When treating the 3rd instar larvae of the diamondback moth (DBM), Plutella xylostella, with sublethal doses (LC10) of chlorantraniliprole, indoxacarb and spinosad via leaf dipping, their tolerance to insecticides was significantly enhanced. By analyzing the differentially expressed genes (DEGs), we found a number of genes that respond commonly or specifically to the test insecticides. With the criteria of p value < 0.05 and Log2FC > 1/ < -1, a total of 476, 367 and 410 genes were determined to respond specifically to chlorantraniliprole, indoxacarb and spinosad, respectively. Gene Ontology (GO) analysis revealed that the cuticle reorganization is commonly associated in all treatments and the oxidative stress-related process is also shown in all insecticides except spinosad. Finally, the DEGs seemingly related with enhanced tolerance were chosen for further characterization, and reliability of the transcriptome data were confirmed by quantitative PCR. The functional categories of these DEGs included mostly detoxification related genes, cuticle proteins, energy metabolism and transcriptional regulation. While the commonly responding DEGs suggest that they are likely involved in defense against common intoxication process, the DEGs specifically responded to each insecticide suggests the presence of unique tolerance mechanisms to each insecticide depending on their different structure and mode of action. Their possible roles in the tolerance/resistance development were discussed.

The Ryanodine Receptor in wild type Drosophila melanogaster has an amino acid substitution which is known to cause Chlorantraniliprole resistance in Pluteall xylostella. Even though we have reported that two Chlorantraniliprole resistant Drosophila strains have elevated total esterase activities, our report does not fully explain the significantly increased resistant ratios in two Chlorantraniliprole resistant Drosophila strains. Thus, we further analyzed alteration of reactive oxygen species and mitochondria activities in two Chlorantraniliprole resistant Drosophila strains. Our result suggested that Chlorantraniliprole resistance development in Drosophila requires alteration of various signal transduction pathways.

The beet armywom, Spodoptera exigua Hübner, originated from Southeast Asia is one of important agricultural pests worldwide. The moth having no diapause mechanism has highly migratory capacity which contributes to population outbreaks and geographic expansion. Although the moth was first reported in 1926 from Korea, it has been important since the late 1980s. In July 2018, the species outbreaked in Gimje, Jeonbuk Province causing serious damage to soybean in several paddy fields. In this study, we investigate the genetic diversity of the outbreaking populations using a partial sequence of mitochondrial DNA COI gene. 37 COI sequences obtained from specimens collected at the fields of Gimje, Korea were compared with 249 COI sequences from GenBank. In total, 25 haplotypes were detected from 18 countries. Three haplotypes (H1, H2, and H5) found in Korea were all shared with those in China. Haplotypes H1 and H2 were prominent in Korea as well as in invasive regions worldwide. This suggest that outbreaking populations in Korea were invaded from China. The migration source was estimated using backward trajectory analysis, and found to be Zhejiang Province, China.

A residual contact vial plus water (RCVpW) bioassay method was established to monitor insectiside resistance in field populations of the melon thrips, Thrips palmi. Resistance level against six major insecticides were evalutated in five regions to test applicability of RCVpW as an on-site resistance monitoring tool. Reduced mortality in response to six test insecticides were exhibited compared to the RDA susceptable strain showing 100 % mortality, indicating different degree of resistance. An apparently reduced mortality to emamectin benzoate and chlofenapyr was observed in some field populations, suggesting uneven distribution of resistance to these insecticides in field populations. In addition, spinosad resistance was high and widely distributed in the test regions. Synergistic bioassay revealed that cytochrome P450-mediated metabolic factor is involved in spinosad resistance in the Korean population.

Sow longevity is important for efficient and profitable pig farming. Recently, there has been an increasing interest in social genetic effect (SGE) of pigs on stress-tolerance and behavior. The present study aimed to estimate genetic correlations among average daily gain (ADG), stayability (STAY), and number of piglets born alive at the first parity (NBA1) in Korean Yorkshire pigs, using the SGE model. The phenotypic records of ADG and reproductive traits of 33,120 and 11,654 pigs, respectively, were evaluated. The direct effect on ADG had a significantly negative genetic relationship with STAY, whereas the social effect on ADG had a neutral genetic relationship. In addition, the genetic correlation between the social effects on ADG and NBA1 tended to be positive, unlike the direct effects. The genetic correlation of the total effect on ADG with that of STAY was negative but non-significant, owing to the social effect. These results suggested that total genetic effect on growth in the SGE model might reduce the negative effect on sow longevity owing to the growth potential of pigs. We recommend including social effects as selection criteria in breeding programs to obtain satisfactory genetic changes in both growth and longevity.

