We are currently developing the smart mosquito counter device (height 1080mm × width 560mm × diameter 320mm, 220V 60Hz 30W), which can attract the blood sucking female mosquitoes by emitting CO2 gas (300ml/min), can count the number of the captured mosquitoes by an infra-red beam area sensor, and can send the captured mosquitoes’ number through the CDMA module at real time. We operated the 8 – 16 devices with mosquito sensor networks and a server at the Youngdeungpo-gu areas in Seoul city of south Korea for three years (2011-2013) and we could efficiently control mosquitoes at the high mosquito density area based on the mosquito sensor’s data. We found that the accuracy of the device was about over 93% compared the real mosquito data and transmitted data by CDMA. We also found the water reservoir areas to control floods in Seoul metro city had relatively higher mosquito density than other normal areas, because those flat water areas were preferred by mosquitoes. Because our pest control office knew the mosquito occurrence peak times and areas from mosquito data transmitted by the mosquito sensor devices, we efficiently controlled mosquito larva and adults at the right time. We could accomplish very systematic mosquito control policy and we had the high credibility with the results. Based on the mosquito occurrence data, we selectively and scientifically controlled mosquitoes. Therefore, we reduced pesticide usage and saved annually pesticide expenses up to 2/3. Conclusively, if there is no mosquito, we don’t have to control mosquitoes.

Habitats for migratory birds provide good blood source for blood sucking insects including mosquitoes, which may lead to high population mosquito species. This study was intended to know mosquito fauna in habitats for migratory birds that have preference for bird’s blood. We selected 7 locations for migratory birds (Ansan: a great reedy marsh in lake of Shihwa; Cheonan, Gyeongju, and Pyeongtaek: pine forest; Seosan: a reclaimed land near bay of Cheonsu ; Ulsan: great bamboo forest around Teahwa river) and subdivided each location with four habitats (forest, swamp, cow shed and downtown area) as mosquito collecting site. We used two types of trap for mosquito collection such as CDC black light trap and BG Sentinel trap. Additionally, we use black light and dry ice as an attractive source, respectively. A total of 27,615 mosquitoes representing 9 genera and 18 species were collected. In Ansan, 9 genera and 17 species were collected and in the other locations only 11 to 12 species. Representing by habitats shows this; in forest 9 genera and 17 species, in swamp 8 genera and 16 species, in cow shed 6 genera and 12 species, in downtown 8 genera and 17 species. The dominant species was Culex pipiens (60%) followed by Aedes vexans (11%), Anopheles spp. (8%), Aedes albopictus (7%), and Armigeres subalbatus (5%).

Melanization is a unique defence mechanism in arthropods involved in wound healing and pathogen encapsulation. Phenoloxidases (PPOs) are key enzymes of melanization, which mediate the enzymatic conversion of tyrosine to eumelanin. A serine-protease (SP) cascade, similar to the blood-clotting cascade of vertebrates, proteolytically activates prophenoloxidases to phenoloxidases. This proteolytic activation is tightly controlled by serpins and other melanization inhibitors. Melanization has been regarded as one of key immune responses against malaria parasites in mosquitoes. The ookinete melanization of both the simian malaria parasite, Plasmodium cynomolgi, and of the rodent parasite, Plasmodium berghei, prevent parasite development in the human malaria vector, An, gambiae. However, the recent studies revealed a melanization response regulated by Serpin-2 and two C-type lectins (CTL4 and CTLMA-2) was shown to result in ookinete melanization but did not affect the development of the natural human parasite P. falciparum in the mosquito. Instead of melanization, TEP1/APL1/LRIM1 complement-like pathway has been identified as major immune response that regulate parasite loads in the natural association of An. gambiae and P. falciparum. The studies by me and my colleagues revealed another melanization response independent on Serpin-2. Genome analyses of mosquitoes revealed a large expansion of the PPO, SP, and serpin genes potentially involved in the melanization pathway. This expansion was devoted to existence of at least two distinct SP-Serpin regulation modules in controlling separate melanization responses, tissue and hemolymph melanization, in the mosquito, Aedes aegypti. Tissue melanization regulated by Serpin-2 has role in melanotic tumor formation, but not in ookinete melanization. Hemolymph melanization regulated by Serpin-1 and a couple of SPs was activated by the infection of various pathogens and is involved in anti-malarial defense against the avian malaria parasite, P. gallinaceum. A new type of regulator, CLSP2, negatively modulate this hemolymph melanization. Cross-talk between hemolymph melanization and complement-like pathway will be discussed.

