In recent years, interest in edible insects has increased, and the number of farmers that breed insects in large quantities is increasing. As a result of mass breeding of insects, the damage from diseases and mites is also increasing. The chief aims of the investigation reached during some work are briefly stated. In this experiment, the kinds of mites and the environment of mites occurring in beneficial insects were investigated. The species with the highest frequency were Sanacassania sp., Tyrophagus sp., Canestriniidae and Gaeolaelaps sp.. Sanacassania sp. and Canestriniidae of them are reported as parasitic mites on beneficial insects.

The frequency and time of the outbreak of insect diseases were investigated among the insect-rearing farms by regional groups. The purpose of this study was to predict the insect diseases and reduce the spread of diseases. From February to October 2016, 87 of diseased insects were collected in seven regions. It turned out that the pathogens for fungal diseases were identified as Metarhizium anisopliae. But in case of bacterial diseases, the pathogenicity of the bacteria isolated from the diseased insects were not confirmed. Bacterial diseases occurred mainly in June and August in Gyeonggi-do and Gangwon-do, while in Chungcheong-do, bacterial and viral disease raged. In Jeolla-do, both fungal and bacterial diseases occurred in June. Generally, bacterial diseases occurred mainly from June to October, while the frugal diseases occurred from January to March. It was concluded that the entomopathogenic fungi, Metarhizium anisopliae, tended to cause diseases during late-winter and early spring and bacteria, uncertain, was prone to cause diseases during summer. Therefore, it necessary to adequately control depending on the type of the entomopathogen.

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.

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.

Since we reported a viral disease extremely fatal to A. dichotoma, had landed on Korea in 2015, we have investigated this disease nationwide and it was turned out the viral disease has spread in the majority of the larva-rearing farms all over the country. The transmission of this disease is most severe when the larvae are harvested and stored for overwintering. During this period, even a few virus-infected larvae can easily transmit the virus and about two hundreds of larvae stored in a container can be killed. In a peroral infection experiment, 80% of infected larvae were killed but survived larvae became adults fully functional physiologically. These survived beetles were confirmed as live virus carrier. Also, about 75% of larvae hatched from the eggs laid by the infected beetles were infected and killed by the virus. This vertical transmission is due to the feeding and secretion activity of the infected parents.

I conducted experiments in Drosophila to investigate the consequences of altered acetylcholinesterase (AChE) activity in the nervous system. In ace hypomorphic mutant larvae, the amount of ace mRNA and the activity of AChE both in vivo and in vitro were significantly reduced compared with those of controls. Reduced Ace in Drosophila larvae resulted in significant down-regulation of branch length and the number of boutons in Type 1 glutamatergic neuromuscular junctions (NMJs). These defects in ace hypomorphic mutant larvae were suppressed when Musca domestica AChE was transgenically expressed. Because AChE inhibitors are utilized for medications for Alzheimer’s disease, we investigated whether pharmacological inhibition of AChE activity induced any synaptic defects. I found that controls exposed to a sublethal dose of DDVP phenocopied the synaptic structural defects of the ace hypomorphic mutant. These results suggest that down-regulation of AChE activity, regardless of whether it is due to genetic or pharmacological manipulations, results in altered synaptic architecture. This study suggests that exposure to AChE inhibitors for 6-12 months may induce altered synaptic architectures in human brains with Alzheimer’s diseases, similar to those reported here. These changes may underlie or contribute to the loss of efficacy of AChE inhibitors after prolonged treatment.

The black soldier fly (BSF), Hermetia illucens, is known as a beneficial insect and feeds on organic materials derived from animals and human, resulting in reduction of food waste and conversion of organic materials. Despite of many studies on the BSF, there have been no reports of cloned genes encoding serine proteases in the BSF. Thus, the primary objective of this study is to clone and to investigate expression pattern of genes encoding serine proteases released from the midgut of the BSF larvae in order to gain a better understanding of expression mechanism of serine proteases. We cloned two serine proteases from the BSF larva. Based on phylogenetic tree analysis, one was chymotrypsin, the other was trypsin. The open reading frame (ORF) of chymotrypsin was 804bp, which encoded a polypeptide of 267 amino acids. In case of trypsin, the ORF was 744bp, which encoded a polypeptide of 247 amino acids. To investigate expression pattern of two serine proteases, we conducted semi-quantitative RT-PCR at different tissues and different developmental stages. A chymotrypsin and trypsin transcripts were revealed strongly in mid gut. Especially, a chymotrypsin was detected largely at feeding stage more than molting stage, while trypsin was expressed similarly between feeding stage and molting stage

