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To determine the species composition, relative abundance and seasonal variation of different mosquitoes Genera (Aedes, Anopheles, Armigeres, Culex, and Culiseta) in different habitats the present research work was carried out in Entomology Research Laboratory of The University of Peshawar. Sampling performed from variety of permanent and temporary breeding habitats was carried out on monthly basis from targeted breeding sites for two consecutive years through dipping method. Species diversity in the survey sites was noted. Collection from these seventeen various types of potential larval habitats, yielded a total of 42,430 immature constituting 41,556 larvae and 874 pupae. Among these only 19,651 adult mosquitoes emerged comprising 11,512 female and 8,139 male mosquitoes. 78% (n= 15333) of mosquito larvae were from permanent and 22% (n=4318) were from temporary breeding sites. This study showed that Peshawar valley harbours 15 species from the genera Aedes, Anopheles, Armigeres, Culex and Culiseta. When the density of each species was examined, Culex quinquifasciatus was found to be dominant (79%) and constant in distribution. Among the temporary habitats Aedes albopictus was found as the most prevalent species particularly from tree holes and water cisterns. The highest intensity of mosquitoes was in June (2243 emerged adults) and November (2667 emerged adults) while the lowest was in January (203 emerged adults). A perfect positive correlation (r = +0.8) was found between temperature and population of mosquitoes (df 10 and α 0.05). The species diversity index for mosquitoes remained between 0.12 and 1.76. The Margalef's richness components was noticeably low for bamboo traps (0.2) and fairly high for rice fields, Percolating water and Animal tracks (1.3) which shows the abundance of mosquito species in these habitats. Similarly Pielou's Evenness was highest for bamboo traps (E=1) showing species uniform distribution. Animal tracks were presumed not only the diverse habitat rather also possessed high value for species richness and species evenness. Temperature, rainfall, humidity and other related attributes responsible for species variation and abundance need to be analysed further to pave way for controlling vector species in their oviposition targeted sites.

Para determinar a composição de espécies, abundância relativa e variação sazonal de diferentes gêneros de mosquitos (Aedes, Anopheles, Armigeres, Culex e Culiseta) em diferentes habitats, o presente trabalho foi realizado no Laboratório de Pesquisa em Entomologia da Universidade de Peshawar. A amostragem coletada a partir de uma variedade de habitats de reprodução permanentes e temporários foi realizada mensalmente a partir de locais de reprodução alvo por 2 anos consecutivos através do método de imersão. A diversidade de espécies nos locais de pesquisa foi anotada. A coleta desses 17 tipos diferentes de habitats larvais potenciais rendeu um total de 42.430 imaturos, constituindo 41.556 larvas e 874 pupas. Destes, emergiram apenas 19.651 mosquitos adultos, sendo 11.512 fêmeas e 8.139 machos. 78% (n = 15333) das larvas do mosquito eram de criadouros permanentes e 22% (n = 4318) de criadouros temporários. Este estudo mostrou que o vale de Peshawar abriga 15 espécies dos gêneros Aedes, Anopheles, Armigeres, Culex e Culiseta. Quando a densidade de cada espécie foi examinada, Culex quinquifasciatus foi considerado dominante (79%) e constante na distribuição. Entre os habitats temporários, o Aedes albopictus foi encontrado como a espécie mais prevalente, principalmente em ocos de árvores e cisternas de água. A maior intensidade de mosquitos foi em junho (2.243 adultos emergidos) e novembro (2.667 adultos emergidos), enquanto a menor foi em janeiro (203 adultos emergidos). Uma correlação positiva perfeita (r = +0,8) foi encontrada entre temperatura e população de mosquitos (DF 10 e α 0,05). O índice de diversidade de espécies de mosquitos permaneceu entre 0,12 e 1,76. Os componentes de riqueza de Margalef foram visivelmente baixos para armadilhas de bambu (0,2) e razoavelmente altos para campos de arroz, água percolada e rastros de animais (1,3), o que mostra a abundância de espécies de mosquitos nesses habitats. Da mesma forma, a uniformidade de Pielou foi maior para armadilhas de bambu (E = 1), mostrando distribuição uniforme das espécies. As pegadas de animais foram presumidas não apenas como habitat diverso, mas também possuíam alto valor para riqueza e uniformidade de espécies. Temperatura, chuva, umidade e outros atributos relacionados responsáveis pela variação e abundância das espécies precisam ser analisados mais a fundo para abrir caminho para o controle de espécies de vetores em seus locais de oviposição alvo.