One of the overlooked points in mosquito blood feeding research is a final step before blood feeding such as finding a best position of blood feeding site and blood vessels underneath. How mosquitoes detect blood vessels especially using chemosensory organs prior to a final stage of blood feeding is totally unknown. Here we provide the anatomical and chemosensory evidence that a piecing structure of the mouthpart of the mosquitoes is an essential apparatus for the penultimate stage in blood feeding in mosquitoes. Indeed, mosquito mouthparts possesses a set of olfactory receptor neurons in sensory hairs, which are sensitive to volatile compounds present in host blood. Furthermore, the inhibition of gene expression of these odorant receptors delayed blood feeding of the mosquito from host animals. Taken together, these results identify that chemosensory perception in mouthpart is involved in mosquito blood feeding behaviors, which in turn allows mosquito to locate a feeding site more precisely.

본 연구는 김포시에서 모기성충의 계절적 발생소장과 얼룩날개모기류 유충의 발생을 파악하기 위해서 실시되었다. 성충모기는 6지점에서 유문등을 이용하여, 2008년 5월부터 9월까지 조사되었다. 조사결과 8속 16종 48,919마리가 채집되었다. 금빛숲모기(Aedes vexans nipponii)가 43%로 가장 많았고, 중국얼룩날개모기(Anophels sinensis)가 34%, 작은빨간집모기(Culex tritaeniorhynchus)가 14%로 이 3 우점종이 전체의 91%를 차지했다. 얼룩날개모기류의 계절적 발생소장은 작은빨간집모기와 비교하여 다른 피크를 보였다. 얼룩날개모기류 유충은 203지점 중 138지점(63%)에서 확인되었다. 지점당 정량조사 결과에서 평균유충밀도는 연꽃 재배지가 6.9개체로 가장 높았으며, 다음으로 수로가 4.5개체, 미나리꽝이 3.4개체, 유수지가 3.2개체, 휴경논이 3.1개체, 논이 1.8개체, 습지가 1.4개체, 하천이 0.2개체 순이었다. 유충밀도와 용존산소량, 산도, 염분도, 흡밀원(축사, 돈사, 계사) 사이에 유의한 관계성은 없었다. 최근린평균거리분석(ANNA)의 결과에서, 유충 조사지점간 분포패턴은 전체 조사지점간과 4.0개체 이상 확인된 지점간에서 각각 밀집분포와 불규칙분포였다. 하성면에서는 유충이 3.0 개체 이상 확인된 지점간 분산분포를 나타냈다.

We developed two kinds of selective mosquito traps. The first selective mosquito trap called Mos-hole was developed with emitting carbon dioxide. The principle was that CO2 gas was obtained from burning liquid naphtha. The process principle was very unique that some heat and moisture which cannot be obtained by using dry ice could be generated additionally. It is the main cause to bring more mosquitoes. The trap is consisted of the acidic and CO2-baited suction system. CO2 was so powerful mosquito attractant gas, and the color and shape of a suction trap was also very important factors for improving the mosquito capturing efficiency. The trap burned naphtha in a rate of 1.3g/hr~3.0g/hr (CO2:50ml/min-110ml/min) and the efficiency of the trap was higher at the burning rate with the high number of female mosquitoes. The second mosquito trap called DMS (Digital Mosquito Monitoring System) is developed for reporting the number of captured mosquito automatically every day. This automatic reporting device called DMS uses CO2 gas as a mosquito attractant and it has a IR array sensor for counting mosquito. We established a sensor network with several DMSs and one server. The server collected the data of each DMS through Internet or CDMA RF communication system. This data were analyzed in the GIS pest prevention information system and were sometimes used as a reference for the next pest control activities. The DMS systems emit CO2 about 300cc/min. CO2 was very effective for attracting mosquito. DMS systems were very effective to count the number of mosquitoes at the certain areas. By using two kinds of mosquito traps together, we could determine the mosquito population size increase and decrease at certain areas

