The two-spotted spider mite, Tetranychus urticae, and gray mold disease caused by Botrytis cinerea, are importantpest and plant disease. To control these, many people have been relied on chemical methods for a long time. However,their continuous use has resulted in resistance of pest and disease. To surmount or avoid these problems, we evaluatedantifungal activity of the selected fungi with high virulence to mite to explore the potential for the dual control of notonly T. urticae but also B. cinerea. To maximize the use of spores and cultural filtrates, the virulence to mite was evaluatedusing culture products, and effective culture condition was investigated against blastospore production and antifungal activity.Consequently, the 2 fungal isolate selected in this study were confirmed to have diverse potential and would be usedeffectively for dual control agents against the two-spotted spider mite and plant diseases

The two-spotted spider mite, Tetranychus urticae, is one of the most important pests of crops. However, chemical acaricides are not always effective and their continuous use has resulted in resistance among two-spotted spider mite populations. To reduce or replace use of chemical acaricides, the entomopathogenic fungi having acaricidal activity were investigated. As results, 12 isolates could be selected from 342 isolates of fungi against two-spotted spider mite. To show the multiple roles of entomopathogenic fungi against plant pathogen, the antimicrobial activity of selected 12 isolates were evaluated to plant pathogenic bacterium Ralstonia solanacearum and fungus Botrytis cinerea. Various antimicrobial activities were observed against these plant pathogens. Consequently, these entomopathogenic fungi would be offered an alternative for dual control agents against the two-spotted spider mite and plant diseases.

Varroa destructor is a devastating ectoparasitic mite which attacks Honeybee, Apis mellifera. V. destructor feeds on honeybee hemolymph, and often harbors small RNA viruses such as the deformed wing virus to transmit these viruses in the infested bee hive. To survey the genes of V. destructor, total RNA was subjected to high-throughput transcriptome sequencing to construct in silico cDNA library by using the Illumina HiSeq 2000 platform. Total of 2×107,748,792 paired-end short reads were obtained and quality filtered reads were subjected to Trinity de novo assembler followed by TransDecoder, and CD-HIT program to make a V. destructor reference cDNA library containing 28,023 of clustered contigs with protein coding capacity. These cDNA sequences will help us to understand the molecular biology of V. destructor.

The bulb mite (BM), Rhizoglyphus echinopus, is hard to control in the harvested onion and garlic. Methyl bromide (MeBr) fumigation is the only option to eradicate BM at present. However, MeBr causes phytotoxic damage (index 3) to onion and garlic and highly toxic to fumigators. To replace MeBr, we evaluated ethyl formate (EF) and phosphine gas (PH3) to BM at 5℃ which is current practical fumigation temperature. The >140 g·h m-3 of EF for 24 h could completely control BM and this CT (concentration × time) product was slightly (index 1) phytotoxic to onion and garlic. Fumigation of 2 g PH3 required >120 h exposure to kill 100% of BM without any pyhtotoxic damage. Further researches are being planned to shorten the exposure time with synergistic effect between EF and PH3.

The two-spotted spider mite Tetranychus urticae is being steadily problematic on strawberry. To effective control of this pest, one combination application using predatory mite Phytoseiulus persimilis plus a pesticide Acequinocyl suggests. Prepared six beds (1.5 × 3 m; 20 strawberry plants) on glass house, 100 T. urticae was inoculated on per 20 plants. Four plots prepared - Acequinocyl treatment, P. persimilis application, Acequinocyl+P. persimilis double application, and the control. The change of T. urticae density was investigated in the seven-day intervals. In an Acequinocyl treated plot, T. urticae density was decreased after Acequinocyl sprayed, but began to increase steadily one month later. In a P. persimilis applied plot, T. urticae density began to decrease at 20 days after P. persimilis inoculation. In an Acequinocyl + P. persimilis double applied plot, T. urticae density was dramatically decreased after application and then no found the T. urticae. To practical use in farmhouse, it will be possible to control by inoculation of P. persimilis only when low density of T. urticae; however, double application with spray pesticide Acequinocyl plus apply the natural enemy P. persimilis will be good when high density of T. urticae.

