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West Nile virus (WNV) became established in New York in 1999, in the first outbreak in the Western Hemisphere. WNV is propagated in many species of birds and has been detected in more than 300 bird spe-cies in the United States, although there are great differences in the viremia level among the various bird species. Culex mosquitoes, including Cx....
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Context 1
... Tokyo, Japan in 2003 and 2004. The collection sites beside houses were located in areas with high population densities. A bat- tery-operated trap with 1 kg of dry-ice was operated weekly for 24 hrs. A total of six mosquito species were collected from 18 collection sites, and three species, including the Cx. pipiens group (pallens and molestus, Fig. 1A) and Ae. albopictus (Fig. 1B), accounted for more than 99% of the collected mosquitoes (Table 1). The average number of female mosquitoes /trap/day for the Cx. pipiens group and Ae. albopictus was 7.4 and 1.8 in and 9.4 and 2.0 in 2004(Tsuda et al., 2006a, respectively. There were large variations in the number of collected mosquitoes ...
Context 2
... 2004. The collection sites beside houses were located in areas with high population densities. A bat- tery-operated trap with 1 kg of dry-ice was operated weekly for 24 hrs. A total of six mosquito species were collected from 18 collection sites, and three species, including the Cx. pipiens group (pallens and molestus, Fig. 1A) and Ae. albopictus (Fig. 1B), accounted for more than 99% of the collected mosquitoes (Table 1). The average number of female mosquitoes /trap/day for the Cx. pipiens group and Ae. albopictus was 7.4 and 1.8 in and 9.4 and 2.0 in 2004(Tsuda et al., 2006a, respectively. There were large variations in the number of collected mosquitoes among the collection sites. ...
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Lineage 2 West Nile virus (WNV), previously found only in sub-Saharan Africa and Madagascar, was identified in Hungary in 2004 and has rapidly expanded in Europe in the past decade. Following a significant outbreak of West Nile fever with neurological cases caused by lineage 1 WNV in Romania in 1996, scattered cases have been recorded in the south-...
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In 2000, the South of France witnesses a West Nile outbreak in Camargue, where the mosquito Culex modestus is the potential vector. Using field data of mosquito collected by Mouchet et al. in 7966 at. La Capelière, we have developed a model to describe Culex modestus aggressiveness as a function of meteorological data. We found that Culex modestus...
Culex pipiens mosquito is a species widely spread across Europe and represents a competent vector for many arboviruses such as West Nile virus (WNV), which has been recently circulating in many European countries, causing hundreds of human cases. In order to identify the main determinants of the high heterogeneity in Cx. pipiens abundance observed...
Citations
... In northeast Japan, oocysts and sporozoites of several avian malaria lineages have been detected from Cx. inatomii (Kim and Tsuda 2012). However, persistence of a vector-borne pathogen is not achieved if the vector density is too low, even if competent vector species are present (Valki unas 2005;Kobayashi et al. 2008;Randolph and Dobson 2012;Tsuda 2017). It is therefore unknown whether Cx. inatomii contribute to disease transmission within the area. ...
Although wild bird rehabilitation facilities are important for the conservation of wild species, individuals may be kept within the facilities for long periods, consequently posing a risk for the bird to be infected with pathogens to which they are not naturally exposed. In turn, novel pathogens may be introduced through rescued migratory species. Avian malaria and West Nile fever are important avian diseases transmitted by mosquitoes. To understand the transmission dynamics of such diseases at rehabilitation facilities, the ecology of vector mosquitoes, including species composition, seasonality, and feeding behaviors, were explored. Mosquitoes were collected at a wild bird rehabilitation facility and wildlife sanctuary in Japan from 2019 to 2020 using mouth aspirators, sweep nets, and light traps. A total of 2,819 mosquitoes of 6 species were captured, all of which are potential vectors of avian diseases. Culex pipiens pallens and Cx. pipiens form molestus were the dominant species (82.9% of all collected mosquitoes). Density and seasonality differed between sampling locations, presumably because of differences in mosquito behaviors including feeding preferences and responses to climatic factors. Blood-fed Culex mosquitoes fed solely on birds, and many mosquito species are thought to have fed on birds within the facility. Particularly, Cx. pipiens group probably fed on both rescued and free-living birds. The rehabilitation facility may be an important site for the introduction and spread of pathogens because 1) numerous mosquitoes inhabit the hospital and its surroundings; 2) blood-fed mosquitoes are caught within the hospital; 3) there is direct contact between birds and mosquitoes; 4) both birds within the hospital and wild birds are fed upon. Furthermore, blood-fed Cx. pipiens form molestus were observed in the winter, suggesting that pathogens might be transmitted even during the winter when other mosquito species are inactive.