The introduction of new pathogens and disease vectors has been recognized as a major threat to Galapagos Island biodiversity. Here I focus on mosquito species of the Galapagos archipelago, using population genetic and phylogenetic data to understand their historical and current population dynamics. I show that two mosquito species found in the archipelago have very different historical and contemporary evolutionary histories: one species, Aedes taeniorhynchus, naturally colonized the archipelago 200,000yrs ago and is now found widely in the islands, having adapted and spread to a range of different habitats. It has also changed its feeding-behaviour and now frequently feeds on reptiles in addition to mammals, unlike the continental progenitor populat ions. These properties potentially make Aedes taeniorhynchus a key bridge-vector in the archipelago for any new invading mosquito borne diseases. In contrast, I show that Culex quinquefasciatus, a major vector of diseases such as West Nile virus and avian malaria, has been introduced on multiple occasions since 1985 via human transportation networks and that its distribution and movement in the archipelago depend greatly on human activities. These two species might play an important role in the introduction and spread of new diseases in the Galapagos archipelago.

We used the three kinds of mosquito traps (Black-hole with UV light, CO2-baited Mos-hole with the newly developed attracting-solvent, CO2-baited DMS; Digital Mosquito Monitoring System) to know their collecting efficiency for the female mosquitoes in Korean rural areas. The Black-hole mosquito trap caught many kinds of insects including only few female mosquitoes. The Black-hole trap has the UV-light and the light seemed to attract other terrestrial and aquatic insects, such as the common flies, May flies, and the stone flies. Even though the trap was developed to collect mosquitoes, the trap caught only few of female mosquitoes less than 1% of all insects caught. Their selective efficiency to collect the female mosquitoes was relatively lower than other two kinds of traps. The Mos-hole and CO2-baited DMS traps had the collecting efficiency of over 80% to collect the female mosquitoes. The two traps caught the relatively lower number (less than 3% of total insects) of other insects, such as few Coleoptera and Diptera, and their collecting efficiency for the female mosquitoes was very higher. Generally speaking, mosquitoes disliked the UV light but they relatively preferred CO2 gas including the attracting-solvent. They had also been attracted the acidic solvent with CO2 gas. If we could use the efficient and selective mosquito traps with the fully understanding about the mosquito habits, we could assume that we can keep the biodiversity high around the mosquito habitats as well as to save money for the insect pest control.

We developed two kinds of selective mosquito traps. The first selective mosquito trap called Mos-hole was developed with emitting carbon dioxide. The principle was that CO2 gas was obtained from burning liquid naphtha. The process principle was very unique that some heat and moisture which cannot be obtained by using dry ice could be generated additionally. It is the main cause to bring more mosquitoes. The trap is consisted of the acidic and CO2-baited suction system. CO2 was so powerful mosquito attractant gas, and the color and shape of a suction trap was also very important factors for improving the mosquito capturing efficiency. The trap burned naphtha in a rate of 1.3g/hr~3.0g/hr (CO2:50ml/min-110ml/min) and the efficiency of the trap was higher at the burning rate with the high number of female mosquitoes. The second mosquito trap called DMS (Digital Mosquito Monitoring System) is developed for reporting the number of captured mosquito automatically every day. This automatic reporting device called DMS uses CO2 gas as a mosquito attractant and it has a IR array sensor for counting mosquito. We established a sensor network with several DMSs and one server. The server collected the data of each DMS through Internet or CDMA RF communication system. This data were analyzed in the GIS pest prevention information system and were sometimes used as a reference for the next pest control activities. The DMS systems emit CO2 about 300cc/min. CO2 was very effective for attracting mosquito. DMS systems were very effective to count the number of mosquitoes at the certain areas. By using two kinds of mosquito traps together, we could determine the mosquito population size increase and decrease at certain areas