Seasonal abundance and distribution of mosquitoes and chigger mites are important for human populations. However, factors affecting the abundance and distribution of vector species are not well - understood. Furthermore, global climate change makes it difficult to predict the population dynamics of vector species. Therefore, it is important to monitor this vector species over a long period of time. In 2015, mosquitoes were collected from three potential mosquito habitats using black light trap and BG-Sentinel trap in Gyeongi-do in April through October. Also, we collected chigger mite using sherman live traps in Cheorwon, Gangwon-do in April, September and October. From the survey, we collected a total of 11,649 mosquitoes in three potential mosquito habitats, and a total of 3,656 chigger mites from 54 wild rodents. In the samples, dominant mosquito species were Aedes vexans nipponii (Species Ratio 70%), Culex pipens pallens (SR 9.8%) in Gyeonggi area and dominant chigger mite species was Leptotrombidium pallidium (SR 59%) in Cheorwon. The results of this study can serve as provide fundamental basis to develop effective management strategy under the global climate change environment.

Expression of hairpin RNA corresponding to the part of COPA transcript was done by agroinfiltration in soybean plants and was confirmed by qRT-PCR. In a pot experiment, T. urticae was infested on agroinfiltrated soybean plants and T. urticae mortality was observed and compared with control plants overtime. Significantly higher mortalities of T. urticae were observed in the COPA-agroinfiltrated soybean plants from post-infestation day 2 (15 ±5%), day 4 (50 ±10 %). At post-infestation day 6, mortality reached to (70 ± 15%). To validate the observed COPA silencing effect in T. urticae fed on the agroinfiltrated soybean plant expressing COPA hairpin RNAs, qRT-PCR analysis was performed. The transcript level of COPA gene was decreased in T. urticae fed on agroinfiltrated soybean plants expressing COPA hairpin RNA from post-infestation day 2. At post-infestation day 2, 4 and 6, COPA transcript levels were reduced by 23.8, 20.7 and 18.8 fold, respectively compared to post-infestation day 1 (control). The results obtained in this study also ruled that the plant mediated production and uptake of silencing (dsRNAs/siRNAs) is an effective way to trigger RNAi in the T. urticae.

국내 미기록종 Pyemotes moseri Yu et Liang (Acarina: Pyemotidae)는 곤충기생성 응애로 매실 씨앗 속 유충에서 처음 발견되었다. 발견 당시 응애가 기생하고 있었던 기주의 미토콘드리아 유전자를 증폭하여 염기서열을 분석한 결과 복숭아씨살이좀벌의 유충으로 밝혀졌다. 본 연구 는 실험실 조건하에서 P. moseri의 번식과 기생 능력을 조사하였다. 복숭아씨살이좀벌의 유충을 기주로 이용하여 P. moseri의 교미한 암컷 성충을 사육하면서 주기적으로 관찰하여 새로 태어나는 자손의 수와 성별을 조사한 후 제거하였다. 기생 능력 조사는 원예용 상토가 깔린 스테인레스 바 트에 대량 사육한 응애가 들어 있는 튜브와 복숭아씨살이좀벌 유충이 가해한 매실 씨앗을 함께 담은 후 지퍼백에 넣어 인큐베이터에 보관하였다. 복숭아씨살이좀벌 유충 또는 번데기에 응애의 기생 여부를 확인하고자 한달 후 매실 씨앗을 조사하였으며 본 실험은 5반복씩 3회 실시하였다. 교 미한 암컷이 기생하기 시작한 이후부터 생식이 끝날 때까지의 기간은 평균 24.4일(n=8)이었으며 교미한 암컷 한 마리당 평균 104.0마리(n=8)의 암컷을 낳았디. 복숭아씨살이좀벌의 유충 또는 번데기가 들어 있는 매실 씨앗은 바트당 평균 7개 이상이었고 이중 단 2개의 씨앗에서만 기생에 성 공한 응애를 관찰하였다.

Trombiculid mites are known to be the vector of scrub typhus by transmitting rickettsial pathogen, Orientia tsutsugamushi, to human. In this study, we tried to establish a monitoring system for trombiculid mites using chigger mite collecting traps instead of the conventional rodent-capture method. For selection of collecting points, 10 environmental points were chosen from three regions (Taean, Jinan and Chungju) and two field collections were performed in spring (March-May) and autumn (October-November) seasons from 2013 to 2014. Among 10 environmental points, waterway (37.9%), grass field (28.0%), rice field and field near mountain side (11.4%) and reservoir/wet field (7.3%) showed high collecting rates and they should be included for the representative collecting points for surveillance using chigger mite collecting trap. In order to test the possibility that the dried chigger mites from collecting trap can be used for detection of O. tsutsugamushi, we pooled 30, 10 and 5 chigger mites separately and performed the nested PCR. The infection of O. tsutsugamushi was successfully detected from 5 chigger mites pooling sample. This study shows that chigger mite collecting trap could be an alternative method for monitoring system of scrub typhus vectors.