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Usually, Culex mosquitoes are responsible for spreading several human diseases such as malaria, Japanese encephalitis, yellow fever, filariasis, and Zika. Lymphatic filariasis and Zika cases are increasing in Thailand with more prevalent in southern Thailand. In this study, our aim is to examine how seasons and water container types affect Culex spp. larvae numbers in Lansaka district, Nakhon Si Thammarat province, southern Thailand. This study was conducted in five sub-districts (Lansaka, Khaokaew, Thadi, Kamlon, and Khunthale) in Lansaka district. In each subdistrict, 120 houses were randomly selected to study the breeding sites of Culex mosquito in dry (March-May, 2018) and wet (October-December, 2018) seasons. Mosquito larvae were collected from indoor, outdoor, natural, artificial, darkcoloured, light-coloured, with lid, and without lid containers. It was observed that in all sub-districts, Culex larvae numbers were higher in dry season compared to wet season. In both seasons, outdoor, without lid, dark-coloured, and artificial containers contained more Culex larvae than inside, with lid, light-coloured, and natural containers, respectively. This study shows that seasons and water container types affect Culex mosquito larvae. Since the larvae numbers are higher in dry season, as well as in outdoor, without lid, dark-coloured, and artificial containers, people should reduce the usage of these containers, especially in the dry season, to prevent Culex borne diseases.

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Usually, Culex mosquitoes are responsible for spreading several human diseases such as malaria, Japanese encephalitis, yellow fever, filariasis, and Zika. Lymphatic filariasis and Zika cases are increasing in Thailand with more prevalent in southern Thailand. In this study, our aim is to examine how seasons and water container types affect Culex spp. larvae numbers in Lansaka district, Nakhon Si Thammarat province, southern Thailand. This study was conducted in five sub-districts (Lansaka, Khaokaew, Thadi, Kamlon, and Khunthale) in Lansaka district. In each subdistrict, 120 houses were randomly selected to study the breeding sites of Culex mosquito in dry (March-May, 2018) and wet (October-December, 2018) seasons. Mosquito larvae were collected from indoor, outdoor, natural, artificial, darkcoloured, light-coloured, with lid, and without lid containers. It was observed that in all sub-districts, Culex larvae numbers were higher in dry season compared to wet season. In both seasons, outdoor, without lid, dark-coloured, and artificial containers contained more Culex larvae than inside, with lid, light-coloured, and natural containers, respectively. This study shows that seasons and water container types affect Culex mosquito larvae. Since the larvae numbers are higher in dry season, as well as in outdoor, without lid, dark-coloured, and artificial containers, people should reduce the usage of these containers, especially in the dry season, to prevent Culex borne diseases.(AU)

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BACKGROUND: Aedes aegypti-borne diseases are becoming major public health problems in tropical and sub-tropical regions. While socioeconomic status has been associated with larval mosquito abundance, the drivers or possible factors mediating this association, such as environmental factors, are yet to be identified. We examined possible associations between proximity to houses and roads and immature mosquito abundance, and assessed whether these factors and mosquito prevention measures mediated any association between household environmental factors and immature mosquito abundance. METHODS: We conducted two cross-sectional household container surveys in February-March and November-December, 2017, in urban and rural areas of Quetzaltenango, Guatemala. We used principal components analysis to identify factors from 12 variables to represent the household environment. One factor which included number of rooms in house, electricity, running water, garbage service, cable, television, telephone, latrine, well, and sewer system, was termed "environmental capital." Environmental capital scores ranged from 0 to 5.5. Risk factors analyzed included environmental capital, and distance from nearest house/structure, paved road, and highway. We used Poisson regression to determine associations between distance to nearest house/structure, roads, and highways, and measures of immature mosquito abundance (total larvae, total pupae, and positive containers). Using cubic spline generalized additive models, we assessed non-linear associations between environmental capital and immature mosquito abundance. We then examined whether fumigation, cleaning containers, and distance from the nearest house, road, and highway mediated the relationship between environmental capital and larvae and pupae abundance. RESULTS: We completed 508 household surveys in February-March, and we revisited 469 households in November-December. Proximity to paved roads and other houses/structures was positively associated with larvae and pupae abundance and mediated the associations between environmental capital and total numbers of larvae/pupae (p ≤ 0.01). Distance to highways was not associated with larval/pupal abundance (p ≥ 0.48). Households with the lowest and highest environmental capital had fewer larvae/pupae than households in the middle range (p < 0.01). CONCLUSIONS: We found evidence that proximity to other houses and paved roads was associated with greater abundance of larvae and pupae. Understanding risk factors such as these can allow for improved targeting of surveillance and vector control measures in areas considered at higher risk for arbovirus transmission.

