The purpose of this study was to determine the safe and effective method for preventing the occurrence of Oryctes rhinoceros Nudivirus in Allomyrina dichotoma on agricultural farms. There is a high demand for the use of A. dichotoma larvae in animal feed and as pet for educational purpose. Recently, we reported that OrNV is fatal virus diagnosed in A. dichotoma larvae in local farms in Korea. Mulberry leaves contain 1-deoxynojirimycin that represented anti-inflammatory, anti-virus, and anti-tumor effects. To prevent OrNV, we have fed the sawdust combined with 1% and 5% mulberry leaves powder to OrNV infected 2nd and 3rd stage larvae of A. dichotoma, and identified the mortality rate(%) during ten weeks. As a results, the 2nd stage larvae which were fed the sawdust combined with 5% mulberry leaves treatment recorded 60% mortality rate after ten weeks compared to the 100% mortality rate in the control. And the fatality rate of 3rd stage larvae which were fed 5% mulberry leaves treatment decreased 70% compared to the control. Therefore, application sawdust combined with mulberry leaves might be effective in the prevention and control of OrNV disease in A. dichotoma. Additionally, in the ten insect breading farms application test, OrNV virus disease have not appeared in the mulberry leaf powder treatment group.

대표적인 산업곤충에는 장수풍뎅이(Allomyrina dichotoma), 흰점박이꽃무지(Protaetia brevitarsis seulensis), 쌍별귀뚜 라미(Gryllus bimaculatus), 갈색거저리(Tenebrio molitor) 등이 있으며 식용, 약용, 학습애완용 등 다양한 용도로 이용되고 있다. 곤충 산업의 발달로 인한 산업곤충의 집단사육은 곤충을 시간적 제약 없이 대량으로 공급할 수 있다는 장점이 있다. 그러나 밀폐된 공간에서 대량사육은 질병 발생 시 집단 감염 확률이 높고 결국 농가의 소득감소로 이어진다. 산업곤충 유충에서 주로 발생하는 곰팡이병과 세균병, 바이러스병은 유충의 성장을 방해하며 유충이 죽을 때 까지 감염 여부를 알기 어렵다. 따라서 이 연구는 곤충 질병 발생 조기 진단방법 개발을 위한 기초자료를 제공하고자 수행되었다. 장수풍뎅이를 대상으로 질병 감염이 의심되는 유충과, 감염되지 않은 건강충의 장내 미생물 군집에 차이가 나타나는지 비교하였다. 병사충과 건강충의 장내 미생물 군집 구조 차이 구명을 통해 병원성 미생물 감염여부를 조기에 진단하고, 질병의 대량 발생을 예방 할 수 있을 것으로 기대한다.

Allomyrina dichotoma (order Coleoptera, family Scarabaeidae) is used for development of pharmaceuticals, pet or educational purposes and animal feedstuffs. The disease occurrence and distribution of Oryctes rhinoceros Nudivirus were investigated in Allomyrina dichotoma in Korea using PCR and analyzed the DNA seqeunces using BLAST(Basic Local Alignment Search Tool). The virus infected larvae were collected from 10 insect rearing farms in five different regions (Gyounggi, Chungbuk, Chungnam, Jeonnam, Daejeon). Frequency of OrNV virus infection appeared differently depending on the regions or rearing facilities (open field, vinyl house, indoor breeding system and etc.). The collected samples of Allomyrina dichotoma raised on open fields showed the highest possibilities of OrNV virus infection. The OrNV average infection rate of open fields rearing systems was 50.0%.

Mass breeding of Protaetia brevitarsis seluensis results in the entomopathogenic fungal infection, usually Metarhizium anisoplaie. 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 for 30d, 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%.

The purpose of this study was to identify the new fungal disease of Scopendra subspinipes mutilans (Chilopoda: Scolopendridae) from Jeju island in Korea. Scopendra subspinipes mutilans are also known the Chinese red head and average 20cm in length. It is used for traditional medicine for skin-disease and tumor and S. s. mutilans is recently raised in Jeju island to use healing properties. We isolated fungi from surface of infected S. s. mutilans and incubated in SDBA at 24℃ for 14days, and then identified the morphology of the fungi by light and electron microscopy. For the specific diagnosis of Metarhizium spp. in S. s. mutilans, 18srRNA of fungi was amplified by primers ITS4_MF and LR3_MR and sequenced by using the BLAST server at the National Center for Biotechnology Information. The result of the 18srRNA sequencing alignment was Metarhizium anisopliae (99.9%). The entomopathogenic fungi, M. anisopliae would be fatal cause of higher mortality to S. s. mutilans, and it is needed in vivo assay to confirm the pathogenic activities of M. anisopliae to S. s. mutilans.

Many insects have gained increasing attention as an alternative protein for humans. Among those, the two-spotted cricket, Gryllus bimaculatus (Orthoptera: Gryllidae), was recently approved as a general food ingredient by the Korean Ministry of Food and Drug Safety. For industrial utilization of G. bimaculatus, mass rearing techniques and production system should be standardized first. In this study, we investigated the effects of five different feeds on the growth and development of G. bimaculatus. Feed is the one of the key factors that has considerable effects on rearing insects. With five different kinds of feed on 1st, 3rd, and 5th instar nymphs, the change of survival rate, body weight were monitored up to eight weeks after hatching. We concluded that 50% of soybean flour, 20% of corn powder, 10% of rice bran, 9% of milk serum, 10% of rice flour, 0.5% of microorganisms, and 0.5% of multivitamins and minerals (diet C) was the best mix for promoting growth and development of 3rd instar nymphs compared to the control diet.