... Therefore, control of mosquito larva prevents growing adult mosquito thus preventing illness (Mackey et al., 2014). Many plant species have been shown to be powerful against a variety of insect species including mosquitoes (Kobayashi et al., 2008). Plants have rich contents of bioactive compounds (phytochemicals) including phenolics, terpenoids, coumarins and alkaloids. ...
Mosquito-borne diseases are one of the major contributors to human mortality and morbidity, both in the tropics and in semi-tropics. The synthetic pesticides are being used for the control of vectors of these diseases, although there are cases where their continuous use can cause permanent debris and incidents that affect health of humans as well as animals. Aqueous, chloroform, methanol and ethanol extracts of grass weed Setaria viridis caused mortality against larvae of the genus Anopheles stephensi and Culex quinquefasciatus. Mortality was recorded after 24 h of exposure. For Anopheles stephensi 24 h LC50 for aqueous, chloroform, ethanol and methanol extracts of S. viridis has been recorded as 39.538, 38.586, 35.531 and 37.797 ppm, respectively. For Culex quinquefasciatus 24 h LC50 for aqueous, chloroform, ethanol and methanol extracts of S. viridis has been recorded as 53.471, 51.565, 48.103 and 49.787 ppm, respectively. It is inferred that extracts of S. viridis is more effective on Anopheles stephensi as compared to Culex quinquefasciatus.
... Rydzanicz concluded that CBs served as major development and resting sites for anthropophilic and zoophilic mosquitoes in urban Poland [15], Harbison suggested that CBs (numbers up to 200,000) are the primary source of potentially disease-carrying mosquitoes in the Chicago metropolitan area [19]. Kobayashi confirmed that catch basins were the main larval habitats in urban environments of Japan [20], and herein we have shown that this also holds true in urban Shanghai. Our study demonstrated that nearly half (49.5%) of CBs examined held water and that a fairly high percentage (43.4%) ...
Background:
The near-surface urban drainage system in Shanghai is highly complex, with hundreds of thousands of catch basins (CBs) and manhole chambers (MCs). Comparatively little is known about the breeding of mosquitoes in this vast system, especially for the locally predominant species Aedes albopictus. A cross-sectional mosquito sampling study was conducted from late July to early August of 2017 using 539 CBs and 309 MCs located in 10 communities of downtown Shanghai. We measured the water-holding status of the drainage systems and density of mosquito larvae. Mosquito species were examined on site and in the laboratory later.
Results:
The CBs were characterized by a lower percentage of standing water compared to MCs (47.0% vs. 79.9%, respectively; X2 = 76.407, P<0.001), but CBs contained a higher percentage of stagnant water percent than MCs (45.2% vs. 35.3%, respectively; X2 = 11.465, P = 0.001). There were exclusively two species of mosquito larvae found in the drainage systems, Ae. albopictus and Culex pipiens complex. Compared with MCs, the structures of CBs were more conducive to larval production and yielded more larvae-positive samples (43.4% vs 14.2%, X2 = 53.136, P<0.001) and higher larval density (8.23 vs. 4.09 per dipper, t = 3.287, P = 0.001). Aedes albopictus was the predominant species in CBs, with a constituent ratio of 71.7%. Regarding structures with different features in different locations, CBs that had a vertical grate with an unsealed lid and MCs with plastic composite covers were the most favorable types for mosquito breeding, and residential neighborhoods yielded the highest number of Ae. albopictus.