The black soldier fly (BSF), Hermetia illucens, is known as a beneficial insect and feeds on organic materials derived from animals and human, resulting in reduction of food waste and conversion of organic materials. Despite of a lot of study about the BSF, there is a less information about composition of digestive enzyme of the BSF larva. Experimentally, there is no evidence about characterization of digestive enzyme of the BSF. We investigated biochemical property of digestive enzyme released from the salivary and gut of the BSF. Through digestive enzyme assay, we found that the BSF has amylase, lipase and protease activity in gut extracts, resulting in that the BSF belong to polyphagous insect group. In the BSF gut, trypsin-like protease activity showed one peak at various temperature and pH condition. This result means the BSF has probably a similar form of trypsin-like enzymes. On study of comparison of enzyme activity between the BSF and the housefly using the apiZYM kit, the BSF had more strongly digestive enzyme activity than one of the housefly about leucine arylamidase, alpha-galactosidase, beta-galactosidase, alpha-mannosidase and alpha-fucosidase. This finding supports that the BSF can ingest raw waste far more efficiently than any other known species of fly as reported previously.

Taxonomic resolution of the Nosema/Vairimorpah clade has been augmented with DNA sequences of the small subunit (SSU) and large subunit (LSU) ribosomal RNA (rRNA) and the arrangement of SSU and LSU. Based on the two characteristics, the clade is largely divided into two, i.e. 'true' Nosema sub-group and 'non-true' Nosema sub-group within the clade. Our study shows that a novel Nosema species isolated from Pieris rapae has mixed characteristics of the 'true' and non 'true' Nosema sub-group based on the topology of SSU and LSU sequences, and rRNA of the isolate is normally organized. Additionally, the length of ITS can be a diagnostic tool to distinguish 'true' Nosema from non 'true' Nosema in the Nosema/Vairimorpha clade based on its nucleotide length as reported before. To our knowledge, this is the first report of recombination event in the Nosema/Vairimorpha clade.

This study was conducted to investigate insect fauna in the four insect garden sites of Suwon, Yeongyang, Buyeo and Yecheon from 2005 to 2007. Seasonal population size of insects was largest from June to August in all the four sites. In the four sites, Coleopteran insects were dominant followed by Hemiptera and Orthoptera. Unique education/learning programs are successfully run at the insect gardens based on the three geographic types (i.e. urban, mountainous and rural). These activities will help preserve insect biodiversity in the area and visitors better understand life forms such as insects found in the areas.

Microsporidia are obligate fungal intracellular parasites of all animal taxa. Among them the genus Nosema (Nosematidae) is known as the most common entomopathogen. Of these parasites, the ribosomal organization is one of the most pronounced molecular characteristics. One type is the normalarrangement of small subunit (SSU)-internal transcribed spacer (ITS)-large subunit (LSU) in the DNA sequence order. The other is the reverse arrangement of LSU-ITS-SSU. The latter is assigned to be the ‘true’ Nosema in the Nosema/Vairimorpha clade. However, we found that the SSU sequence of a strain of Nosema species having the normal arrangement of its rRNA sequence seemed to be more closely related to the ‘true’ Nosemagroup. Consequently we have further analyzed the complete sequence of rRNA. The results imply that there might be arecombination event in its rRNA evolution and/or the strain may form a novel group near the ‘true’ Nosema group. Interestingly both SSU and LSU of the ‘true’ Nosema and others may be under different selection pressure. We have also found that the size of ITS is distinct between the ‘true’ Nosema and other microsporidian species within the Nosema/Vairimorpha clade. This feature should be a useful diagnostic tool to distinguish the ‘true’ Nosema from others in the clade.