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.

한국에 서식하는 모기종 중 흔히 볼 수 있는 금빛숲모기(Aedes vexans nipponii)는 미국에서 West Nile Virus의 주요 매개종으로 알려져 있다. 또한 지카바이러스를 포함한 30가지가 넘는 바이러스의 매개체로 작용할 가능성이 있다고 보고되고 있다. 이들을 방제하기 위한 방법으로 화학적 방제는 매우 효과적일 수 있으나 지속적인 살충제 사용은 저항성 문제를 불러일으킬 수 있다. 현재 금빛숲모기의 경우 이에 대한 관련 연구가 거의 이루어지지 않은 상황이다. 본 연구는 근연종인 흰줄숲모기와 이집트숲모기의 연구를 참고하여 합천에 위치한 축사에서 채집된 금빛숲모기 샘플로부터 기존에 알려진 Acetylcholinesterase-1(Ace-1)의 target site mutation인 G119, T506과 knockdown resistance(kdr) target site mutation인 V410, L982, S989, I1011, L1014, V1016, T1520, I1532, F1534, D1763을 분석하였다. 분석결과, 저항성을 가진 개체는 발견되지 않았으며 mutation site에 관해 정확히 알려진 바가 없으므로 bioassay를 통한 추가조사가 필요할 것으로 판단된다.

중금속이 곤충에 미치는 영향을 조사하기 위하여 빨간집모기 (Culex pipiens pallens) 금속용액 (Cu, Cd, Hg, Pb, Zn)에서 사육한 후 50% 치사농도 (LC50) 용화시기, 총 지질함량, 지질조성, 총 단백질 함량변화를 측정하였다. 50% 치사농도 (LC50)는 3령 유충으로 24시간 처리한 Hg 처리군에서 0.45 mg kg-1으로 나타나 다른 금속에 비해 독성이 강한 것으로 나타났고, 용화 시기는 처리군이 대조군 (129시간)에 비해 지연되었으며 Cd가 처리군 중 273시간으로 가장 늦게 용화되었다. 중금속에 노출된 모기시료에서 총 여섯 종류의 지질 band가 분리되었으며, 이 중 5종의 지질이 동정되었다 (phospholipid, cholesterol, fatty acid, triglyceride, cholesterol ester). 모든 처리군의 총 지질함량은 대조군에 비해 감소하였다. 또한, 대조군의 단백질 함량 (0.51 mg ind.-1)이 처리군의 단백질 함량에 비해 높게 나타났으며, 처리군 중 Hg과 Cd을 처리한 유충의 단백질 함량이 매우 낮게 나타났다. 결론적으로 중금속이 처리된 용액에서 사육된 모기유충은 오염된 환경에 의한 먹이섭취의 장애 및 중금속의 독성으로 인해 단백질 함량과 지질의 감소가 일어나 발육이 느려지고 용화시기가 길어지는 것으로 생각되며 이는 중금속에 의한 체내 물질대사의 변화를 의미한다. 이러한 결과는 중금속 오염이 모기의 생존과 성장을 억제시켜 모기 개체군 크기에 영향을 줄 것을 나타내며, 추후 연구를 통해 모기의 생육정도를 이용한 오염도 측정에 활용이 가능할 것으로 기대된다

This study investigated number of eggs, hatch rate, toxicities and LT (lethal time) values of Culex pipiens and Aedes albopictus using Aquatain™(Aqua mosquito film). Aquatain™ is a covering agent applied on the surface of water for the control of larva and pupa of mosquito. It forms molecule layer on the surface of the water to lower the surface tension of the water, to prevent flooding of the larva of the mosquito larvae, or to suffocate by obstructing breathing. Cx. pipiens and Ae. albopictus larvae observed 99.9% and 1% larvicidal effect after 24h, respectively. However, both mosquito pupae were showed 100% mortality after 24 h. The AMF™ was treated with three doses (0.5, 1, 2 folds) to observe the LT value in larvae and pupae stages of Cx. pipiens and Ae. albopictus. The LT values of Ae. albopictus pupa was similar regardless of dose, but the LT value of Cx. pipiens pupa decreased as the dose increased. However, Ae. albopictus larvae showed 18.6 folds longer LT90 time than Cx. pipiens larvae. Both species mosquito showed statistically significant differences in the number of eggs laid and hatch rate at recommended dose. Therefore, Aquatain AMF™ may be used to control mosquitoes, although the activity varies depending on the species of mosquito.

