경기지역 원예작물 시설재배지에 발생하는 꽃노랑총채벌레 (Frankliniella occidentalis)에 대한 약제 감수성을 검정한 결과는 다음과 같다. 재배작물과 관계없이 acetamiprid (8%) SP, clothianidin (8%) SC, imidacloprid (10%) WP, thiacloprid (10%) WG와 같은 네오니코티노 인드계 약제에 대한 저항성이 두드러지게 나타났다. 과채류 재배지 채집 꽃노랑총채벌레에 대해 acetamiprid + spinetoram (6+4%) SC와 clothianidin + spinetoram (6+4%) SC, methoxyfenozide + spinetram (6+4%) SC가 90% 이상의 살충활성을 보였다. 실내에서 꽃노랑총 채벌레에 살충효과가 높았던 약제를 대상으로 채집지역과 대상작물을 동일하게 화성지역 오이 시설재배지에서 포장검정을 수행한 결과 spinetoram (5%) WG의 경우 약제 처리 3, 6, 9일 경과 후 방제효과는 87.4, 88.0, 98.3%로 높아지는 경향을 보인 반면 imidacloprid (10%) WP는 약제 처리 3, 6, 9일 경과 후 방제효과는 1.7, 24.1, 43.6%로 나타나 실내검정 결과와 유사한 경향을 보였다. 따라서 원예작물 꽃노랑총채 벌레 방제를 위해서 살충제 선택의 폭이 좁은 가운데, 스피노신계와 피롤계의 약제들이 타 계통의 약제에 비해 효과가 우수한 것으로 보이며, 구 체적으로는 스피노신계의 spinetoram과 spinosad의 함량을 각각 4, 10% 이상 함유하거나 피롤계의 chlorfenapyr가 5% 이상 함유된 단제 또는 혼합제를 선택해야 할 것으로 보인다.

The susceptibility values for field-collected (BG-BG) and laboratory (KS-BG) strains of German cockroaches, Blattella germanica (L.) to 5 synthetic pyrethroids and 3 organophosphates were assessed by topical application. Both KS-BG and BS-BG demonstrated the highest levels of susceptibility to deltamethrin. The KS-BG demonstrated the lowest susceptibility level to fenthion, while the BS-BG field population showed the lowest susceptibility to bifenthrin. The BS-BG field population showed resistance levels of 50 to 640 fold higher against the eight pesticides evaluated compared to the KS-BG. The resistance ratios (RR) of the eight pesticides were compared using populations of B. germanica that were collected from the same locality during 2007 and 2014. The field population of B. germanica collected during 2014 demonstrated significantly high resistance to an organophosphate and all pyrethroids when compared with those collected during 2007, but RR values were < 10 except for chlorpyrifos-methyl and chlorpyrifos with RR values of 74 and 104, respectively.

Anopheles sinensis is an important vector for Plasmodium vivax and thus has been targeted with organophosphates in Republic of Korea. Using the direct contact mortality bioassay, two field populations of An. sinensis from Paju-si and Yeoncheon-gun were characterized for their resistance to organophosphats with RR ratio values (Resistant ratio to imidacloprid) of 446.9 to 756.3 folds and 502.1 to 861.7 folds, respectively. Genomic DNA was used for Allele-specific PCR (AS-PCR) genotyping of the acethylcholine esterase to detect Gly119Ser mutations. The homozygous susceptible Ser/Ser genotype in Paju-si and Yeoncheon-gun was 20.0% and 20.9% and the resistance genotypes were 80.0% and 79.1%, respectively. The homozygous Gly/Ser resistance genotype was the most prevalent as 60.7% in Paju-si and 41.9% in Yeoncheon-gun. Hence, this study suggests that malaria vector control programs should be prepared for the management of organophosphate insecticide resistance.

