Aedes albopictus is an invasive mosquito that can be found in all continents. This species, considered as secondary vector of Dengue virus, has recently been suggested to play a role in the transmission of Zika virus in several countries bordering Brazil. In this study, We surveyed the distribution, abundance and main micro habitats of Ae. albopictus in Koera. The main bloodmeal source of this mosquito was mammals (71%) followed by birds (26%), and fish (1%). In flavivius detection, no virus was detected in this mosquito, but a total of six Japanese encephalitis virus (JEV) positive pools were detected from Culex orientalis and Culex pipiens. To investigate the possibility of using Wolbachia, as one of biological control strategy, we investigated the distribution of Wolbachia infection in Ae. albopicutus according to geographical distribution. Over 99% of the collected this mosquitoes harbored Wolbachia.

A seasonal chigger-borne disease surveillance program was established at Geoje from March to November of 2018 in Gyeongnam Province, Republic of Korea. Two species of 84 wild rodents were collected by using Sherman traps for Geoje in 2018. Chigger mites were collected from the live-captured rodents to figure out seasonal prevalence of mite species and to identify chigger-borne pathogens. A total of 4,611 chiggers were collected from two species of the rodents in 2018. The chigger mites were collected mainly from A. agrarius (Chigger Index; CI 68.3). A vector of scrub typhus, Leptotrombidium orientale was predominant species (CI 14.9, Species Ratio; SR 27.2%) followed by L. pallidium (CI 14.2, SR 25.9%) and L. scutellare (CI 13.2, SR 24.2%) in 2018. In the results of the isolation of Orientia tsutsugamushi from the chigger mites, no pathogens detected from the DNA of the 171 pools of the mites in 2018, using a Polymerase Chain Reaction method.

A tick survey was conducted to monitor ticks using tick traps attached dry ice and a flagging method at each four sites in Busan, Ulju, and Geoje areas of Gyeongnam Province from April to November, 2018. Haemaphysalis longicornis was the most frequently collected, representing 99.8% in Ulju. A total of 27,247 ticks were collected as H. longicornis (Trap Index; TI 283.2), H. flava (TI 0.3), and Ix. nipponensis (TI 0.3). In the collection environment, a total number of 15,672, 5,798, 4,876, and 901 ticks were collected from glassland, tump, tomb, and mountain path, respectively. On the other hand, H. longicornis and Ix. nipponensis were collected with flaggings at the four sites in Ulju, Busan, and Geoje in May and June, 2018. A total of 1,517 ticks collected H. longicornis (Flagging Index; FI 9.3) and Ix. nipponensis (FI 0.1) in Ulju. Haemaphysalis longicornis were collected 2,183 (FI 13.6) and 1,596 (FI 10.0) in Geoje and Busan, respectively. In the results of the isolation of Severe Fever with Thrombocytopenia Syndrome (SFTS) from the ticks, no pathogens detected from RNA of 557 pools of the ticks using a Polymerase Chain Reaction method in 2018.

Surveillance of the vectors were conducted at a total of 7 locations from March to November, 2018 in Gyeongnam province. In the surveillance, a total of 13 species belonging to seven genera were collected in a total of 15,935 females and 126.5/trap/night (TI; Trap Index) in 2018. Among the collection sites, a bird refuge in Busan, Eulsukdo recorded the highest TI 230.4 (Species Ratio; SR 60.1%) for Cx. tritaeniorhynchus females in 2018. A Cx. tritaeniorhynchus female collected firstly for 2018 in the nation at the pigsty of Busan at 1st April. In the results of isolation of viral RNA from 12 mosquito species including Cx. tritaeniorhynchus, Cx. pipiens, Ae. vexans, Ae. albopictus, and Oc. togoi. Chaoyang virus was positive at a pool of Ar. subalbatus collected at a bird refuge but negative in the other 543 pools (14,295 individuals) in 2018.