한반도에서의 기후 변화는 최근까지 해충이 아니던 토착 곤충이나 비례 곤충들이 해충화 될 수 있는 가능성을 높여주고 있다. 가장 중요한 예가 토착 곤충이던 풀무치의 대량 발생에 따른 해충화가 있다. 낮은 밀도에서는 식생에 위험을 주지 않는 단독형으로 존재를 하던 풀무치가 평균온도의 상승과 강우 패턴의 변화로 대량 발생을 하여 강력한 이동성을 가지고 식생을 파괴하는 군집형으로 변화된 예가 있다. 하지만, 아직까지, 단독형에서 군집형으 로의 변화에 대한 기전이해는 완성이 되지 않은 상태이다. 기후의 변화는 겨울철 평균기온의 상승을 가져와서 한반도에서 월동이 불가능했던 해충이나 약제 저항성 계통들이 급속도로 번식할 수 있는 가능성을 열어 놓았다. 그러므로, 이러한 약제 저항성과 기후변화와 관련성에 대한 유전자 수준에서의 변화에 대한 이해가 필요한 실정이다. 위의 목적을 달성하기 위하여 우리는 다중분석학을 이용하여 연구를 진행하여 왔고, 연구 결과를 바탕으로 종 특이적이면 환경 친화적인 방제방법의 개발 연구를 진행하여 와서 이에 대한 연구결과를 발표한다(RDA Grant No. PJ010821032018).

To identify genes that commonly respond to the treatment of different insecticides and are responsible for the toleranceenhancement, transcriptomic profiles of larvae treated with sublethal doses of the five insecticides were compared withthat of untreated control. A total of 117,181 transcripts with a mean length of 662 bp were generated by de novo assembly,of which 35,329 transcripts were annotated. Among them, 125, 143, 182, 215 and 149 transcripts were determined tobe up-regulated whereas 67, 45, 60, 60 and 38 genes were down-regulated following treatments with these five insecticides.The most notable examples of commonly responding over-transcribed genes were two cytochrome P450 genes and ninecuticular protein genes. In contrast, several genes composing the mitochondrial energy generation system were significantlydown-regulated in all treated larvae. Considering the distinct structure and mode of action of the five insecticides tested,the differentially expressed genes identified in this study appear to be involved in general chemical defense at the initialstage of intoxication. Their possible roles in the tolerance/resistance development were discussed.

The diamondback moth, Plutella xylostella (DBM) is a major pest of cruciferous vegetables. The insecticide resistance of this pest is very serious and has been reported in more than 600 cases. It is important to evaluate insecticide response to manage the resistant populations In this study, we investigated the insecticide susceptibility of local DBM strains collected from five major cabbage cultivation area in Korea to the ten commercial insecticides with leaf dipping method . As a result, the resistance ratio(R/R) of almost all the tested pesticides was 0.1∼3.3 (low resistant) and there was no differce within local regions. But dinotefuran showed middle resistance with regional differences (R/R , 5.9∼69.4) For the estimate the control effectiveness, we calculated the log value of the recommendation concentration divided by LC90 of pesticides. The result showed that the efficiency of neonicotinoids was generally low and that of emamectin benzoat every high. In conclusion, neonicotinoids was to use carefully and emamectin benzoate was very good alternative in DBM control in Korea

Both Nilaparvata lugens Stål and Laodelphax striatellus Fallén has been known as the major rice pests which were irregularly migrated into Korea by wind current from China. We re-arranged and compared the resistance profiles to detect the existence convergent adaptation by using the previously published dataset (N. lugens at 2014, 17:711-716 and L. Striatellus at 2016, 19:247-252 in J. Asia Pac. Entomol., respectively). Both species commonly exhibited the high level of resistance to imidacloprids. Especially, the immigrant populations of L. Striatellus exhibited higher resistance level to indigenous populations, suggesting that they would settle down in Korea with insecticide resistance traits being predisposed. To detect the convergent adaptation to insecticide, pearson correlation analysis were employed by comparing mean dosage of LD50 and resistance ratio to nine insecticides. Strikingly, high and similar dosage responses were observed between the two species with high correlation coefficients of 0.928 (df=7, P <0.001) and 0.950 (df=7, P <0.001), respectively, in the comparison of LD50 vs. resistance ratio. This finding indicates that convergent adaption has occurred in both species through consistent selection by insecticides with similar usage patterns.