Anopheles sinensis is an important vector for Plasmodium vivax and thus has been targeted with pyrethroids in Republic of Korea. Using the direct contact mortality bioassay, two field populations of An. sinensis from Paju-si and Yeoncheon-gun were characterized for their resistance to pyrethroids with RR ratio values (Resistant ratio to imidacloprid) of 96.8 to 167.2 folds and 34.2 to 98.4 folds, respectively. Genomic DNA was used for Allele-specific PCR (AS-PCR) genotyping of the sodium channel genes to detect L1014S mutations. The homozygous susceptible Leu/Leu genotype in Paju-si and Yeoncheon-gun was 3.3% and 37.1% and the resistance genotypes were 96.7% and 62.9%, respectively. The homozygous Phe/Phe resistance genotype was the most prevalent as 45.0% in Paju-si and 31.5% in Yeoncheon-gun. Hence, this study suggests that malaria vector control programs should be prepared for the management of pyrethroid insecticide resistance.

Increasing numbers of insecticide resistant insect is one of the main problem in current agriculture. To manage the insecticide resistance, IRAC suggest some tips for farmers : First, sequence or alteration of insecticide based on MOA. Second, choosing the effective insecticide. In this point raised following question : How to distinguish the effective or non-effective insecticide. Until now, bioassay is the right answer. However that is time-consuming, labor-intensive and costly process. So we have been steadily advancing molecular based insecticide resistance diagnosis for supporting and/or substitution of classical bioassay. It can summarized following steps : First, identification of insecticide resistance mechanism. Second, marker development. Third, development molecular diagnosis such as PASA, LAMP etc. Forth, application on field collected insects. Here we discuss some case of these study particular several major pests in highland agriculture.

Worldwide, increasing numbers insecticide resistant insect is one of the main problem in this agricultural era. To manage the insecticide resistance, IRAC suggest some tips for farmers : 1. Sequence or alteration of insecticide based on MOA 2. Choosing the effective insecticide. In this point raised following question : How to distinguish the effective or non-effective insecticide. Until now, bioassay is the right answer. However that is a very time-consuming, labor-intensive, and costly process, so we were hoping that molecular based diagnosis could be alternate. It can summarized following steps : 1. Identification of insecticide resistance mechanism 2. Marker development 3. Molecular diagnosis 4. Selection of non-effective insecticide. Here we focused on the development of insecticide resistance marker. Point mutation in target site of insecticide is a good example. Up or down-regulation of specific gene and/or existence of chimeric gene is another example from Helicoverpa armigera.

Chemical pesticides have been used to control persimmon pests, however the overuse of the pesticides caused insect resistance. Herein we investigate the potential of eco-friendly organic pesticides (EFOP) on the control persimmon pests, Stathmopoda masinissa and Riptortus pedestris. Eleven commercially available EFOP were sprayed on the target insects in laboratory conditions. The chemical pesticide, buprofezin+dinotefuran wettable powder served as a positive control. In the bioassay against persimmon fruit moth, the mixture of Chinese scholar tree, goosefoot and subtripinnata extracts (EFOP-2) treatment showed the highest control efficacy: 27.7% (5 days) of survival rates. In the bioassay against bean bugs, the EFOP-2 showed the highest control efficacy: 20.0% (5 days) of survival rates. These results suggest that the mixture of three plants extracts (EFOP-2) has high and multiple potential in the management of the persimmon pests.

We had evaluated of insecticidal effect from Insecticide-treated net (ITN) that coated by deltamethrin against Monochamus alternatus which serves as a vector for Bursaphelenchus xylophilus. In this experiment, vector has been shown that rapid insecticidal effect response time within 1 hour when they were contacted with ITN. In addition, vectors were showed high mortality within 48 hours. To evaluate insecticidal persistency of ITN and whether releasing insecticide to water, ITNs were soaked in water over various time periods. Water has not shown insecticidal effect to vectors and small amount of insecticide were detected that would not be harmful to other non-target organic being such as honeybee. Also, reduction of insecticidal effect was not observed from the ITN. Taken together, our results suggest that ITN had got highly insecticidal effect to vector as well as could be applied to effectively prevent dispersal of the vector on the field.

