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ABSTRACT Background: Information regarding the distribution of Culicidae species in the northeastern region of Brazil is scarce. Methods: Immatures were collected from approximately four fragments of the Atlantic Forest. Results: This study presents new occurrences of 18 Culicidae species in Pernambuco state: Anopheles kompi, Georgecraigius fluviatilis, Culex bidens, Culex chidesteri, Culex bastagarius, Culex imitator, Mansonia humeralis, Wyeomyia incaudata, Uranotaenia apicalis, Culex mollis, Culex usquatus, Culex dunni, Culex serratimarge, Culex ybarmis, Culex microphyllus, Sabethes purpureus, Wyeomyia pilicauda, and Wyeomyia airosai. The last nine species were also new records for the northeast region. Conclusions: With the inclusion of these newly recorded species, the total number of mosquitoes documented in Pernambuco state now rises to 94.
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Introducción: A nivel mundial, Aedes aegypti es el culícido más importante en cuanto a la transmisión de arbovirus de impacto en salud pública. Objetivo: Profundizar en los conocimientos ecológicos de Ae. aegypti en República Dominicana, a través de los recipientes o contenedores que utiliza para desarrollar sus formas preimaginales. Métodos: El estudio se extendió desde octubre a diciembre de 2017. Se muestrearon aleatoriamente 100 viviendas, en las que se revisaron todos los recipientes con potencialidad para albergar larvas y/o pupas de mosquitos, dentro y fuera del domicilio. Se cuantificó el tipo y total de cada depósito positivo según su ubicación en cada vivienda, para calcular el porcentaje de representatividad, junto al Índice Pupal por Depósitos específicos (IPDe) para cada receptáculo con pupas. Resultados: Se detectó presencia de Ae. aegypti en el 41 por ciento de las casas visitadas. De los 419 recipientes analizados, 74 resultaron positivos a larvas y/o pupas (17,66 por ciento). Se clasificaron 28 tipos de depósitos atendiendo a su función y material. Cuantitativamente, los depósitos permanentes fueron los más representativos con un 54,05 por ciento. Las mayores capturas se realizaron en el peridomicilio. El tanque plástico fue el más relevante, pues aportó el 28,37 por ciento del total de depósitos positivos, así como un elevado IPDe. Conclusiones: Los resultados evidencian elevados niveles de infestación en los domicilios de Jarabacoa que deben ser controlados a fin de disminuir el riesgo en la transmisión de arbovirosis. El control de los recipientes artificiales, como los contenedores desechables, los neumáticos y sobre todo los tanques de agua, es la piedra angular de cualquier esfuerzo para prevenir estas enfermedades(AU)
Introduction: Aedes aegypti is the most important culicid worldwide in terms of transmission of arbovirus infections of a high impact on public health. Objective: Broaden ecological knowledge about Aedes aegypti in the Dominican Republic, particularly about the containers and other sites where immature development occurs. Methods: The study extended from October to December 2017. One hundred households were randomly surveyed, checking all the containers with a potential to host mosquito larvae and/or pupae both inside and outside the house. Quantification was made of the type and total of positive containers according to their location in each household, to estimate the percentage of representativeness and the pupal index per container identified (PICI) when pupae were found in them. Results: Aedes aegypti was found to be present in 41 percent of the houses visited. Of the 419 containers analyzed, 74 were positive for larvae and/or pupae (17.66 percent). Containers were classified into 28 types according to their function and material. Quantitatively, permanent containers were the best represented with 54.05 percent. The largest captures were made in the area around the house. Plastic water tanks were the most relevant, with 28.37 percent of the total positive containers and a high PICI. Conclusions: Results show high levels of infestation in Jarabacoa households. These should be controlled to reduce the risk of arbovirus infection transmission. Control of artificial breeding sites, such as disposable containers, tires and especially water tanks, is the cornerstone of any effort to prevent these diseases(AU)
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Humans , Male , Female , Ecosystem , Aedes/microbiology , Disease Vectors/classification , Larva/growth & developmentABSTRACT
