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.