Conclusion:
Aedes albopictus was the predominant species in both CBs and stormwater MCs, especially in residential neighborhoods. CBs, particularly those with vertical grates, were a major source of mosquito production in downtown Shanghai. MCs featured more running water and fewer larvae by percentage, and few larvae were found in Sewage MCs. However, due to the tremendous baseline amount, MCs were still an important breeding source of mosquitoes. We suggest that Aedes control in Shanghai should focus on CBs or other potential larvae habitats in and around residential neighborhoods. The use of permeable materials and completely sealed covers should be adopted in the construction of CBs and MCs henceforth.
... The contribution of subterranean and surface storm water systems to vector abundance and potential disease transmission is known only in some regions (Norris 2004). It is well documented that catch basins are convenient sites for the development of the larvae of many mosquito species, both indigenous and invasive in the USA, Europe, and Japan (Anderson et al. 2006;Bellini et al. 2009;Kobayashi et al. 2008;Andreadis and Wolfe 2010;Becker et al. 2012). Probably, the introduction to many European countries with exotic mosquito species such as Aedes albopictus (Skuse) and Ochlerotatus japonicus japonicus (Theobald) is affected by many different factors such as the transformation of environment, climate change, and globalization (Scholte et al. 2007;Pluskota et al. 2008;Becker 2009). ...
In urban environments, catch basins serve as major developmental and resting sites for anthropophilic and zoophilic mosquitoes. However, the use of this habitat is inconsistent, with abundance of larvae varying significantly across catch basins at a fine spatial scale. During seasonal summer investigations on mosquito species composition, their spatial and temporal distribution and the environmental characteristic of the breeding sites in the underground storm drain systems of the Wrocław urban area (SW Poland) were assessed from May to September in 2012–2013. The study was conducted in order to develop a rational strategy to control mosquito populations and prevent the potential human exposure to mosquito-transmitted pathogens. Mosquito larvae and pupae were collected and identified weekly from 100 regularly inspected street catch basins located in the town center. All existing and potential breeding habitats in the study area were recorded using a GPS receiver (Magellan MobileMapper CX) and transferred to the computer database. Collected data on the geographical location of inspected breeding places, water quality parameters in inspected catch basins, daily temperature, and precipitation were imposed on orthophotomap in ArcGIS (ESRI, USA). Water quality parameters including pH, electrical conductivity, and water temperature were measured by standard methods. Chemical water analysis of cations (Na+, NH4+, K+, Mg2+, Ca2+) and anions (Cl−, NO2−, NO3−, SO42−) were carried out using Waters Alliance high-performance liquid chromatograph (HPLC) 2695 with 432 Conductivity Detector and 2998 Photodiode Array Detector, an IC-Pak Anion HR column (glauconate/borate eluent) and IC-Pak Cation M/D column (EDTA/HNO3 eluent). Over two seasonal studies and 3739 samplings in total, 3669 mosquito larvae and 274 pupae/1 dip (from 0 to 110 individuals/dip) were collected by dipper. Culex pipiens s.l. (L.) and Cx. torrentium (Martini) prevailed at all catch basins of the study area as the predominant species. In all examined catch basins, autogenous individuals dominated by far. Breeding activity was first detected in early May. Peak abundance of Culex spp. population in many catch basins was observed in June 2012 and August 2013 when average daily temperatures were increasing and rainfall had declined. Dry periods between rainfalls varied during 2 years of the study period and were noted on June 2012 as well as on July and August 2013. Organically enriched catch basins with significant higher concentrations of Na+ and NO3− were found to be more productive breeding habitats. Differences in the Culex immature stage density based on the variables of habitat type, temperature, and precipitation support the need for ongoing surveillance in communities to guide public health officials in planning for and prioritizing mosquito control efforts.
... Stormwater catch basins are common sources of permanent or semipermanent standing water that are routinely targeted for mosquito larvicide applications by local mosquito control programs to reduce local mosquito populations and incidence of mosquito-borne diseases. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] A common practice is to treat the stagnant water in all or most of the tens of thousands or sometimes hundreds of thousands of basins that can exist in an agency's operational area with at least one application of an extended-release larvicide formulated to last up to 150-180 days. Since the mid-1990s, extended-release larvicides (eg, Altosid® XR, FourStar®, and Natular™ XRT) have been used by the North Shore Mosquito Abatement District (NSMAD), a publicly funded mosquito control agency serving the northeast Chicago metropolitan area, to reduce mosquitoes in ∼50,000 catch basins each season. ...