Repetitive applications of drugs to tumor tissues and animals induced resistance and/or tolerances which caused severe problem in agriculture and medicine. However, we still do not clearly understand the molecular and cellular mechanisms underlying development of resistance and tolerance to chemicals. Drosophila is one of the most widely used model for studying fundamental phenomena in sciences using its available genetic and genomic resources. To investigate unknown molecular and cellular basis of drug resistance development, we applied Drosophila with two different concentrations of a chemical after treating them with Ethyl methanesulfonate mutatgenesis. We found that flies treating with two different concentration of chemicals showed different susceptibility to a chemical. We have established two different lines showing different susceptibility to a chemical. We will use these lines to compare any differences in mRNA expression profiling and enzyme activities. (This work was supported by project title: Investigation on cross drug resistance mechanisms using Drosophila as a model (PJ010821032016) from Rural Development Administration).

Bi0.5Na0.5TiO3 (BNT) based ceramics are considered potential lead-free alternatives for Pb(Zr,Ti)O3(PZT) based ceramics in various applications such as sensors, actuators and transducers. However, BNT-based ceramics have lower electromechanical performance as compared with PZT based ceramics. Therefore, in this work, lead-free bulk 0.99[(Bi0.5Na0.5)0.935Ba0.065](1-x)LaxTiO3-0.01SrZO3 (BNBTLax-SZ, with x = 0, 0.01, 0.02) ceramics were synthesized by a conventional solid state reaction The crystal structure, dielectric response, degree of diffuseness and electric-field-induced strain properties were investigated as a function of different La concentrations. All samples were crystallized into a single phase perovskite structure. The temperature dependent dielectric response of La-modified BNBT-SZ ceramics showed lower dielectric response and improved field-induced strain response. The field induced strain increased from 0.17% for pure BNBT-SZ to 0.38 % for 1 mol.% La-modified BNBT-SZ ceramics at an applied electric field of 6 kV/mm. These results show that Lamodified BNBT-SZ ceramic system is expected to be a new candidate material for lead-free electronic devices.

The insecticidal activity of cinnamon essential oils, cinnamon bark, cinnamon technical, cinnamon green leaf oils and their constituents and structurally related compounds against citrus flatid planthopper, Metcalfa pruinosa, was examined using a direct contact application. At 500 mg litre-1 very strong mortality (100%) was observed in cinnamon technical, cinnamon bark, cinnamon green leaf, mortality against flatid planthopper M. pruinosa. The cinnamon oils constituents were identified by GC-MS. The active principles were determined to be hydrocinnamic acid (24 h LC50, 30.66 mg/L), geranic acid (24 h LC50, 31.23 mg/L), cinnamaldehyde (24 h LC50, 32.65 mg/L), hydrocinnamaldehyde (24 h LC50, 39.11 mg/L) and trans-cinnamaldehyede (24 h LC50, 39.54 mg/L) were the most toxic against both nymph and adult of citrus flatid planthopper, M. pruinosa. The moderate activity was observed with cinnamyl acetate, dibutyl pthalate, anethole, α -cyano cinnamic acid, cinnamyl alcohol, methyl cinnamaldehyde, eugenol, 2.4-dihydrocyl cinnamic acid, bornyl acetate (24 h LC50, 53.35- 97.17 mg/L) respectively. The other constituents were showed less or no activity against adult of M. pruinosa. Global efforts to reduce the level of highly toxic synthetic insecticides in the agricultural environment justify further studies on the active cinnamon oils active principles act as potential insecticides for the control of M. pruinosa populations as direct spray with contact action.

We have used bulked segregant analysis to screen the strain-specific DNA marker associated psychrophilic strain of Pleurotus eryngii. Bulked genomic DNAs of Pleurotus eryngii were amplified by randomly amplified polymorphic DNA (RAPD) using OP-A, OP-B, OP-L, OP-P, OP-R and OP-S primers to screen the strain-specific DNA marker. A unique DNA fragment of 490 bp was amplified with OP-L18 primer from the psychrophilic strain and sequenced. A sequence characterized amplified region (SCAR) marker was designed on the basis of the determined sequence and named as OP-L18-1. The PCR analysis with the OP-L18-1 primer showed that this SCAR marker clearly distinguish the psychrophilic strains from the control strains.