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Pythium insidiosum is a straminopilan pathogen causing life threatening infections in mammals inhabiting temperate, tropical and subtropical areas of the world. The concept that P. insidiosum could also infect mosquitoes was mentioned earlier by investigators conducting phylogenetic analysis on available P. insidiosum isolates deposited at different culture collections. However, an official report and details on its pathological features in mosquitoes are not available. We are reporting the isolation of P. insidiosum from infected mosquito larvae during a survey conducted in central Brazil. At least three oomycotan isolates were recovered during the survey. Due to their ability to infect mosquito larvae the isolates were deposited in the U.S. Department of Agriculture, Agricultural Research Service Collection of Entomopathogenic Fungi (ARSEF; Ithaca, New York) as putative Lagenidium species. The investigated isolates developed very well at 37 °C, produced typical Pythium-like vesicles containing numerous biflagellate zoospores, hydrolyzed sucrose, and their cultured extracted proteins were recognized in serological analysis by anti-P. insidiosum antibodies. Phylogenetic analyses using ITS and partial COXII DNA sequences identified the isolates as P. insidiosum within the American Cluster I. This is the first official report of P. insidiosum recovered from infected mosquito larvae, indicating that this mammalian pathogen, in addition to plants, it could also use mosquito larvae to complete its life cycle in nature.

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Poecilia vivipara, a small euryhaline guppy is reported at the Maceió River micro-basin in the Fernando de Noronha oceanic archipelago, northeast Brazil. However, the origin (human-mediated or natural dispersal) of this insular population is still controversial. The present study investigates how this population is phylogenetically related to the surrounding continental populations using the cytochrome oxidase I mitochondrial gene from eleven river basins in South America. Our phylogenetic reconstruction showed a clear geographical distribution arrangement of P. vivipara lineages. The Fernando de Noronha haplotype fell within the 'north' clade, closely related to a shared haplotype between the Paraíba do Norte and Potengi basins; the geographically closest continental drainages. Our phylogenetic reconstruction also showed highly divergent lineages, suggesting that P. vivipara may represent a species complex along its wide distribution. Regarding to the insular population, P. vivipara may have been intentionally introduced to the archipelago for the purpose of mosquito larvae control during the occupation of a U.S. military base following World War II. However, given the euryhaline capacity of P. vivipara, a potential scenario of natural (passive or active) dispersal cannot be ruled out.

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The organophosphate temephos has been the main insecticide used against larvae of the dengue and yellow fever mosquito (Aedes aegypti) in Brazil since the mid-1980s. Reports of resistance date back to 1995; however, no systematic reports of widespread temephos resistance have occurred to date. As resistance investigation is paramount for strategic decision-making by health officials, our objective here was to investigate the spatial and temporal spread of temephos resistance in Ae. aegypti in Brazil for the last 12 years using discriminating temephos concentrations and the bioassay protocols of the World Health Organization. The mortality results obtained were subjected to spatial analysis for distance interpolation using semi-variance models to generate maps that depict the spread of temephos resistance in Brazil since 1999. The problem has been expanding. Since 2002-2003, approximately half the country has exhibited mosquito populations resistant to temephos. The frequency of temephos resistance and, likely, control failures, which start when the insecticide mortality level drops below 80%, has increased even further since 2004. Few parts of Brazil are able to achieve the target 80% efficacy threshold by 2010/2011, resulting in a significant risk of control failure by temephos in most of the country. The widespread resistance to temephos in Brazilian Ae. aegypti populations greatly compromise effective mosquito control efforts using this insecticide and indicates the urgent need to identify alternative insecticides aided by the preventive elimination of potential mosquito breeding sites.