Field-collected populations of mayflies, Ephemera orientalis were tested for susceptibility to 10 different insecticides using a direct-contact mortality bioassay. Ephemera orientalis subimagoes were susceptible to the insecticides chlorpyrifos, fenitrothion and chlorfenapyr with LD50 values of 69.7, 78.8 and 81.9μg/♀, and adults had LD50 values of 71.9, 78.8 and 85.4μg/♀, respectively. Susceptibility ratios(SRs) of subimagoes and adults of E. orientalis to the 10 insecticides were 1.0 to1.2 folds. The mayflies showed higher susceptibility to organophosphates than to pyrethroids. The SRs of Anopheles sinensis to E. orientalis were 514 to 1,438 fold higher for organophosphates (LD50 values of 0.05 to 0.23μg/♀) and 62 to 1,155 fold higher forpyrethroids (LD50 values of 0.13 to 2.41μg/♀). The SRs of Culex pipiens to E. orientalis were 606 to 3,595 fold higher for organophosphates with LD50 values of 0.02-0.17μg/♀ and 81 to 1,365 fold higher for pyrethroids with LD50 values of 0.11- 1.83μg/♀. These results indicate that the use of ineffective insecticides will result in unsatisfactory control against field populations of the subimagoes and adults of E. orientalis. This work was supported by a research grant from the National Vector Control and Surveillance work performed by the Korean National Institute of Health.

The repellency, insecticidal activity and repellency duration effect of dagalet thyme, Thymus quinquescostatus against Asian tiger mosquito, Aedes albopictus larvae and adults was investigated. Whole plant body of T. quinquescostatus proved to have the repellent activity of 91.2% against A. albopictus adults. The constituents of T. quinquescostatus were analyzed using GC-MS as follows: α -pinene (1.1%), α-thujene (2.7%), camphene (1.3%), myrcene (4.7%), α-terpinene (5.0%), ɤ-terpinene (33.0%), ρ-cymene (8.3%), β-caryophyllene (4.0%), β-bisabolene (8.9%), thymol (29.9%), and carvacrol (1.2%). Among them, thymol has the perfect repellency on A. albopictus adults and confirmed the electrophysiological response on the antenna of A. albopictus adults. To enhance the maintenance, vanillin was added. Duration of effectiveness of mixture with vanillin (0.18 : 0.36 ㎕/㎠) were significantly more prolonged than thymol alone. The constituents on its original oils were applied onto A. albopictus larvae. The thymol, α-terpinene and carvacrol (LC50 = 9 mg litre-1) revealed to have high insecticidal activity.

Density of malaria vector mosquitoes, Anopheles mosquitoes, and infection of Plamodium vivax from the vector mosquitoes were monitored at 9 surveillance points in Incheonsi, 12 in Gyeonggi province and 7 in Gangwon province in the Republic of Korea (ROK) from April to October of 2010. The seasonal numbers of Anopheles mosquitoes collected weekly showed a high degree of variability. A total of 4,435 mosquitoes were captured using black light traps. Members of the Anopheles mosquito group were the most abundant species and accounted for 71.8% of the mosquitoes collected. The majority of this species were collected from Incheonsi (86.2%), particularly from Ganghwagun (84.8%). During June, populations of this species steadily increased and peak at second week of July. Thereafter, populations of this species decreased by the second week of August and increased by the third week of August, again. Anopheles mosquitoes steadily decreased from the fourth week of August. First Anopheles mosquitoes were reported in Wolgotri (15th weeks/year), Ganghwagun, Incheonsi, followed by Tanhyundong (16th weeks/year), Pajusi, Gyeonggi Province and Daemari (17th weeks/year), Cheolwongun, Gangwon Province. In Ganghwagun in which the most abundant malaria patients (102 patients) were reported, Anopheles mosquitoes demonstrated the highest species portion (over 70%) among collected mosquito species from July to September. Infection rate of P. vivax from the Anopheles mosquitoes also was the highest in Ganghwagun. In Gangwon and Gyeonggi provinces, collection rate of Anopheles mosquitoes and infection rate of P. vivax were relatively lower than those of Ganghwagun. Reported malaria patient cases in Gangwon and Gyeonggi provinces also were relatively lower than those of Ganghwagun. However, detailed results showed that there were some sites in which any correlation between malaria patients and vector mosquitoes were not. This may be resulted from size of surveillance area. Smaller size of surveillance area was, higher accuracy of analysis on correlation between vector mosquitoes and patients was. Further studies on relationship between malaria vector and patients may need for more accurate analysis, such as increase of collection site and so on.

