Short Communication : Effect of a Cys-Motif Protein, VHv1.4, of Campoletis sonorensis Ichnovirus on the Translation of Lysozyme mRNA

( Yong Gyun Kim ),( Bruce A. Webb ) 한국응용곤충학회 2003 Journal of Asia-Pacific Entomology Vol.6 No.2

Eicosanoid Biosynthesis Inhibitors as Novel Synergists for Microbial Insecticides

Yonggyun Kim 한국농약과학회 2017 한국농약과학회 학술발표대회 논문집 Vol.2017 No.4

Age Variation in Insecticide Susceptibility and Biochemical Changes of Beet Armyworm, Spodoptera exigua(H$\ddot{u}$bner)

Yonggyun Kim,Joonik Lee,Sungyoung Kang,Sangchan Han Korean Society of Applied Entomology 1998 Journal of Asia-Pacific Entomology Vol.1 No.1

The susceptibility of Spodoptera exigua(H$\ddot{u}$bner) to bifenthrin and chlorpyrifos-methyl in relation to larval development was investigated. Increased tolerances to these insecticides were associated with increasing larval instars. The insecticide tolerance increased linealy with larval body weights in bifenthrin but did exponentially in chlorpyrifos-methyl. Esterase(EST), acetyl-cholinesterase(AChE), and glutathione S-transferase(GST) of different larval ages were analyzed to elucidate variation of insecticide susceptibilities according to larval development within a population. Total EST activity increased linearly with body weights though the specific activities were not varied among ages. Both total and specific activity changes of GST, however, surpassed the rates of body weight gains as the larvae developed. AChE activities was due to the developmental change of its catalytic function. The fifth instar larvae had the lowest catalytic capacity: the highest $K_{m}$ (187.39$\mu\textrm{M}$) and the lowest $V_{max}$ (0.58nM/min/$\mu\textrm{g}$). Therefore, different insecticide tolerance of S. exigua according to larval ages can be explained by both enhanced detoxification enzymes and altered AchE.

Disruption of insect physiological processes and novel control strategies

Yonggyun Kim 한국응용곤충학회 2011 한국응용곤충학회 학술대회논문집 Vol.2011 No.05

Post-harvest Insect Pest Control Using CATTS

Yonggyun Kim 한국응용곤충학회 2015 한국응용곤충학회 학술대회논문집 Vol.2015 No.04

A fumigant, methyl bromide (MB), has been widely used to control insect pests on various post-harvest agricultural products. Due to its negative side effects, such as ozone deplete and phytotoxicity, MB should be replaced and alternative control technique ought to be developed. Furthermore, organic agricultural products need to be treated with non-chemical methods. To meet these needs, controlled atmosphere and temperature treatment technique (CATTS) has been developed to control insect and mite pests infesting various post-harvest fruits. CATTS uses heat treatment at 46℃with a gradual increase of temperature program under ananoxia condition (less than 1% O2 and 15% CO2). The heating rate at ramping step is crucial to prevent any heat damage to fruits by mimicking natural conditions during summer period experienced by fruits in orchards. The exposure period to the high temperature is minimized by anoxia condition, which prevents any recovery metabolism occurring in the target insect/mite pests after the heat treatment. To develop MB alternative technique for exporting apples, CATTS conditions have been determined against several quarantine insect/mite pest, which are restricted from Korean apple import countries. Target insect pests include Grapholita molesta, Adoxophyes paraorana, Tetranychus viennensis, Conogethes punctiferalis, and Carposina sasakii. In each insect species, differences in susceptibility to high temperature were analyzed in all developmental stages. The highest tolerant developmental stages were adults in T. viennensis, but the fifth instar larvae in G. molesta, C. punctiferalis, C. sasakii, and A. paraorana. Gas conditions of CATTS kept 1% O2 and 15% CO2. After the internal fruit temperature increase from 25℃ to 44℃ during ramping stage (120-150 min), CATTS treatment lasted for 1-2 h. Under 1 h CATTS treatment, 100% mortality was recorded in all assays using more than 3,000 individuals of each species of T. viennensis adults, G. molesta fifth instar, C. sasakii fifth instar, and A. paraorana fifth instar. With 2 h CATTS treatment, 100% mortality was recorded in C. punctiferalis assay using 3,022 fifth instar larvae. Under 1 h CATTS treatment, no fruit damage was recorded in Fuji variety of apples. Treatment cost of CATTS is higher than that of methyl bromide (MB) treatment. However, once CATTS is equipped with nitrogen generator, it would be cheaper than MB in treatment cost. CATTS is a promising post-harvest pest control technique to replace MB treatment. Especially, CATTS would be an ideal control technique to disinfect any pests against organic agricultural products.

Sub-bituminous coal particles combustion in O₂/N₂ and O₂/CO₂ Atmosphere

Yong-Gyun Kim,Ju-hun Song,Chung-Hwan Jeon 한국연소학회 2010 KOSCOSYMPOSIUM논문집 Vol.- No.40

Oxy-coal combustion is the one of the promising alternatives to achieve carbon dioxide capture and clean coal technology. In this study, the characteristic of sub-bituminous coals combustion mainly on devolatilization and char oxidation processes, were investigated through flame structure and length. The effects of particle and oxygen mole fraction in N₂ and CO₂ diluent gases respectively were studied in a Laminar Flow Entrained Reactor system that produces similar environment of utility furnace in terms of high heating rate and temperature O₂ mole fraction is varied 0~50%. There is a little difference of burning time between two different sub-bituminous coals and the larger size shows thicker and longer flame. The flame length becomes shorter as increase of O₂ concentration. It means that the reactivity in both devolatilization and char oxidation process is increased in higher O₂ concentration environment. It is barely seen that volatile burning realm became shrink and O₂ diffusion speed is accelerated and the luminosity is concentrated on near burning particle as increasing O₂ concentration. In the comparison of two O₂/CO₂ and O₂/N₂ environment effect, the flame in the oxy-fuel condition is seen shorter than that in the O₂/N₂ condition.