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Mosquitoes represent a threat to human health and animals because they act as vectors of several diseases. Native fish species are potential candidates to be considered for biological control populations of mosquitoes. Tests of half-hour and 24-hour consumption of Culex pipiens (Linnaeus, 1758) larvae by Cnesterodon decemmaculatus (Jenyns, 1842) and Jenynsia multidentata (Jenyns, 1842) were carried out, measuring the standard length, mouth width and weight in individuals of the two species of fishes. In both tests J. multidentata consumed more C. pipiens than C. decemmaculatus, being C. decemmaculatus female consumption higher than male consumption (and equal than both sexes of J. multidentata in the 24-hour test). These results remained unchanged when making comparisons of absolute or relative consumption in the half-hour test, but when consumptions relative to weight were compared no difference between species was found in the 24-hour test. Regression analysis between morphometric variables and weight vs. consumption rates showed low explanatory value for the half-hour test, while in the 24-hour test these variables had higher explanatory value, especially for the mouth width. Finally, a half-hour test was performed over C. decemmaculatus females using C. pipiens and Aedes aegypti (Linnaeus, 1742) larvae and it showed a strong preference for the latter ones. This work allowed us to observe that there are large differences in consumption rates of C. pipiens larvae between the fish species under study in short periods. Differences are attenuated when consumption times are longer and may even disappear when weight is taken into account.

Los mosquitos representan una amenaza para la salud del hombre y de los animales debido a que actúan como vectores de distintas enfermedades. Especies de peces nativos son potenciales candidatos a tenerse en cuenta para control biológico de poblaciones de culícidos. Experiencias de consumo de media hora y de 24 horas por Cnesterodon decemmaculatus (Jenyns, 1842) y Jenynsia multidentata (Jenyns, 1842) se llevaron a cabo con larvas de Culex pipiens (Linnaeus, 1758), midiéndose longitud estándar, ancho de boca y peso en individuos de las dos especies. En ambas pruebas, J. multidentata consumió más C. pipiens que C. decemmaculatus, consumiendo las hembras de esta última especie más que los machos (e igual a ambos sexos de J. multidentata en la prueba de 24 horas de duración). Estos resultados no variaron cuando se compararon tantos consumos absolutos o relativos para las pruebas de media hora, sin embargo cuando se compararon los consumos relativos al peso no se encontraron diferencias entre las especies para las pruebas de 24 horas. Análisis de regresión entre las tasas de consumo versus las variables morfométricas y el peso mostraron poco valor explicativo en las pruebas de media hora de duración, mientras que en las pruebas de 24 horas de duración los análisis de regresión tuvieron un mayor valor explicativo, especialmente con el ancho de la boca. Por último, pruebas de media hora de duración fueron llevadas a cabo exponiendo a hembras de C. decemmaculatus con larvas de C. pipiens y Aedes aegypti (Linnaeus, 1742) observándose una fuerte preferencia por las últimas. Este trabajo permitió evidenciar que las especies de peces en estudio presentan grandes diferencias en las tasas de consumo de C. pipiens en periodos cortos. Estas diferencias se atenuaron cuando las tasas de consumo se prolongaron y hasta llegar a desaparecer cuando el peso se tuvo en cuenta.

