy, narrow spectrum or difficulties in long-term storage. Therefore, many people focus on overcoming these issues as a big trend. Suggested solutions include the investigation of synergy between microorganisms, the use of genetic engineering, improving the pesticide life shelf, etc. As a result, biopesticides market has grown by more than 17% over the last decade. In this context and aiming to develop new entomopathogenic fungi–based pest management tools, we constructed a fungal library by isolating insect pathogenic fungi from soil. A total of 581 isolates belonging to 35 species were isolated and characterized. Beauveria bassiana was the most abundant, representing 38.55% of the total strains, followed by Metharizium anisopliae (22.55%) and bubillosa (8.6). …% of the total isolates were highly virulent against Tenebrio molitor killing most of the treated insects in 2 to 3 days.

Japanese pine sawyer, Monochamus alternatus, is the main pest that mediates pine wilt nematode, Bursaphelenchus xylophilus, that causes serious damage to pine forests. In this study, we studied the strategy to control M. alternatus using entomopathogenic fungi. The fungi were collected from soil by an insect-baiting method and two fungal isolates (Metarhizium anisopliae JEF-197 and JEF-279) showed high virulence against M. alternatus. The Metarhizium isolates were evaluated for insecticidal activity against M. alternatus by spray treatment on live pine trees and wintering trees, and the M. anisopliae JEF-197 showed high insecticidal activity. In addition, the interaction of fungi and M. alternatus were analyzed by RNA-seq. This result can contribute to the development of insect control agents using entomopathogenic fungi.

The Asian corn borer, Ostrinia furnacalis (Lepidoptera: Crambidae), produces final instar larvae of overwintering stage in response to decreasing day-length and temperature, and then those larvae pupate after about 6-8 month. In this study, we investigated a few properties related to cold hardiness during overwintering of the insect. Overwintering larvae collected in December could survive at least for 16 days at -20oC, while all larvae of a laboratory colony, which was reared at 25oC, 15L/9D, died within 2 hours. Supercooling points of overwintering larvae were below -20oC, and the temperatures were significantly lower than those (ca. -10oC) of the laboratory colony. It was estimated that higher content of hemolymph glycerol is responsible for cold-hardiness as a cryoprotectant during overwintering of O. furnacalis.

Beauveria bassiana is widely studied for its potential as biopesticide. However, little is known about the factors to influence genetic diversity among isolates. In this work, we aimed to study the gene diversity of 42 isolates to figure out the impact of sequences variability on various biological features. The accumulated data showed no correlation between sequence variability and the fungal geographic localization. Meanwhile, weak to strong correlations have been obtained between the sequence diversity of various genes and the studied biological features. Interestingly, Biotrophy-associated gene 2 gene variability was correlated with all the studied biological features, being an important marker to determine isolates of interest for biological control. Therefore, the obtained data would serve as a database to focus on interesting genes related to improving or screening highly virulent isolates as biological control agents.

A species of Beauveria bassiana is widely used for biological pest management in many countries. Many efforts have been given to figure out the clear fungal mode of action to enhance the insecticidal activity. Homologous recombination (knock-out) or hairpin RNA (knock-down) is popularly used in fungal gene function study, but gene cloning and generation of knock-out or -down mutants takes long time or temporarily knock-downed. Here in this work, we used previously generated egfp-expressing B. bassiana strain (Bb-egfp #3) and integrated dsegfp to the Bb-egfp #3 using a protoplast integration method. This work suggests that protoplast integration with dsRNA possibly generate significantly reduced gene expression in B. bassiana and the reduction is quite stable over generations which provide easy of functional study for fungal mode of action.

The serious emergence of chemical-mediated residual toxicity and insect resistance have been enforced the regulation of synthetic pesticides. Future decisions to select more realistic control options probably depend on the speed of technological development in chemical and biological pesticides. Now, a strategic collaboration between synthetic pesticides and biopesticides has been progressed, such as distribution and R&D in collaboration and M&A for obtaining microbial resources. Recently registered microbial pesticides are entomopathogenic fungi in pest management. A concept of e-biopesticide could be properly combined with digital agriculture and accelerate the use of biological control agents in the future farming.