The Hawthorn spider mite Amphitetranychus viennensis is an important pest of various fruit trees as well as a variety of ornamental plants. Its presence has been reported in China, Japan, Korea, and middle east and European countries including Grorgia, Russia, Turkey, Ukraine. Thus, it is a quarantine species in American countries and Australia. Intra-specific variation of A. viennensis was investigated using 555 bp of ITS2 ribosomal DNA and 453 bp of the cytochrome oxidase I (COI) gene. Its variation of ITS2 and COI among China, Japan and Korea were 1.7-2.2% and 0.2-0.7%, respectively. In addition, we collected samples from 14 location in Korea. Intra-specific diversity of ITS2 and COI within Korean populations were ranged into 0.5-0.9% and 0.2-0.5%, respectively. Thus, A. viennensis is not much genetically diverse in different populations.

Tropilaelaps mercedesae is an ectoparasite of immature honey bees belonging to the genus Tropilaelaps (Acari: Laelapidae). T. mercedesae has become a major threat to the Western honey bee Apis mellifera in Asia, including Korea, and is expanding its geographical range to northern regions due to global warming. To establish gene resources of T. mercedesae, the whole transcriptome was analyzed by RNA sequencing. An mRNA-focused library was generated from total RNA extracted from the mixed stages using the TruSeq RNA Library Preparation kit and sequenced using the HiSeq 2000 platform. A total of 6.0 Gb reads were obtained with 85% Q30 value. Trimmed sequence data were de novo assembled using the CLC Assembly Cell v 4.2. A total of 64,868 non-duplicate contigs were finally obtained and annotated by the Blast2GO using the NCBI nr database. The most abundant species in the resulting 14,336 Blast hits (22.1%) was Metaseiulus occidentalis, a predatory mite, followed by Ixodes scapularis and Tribolium castaneum, suggesting that the T. mercedesae transcriptome matches well with closely related other arthropod species, including mites and ticks. In order to provide basic information for efficient control and monitoring of potential resistance in T. mercedesae, acaricide target genes were annotated and characterized. One voltage-sensitive sodium channel gene encoding the molecular target of fluvalinate, a pyrethroid acaricide most widely used for the control of T. mercedesae, was identified and its molecular properties were investigated. In addition, other acaricide target genes, including acetylcholinesterase and glutamate (or GABA)-gated chloride channel, were identified and characterized.

Leptotrombidium pallidum is the major vector mites for Orientia tsutsugamushi, the causative agent of scrub typhus. To understand the molecular mechanism of L. pallidum, we sequenced the whole genome using Illumina sequencing technology. Totally four genomic libraries with different insert sizes ranging from 280 bp to 8 kb were used to generate 45.1 Gb of genome in the combination of paired-end and mate-pairs sequencing reads. Quality filtering and correction of paired-end reads for very small and/or bad-quality sequences yielded 26.9 Gb of high-quality sequences, which are used to estimate the genome size as 175 Mbusing kmer methods and assembled into a 193.7 Mb genomic sequence scaffolds with N50 length of 92,945 bp. Furthermore, 94% of CEGMA completeness score were obtained from genome scaffold assembly. To facilitate gene annotation, we used a combination of de novo and homology based tools to predict gene models in the chigger mite genome. A combination of evidence-based and de novo approaches predicted 15,842 high-confidence protein-coding genes with an average transcript length of 1,511 bp and 2.4 exons per gene which corresponds to about 12.4% total gene length. Bacterial endosymbiosis are very common in mite species and can range from mutualistic to pathogenic associations. Henceforth, the endosymbionts in L. pallidum were predicted using the NCBI microbial draft genomes and mitochondrial genome. Besides, this L. pallidum draft genome can be used as a significant reference for comparative genomic studies across mite species.

Calepitrimerus vitis (Nalepa) is a grapevine pest and distributed worldwide. This study was conducted to identify grapevine damage related to density of C. vitis and to suggest an effective control time. The damaged flower buds displayed retarded growth and became dried up, and symptoms of damaged leaves such as malformed and bronzed leaves were observed. Flower cluster and leaves were collected and density of the grape rust mite were observed by using a washing and sieving method. The highest mean density (±SE) of C. vitis was found to be 672.6±112.9 per flower cluster with mid-level damage, and 450.1±66.5 per 2 leaves was found on the damaged leaves. These severe damage symptoms were observed in the early spring, and the density of the grape rust mite was significantly higher as 80 times in damaged vineyard than in the undamaged at the early growth stages of the grapevine. To determine the emergence time of the grape rust mite from lower part of a winter bud the ratio of density of C. vitis on upper-bud to lower-bud was observed. On 13 April 2015, 80% of the grape rust mites were observed on upper-bud where the mite could feed at the bud burst stage. Therefore, once the symptoms of damaged flower clusters and leaves are observed, acaricides should be sprayed before inflorescence emergence, and at the early growth stage between bud burst and leaf development in following year. This would allow the decrease of the density of C. vitis in early spring, and the progression of severe damage could be prevented.