무가온 시설토마토 재배지내에서 토마토녹응애 발생양상은 4월 중하순경 최초로 발생하기 시작하여 6월 중하순경 최대 발생을 나타냈다. 하지만 야간기온이 낮을 경우 번식력이 증가하게 되고 주간기온이 높을 경우에는 분산이 활발해져 고온기인 7월에도 지속적으로 증가하는 것으 로 조사되었다. 유기농업자재 11종에 대한 토마토녹응애의 살충독성 실내검정 결과, EOIMa (Matrin 0.6%), EOICo (Clove oil 10%)가 500 배에서 각각 92.1%와 95.1%로 90% 이상의 살충효과를 보였다. 특히 EOIMa 1,000배에서는 90.4%로 90%, EOIMa 2,000배에서는 88.2%의 높은 살충효과를 보였다. 포장검정에서도 EOIMa 1,000배와 EOICo 500배는 각각 91.5%와 93.9%의 살충효과를 보여 두 약제 모두 농약을 대 체하기에 충분하였고 EOIMa의 경우 2,000배에서도 살충효과가 90%에 가까웠기 때문에 예방적 활용도 가능할 것으로 판단되었다.

지구 기후변화에 따라 아열대성 해충이 온대지역으로 이주를 통해 서식지를 넓히고 있다. 아열대성 해충인 콩명나방(Maruca vitrata)이 국 내에서 팥을 비롯한 콩과작물에 경제적 피해를 일으키고 있다. 비교적 유전적 변이가 큰 곤충으로 알려진 콩명나방에 대해서 국내 집단의 기원에 대해서 의문을 갖게 되었다. 국내 콩명나방 집단의 유전적 특성을 이해하기 위해 cytochrome oxidase subunit 1 (cox 1) 유전자의 염기서열을 판독 하였고, 이를 다른 지역 집단들과 분자계통학적으로 분석하였다. 전 세계에 분포하고 있는 콩명나방은 크게 3 그룹(아시아-아프리카, 아메리카, 오세아니아)으로 분류되었다. 이 가운데 국내 콩명나방은 아시아-아프리카 그룹에 속했다. 국내 집단의 살충제 감수성을 분석하기 위해 작용기작이 서로 다른 7 가지(4 종류의 신경독 약제, 1 종류의 곤충성장조절제, 2 종류의 생물농약)의 약제로 평가하였다. 콩명나방의 어린 유충은 분석된 모든 약제에 비교적 감수성이 높았다. 그러나 노숙 유충의 경우는 어린 유충에 비해 감수성이 현저하게 저하되었다. 처리 후 7 일간 분석된 살충력 조사에서 조사된 어느 약제도 콩명나방의 최종령 유충을 효과적(> 50% 방제가)으로 방제하지 못하였다.

우리는 시설토마토에서 4가지 침투이행성약제가 사용된 가지를 트랩식물로 활용하여 담배가루이 성충의 방제효과를 조사하였다. 침투이 행성약제가 추천된 농도로 사용되었을 때, 담배가루이 성충에 대한 dinotefuran SG 50% 방제효과는 80%로 방제효과가 각각 51.0%, 12.4%, 11.0%인 cyantraniliprole, pyridaben, clothianidin 보다 높았다. 살충효과가 뛰어난 dinotefuran을 농도별로 처리하였을 때, 200 ppm에서 살충률이 88.4%로 가장 효과적이었다. Dinotefuran의 방제효과는 가지에 적용된 약 9일까지 지속되었고 그 이후 담배가루이 밀도는 증가하였 다. 포장실험에서 가지 트랩식물로부터 0, 15, 20 m 떨어진 토마토 신초에서의 담배가루이 밀도가 가장 높았고 5 m와 10 m에서 가장 낮았다. 담배가루이의 밀도가 낮고 dinotefuran SG 50%가 처리된 가지를 10 m 간격으로 투입했을 때, 담배가루이 성충의 밀도가 전체적으로 낮았으며, 또한 담배가루이의 밀도는 하우스 내부보다는 측면에서 밀도가 더 높았고 가지로부터 멀리 떨어진 곳에서 밀도가 높았다. 담배가루이 밀도가 높 고 dinotefuran SG 50%가 처리된 가지를 5 m간격으로 투입했을 때, 담배가루이 밀도가 낮아졌다. 이러한 결과로 볼 때 가지는 시설토마토 재배 시 담배가루이 성충을 유인하는데 효과적인 트랩식물이며 dinotefuran SG 50% 과 함께 사용한다면 담배가루이 밀도를 효과적으로 감소시킬 수 있을 것이다.