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 correlation between reflecting luminous intensity of colors and preference for blood feeding activity. Laboratory evaluations were performed and the mosquito preferences were compared to three different color brightness such as light, primary, and dark for five fundamental color series including 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 three different luminous intensities such as light, primary, and dark for each different color of paper 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. Each experiment was replicated four times. As a result, reflecting luminous intensity (L-value) affected and correlated negatively to the preference of the two mosquito species but the fundamental colors, green-red (a-value) and blue-yellow (b-value) were not correlated significantly to the preference (p=0.05). Aedes ablopictus females were preferred for feeding activity more to lower L-values of the colors and correlated negatively between color preference of the mosquitoes and the L-values such as r = -0.584 (p=0.003) for red, r = -0.606 (p=0.002) for yellow, r = -0.620 (p=0.001) for green, and r = -0.463 (p=0.023) for blue except purple (r = -0.129; p=0.549). Similarly, Cx. pipiens females were correlated negatively such as r = -0.590 (p=0.002) for red, r = -0.564 (p=0.005) for yellow, r = -0.687 (p=0.000) for green, r = -0.623 (p=0.001) for blue, and r = -0.689 (p=0.000). In conclusion, the color brightness were negatively correlated to the feeding activity of the two vector mosquito species but not the wavelength of visible ray. Also, the mosquito females preferred significantly darker ones in the same color series (p<0.05) except purple for Ae. ablopictus females.

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.

Population density of Culex tritaeniorhynchus was annually monitored to predict the possibility of a Japanese encephalitis (JE) outbreak at 10 collection sites throughout Republic of Korea (ROK) during mosquito season from 2011 to 2015. Prevalence of Cx. tritaeniorhynchus in ROK was spatially and timely very variable and was significantly highest at Busan city during August. Monthly average population density of Cx. tritaeniorhychus showed high correlation to the monthly average daily average temperature and monthly average precipitation. Two models for the estimation of occurrence of Cx. tritaeniorhynchus based on annual monthly daily average temperature and monthly precipitation are shown with linear regression equations of exp(0.413×temperature-0.949) and exp(0.01258×precipitation+3.777). JE vector surveillance and vector control is warranted as part of an effective JE management program at ROK.

This study tested a hypothesis that the bacterial immunosuppresants enhance BtI susceptibility of two mosquitoes, the forest mosquito (Aedes albopictus) and the house mosquito (Culex pipiens pallens). Three symbiotic bacteria Xenorhabdus nematophila (Xn), X. hominickii (Xh), and Photorhabdus temperata subsp. temperata (Ptt) were isolated from their symbiotic nematodes and cultured in nutrient broth to allow them to produce the secondary metabolites. BtI gave significant toxicities to A. albopictus and C. pipiens pallens larvae: 50% of lethal concentration to be 2.9 × 105 spores/mL and 2.2 × 105 spores/mL at 16 h after treatment, respectively. Addition of each bacteria-cultured broth significantly enhanced BtI toxicity to the mosquito larvae by lowering LC50 values of BtI to A. albopictus larvae (1.5 × 105 to Xn, 1.7 × 105 to Xh, and 1.9 × 105 to Ptt, respectively) and to C. pipiens pallens larvae (1.2 × 105 to Xn, 1.3 × 105 to Xh, and 1.5 × 105 to Ptt, respectively). Based on these results, we developed a new mosquitocidal Bt formulation called ‘Dip-Kill’, which consisted of 80% Xn-cultured broth, 10% BtI (1010 spores/mL), and 10% preservative. Only 400 ppm of Dip-Kill showed 100% mortality to fourth instar larvae of A. albopictus and C. pipiens pallens 16 h after treatment.

Recently, climate change has been increasingly reported to be associated with vector-borne diseases including West Nile Virus, avian poxvirus, bluetongue virus. These diseases, which are of medical and veterinary importance, are known to affect the health status of wildlife. In this sense, it is vital to understand the distribution of mosquitoes and biting midges as the disease-vectors in the habitat of wildlife. In order to do this, nocturnal insects were collected using CDC Mini Night Traps (cat. no. 2836BXQ, BioQuip, CA, USA) in the coniferous and deciduous forest near the ponds in National Institute of Ecology (NIE) on the weekdays from June to September. As a result, 920 mosquitoes belonging to 13 species of 7 genus and 5,129 biting midges belonging to 8 species of Culicoides were collected in total. For mosquitoes, Aedes vexans nipponii and Culex orientalis were the predominant species consisting about two thirds of all the mosquitoes. For biting midges, Culicoides arakawae was the prevalent species present and 97.3% of this kind appeared to have preference to feed on birds. The number of mosquitoes collected remained relatively constant as opposed to the number of biting midges which showed the tendency to fluctuate - the second or third week of each month had the highest number of Culicoides spp. Forest ecology had more diverse distribution of species than livestock farms and reflected the abundance of birds in NIE. In addition, further evaluation of the effect of environment, such as climatic factors, on the ecology of these disease vectors would be required.