The longhorned tick, Haemaphysalis longicornis, is one of the vectors of severe fever with thrombocytopenia syndrome virus (SFTSV) in human. The use of pyrethroid insecticides induced pest resistance and environmental residual toxicity. Here in this work, our interest was given to the selection of highly virulent fungi against longhorned tick. A total of 101 fungal pathogens were assayed by dipping the nymph stage of ticks into a conidial suspension. Interestingly of the several species, one species showed high virulence and mycosis were observed in 7-15 days. Highly virulent strains were selected, and semi-field experiments were conducted. As a result, the control efficacy of the isolate was over 80% at 30 days of treatment. This work suggests that entomopathogenic fungi could be used to effectively control longhorend ticks.

Mosquitoes are primary medical insect pests due to their diseases transmission as vectors. In Korea, the insecticide-resistant populations of disease vector mosquito species, such as Anopheles sinensis, Culex pipiens and Culex tritaeniorhynchus, have constantly increased. Thus, management of insecticide resistance to major insecticides including pyrethroids and organophosphates is required for more efficient control of resistant populations. In this study, the quantitative sequencing (QS) protocols were established to detect the frequencies of three mutations (the L1014F on voltage sensitive sodium channel and the G119S and F331W on acetylcholinesterase 1) that are associated with either pyrethroids or organophosphates. Based on the QS protocol using newly designed non-polymorphic primers, resistance allele frequencies (RAFs) were estimated in field populations of An. sinensis, Cx. pipiens and Cx tritaeniorhynchus collected from an identical site in Korea. The dynamics of each resistance allele frequency over time in the same populations were also evaluated.

Silverleaf whitefly, Bemisia tabaci is a worldwide agricultural pest that cause serious damage to crops. However, since this insect developed resistance to variety of chemicals, alternative control strategy needs to be studied. In this study, we aimed to evaluate the potential of entomopathogenic fungi as biological control tools against this pest. We developed a dipping method in laboratory conditions to screen insecticidal activity of different fungal species and isolates against the nymphal stage of whitefly. The highly virulent isolates were characterized and 2 isolates were further selected based on their high conidial productivity and thermotolerance. Finally, several grain substrates were used to confirm the conidial productivity and thermotolerance of the selected isolates, revealing optimum conidial production when the fungi were cultured on millet grains. Both isolates could be used in further millet grain-based formulations to control the whitefly in fields.

Red mite, Dermanyssus gallinae is one of the serious pests, damaging to the egg production in chickens. Moreover, the overuse of chemical insecticides caused pest resistance and environmental residual toxicity. Therefore, this work provides a screening method to select entomopathogenic fungi as a candidate of environmentally safe control agent, having high miticidal activity against D. Gallinae. The virulence test was conducted using a spraying method. Of the several species, Beauveria species showed high virulence and mycosis were observed. Some isolates were produced on eight cereal grains in Petri dish conditions. Millet, perilla seed and barley showed the high conidia production. Conidia of the isolates produced on millet and rice showed high thermal stability, when exposed to 45℃. Based on these results, this work suggests that entomopathogenic fungi could be used to control the D. Gallinae.

Malaria is notorious disease to transmitted by Anopheline mosquitoes. In Korea, Plasmodium vivax malaria was re-introduce in 1993 and exceed to more than 4,000 cases in early 2000s. Based upon our control efforts, it was sharply decreased and diagnosis 576 cases in last year. We made Action Plan in this year for certification of malaria elimination by WHO until year 2024. In this plan, we need to strengthen our capacity of vector surveillance and control. For vector surveillance, we will introduce daily mosquito population monitoring system. In 2020, every malaria high risk area install two mosquito counters and send information to main server. For vector control, we will try building capacity of malaria mosquito control people in the Public Health center and military section. To decrease no. of mosquitoes, we will concentrate our resource to cattle shed, which is main blood source of Anopheline mosquitoes. Based on the ecological characteristic of Anopheline, we will adopt Integrate Vector management (IVM) including physical, chemical and biological method. Based on the reconciliation with North Korea, we will support technical and material support for malaria elimination.