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.

Currently, major controlling tools for insect pests depend on conventional chemical insecticides and genetically-modified organisms. These methods target neuro-synapses, channels and/or receptors that result in neurotoxicity or physiological imbalance. Unfortunately, this mode of action affects non-target animals and difficult to control insect species-specific. The application of classic insecticides is more and more restricted due to many problematic side effects, such as human and environmental toxicity, non-target insect and animal effects, and resistance. During the past decades new genomics/proteomics technologies such as RNA interference (RNAi), allow development of new classes and/or mode of action of insecticides and functionally screen bioactive compounds. Insect neuropeptides are the largest group, more than 90%, of all insect hormones that are involved in almost all physiological functions during the developmental and adult stages. Therefore, insect neuropeptide hormones and their receptors are good targets for discovery of insecticides such as RNAi and bioactive agents. In the presentation, insect case studies using neuropeptides and receptors suggest the possibility of novel biologically-based insect pest control methods.

The small brown planthopper (SBPH), Laodelphax striatellus Fallen, is an important pest that causes severe yield losses by transmitting plant viruses to rice. For the efficient control of SBPH in Korea, the respective resistance levels in the immigrant and indigenous populations need to be discerned. The resistance levels to 10 insecticides (three carbamates, an organophosphate, four neonicotinoids, and a phenylpyrazole) were evaluated in 21 field populations collected from either SBPH-immigrating or indigenous regions during two different seasons (early spring vs. late summer). Imidacloprid resistance was most widely observed in many regional populations, followed by thiamethoxam resistance. Interestingly, the resistance level to imidacloprid was significantly higher in both immigrant and late-summer-collected populations than in indigenous and early spring-collected populations, respectively [3.3- (p = 0.018) and 2.6-fold (p = 0.026)]. Moreover, the late summer immigrant population exhibited higher imidacloprid resistance (2.4-fold) than the early spring-collected population from the same region, suggesting that the migratory SBPH that immigrated into Korea already exhibited imidacloprid resistance traits and were further selected after inhabitation. All field populations showed little resistance to fipronil (0.1- to 0.7-fold), suggesting that it is the most effective among the tested insecticides to control field populations of SBPH. The coefficient of variation of the resistance ratio (RR) among different regional populations and the correlation coefficient of RR among different insecticides have been suggested as supplementary parameters when determining appropriate insecticides as respective indicators for the dispersion status of resistance among SBPH populations and the possibility of cross resistance among tested insecticides.