In 2015, we reported a viral disease extremely fatal to Allomyrina dichotoma larvae spread in the majority of the larva-rearing farms in Korea. Currently, the virus-infected larva is diagnosed by PCR-based amplification but this requires laboratory equipment and agarose gel electrophoresis. Loop-mediated isothermal amplification (LAMP), a highly sensitive DNA amplification method, uses DNA polymerase isolated from Bacillus stearothemophilus and a set of six primers. It has great potential for field use because DNA is amplified under single temperature and the overall reaction completes in 30 min without laboratory equipments. Here, we report the development of on-site diagnosis method for Korean horn beetle larva infected by Allomyrina dichotoma Nudivirus.

The purpose of this stduy was to identify accurately and promptly the Microsporidia disease of bumble bees from Gangwon in Korea. Bumble bees are crucial pollinators of various crops and microsporidia are the critical infections of these hosts. Also, the various species of bumble bees have been used: Bombus terrestris, B. lucorum, B. occidentalis, B. ignites and B. impatiens etc. The symptoms of bumble bees infected microsporidia: their abdomens become distended, paralyzed and become sluggish and die early. We have identified the morphologies of the microsporidium by electron microscopy and found that the morphology of the microsporidium is rounded spore morph, with fairly small spores as described before in many other articles. For the specific and sensitive diagnosis of Nosema in bumble bees, we have developed the improved method of Polymerase Chain Reaction (PCR) conditions for expeditious diagnosis. Two pairs of primers were tested on N. bombi and the related microsporidia; Nosema apis and Nosema sp., both of which infect bumble bees and honey bees and further we have verified and analyzed DNA sequence data of N. bombi in bumble bees by using the BLAST server at the National Center for Biotechnology Information.

The white-spotted flower chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae), is traditionally considered to be an important source of medicinal properties of suppression of cancer and prevention of liver-related diseases. Recently, it was listed as a temporal food ingredient by the Korean Ministry of Food and Drug Safety. To use this insect species without endangering wild populations and produce better quality insects, a mass rearing technique and the suitable rearing conditions are needed. The present study was carried out to determine whether different diets and temperatures can affect the larval weight of this beetle. The larval weight change of third instar larvae was tracked for 14 weeks with different combination of three rearing temperatures – 25, 27.5, and 30℃ - and two feed ingredients – soybean cake and rice bran. Among three temperatures, 27.5℃ was the best temperature condition for rearing this beetle. Among four combinations of two feed ingredients, the addition of soybean cake made significant weight increasement for third instar larvae. These results showed that adding soybean cake at 27.5℃ was the best rearing condition for larval weight gain. This rearing condition can be considered in terms of producing better insects and maximizing producers’ benefits.

The white-spotted chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae) was recently listed as a temporal food ingredient by the Korean Ministry of Food and Drug Safety. Traditionally, this beetle has been regarded as a medicine for suppressing live cancer and preventing liver-related disease. Based on these facts, this beetle has been focused as a economically important insects in Korea. Therefore, this beetle is commercially reared and distributed in Korea. As the economic importance is growing, we have investigated to enhance insect rearing conditions for better commercial value. In this study, we compared two food supplements, clay and charcoal, on the larval weight gain for second instar larvae of P. brevitarsis. Clay and charcoal are generally known as a good adsorbent for heavy metals and bio-waste. However, clay and charcoal is not a conventional feed supplements, so its effects were not investigated for insect rearing. The second instar P. brevitarsis larvae were fed fermented sawdust with seven different combinations of cla and/or charcoal, and measured body weight for 17 weeks until pupated. Addition of clay at 2.5 % w/w of the fermented sawdust diet had no negative effect on larval weight gain, and thus may improve the quality of P. brevitarsis as a commercial food.

The purpose of this multiplex PCR assay is establishment and application for rapid and simultaneous detection of six pathogens related with insect diseases. Five pathogens were chosen based on the insect disease incidence rate in South Korea and specific primers of those pathogen were designed to detect insect diseases and test multiplex PCR for detecting Fungi; Beauveria bassiana(Bb), Metarhizium anisopliae(Ma), Bacteira; Bacillus thuringiensis(Bt), Pseudomonas aeruginosa(Pa), and Serratia marcescens(Sm). This research carried out the results detecting five kinds of insect pathogen of P. b. seulensis by multiplex PCR. Multiplex PCR is effective and save time to detect simultaneously these insect pathogens and multiple infections to prevent insect disease. In our study, using multiplex PCR, we demonstrated that P. b. seulensis was frequently infected with S. marcescens and co-infected with M. anisopliae in more than 80% of cases, indicating that such an analysis can be useful for pathogen identification, especially if different pathogens produce similar symptoms.

The white-spotted chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae), is the one of the mass-rearing insects in Korea. Traditionally, it has been considered as a medicine for preventing liver-related diseases and suppressing cancer. In addition, this beetle was recently enlisted as a temporal food ingredient by Korean Ministry of Food and Drug Safety. As the economic importance of this beetle is growing, the suitable rearing conditions are needed for more detailed investigation. In this study, we compared three different temperature conditions – 25, 27.5, and 30°C – and the four combinations of two ingredients – soybean cake, and rice bran. With these treatments, the weight change of third instar larvae was tracked for ten weeks. Among three temperatures, 27.5°C was identified as the best temperature condition for rearing this beetle. Among four combinations of different ingredients, the addition of soybean cake made significant weight incensement for third instar larvae. Based on these results, we concluded that adding soybean cake at 27.5°C is the best rearing condition among 12 combinations of temperatures and feed ingredients. In addition, we observed the body weight was reduced when the larvae were closed to the pupation period. Therefore, we recommend that ca. seven weeks after third instar is the best time to distribute it to the market.