BACKGROUND Nyssorhynchus dunhami, a member of the Nuneztovari Complex, has been collected in Brazil, Colombia, and Peru and described as zoophilic. Although to date Ny. dunhami has not been documented to be naturally infected by Plasmodium, it is frequently misidentified as other Oswaldoi subgroup species that are local or regional malaria vectors. OBJECTIVES The current study seeks to verify the morphological identification of Nuneztovari Complex species collected in the peri-Iquitos region of Amazonian Peru, to determine their Plasmodium infection status, and to describe ecological characteristics of their larval habitats. METHODS We collected Ny. nuneztovari s.l. adults in 2011-2012, and Ny. nuneztovari s.l. larvae and adults in 2016-2017. When possible, samples were identified molecularly using cytochrome c oxidase subunit I (COI) barcode sequencing. Adult Ny. nuneztovari s.l. from 2011-2012 were tested for Plasmodium using real-time PCR. Environmental characteristics associated with Ny. nuneztovari s.l. larvae-positive water bodies were evaluated. FINDINGS We collected 590 Ny. nuneztovari s.l. adults and 116 larvae from eight villages in peri-Iquitos. Of these, 191 adults and 111 larvae were identified by COI sequencing; all were Ny. dunhami. Three Ny. dunhami were infected with P. falciparum, and one with P. vivax, all collected from one village on one night. Ny. dunhami larvae were collected from natural and artificial water bodies, and their presence was positively associated with other Anophelinae larvae and amphibians, and negatively associated with people living within 250m. MAIN CONCLUSIONS Of Nuneztovari Complex species, we identified only Ny. dunhami across multiple years in eight peri-Iquitos localities. This study is, to our knowledge, the first report of natural infection of molecularly identified Ny. dunhami with Plasmodium. We advocate the use of molecular identification methods in this region to monitor Ny. dunhami and other putative secondary malaria vectors to more precisely evaluate their importance in malaria transmission.
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Humans , Plasmodium/pathogenicity , Malaria/transmission , Anopheles , Anopheles/drug effects , Leishmania braziliensisABSTRACT
Background & objectives: The quality of breeding sites is reflected through the pupal productivity and the life history traits of Aedes mosquitoes. Using nutrient reserves and pupal productivity of Aedes as indicators, the larval habitats including sewage drains were characterized to highlight the habitat expansion and vector management. Methods: The pupae and adults collected from the containers and sewage drains were characterized in terms of biomass and nutrient reserves and the data were subjected to three way factorial ANOVA. Discriminant function analyses were performed to highlight the differences among the habitats for sustenance of Aedes mosquitoes. Results: Survey of larval habitats from the study area revealed significant differences (P<0.05) in the pupal productivity of Aedes among the habitats and months. Despite sewage drains being comparatively less utilized for breeding, the pupae were of higher biomass with corresponding adults having longer wings in contrast to other habitats. The nutrient reserve of the adults emerging from pupae of sewage drains was significantly higher (P<0.05), compared to other habitats, as reflected through the discriminant function analysis. Interpretation & conclusions: The present results showed that for both Ae. aegypti and Ae. albopictus, sewage drains were equally congenial habitat as were plastic, porcelain and earthen habitats. Availability of Aedes immature in sewage drains poses increased risk of dengue, and thus vector control programme should consider inclusion of sewage drains as breeding habitat of dengue vector mosquitoes.
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El Municipio Sifontes, ubicado en el noreste del estado Bolívar, Venezuela, constituye uno de los principales focos de malaria del país debido a causas naturales y antrópicas.Durante el decenio 2004-2013, se registró en este municipio un aumento considerable del número de casos, cerrando 2013 con 42.981 casos, 56% de la malaria del país. Con el objeto de describir la dinámica poblacional de las principales especies de anofelinos, en fase pre-adulta, entre septiembre 2002 y diciembre 2003, se hicieron colectas mensuales en cuerpos de agua representativos de los diferentes tipos existentes en el municipio. Anopheles triannulatus Neiva & Pinto sensu lato fue la especie más abundante y ubicua en toda el área de estudio, seguida de An. albitarsis Lynch Arribalzaga s.l., mientras que An. darlingi Root fue encontrada principalmente en lagunas y ríos. La variabilidad estacional en la abundancia larval estuvo condicionada principalmente por la especie de anofelino y el tipo de hábitat que ésta coloniza, de tal forma que el efecto de la lluvia sobre la abundancia de las especies depende de la dinámica hídrica del hábitat larval, si bien en general, la abundancia de larvas tiende a ser mayor durante el periodo de transición lluvia-sequía y sequía. Los resultados de este estudio contribuyen a dilucidar la relación de la dinámica poblacional de los anofelinos con el patrón de lluvias en la región estudiada.