During the last century, the overuse of synthetic chemical insecticides led to problems associated with natural environment such as harmful effects on nontarget organisms and development of resistance. Therefore, the application of insect pathogenic microorganisms including Bacillus thuringiensis (Bt), baculoviruses, and entomopathogenic fungi has been an environmentally favorable methods for insect control. However, their use has been limited by several factors such as narrow host spectrum and slow speed of insecticidal activities. A number of approaches have been taken to overcome these defects of microbial insecticides. A novel recombinant baculovirus, NeuroBactrus, was constructed to develop an improved baculovirus insecticide with additional beneficial properties, such as a higher insecticidal activity and improved recovery, compared to wild-type baculovirus. For the construction of the NeuroBactrus, the Bt cry1-5 crystal protein gene was introduced into the Autographa californica nucleopolyhedrovirus (AcMNPV) genome by fusion of polyhedrin-cry1-5-polyhedrin under the control of the polyhedrin promoter. In the opposite direction, an insect-specific neurotoxin gene, AaIT, from Androctonus australis was introduced under the control of an early promoter from Cotesia plutellae bracovirus by fusion of a partial fragment of orf603. The Polyhedrin-Cry1-5-Polyhedrin fusion protein expressed by the NeuroBactrus was not only occluded into the polyhedra, but also activated by treatment with trypsin, resulting in an approximately 65-kDa active toxin. The NeuroBactrus showed a high level of insecticidal activity against Plutella xylostella larvae and a significant reduction in the median lethal time (LT50) against Spodoptera exigua larvae compared to those of wild-type AcMNPV. Expression of the foreign proteins (Bt toxin and AaIT) was continuously reduced during the serial passage of the NeuroBactrus. These results suggested that the NeuroBactrus could be recovered to wild-type AcMNPV through serial passaging. The cry gene from Bt, encoding the Cry protein, has been recently introduced into crops to generate transgenic plants that are resistant to pest insects. Through the 3D structure prediction and accompanying mutagenesis study for the Mod-Cry1Ac, 7 and 16 amino acid residues from domain I and II, respectively, responsible for its insecticidal activity against larvae of S. exigua and Ostrinia furnacalis were identified. We used site-directed mutagenesis to improve the insecticidal activity of Mod-Cry1Ac, resulted 34 mutant cry genes. These mutant cry genes were expressed, as a polyhedrin fusion form, using a baculovirus expression system. The expressed proteins were 95 kDa and SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded into polyhedra and activated stably to 65 kDa by trypsin. When the insecticidal activities of these mutant Cry proteins against to larvae of P. xylostella, S. exigua and O. furnacalis were assayed, they showed higher or similar insecticidal activity compared to those of Cry1Ac and Cry1C. Especially, Mutant-N16 is considered to have the potential for the efficacious biological insecticide since it showed the highest insecticidal activity.

Transcriptome analysis was conducted for the identification of genes associated with insecticide resistance in Frankliniella occidentalis. Resistant strain (FO_RDAHC) exhibited 39.2- ~ 533-fold resistance to acrinathrin, spinosad, emmamectin benzoate and thiamethoxam compared with a susceptible FO_RDA strain. Average 7.6 million reads (± 5,068,895 reads) were obtained from the pyrosequencing and were assembled into the draft CDS database. Gene annotation was conducted by BLAST (UniProt), Pfam, FUNCAT and COG analysis. In the deferentially expressed gene (DEG) analysis, 838 genes were up-regulated and 815 genes were down-regulated over 2-fold ratio in FO_RDAHC strain. Highly up-regulated genes included genes encoding several cuticle-related proteins, cytochrome P450s, esterases and transporter genes. An autotransporter protein gene exhibited the highest up-regulation (596 fold) whereas a GMC oxido-reductase revealed the highest down-regulation (12 fold). Further study would be necessary to validate the actual transcript levels of DEGs and to investigate their functional roles in insecticide resistance.

This study compared the development, reproduction, and DNA damage in insecticide (acequinocyl, bifenazate, and etoxazole)-resistant (AR, BR, and ER) and -susceptible (S) strains of Tetranychus urticae by electron beam irradiation. When eggs were irradiated with 150 Gy, the egg hatching was completely inhibited in all strains. When nymphs were irradiated, their emergence rate was decreased with increasing doses of electron beam irradiation. When adults were irradiated, the longevity and the number of eggs was not affected at all target dose in all strains. However, hatchability of F1 generation was perfectly inhibited at 400 Gy in all strains. The DNA damage caused by electron beam irradiation was evaluated by an alkaline comet assay. These results suggest that electron beam irradiation induced abnormal development and reproduction in S, AR, BR, and ER strains of T. urticae.