3년간(2016-2018년) 청주지역에서 채집된 모기의 발생분포를 채집지 3곳(주거지와 철새도래지, 축사)에서 2종의 트랩(BL트랩과 BG트 랩)을 이용하여 비교 조사하였다. 주거지에서 가장 많이 채집된 모기 종은 빨간집모기였으며, 철새도래지와 축사에서는 금빛숲모기가 가장 많이 채집되었다. 철새도래지와 주거지에서는 BG트랩이 BL트랩보다 모기가 더 많이 채집되었으나 축사에서는 BL트랩에서 더 많은 모기가 채집되 었다. 빨간집모기와 흰줄숲모기, 큰검정들모기는 BG트랩에서 많이 채집되었고 금빛숲모기, 얼룩날개모기류, 동양집모기는 비교적 BL트랩을 선호하는 것으로 조사되었다. 채집된 모기를 분류 ․ 동정한 결과 2016년에는 10종 22,679개체가 채집되었고, 2017년에는 8종 6,502개체가 채집 되어 2016년보다 3.49배 감소하였다. 2018년에는 6,803개체가 채집되어 2016년보다 3.33배 감소하였다. 이러한 결과가 강수량과 관련이 있을 것으로 보이며 기상조건과 여러 변인들(채집지역과 모기종류, 트랩종류)에 의한 모기밀도와의 관련성을 비교한 결과 특정 관련성을 확인할 수는 없었다. 채집된 모기의 병원체 감염을 확인한 결과, 2016년도 축사에서 채집한 금빛숲모기 2개 pool, 2018년에 축사에서 채집한 빨간집모기 1개 의 pool에서 차오양바이러스(chaoyang virus)가 검출되어 각각 0.088와 0.147의 최소감염율(MIR)을 보였다. 2017년에는 바이러스가 검출되 지 않았다.

The purpose of the present study was to evaluate if main domestic vector mosquitoes, Aedes albopictus as a diurnal species and Culex pipiens as a nocturnal species, have color preference for blood feeding activity. Laboratory evaluations were performed and compared to assess color attractiveness using seven fundamental colors including black, white, red, yellow, green, blue, and purple. The test bodies selected for these experiments were BioGents Sentinel traps (BG traps) with 20g dry ice in each falcon tube, which covered outside of the traps attached with each different color of vinyl sheets. In each experiment, a pair of BG traps was placed 0.6 m away from each other in a 1.8 m x 3.7 m x 1.8 m screened enclosure. The enclosure maintained at 26±2℃, 65±5% RH, and 100 lux illumination. Evaluations were performed for two hours between 10:00 and 16:00 for each 25 Ae. ablopictus females and 15 hours from 18:00 to 9:00 for each 25 Cx. pipiens females. The attraction rates were determined by a series of 42 simultaneous pairs of sample counts of the number of mosquitoes caught in the traps at every 30 minutes. As a result, black traps collected the largest number of Ae. albopictus as a mean 0.7 of 1.0 for Mosquito Preference Index (MPI), followed closely by red, blue, and purple (MPIs, 0.6) that were significantly higher (p<0.05) than those of green (MPI, 0.5), white (MPI, 0.3), and yellow (MPI, 0.2). Similarly, the MPIs for Cx. pipiens were significantly higher at black and red traps (MPIs, 0.7) but the MPIs (0.3) at white and yellow traps were significantly lower than those of the other colors.

Imported 313 cases of Dengue fever and 16 cases of Zika virus disease were reported in the ROK during 2016. Aedesalbopictus has been reported as a major vector mosquito for Dengue and Zika virus. Various class of pesticides havebeen used locally different pesticide class. To investigate the pyrethroid and organophosphate pesticide resistance, genomicDNA was used for Allele-specific PCR (AS-PCR) genotyping of the acethylcholine esterase to detect Gly119Ser mutationsand kdr gene to detect Phe1534Cys mutations. Detoxification enzyme activities were assessed using Ae. albopictus fromYeosu and Jeju. Activities of four detoxification enzymes eg., glutathione S-transferase (GST), Non specific esterases (α-naphthylacetate and β-naphthyl acetate), and cytochrome C oxidase were determined for each Ae. albopictus strain. In our studies,Ae. albopictus showed only susceptible sequences for AchE and kdr. Activity of cytochrome P-450 and non specific esterasewas higher in a field population than a laboratory strain, except for GST. This study might be helpful to understandthe insecticidal susceptibility and resistant for effective vector mosquito control program.

Wolbachia is intra-cellular bacteria and frustrate host biology, such as parthenogenesis, feminization, male killing andsperm-egg incompatibility. It has been reported that > 90% of Aedes albopictus are infected with Wolbachia in the Republicof Korea (ROK). However any roles of the Wolbachia strains have not been reported in ROK. In this study, we infectedWolbachia to Vero cell line to investigate the cell migration which is related with the development of multi-cellular organisms,immune response and inflammation. Changes of wound healing and viability in vero cell after Wolbachia infection wereassessed. Cell migration was induced by Wolbachia after 24hr. Cell viability was not affected by Wolbachia after 24hr.This study will be helpful to understand the role of Wolbachia strain and support various information in Dengue andZika vector management programs.