Stormwater catch basins are commonly treated with larvicides by mosquito control agencies to reduce local populations of mosquito species capable of transmitting West Nile virus. Recent evidence suggests that extended-release larvicides formulated to last up to 180 days in catch basins may not be effective in some basins due to chronic flushing, rapid dissolution, or burying of treatment in sump debris. To investigate if increasing the number of applications could improve effectiveness, a small study was performed over 13 weeks in 2015 to evaluate two extended-release larvicides (Natular™ XRT 180-day tablets and Natular™ T30 30-day tablets) and a larvicide oil (CocoBear™). Over the course of 13 weeks, three groups of eight basins were monitored for mosquitoes, each group receiving Natular™ XRT, Natular™ T30, or CocoBear™ larvicides. All basins received a single application at the beginning of the study period. Once mosquitoes in a basin surpassed the treatment threshold during weekly monitoring, an additional application of the associated larvicide was given to that basin. The number of applications during the study period ranged from 1 to 10 for CocoBear™ basins, 1 to 7 for T30 basins, and 2 to 8 for XRT basins. Overall, the average number of applications and the cost of larvicide per basin were 4.4 applications at $0.66 per Coco-Bear™ basin, 4.4 applications at $6.26 per T30 basin, and 4 applications at $16.56 per XRT basin. Basins treated with XRT and T30 needed reapplications more often than expected, yet were no more effective than CocoBear™, suggesting that increasing the frequency of application of these larvicide formulations may not provide increased mosquito reduction in some basins.
... As part of efforts to decrease local vector populations of West Nile virus (WNV) and other mosquito-borne diseases, stormwater catch basins are often targeted for routine larvicide applications in urban areas around the world. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] The North Shore Mosquito Abatement District (NSMAD) treats approximately 50,000 catch basins each season in the District's 207 sq km (80 sq mi) located in the northeastern greater Chicago IL metropolitan area. Treatment is with extended-release, 180-day larvicides, and the specific objective is to reduce local populations of the local WNV vectors Culex pipiens and Cx. ...
In the northeastern part of the greater Chicago metropolitan area, the North Shore Mosquito Abatement District (NSMAD) treats approximately 50,000 catch basins each season with larvicide tablets as part of its effort to reduce local populations of the West Nile virus (WNV) vector Culex pipiens. During the 2014 season, an NSMAD technician monitored a subset of 60-195 basins weekly for 18 weeks among the communities of the District for the presence of mosquitoes. Monitoring found no clear evidence in the reduction of mosquitoes with the use of larvicides, and visual inspections of 211 larvicide-treated basins found that the majority (162, 76.8%) were missing tablets 1-17 weeks after applications. This loss of treatment may be due to the rapid dissolution or flushing of larvicides and would help explain why the larvicide appeared to be ineffective.
... These infectious diseases are more or less encountered in the Middle East Countries (Mackey et al, 2014). Generally, all water sources are common habitats for the immature stages of mosquito species and reducing mosquito-diseases morbidity in both urban and rural areas where a sufficient proportion of lar-val habitats can be targeted (Kobayashi et al, 2008). So, control of mosquito larvae is important in preventing adults emerging and their pathogens (Osório et al, 2014). ...