An easy and rapid resistance detection protocol for the Western flower thrips Frankliniella occidentalis was established based on the residual contact vial bioassay (RCV), in which insecticide resistance levels can be estimated at 8 h-post treatment of diagnostic doses. The RDA strain was used as a reference susceptible strain, which has been reared under laboratory conditions over 10 years without exposure to any insecticides. Seven insecticides were tested for the determination of diagnostic dose. Among them, five insecticides (chlorfenapyr, acrinathrin, spinosad, emmamectin benzoate and thiamethoxam, ranged as 0.03 ~ 0.42 μg-1cm2) were applicable to the RCV. However, two insecticides (omethoate and imidacloprid) were not able to be used for the RCV because the treated inner surface of glass vials by these insecticides were too viscous, causing non-specific mortality. The RCV detection kit was employed for the estimation of resistance levels for the five insecticides in five local populations. Almost field-collected populations revealed high levels of resistance to the four insecticides (acrinathrin, spinosad, emmamectin benzoate and thiamethoxam) by showing less than 50% mortality. The baseline resistance detection by RCV method will facilitate the selection of proper insecticides for farmers to manage insecticide resistant-populations of F. occidentalis.

Nilaparvata lugens Stål is one of the important migratory pests of rice paddy fields in Korea. Resistance levels to nine insecticides were monitored in 12 local strains and correlation analysis was conducted to determine cross-resistance relationships among the tested insecticides. The local strains revealed 1.3- to 28.0-, 1.6- to 6.0-, 2.8- to 237.0-, 0.6- to 0.9-, and 0.7- to 1.3-fold resistance to carbamates, organophosphates, neonicotinoids, fipronil and etofenprox, respectively. Organophosphates revealed moderate correlations with benzofuranyl methylcarbamate (r = 0.566 - 0.614, p > 0.01). Three neonicotinoids were not correlated each other, but imidacloprid and clothianidin were moderately correlated with several benzofuranyl methylcarbamate and organophosphate insecticides (r = 0.590 - 0.705, p > 0.05), indicating that unknown common factors (such as detoxification enzymes) might contribute to resistance to both insecticides. Fipronil and etofenprox exhibited low levels of resistance and cross-resistance with other insecticides, suggesting their potential as an effective insecticide for field application. Resistance level monitoring and correlation analysis would be valuable for the selection of appropriate insecticides to control insecticide-resistant N. lugenes, a typical migratory pest in Korea.

2009~2011년 동안 국내 주요 배추 재배지 5개 지역(평창, 홍천, 봉화, 무주, 제주)에서 살충제에 대한 복숭아혹진딧물의 저항성 발달 정도를 조사하고, 야외 개체군에 적용 가능한 살충제 저항성 마커를 개발하기 위해 본 연구를 수행하였다. 조사된 5개 지역 개체군 모두 여러 살충제 종류에 대하여 다양한 저항성을 보였다. 다양한 저항성을 보인 5개 지역 야외 개체군으로부터 여라 살충제에 대하여 복합적으로 저항성을 보이는 복합저항성 계통(MR)을 선발하였고, 이 MR과 모든 지역 채집 개체군에 대해 등전점전기영동과 정량염기서열분석(quantitative sequencing, QS)을 통하여 에스터레이즈 과발현과 살충제 작용점 내 돌연변이를 확인하였다. MR을 포함한 모든 야외 개체군에서 에스터레이즈의 과발현과 아세틸콜린에스터레이즈 1 유전자(ace1)의 StoF 돌연변이를 확인할 수 있었다. 넉다운 저항성 돌연변이로 잘 알려진 파라 타입 나트륨 채널 유전자(para)의 LtoF 돌연변이는 모든 지역 채집 개체군은 물론 비펜스린에 대해 3,461배 저항성을 보이는 MR에서도 발견되지 않았다. 그 외에 MtoL 돌연변이를 발견하였는데, 생물검정 결과 저항성 수준과 돌연변이 발생 빈도가 일치하였다. 따라서 생물검정 대신, 이러한 분자 마커를 활용 한다면 더 효율적으로 살충제 저항성 평가가 가능할 것이다. 이러한 분자 마커들(ace1의 StoF, para의 MtoL)은 정량염기서열분석, PCR amplification of specific alleles (PASA) 등의 진단 방법에 쉽게 응용이 가능 하고, 이러한 방법은 야외 복숭아혹진딧물 저항성 관리에 적용이 가능 할 것이다.