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Mosquitoes represent a threat to human health and animals because they act as vectors of several diseases. Native fish species are potential candidates to be considered for biological control populations of mosquitoes. Tests of half-hour and 24-hour consumption of Culex pipiens (Linnaeus, 1758) larvae by Cnesterodon decemmaculatus (Jenyns, 1842) and Jenynsia multidentata (Jenyns, 1842) were carried out, measuring the standard length, mouth width and weight in individuals of the two species of fishes. In both tests J. multidentata consumed more C. pipiens than C. decemmaculatus, being C. decemmaculatus female consumption higher than male consumption (and equal than both sexes of J. multidentata in the 24-hour test). These results remained unchanged when making comparisons of absolute or relative consumption in the half-hour test, but when consumptions relative to weight were compared no difference between species was found in the 24-hour test. Regression analysis between morphometric variables and weight vs. consumption rates showed low explanatory value for the half-hour test, while in the 24-hour test these variables had higher explanatory value, especially for the mouth width. Finally, a half-hour test was performed over C. decemmaculatus females using C. pipiens and Aedes aegypti (Linnaeus, 1742) larvae and it showed a strong preference for the latter ones. This work allowed us to observe that there are large differences in consumption rates of C. pipiens larvae between the fish species under study in short periods. Differences are attenuated when consumption times are longer and may even disappear when weight is taken into account.(AU)

Los mosquitos representan una amenaza para la salud del hombre y de los animales debido a que actúan como vectores de distintas enfermedades. Especies de peces nativos son potenciales candidatos a tenerse en cuenta para control biológico de poblaciones de culícidos. Experiencias de consumo de media hora y de 24 horas por Cnesterodon decemmaculatus (Jenyns, 1842) y Jenynsia multidentata (Jenyns, 1842) se llevaron a cabo con larvas de Culex pipiens (Linnaeus, 1758), midiéndose longitud estándar, ancho de boca y peso en individuos de las dos especies. En ambas pruebas, J. multidentata consumió más C. pipiens que C. decemmaculatus, consumiendo las hembras de esta última especie más que los machos (e igual a ambos sexos de J. multidentata en la prueba de 24 horas de duración). Estos resultados no variaron cuando se compararon tantos consumos absolutos o relativos para las pruebas de media hora, sin embargo cuando se compararon los consumos relativos al peso no se encontraron diferencias entre las especies para las pruebas de 24 horas. Análisis de regresión entre las tasas de consumo versus las variables morfométricas y el peso mostraron poco valor explicativo en las pruebas de media hora de duración, mientras que en las pruebas de 24 horas de duración los análisis de regresión tuvieron un mayor valor explicativo, especialmente con el ancho de la boca. Por último, pruebas de media hora de duración fueron llevadas a cabo exponiendo a hembras de C. decemmaculatus con larvas de C. pipiens y Aedes aegypti (Linnaeus, 1742) observándose una fuerte preferencia por las últimas. Este trabajo permitió evidenciar que las especies de peces en estudio presentan grandes diferencias en las tasas de consumo de C. pipiens en periodos cortos. Estas diferencias se atenuaron cuando las tasas de consumo se prolongaron y hasta llegar a desaparecer cuando el peso se tuvo en cuenta.(AU)

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Los trichomycetes incluyen un interesante grupo de hongos filamentosos de distribución cosmopólita que se han adaptado a vivir como comensales obligados en el intestino de diversos grupos de artrópodos. Al menos una especie de Smittium es patogénica para los mosquitos que infecta. Esta investigación se realizó con el propósito de establecer que tan amplia es la infestación de Smittium culisetae en larvas de mosquito colectados en el Valle Central de costa Rica entre 1998 y el 2001. Se empleó técnicas entomológicas usuales para la colecta de los insectos, su cría con fines de identificación taxonómica y larvas de 3er. y 4o estadío se disecaron para exponer y estudiar el contenido del tracto digestivo. Se encontró un porcentaje de infestación de 25.8 por ciento, un valor semejante a lo informado por otros autores en otras regiones. No se encontró parásitos de otro tipo en los especímenes colectados.

Trichomycetes constitute a cosmopolitan group of filamentous fungi which are obligate symbionts in the digestive tracts of arthropods. Although this relationship in most species is apparently of a commensalistic nature, at least one species of Smittium has been reported as pathogenic. This study was conducted to determine the level of infestation of S. culisetae in mosquito larvae in the central region of Costa Rica, and to detect other parasites of this medically important group of insects during 1998-2001. Larvae were reared using standard entomological techniques to obtain adults for taxonomic identification; third and fourth stage larvae were dissected to reveal gut contents. A total of 27 mosquito species were collected. The infestation rate in 670 larvae examined was 25.8% which is similar to findings in other areas. Infested larvae did not show any pathological symptoms nor were other parasites of mosquitoes found.

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