The study evaluated the efficacy of methanolic extracts of Ruta chalepensis (Rutaceae), Withania somnifera (Solanaceae), Cleome paradoxa (Capparaceae) and Heliotropium longiflorum (Boraginaceae) aerial parts against Culex pipiens larvae. Different concentrations (100-500 ppm) of the methanolic extracts of the plants were tested towards larval mortality and development of C. pipiens separately. Larval mortalities were counted at 2, 4 & 10 days after treatment. Egg hatchability was determined at 4 & 7 days after treatment. Successful pupation and adult emergence percentage were recorded daily till all control adults emerged. All plants extracts exhibited variable activities. The greatest effect was with R. chalepensis which showed acute (2 days) and chronic (10 days) LC50 of 132.6 & 96.56 ppm, respectively. Larval mortality up to 84.47% &85.53%, were observed with C. paradoxa and R. Chalepensis respectively. Egg hatch was significantly reduced about equal with R. chalepensis and W. somnifera extracts. Concentration levels of C. paradoxa (≥200 ppm) and H. longiflorum (>400 ppm) showed significant hindrance to the larval development and reduction to resulting pupae and adults. Drastic development retardation was shown with extract of C. paradoxa leaves (300 ppm), but only 15.3% & 5.6% of larvae reach pupal and adult stages respectively. The larvicidal activity of methanolic extracts of R. chalepensis, W somnifera, C. paradoxa, H. longiflorum proved to be effective against C. pipiens larvae without any human or animal risk.
... These infectious diseases are more or less encountered in the Middle East Countries (Mackey et al, 2014). Generally, all water sources are common habitats for the immature stages of mosquito species and reducing mosquito-diseases morbidity in both urban and rural areas where a sufficient proportion of lar-val habitats can be targeted (Kobayashi et al, 2008). So, control of mosquito larvae is important in preventing adults emerging and their pathogens (Osório et al, 2014). ...
... In urbanized areas throughout the world, catch basins (subsurface vaults designed to capture urban storm water runoff) are common habitats for the aquatically confined immature stages of vector mosquito species. [1][2][3][4][5][6][7] In the United States, West Nile virus (WNV) vector species in the Culex pipiens complex are found consistently within these structures, making catch basins an important focus of local vector control programs. [8][9][10][11] In some urbanized regions, including the Chicago metropolitan area, these structures may even be the most prevalent source of these species. ...
The tens of thousands of catch basins found in many urban areas are a primary target of local vector control agencies for seasonal application of extended-release larvicides. A concern with using larvicides in these structures is that active ingredients can be hampered by high flows, debris, and sediment, all of which are common to these structures. As such a certain proportion of basins may be "resistant" to larvicide treatments due to site specific characteristics that may promote these and other factors that hinder larvicide action and/or promote mosquito infestation. Analyses from three years of larvicide efficacy trials suggest that over a quarter of basins in the study area may not be receiving adequate protection from a single dose of larvicide that is routinely applied. Implications of increasing the dose and/or toxicity of larvicide treatments are discussed further.
... Aedes albopictus is a most important urban mosquito in Japan because of its wide geographic distribution Tsuda et al., 2006a, b), high biting density during the summer (Makiya, 1974;Toma et al., 1982;Suzuki et al., 1993;Tsuda and Kim, 2012) and the high preference of biting females for humans (Hawley, 1988;Kobayashi et al., 2008;Kim et al., 2009;Sawabe et al., 2010). The geographic distribution of Ae. albopictus has been expanding from Southeast Asian countries to at least 28 other countries since the 1980s (Benedict et al., 2007) and its medical importance as a vector of chikungunya virus and dengue virus has been increasing in newly established areas in temperate regions (ECDC, 2007(ECDC, , 2009Reiter, 2010). ...
An individual marking method by placing spots of paint at five different sites on the thorax of mosquitoes was applied and a short-term ecological study on movement of Ae. albopictus and Armigeres subalbatus was conducted during 18 to 27 March 2013 in a residential area on Ishigaki island, Japan. There were 2 preservation areas with vegetation, human dwellings, shops and buildings, and habitats of Ae. albopictus were distributed patchily in the study area of 230 m×250 m. Individual marking was carried out during the first 7 days, and 232 and 216 females of Ae. albopictus and Ar. subalbatus, respectively, were marked and released from 4 collection sites. The overall recapture rate of released females was significantly higher for Ae. albopictus (0.21=48/232) than Ar. subalbatus (0.09=20/216). The recapture rate of Ae. albopictus varied among collection sites. Analysis of the movements of released mosquitoes among collection sites indicated that the collection site inside the large preservation area was suitable for resting/searching Ae. albopictus and Ar. subalbatus and many females were accumulated through directional movements from the surrounding habitats. The individual marking method used in this study is applicable to field studies of the movements of Ae. albopictus and Ar. subalbatus.