Differential Parasitic Capacity of Cotesia plutellae and C. glomerata on Diamondback Moth, Plutella xylostella and Dichotomous Taxonomic Characters

Yonggyun Kim,Ahmed M. A. Ibrahim,Sungchae Jung,Min Kwoen 한국응용곤충학회 2006 Journal of Asia-Pacific Entomology Vol.9 No.3

Two closely-related endoparasitoids of Cotesia plutellae and C. glomerata parasitize the diamondback moth, Plutella xylostella. The parasitized hosts by either parasitoid species exhibited the extended larval period and died without further metamorphosis to pupal stage. However, two parasitoid species exhibited significantly different parasitic capacity and developmental rate, in which C. plutellae showed higher parasitism and faster development in the parasitized P. xylostella. To discriminate these two similar species, morphological and molecular differences were analyzed. Three dichotomous morphological characters including antennal flagellum, hind-leg femur, and terminal abdominal terga were determined. Based on the presumptive polydnaviral particles found in the ovarian calyx of C. glomerata, three genes similar to C. plutellae bracoviral genes were cloned in the C. glomerata genome and compared in their cDNA and the deduced amino acid sequences. Several polymorphic sites were detected to be applicable to design molecular markers to discriminate these two species.

Parasitism of Cotesia plutellae Alters Morphological and Biochemical Characters of Diamondback Moth, Plutella xylostella

Yonggyun Kim,Yerim Son 한국응용곤충학회 2006 Journal of Asia-Pacific Entomology Vol.9 No.1

solitary endoparsitoid,Cotesia plutellae,has ben regarded as a major biological regulatorto manipulate field population of diamondback moth(DBM),Plutella xylostella. It parasitizes DBM andalters its physiology into a favorable condition forthe parasitoid evelopment. This research has beenfocused on the physiological changes in terms ofinternal morphology and biochemical changes of theparasitized DBM. The parasitized DBM exhibitedsignificantly hypotrophied structures in Malpighianapparent change in the digestive organ structure. Theparasitoid represented almost 70% of total bodyweight of the parasitized DBM. This estimate waswell corresponded to the measurements of the majornutrient amounts in the parasitized DBM. This studyclearly indicates that the major nutrients obtained bythe parasitoid DBM are exploited by the koinobiontparasitoid for its own development.Key words Cotesia plutellae, Internal morphology,Nutrient, Parasitism,Plutella xylostella

Thrips infesting hot pepper in greenhouse

Yonggyun Kim 한국응용곤충학회 2021 한국응용곤충학회 학술대회논문집 Vol.2021 No.10

Insect Growth and Metamorphosis

Yonggyun Kim 한국응용곤충학회 2015 한국응용곤충학회 학술대회논문집 Vol.2015 No.04

Insect growth includes a mixture of continuous increase of body weight and discontinuous increase of exoskeleton size. Like other poikilothermic animals, insect growth varies with ambient temperatures, which determine the rates of various biochemical reactions of internal body metabolism. In addition, nutrient supply from food diet is necessary for insects to grow. The nutrient signal in insects is delivered to all internal tissues via insulin-like peptide (ILP). ILP signal transduction pathway in the target cells is highly similar to that of vertebrates. Insulin receptor (InR) specifically binds to ILP and activates PI3K to increase PIP3 intracellular level. The secondary messenger activates a specific serine-threonine kinase (Akt). Akt phosphorylates a nuclear receptor, FOXO, to prevent its translocation into nucleus and activates R6 kinase to upregulate protein synthesis. Insect exoskeleton is a physical barrier for growth and should be replaced with a new and greater size cuticle by molting at every growth. Upon reaching a critical body size for molting, the brain releases PTTH to stimulate 20-hydroxyecdysone (20E) biosynthesis in the PTG. The secreted 20E binds to EcR in the epidermal cells and forms a heterodimer receptor complex with USP. The active receptor enters the nucleus and activates molting-associated genes by inducing a specific upstream transcription factors. Decrease of 20E levels triggers apolysis to detach the old cuticle from the newly synthesized cuticle. With a series of neuropeptides, such as corazonin, ETH, EH, and CCAP, a sterotyped ecdysis behavior is released. The newly molted cuticle is then sclerotized by quinone molecules via bursicon signal. Metamorphosis is one of the most remarkable and characteristic physiological phenomena in insects among animals. Amphibians like frogs also exhibit the metamorphic development from an immature tadpole to a matured adult via two antagonistic developmental hormones, prolactin and thyroxine. In insects, juvenile hormone and 20E regulate the metamorphic developments, such as nymph-to-adult, larva-to-pupa, and pupa-to-adult. Insects are useful to monitor climate change by analyzing annual variation in their season phenology. Day-degree model has been widely used to predict insect occurrence based on climate change scenarios. However, insect growth depends on nutrient availability and quality as well as ambient temperature. Furthermore, insects also evolve in their growth and metamorphic developmental patterns according to climate change probably via epigenetic mode followed by genetic differentiation. Thus, we need to refine the prediction model of insect occurrence based on day-degree model with a fixed developmental threshold temperature.