Sifontes Municipality in the north-east of Bolivar State is one of the main malaria foci in Venezuela due to both natural and anthropic factors. Between 2004 and 2013 a significant increase in the number of cases were reported for this region: at the close of 2013, 42.981 cases had been registered representing 56% of the total number of cases reported in the country. Between September 2002 and December 2003 anopheline larvae were collected monthly to study population fluctuations in different habitats representative of the study area. Anopheles triannulatus Neiva & Pinto sensu lato was the most abundant species collected followed by An. albitarsis Lynch Arribalzaga s.l., while An. darlingi Root was mainly found in lagoons and rivers. Seasonal variations in larval abundance were mainly determined by anopheline species and the type of larval habitat exploited by each one. Anopheline species are thus differentially influenced by rainfall according to the water dynamics of their larval habitats, but in general abundance is higher during the transitions between rainfall-drought and the dry season. These results help us to understand the relationships between anopheline population dynamics and rainfall patterns in this region. In addition, they contribute to our basic knowledge of the bio-ecology of anopheline vectors important for the epidemiology, surveillance and control of malaria in Sifontes Municipality.
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Objective: To determine the effects of environmental characteristics of larval habitats on distribution and abundance of anopheline mosquitoes in Bashagard county, a malarious area in southeast of Iran. Methods: Larvae were collected monthly using the standard dipping method and identified using a morphological-based key. Environmental characteristics of the larval habitats were recorded. Water samples were taken from habitats during larval collection for physico-chemical characterization. Statistical analyses were performed. Results: In total 5150 anopheline larvae from 36 larval habitats were collected and identified. They comprised of six species: Anopheles culicifacies (29.36%), Anopheles moghulensis (25.20%),Anopheles dthali stephensi (5.01%). (18.02%), Anopheles superpictus (17.24%), Anopheles turkhudi (5.17%) and Anopheles The most common larval habitats were natural and clear water bodies such as riverbeds with sandy substrates and still water. Furthermore, the anopheline larvae were abundant in permanent and full sunlight habitats without vegetation and algae. Larval density was positively correlated with water temperature. Chemical characteristics including conductivity, total alkalinity, sulphate and chloride had significant effects on distribution and abundance of anopheline species.Conclusions:The result of this study indicates a correlation between some environmental characteristics and anopheline larvae abundance which can be considered for effective planning and implementing malaria elimination program in Iran.
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<p><b>OBJECTIVE</b>To determine the effects of environmental characteristics of larval habitats on distribution and abundance of anopheline mosquitoes in Bashagard county, a malarious area in southeast of Iran.</p><p><b>METHODS</b>Larvae were collected monthly using the standard dipping method and identified using a morphological-based key. Environmental characteristics of the larval habitats were recorded. Water samples were taken from habitats during larval collection for physico-chemical characterization. Statistical analyses were performed.</p><p><b>RESULTS</b>In total 5 150 anopheline larvae from 36 larval habitats were collected and identified. They comprised of six species: Anopheles culicifacies (29.36%), Anopheles moghulensis (25.20%), Anopheles dthali (18.02%), Anopheles superpictus (17.24%), Anopheles turkhudi (5.17%) and Anopheles stephensi (5.01%). The most common larval habitats were natural and clear water bodies such as riverbeds with sandy substrates and still water. Furthermore, the anopheline larvae were abundant in permanent and full sunlight habitats without vegetation and algae. Larval density was positively correlated with water temperature. Chemical characteristics including conductivity, total alkalinity, sulphate and chloride had significant effects on distribution and abundance of anopheline species.</p><p><b>CONCLUSIONS</b>The result of this study indicates a correlation between some environmental characteristics and anopheline larvae abundance which can be considered for effective planning and implementing malaria elimination program in Iran.</p>
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The aims of this study were to characterise the ground-level larval habitats of the mosquito Culex quinquefasciatus, to determine the relationships between habitat characteristics and larval abundance and to examine seasonal larval-stage variations in Córdoba city. Every two weeks for two years, 15 larval habitats (natural and artificial water bodies, including shallow wells, drains, retention ponds, canals and ditches) were visited and sampled for larval mosquitoes. Data regarding the water depth, temperature and pH, permanence, the presence of aquatic vegetation and the density of collected mosquito larvae were recorded. Data on the average air temperatures and accumulated precipitation during the 15 days prior to each sampling date were also obtained. Cx. quinquefasciatus larvae were collected throughout the study period and were generally most abundant in the summer season. Generalised linear mixed models indicated the average air temperature and presence of dicotyledonous aquatic vegetation as variables that served as important predictors of larval densities. Additionally, permanent breeding sites supported high larval densities. In Córdoba city and possibly in other highly populated cities at the same latitude with the same environmental conditions, control programs should focus on permanent larval habitats with aquatic vegetation during the early spring, when the Cx. quinquefasciatus population begins to increase.