Tetranychus urticae was collected from greenhouse roses to monitor the development of acaricide resistance. Dose-mortality lines were estimated on 16 regional populations with 13 acaricides. For each acaricide, LC50s of the populations were plotted to check normality. LC50s of eight acaricides showed normal distribution and five others did not. An index of Ln (recommended dose/LC50 for each acaricide) checked the development of resistance to populations. The index is based upon recommended dose to control a pest stage and empirical LC50 got from serial dilution range for each pesticide. We tried to categorize acaricides by index due levels of effectiveness to mites: tebufenpyrad, fenpyroximate, bifenthrin, and fenbutatin oxide as non-effective acaricides with less than index 1.0, chlorpyrifor+bifenthrin and milbemectin as alert level placed between 1.0 and 2.0, acequincyl as caution between 2.0 and 3.0, and abamectin, cyflumetofen, bifenazate, chlorfenapyr+fulacrypyrim and propargite as effective over 3.0. We also tested the similarity of acaricide actions for choosing effective acaricides against resistant mites and of populations for resistance management. We could make several acaricides groups: group1 including abamectin, cyflumetofen, and bifenazate group 2 propargite and chlorpyrifos+bifenthrin group 3 chlorfenapyr and acequinocy and group 4 mibemectin, fenyroximate, and bifenthrin, by which we can suggest not to use acaricide within the same group to avoid the resistance development. Populations grouping would imply similar practices of acaricide use, so we can manage pesticide usage, effectively. Group A includes Gimhae 2, 3, 4, 5, Jincheon2, and Taean, and Group B includes Goyang, Gangjin1, Paju, Gangin2 and Namwon.

The gingival epithelium of the oral cavity is constantly exposed to exogenous stimuli such as bacterial toxins, allergens, and thermal changes. These exogenous stimuli are resisted by innate host defense in gingival epithelial cells. However, it is unclear exactly how the exogenous stimuli affect detrimentally on the human gingival epithelial cells. Here, we investigated whether the allergen, such as house dust mite (HDM) extract, is linked to Ca2+ signaling and proinflammatory cytokine expression in primary cultured human gingival epithelial cells. HDM extract induced an increase in intracellular Ca2+ concentration ([Ca2+]i) in a dose-dependent manner. Extracellular Ca2+ depletion did not affected on the HDM extract-induced increase in [Ca2+]i. The HDM extractinduced increase in [Ca2+]i was abolished by the treatment with U73122 and 2-APB, which are inhibitors of phospholipase C (PLC) and inositol 1,4,5-trisphosphate (IP3) receptor. Moreover, HDM extract induced the mRNA expression of pro-inflammatory cytokine, interleukin (IL)-8. These results suggest that HDM extract triggers PLC/IP3-dependent Ca2+ signaling and IL-8 mRNA expression in primary cultured human gingival epithelial cells.

Leptotrombidium pallidum is the major vector mite for Orientia tsutsugamushi, the causative agent of scrub typhus, in Asian countries, including Korea. The genome size of L. pallidum was previously estimated to be 191 ± 7 Mb (Kim et al., 2014). Genomic DNA (gDNA) was extracted from a single female from a 9-generation inbred L. pallidum colony and used for whole genome amplification (WGA). The resulting amplified gDNA was used for the construction of paired-end and mate-pair libraries and sequenced using Illumina platforms (HiSeq2000 and MiSeq). An unamplified gDNA sample extracted from 20 female mites was also used for sequencing in parallel. More than 45Gb sequence reads from both paired-end and mate-pair libraries of the WGA gDNA were trimmed and then de novo assembled using the CLC Asembly Cell v.4.0 for contig assembly and SSPACE for scaffolding. The assembly generated approximately 6,545 scaffolds with N50 value of 92,945 and total size of ~193Mb, which was in a good agreement with our previous estimation. Repeat analysis showed that about 30% of genome (~58Mb) was masked as repeats, most of which were unclassified novel elements. For gene predictions, generated were the PASA models based on genomic alignments of RNA-seq reads from 4 different chigger mite samples (i.e. male, female, larva, and protonymph) and the GeneWise models based on genomic alignments of protein sequences from 4 closely related species with chigger mite. Independently, ab initio gene predictions were performed with AUGUSTUS and FgeneSH with custom trained matrices optimized for L. pallidum and GENEID with pre-trained matrix for Acyrthopsiphon pisum. By combining all together, 15,842 genes were predicted finally. Manual curation is in progress for various groups of genes, including chemosensory receptor genes, immune-related genes, acaricide target genes, etc.