Field research was undertaken for recovering mosquito larval mermithid parasite, Romanomermis species in rice fields in 54 different areas in period of May through October, 2009. Of 54 area rice fields surveyed, Romanomermis sp. recoveries were made from 4 areas. 32 Anopheles mosquito larvae, malaria disease vector were infected and died from samples collected in Pochon area, and a total of 10 Culex mosquito larvae, house frequenting mosquito were infected to death in 3 different areas, Gimpo, Sangju and Gurae, respectively. On the basis of positive natural infection record, an intensive host-parasite occurrences and/or population study was surveyed in foci area of Pochon in small pond (P) and Rice paddies (A and B) during 5 months till end of October. The natural mermithid infection was continuously occurred from June through October in weekly samples, however the rate of infection was appeared higher in June-July, thereafter the rate gradually decreased in progress of the season. The highest natural infection rate was observed from the Pond 9.1% followed by Rice paddy "A" 5.2%, Rice paddy "B" 2.4%, respectively. Including 2 other Rice paddies "C" and "D", a total mosquito larvae collected was 3,270, an overall average natural infection rate was recorded as 3.7% (121 Anopheles mosquito larvae infected).

Cinnamaldehyde as the main component of Cinnamomum plants is well known as mammalian transient receptor potential ankyrin 1 (TRPA1) agonist, also activated by low temperature stimuli and mechanosensation. The other TRP subfamily, transient receptor potential vanilloid-1 (TRPV1) sensitive to pungent compounds such as capsaicin and allicin mediates the feeling of warmth. Both TRPA1 and TRPV1 channels are abundantly distributed in sensory neurons. Thus, there is possibility that these channels modulate repellent behaviors of mosquitoes and Drosophila through olfactory receptor neurons (ORNs). In order to confirm this hypothesis, we carried out laboratory repellent tests with cinnamaldehyde to Aedes aegypti females using arm-in-cage test and to a wild type and two TRP channel mutants Drosophila lines using a choice assay. Cinnamaldehyde showed strong repellency against Ae. aegypti and Drosophila wild adults at tested concentrations. However, a mutant fly line did not discriminate or detect the existence of the repellent. These behavioral data suggest that cinnamaldehyde may directly target the TRP channel. More studies to elucidate neural correlates of repellency to ainnamaldehyde compound are as follows: 1) Identifying the ORNs mediating cinnamaldehyde detection using single-sensillum recording techniques, 2) Co-localization of TRP genes on olfactory organs of Ae. aegypti and Drosophila using in situ hybridization and 3) Whether the Aedes TRP homologs might function in cinnamaldehyde repellency using rescued TRP chennels of Drosophila.

The toxicity of materials derived from root of Asiasarum heterotropoides against early third instar larvae from susceptible Culex pipiens pallens, Aedes aegypti, and Ochlerotatus togoi was examined using direct contact mortality bioassays. Results were compared with those following the treatment with two currently used mosquito larvicides, temephos and fenthion. The bioactive principles of A. heterotropoides root were identified as asarinin, asarone, methyleugenol, pellitorine, and pentadecane by spectroscopic analysis. As judged by 24 h LC50 values, pellitorine (2.08-2.38 ppm) was the most toxic compound, followed by asarinin (10.49-16.49 ppm) and asarone (22.38-26.99 ppm). These compounds were less toxic than either temephos (0.16-0.20) or fenthion (LC50, 0.23-0.29). Weak activity was produced by methyleugenol (53.30-58.52 ppm) and pentadecane (96.71-99.19 ppm). A. heterotropoides root-derived materials, particularly pellitorine, merit further study as potential mosquito larvicides for protection from humans and domestic animals from vector-borne diseases and nuisance caused by mosquitoes.