Aedes albopictus is an important vector for yellow fever, dengue fever, chikungunya fever and Zika virus. This mosquitohas been exposed to organophosphates and pyrethroids in Republic of Korea for a long time. Using the direct contactmortality bioassay, susceptibility strain and two field populations of Ae. albopictus from Busan, and Damyang. Insecticidalproperty were indicated to RR ratio values (Resistant ratio to strain of susceptibility) of LC50 (Midian Lethal concentration)to organophosphats and pyrethroids. Genomic DNA was used for Allele-specific PCR (AS-PCR) genotyping of the acethylcholineesterase to detect Gly119Ser mutations and kdr gene to detect Phe1534Cys mutations. Detoxification enzyme activitiesof Ae. albopictus from Busan and Damyang were assessed using microplate enzyme activity assays. Activities of fourdetoxification enzymes eg., glutathione S-transferase(GST), Non specific esterases (α-naphthyl acetate and β-naphthyl acetate),and cytochrome C oxidase were determined for each Ae. albopictus strain. This study might suggest that Ae. albopictuscontrol programs should be prepared for the management of organophosphate and pyrethroid insecticide resistance.

West Nile Virus (WNV) is transmitted by infected mosquitoes. Vector mosquitoes usually acquire these pathogens fromfeeding on an infected host, and transmit the pathogens to a naive host during feeding events. To understand the virustransmission dynamics and to survey WNV throughout country, the present study has been conducted. We collected mosquitoesat urban parks in Seongnam, Wonju, Gunsan, Daegu, and Tongyeong using CDC light trap with Dry ice from April toSeptemper in 2017 (mosquito collecting is on going). Among collected mosquitoes, blood-fed mosquitoes were conductedblood meal identification assay and the other mosquitoes were subjected to virus detection using real-time PCR method.A total of 2,290 mosquitoes representing 6 genera and 15 species were collected. The most dominant species was Culexpipiens complex (42.1%) followed by Aedes albopictus (15.1%), Ae. vexans nipponii (14.6%), Ochlerotatus koreicus (9.8%),Cx. orientalis (6.5%), and Armigeres subalbatus (4.4%). The blood meal source were of mammal (93.3%), and birds (6.7%).So far, no WNV has been detected in any mosquitoes.

The members of the genus Flavivirus are noteworthy, as they cause infectious diseases in humans, such as Zika, denguefever, yellow fever, West Nile, and Japanese encephalitis. Due to the increased awareness of the public health risk posedby flavivirus-infected mosquitoes, mosquito collections were performed in six urban parks of South Korea, as the parksare designated for human recreation but also provide suitable habitats for mosquitoes. We examined the diversity andabundance of mosquito species and conducted molecular diagnostics for the detection of flavivirus infections. Monthlycollections were carried out in each park from March to August in 2017. A total of 4,851 mosquitoes (5 genera and13 species) were collected using BG-sentinel traps and then investigated for flavivirus infections. Pathogenic flavivirusinfections causing human diseases were not observed in the field-collected mosquitoes. However, insect-specific flavivirus(ISF) infections were detected in several mosquito pools. ISF has been previously known to enhance or suppress the replicationof medically important flaviviruses in co-infected mosquito cells. In this study, partial sequences of ISF were analyzed.However, further studies are needed in order to determine its genetic characterization and biological function in vivo.

The activities of three class, five acaricides (Permethrin, Deltamethrin, Fenitrothion, Chlorpyrifos, Imidacloprid) againstHaemaphysalis longicornis nymph, a major vector for Severe Fever with Thrombo cytopenia Syndrome (SFTS) and Lymedisease. The ticks distribute at vast open fields and various kind of habitats. Five acaricides were applied to ticks collectedform four areas(Gapyeong, Paju, Chuncheon, Wonju) to confirm the effect of acaricide. This areas was the area whereSFTS disease occurred and a large nember of ticks were collected. As a result, All areas is the most acaricidal effectto Deltamethrin. And two areas(Gapyeong, Paju) has the lowest acaricidal effect to Imidacloprid and two area(Chuncheon,Wonju) has the lowest acaricidal effect to Permethrin. Futher study will need to compare the acaricidal efficacy of theremaining seven province.