The two spotted mite, Tetranychus urticae Koch, is a global pest, and has developed severe resistance to several types of acaricides. Acequinocyl-resistant strain and bifenazate-resistant strain of T. urticae showed higher relative activity level of glutathion-S-transferases (GSTs) than susceptible strain. Studies of resistance in T. urticae have focused on classical detoxifying enzyme system, such as GSTs. We examined the expression of six GSTs genes in T. urticae belong to five different cytosolic classes, including two in delta, one in omega, one in mu, one in zeta, and one mitochondrial GSTs class, kappa. RT-qPCR results showed that, among these six GSTs genes, the relative expression level of delta 1 was significantly higher in bifenazate-resistant strain than in other strains (susceptible, abamectin, acequinocyl, etoxazole and pyridaben strain). Expression level of the delta 2 was also higher in acequinocyl-resistant strain than in other strains. The elevated GSTs gene transcripts following exposure to acequinocyl, bifenazate might be one of the mechanisms involved in detoxification of these acaricide. These results may be caused by different mechanisms in the resistance development of T. urticae to these two different types of acaricides.

The Seoul forest of urban forest park is provide places for relaxation and feeling naturally use inside the city. This study was conducted for investigating diversity of soil microarthropods for Bioblitz. Samples were collected from rose of Sharon in soil. This species was identified as N. harrowi (Collyer), described originally from New Zealand and Austrilia. This is the new record of N. harrowi in Korea. The morphological features of these two species are closely related to each other (N. makuwa (Ehara) and N. harrowi (Collyer)). So, we compared features of this species. Dorsal setae of N. harrowi are generally longer than in N. makuwa. Two posterior seta (Z4, Z5) of N. harrowi are much shorter than in the N. makuwa. In addition, there are some differences in the shape of the spermatheca, the forked atrium is larger in N. makuwa than in the N. harrowi.

This study was conducted to analyze dust mite allergen and bacterial endotoxin concentrations in the subwaycabins. For this aim, we sampled dust using a vacuum cleaner on cabin seats of subway trains operating in threeSeoul Metro Lines from April to May in 2011. The concentration of dust mite allergen and endotoxin were1,137.51±806.26ng/g and 5,742.1(4.68)EU/g, respectively. While, the concentration of dust mite allergen washigher on cabin seats of subway trains in Line B(1,487.61±930.59ng/g) than on those of trains in Lines A andC(641.9±398.3 and 1,344.9±822.4ng/g). All measurements did not exceed the National Workshop Guidelineof 2,000ng/g. While, bacterial endotoxin concentration [GM (GSD)] was higher on cabin seats of subway trainsin Line A [12,373.21(4.97EU/g)] than on those of trains in Line B and C8,520.77(3.98) and 1,631.43(1.88)EU/g. Dust mite allergen concentrations were strongly influenced by the portion of underground (on the subway line)and endotoxin concentrations were significantly correlated with the number of passengers using the subway lines.Seats for seniors and the week showed relatively higher concentrations compared to seats for general passengers.But, no significant difference of dust mite allergen and endotoxin concentrations in the subway cabins was foundrelating to seat type (p=0.451, p=0.564). There was no correlation between the dust mite allergen levels andendotoxin levels in the subway cabins (p=0.439).

The detoxification enzymes activities were investigated to Tetranychus urticae Koch using five acaricide-resistant strains. Activities of detoxification enzymes which are glutathione S-transferase (GST), general esterases (α-naphthyl acetate and β-naphthyl acetate), and cytochrome C oxidase were determined to each resistant strain mite. Acequinocyl-resistant strain and bifenazate-resistant strain of T. urticae were showed 2.1 folds and 1.6 folds higher relative activity (RA) level of GST than susceptible strain. Other three resistant strain mites were not significant different to susceptible strain mite. General esterases and cytochrome C oxidase were not significant to all the strain of T. urticae. Acaricidal activities of acequinocylresistant strain and bifenazate-resistant strain of T. urticae showed cross-resistant both acequinocyl and bifenazate. However, other strain mites were showed susceptible acaricidal activities to two acaricides. In this result suggests that resistance of two acaricides (acequinocyl and bifenazate) might be influenced by glutathione S-tansferase activity.