Thailand suffers from one of the highest rates of dengue and dengue haemorrhagic fever in the world. Since there is no vaccine or any specific treatments for dengue, currently, the only effective way to prevent dengue fever and dengue hemorrhagic fever is vector control. The knowledge of basic biology, ecology, behavior and survival factors of Ae. aegypti is crucial to control mosquitoes. The impact of the environmental factors; temperature, rainfall, and humidity, on the ecology, biology, development, vector density, behavior, fitness of mosquito vectors, and the mosquito-borne disease transmission dynamics will be presented and discussed.

The toxicity of Asarum heterotropoides root steam distillate compounds to third instar larvae of Culex pipiens pallens, Aedes aegypti, and Ochlerotatus togoi (formerly Aedes togoi) was examined using a direct contact mortality bioassay. Results were compared with those following the treatment with fenthion and temephos. A. heterotropoides root steam distillate exhibited good larvicidal activity (21.07-27.64 ppm), based on LC50 values. Potent activity was produced by safrole (LC50, 8.22-16.10 ppm), terpinolene (11.85-15.32 ppm), -terpinene (12.64-17.11 ppm), (–)-β-pinene (12.87-18.03 ppm), (+)-limonene (13.26-24.47 ppm), 3-carene (13.83-19.19 ppm), and α-phellandrene (13.84-23.08 ppm), although the larvicidal activity of these compounds was less toxic than either fenthion (LC50, 0.023-0.029) or temephos (0.016-0.020). A. heterotropoides root steam distillate and its constituents described merit further study as potential mosquito larvicides for protection from humans and domestic animals from vector-borne diseases and nuisance caused by mosquitoes.

Eight Bacillus thuringiensis strains activated against mosquito larva were compared their characterization. Spherical-shaped parasporal inclusion of B. thuringiensis subsp. tohokuensis CAB167 was observed by phase-contrast microscopy and scanning electron microscopy. LC₅₀ values of B. thuringiensis subsp. tohokuensis CAB167 against Culex pipiens molestus, Culex pipiens pallens, and Aedes aegyti were 173, 190 and 580 ng/㎖, respectively. B. thuringiensis subsp. tohokuensis CAB167 had a parasporal inclusion containing 4 major protein components, for example, 135, 80, 49 and 28-kDa by SDS-PAGE. Otherwise, after trypsin digestion of parasporal inclusion, SDS-PAGE was showed new protease-resistant peptides at 72 and 63-kDa. Activated toxins of isolated CAB167 were different from other reference strains on a serological by immuno-diffusion test.

Bioassay of mosquito, Culex pipiens molestus, larva was investigated by several environment-friendly insecticides. These insecticides were Novaluron as chitin synthesis inhibitor, Metho-xyfenozide as ecdysone agonist, Pyriproxyfen as juvenile hormone mimic, and Spiromesifen as lipid biosynthesis inhibitor. The 50% lethal concentration (LC₅₀) of these insecticides were 0.00039, 0.07193, 0.65006 and 0.04839 ppm, respectively. Novaluron has lower concentration than any other insecticide. To determine the treatment time against larval stages, insecticides were applied to different larval stages of C. pipiens molestus. Mortality ratios of mosquito larva treated with Novaluron were 100.0, 84.5, 71.0 and 48.5% on 2, 4, 7 and 10 days after hatching from eggs, respectively. Otherwise, with the other insecticides, mortality ratios were under 80% with 2 days old larva. When exposure periods were tested to 3 or 4 days old larva against 4 insecticides, at least 3 hours were needed to 100% control effect against Novaluron, and over 12 hours with other insecticides.