이시혁 교수

Nilaparvata lugens Stål is one of the important migratory pests of rice paddy fields in Korea. Resistance levels tonine insecticides were monitored in 12 local strains and correlation analysis was conducted to determine crossresistancerelationships among the tested insecticides. The local strains revealed 1.3- to 28.0-, 1.6- to 6.0-, 2.8- to237.0-, 0.6- to 0.9-, and 0.7- to 1.3-fold resistance to carbamates, organophosphates, neonicotinoids, fipronil andetofenprox, respectively. Organophosphate

The two-spotted spider mite, Tetranychus urticae, is one of the most destructive pests of various orchard trees and garden plants. Biochemical mechanisms of abamectin resistance in two T. urticae strains (PTF, 239-fold resistance; AbaR, ca. 4753-fold resistance) were investigated. The involvement of both esterase (Est) and mixed function oxidase (MFO) in abamectin resistance was suggested by synergistic bioassays, in which median lethal time (LT50) values were significantly reduced by pretreatme

The newly sequenced complete mitochondrial genome of the brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is a circular molecule of 16,518 bp with a total A+T content of 76.4% and two exten-sive repeat regions in A+T rich region. Nucleotide compo-sition and codon usage of H. halys are about average when compared with values observed in 19 other pub-lished hemipteran mitochondrial genomes. Phylogenetic analyses using these 20 hemipteran mitochondrial ge-nomes suppor

Acetylcholinesterase (AChE) plays a pivotal role in synaptic transmission by hydrolyzing the neurotransmitteracetylcholine. In addition to the classical function of AChE in synaptic transmission, various non-classicalfunctions have been elucidated. Unlike vertebrates possessing a single AChE gene (ace), invertebrates (nematodes,arachnids, and insects) have multiple ace loci, encoding diverse AChEs with a range of different functions. In the field of toxicology, AChE with synaptic function has lo

The Aphis gossypii imidacloprid-resistant (IR) strain was about 3800-fold resistant to imidacloprid. Synergistic bioassays revealed that metabolic factors were not likely involved in resistance. An isogenic susceptible (IGS) strain was generated and used as references for RNA-seq, qrtPCR and 2DE. There were no noticeable differences between IGS and IR strains in either the transcriptome or proteome profiles, confirming that imidacloprid resistance is likely due to the target site insensitivity.

Owing to the highly developed sociality, division of labor, and passive population management of their colonies, honey bees, Apis mellifera L., have been widely used as model insects to investigate the physiological roles of the genes putatively involved in social development in insects. Quantitative real-time polymerase chain reaction (qRT-PCR) has been broadly applied to investigate the expression patterns of such target genes. However, the selection of suitable reference genes is an essential

Resistances tomonocrotophos, fenpropathrin and abamectin in Tetranychus urticae are primarily conferred by reducedsensitivities of respective target sites [i.e., acetylcholinesterase (TuAChE), voltage-sensitive sodium channel(TuVSSC) and glutamate-gated chloride channel (TuGluCl)], which are due to point mutations (G228S andF439Win TuAChE; L1022V in TuVSSC; G323D in TuGluCl). As a population-based genotyping technique, a quantitativesequencing (QS) protocolwas developed for the determination of

To develop a less technique-dependent bioassay technique that can be conveniently used by practitioners or farmers in the field for the monitoring of acaricide resistance of the two-spotted spider mite, Tetranychus urticae Koch, a residual contact vial (RCV) method was established using a 5-ml glass vial coated with acaricides. The RCV bioassay procedures were optimized by using abamectin and tebufenpyrad, two widely used acaricides. The diagnostic concentrations causing 100% mortality within 8

The hornets Vespa crabro and V. analis are widely distributed in Asia and are known to be aggressive when disturbed, resulting in frequent stinging accidents. To investigate the differences in venom properties and toxicities between these two hornets, the transcriptomic profiles of venom glands, in conjunction with the venom components, were analyzed and compared. A total of 35 venom-specific genes were identified in both venom gland transcriptomes, but their transcriptional profileswere differe

Vespa crabro and V. analis are social hornet species commonly found in Asia, including Korea.Mastoparan is one of themajor venompeptides of these two hornets but its amino acid sequence defers substantially. To examine the differences in the potential toxicity and bioactivity ofmastoparans between these two social hornets, differential toxicological and pharmacological activities of synthesized mastoparan were investigated. V. analis mastoparan showed a 7-fold higher hemolytic activity, suggesti

Thrips are known as cell-feeding sucking pests, but little information is available on which and how much of each subcellular fraction they ingest. In this study, the ingested amounts of nuclei and plastids in two representative thrips species (the western flower thrips, Frankliniella occidentalis, and the garden thrips, Frankliniella intonsa) along with two reference sucking pests (the two-spotted spider mite, Tetranychus urticae, a cell feeder, and the brown planthopper, Nilaparvata lugens, a

To investigate genes differentially expressed in the venom of social and solitary wasps, a comparative transcriptome analysis was conducted. Subtractive expressed sequence tag (EST) libraries specific to the venom gland and sac (gland/sac) of a social wasp species, Vespa tropica and a solitary hunting wasp species,Rhynchium brunneum, was constructed by suppression subtractive hybridization. In BLASTx analysis, 41%and 56% of the total ESTs showed statistically best-matched hits (E ≤ 10−4) in the

Tetranychus urticae populations were collected from ten commercial apple orchards and their susceptibilities to 12 acaricides were tested using a leaf disc bioassay. The resistance of each T. urticae population was reported as the LC50 value, the resistance ratio (RR) and the slope of the probit– concentration regression. Cross resistances of T. urticae populations were estimated using the Spearman's rank correlation coefficient. Most local populations showed low resistance levels (RR≤10). Devel

Lycorma delicatula (White 1845), which has been recently introduced into Korea, is a notorious pest on grapes. This invasive insect has rapidly spread throughout central and southern Korea. To date, we have no behavioral or population genetics information, such as invasion routes and subsequent dispersal rates in Korea, to help understand and control populations of L. delicatula. Here, we have developed 15 novel microsatellite loci for L. delicatula. The isolated loci were polymorphic, with 2 to

Insensitive acetylcholinesterase (AChE) was determined to be involved in an EPN-resistant (ER) strain and a contaminated susceptible (CS) strain of diamondback moth (DBM, Plutella xylostella L.), as estimated by AChE inhibition assay using DDVP as a inhibitor in a nondenaturing electrophoresis gel. The ER strain exhibited very high AChE insensitivity, high resistance ratio, and two point mutations (G324A, A298S) in ace1-type AChE gene (Pxace1). The CS strain showed low AChE insensitivity, low re