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Animals , Animal Distribution/physiology , Culex/growth & development , Ecosystem , Seasons , Magnoliopsida , Argentina , Aquatic Organisms/physiology , Larva , Meteorological Concepts , Mosquito Control/methods , Population Growth , Water/parasitologyABSTRACT
Background & objectives: Entomological surveillance of the dengue vectors using pupal productivity as indicators can be helpful in effective management. On this basis, an assessment was made on the relative importance of the larval habitats of Aedes mosquitoes in Kolkata, an endemic zone for dengue in West Bengal, India. Methods: Monthly collection of larvae and pupae of Aedes from larval habitats categorized as earthen, plastic and porcelain containers and tyres, was carried out from selected sites. Pupal weight was recorded and degree of sexual dimorphism was calculated. The data on pupal weight, sexual dimorphism and immature density were used for regression analysis. Results: The number of positive sites for each type of larval habitats varied with months and mosquito species. Based on mean density per month, the plastic containers were the most productive habitats and the tyres were least productive for both Aedes species. The pupal weight of both Ae. aegypti and Ae. albopictus varied with the relative density and type of larval habitats. Significant differences in pupal productivity, positive sites and the proportion of pupae were observed in the habitats. Species-specific differences in the degree of dimorphism were noted with the females being larger in size than males, irrespective of the habitats. Interpretation & conclusions: Pupal productivity of Aedes mosquitoes in Kolkata differed in terms of the type of the larval habitats with the immature density affecting the body size of the adults. This habitat-based study is a pioneer effort considering Kolkata and calls for a management plan for source reduction of these habitats to minimize Aedes mosquitoes and thus potential risk of dengue.
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Objective:To determine the larval habitats of mosquito fauna and possible impact of land use/land cover changes on the epidemiology of mosquito-borne diseases in Osogbo metropolis, Southwestern, Nigeria. Methods: All accessible larval habitats were surveyed between May and September, 2011 in Osogbo metropolis while Land Use/ Land cover of the city was analyzed using 2 Lansat Multispectral Scanner satellite imagery of SPOT 1986 and LANDSAT TM 2009. Results:A total of six species namely, Aedes aegypti, Aedes albopictus, Aedes vittatus, Anopheles gambiae complex, Culex quinquefasciatus and Eretmapodite chrysogaster were encountered during the study. The occurrence and contribution of disused tyres was significantly higher (P0.05). The accessible land use/land covered of the study area between 1986 and 2009 showed that the wet land coverage and settlement area increased from 0.19 to 9.09 hectare and 1.00 to 2.01 hectare respectively while the forest area decreased from 60.18 to 50.14 hectare. Conclusion: The contribution of the habitats coupled with the increasing rate of flooded environment which could provide ample breeding sites for mosquitoes call for sustained environmental sanitation and management in Osogbo metropolis.
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Background & objectives: Malaria is the most important mosquito-borne disease in Iran. It is endemic in south to southeastern part of the country. Knowledge about bio-ecology of vectors will support authorities for appropriate management of the disease. Bashagard district is one of the main endemic areas for malaria in south of Iran. This study was conducted to determine anopheline fauna, diversity and affinity in the area, characterization of larval habitats, and mapping their potential distribution across the district. Methods: The potential aquatic habitats for Anopheles larvae were extracted from Indian Remote Sensing Satellite (IRS) image and digital elevation model of the area using GIS. Surface water bodies were sampled monthly during 2009–10 for anopheline larvae, while characteristics of their physical environment were recorded and water samples were analyzed. Results: A total of 4511 Anopheles larvae were found during the year with the lowest and highest frequencies in February and April, respectively. Dominant species was Anopheles culicifacies. The Shanon diversity index ranged from 0.570–0.829 at fixed collection sites, while the affinity index was significant among some vector species. Conclusion: Riversides and riverbeds were the main breeding places which provided sandy, rocky, and clay beds for different species. The potential breeding places as well as distribution of collected species were mapped. Knowledge about ecology of malaria vectors provides information to health sector for effective control programs.
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To classify mosquito species based on common features of their habitats, samples were obtained fortnightly between June 2001-October 2003 in the subtropical province of Chaco, Argentina. Data on the type of larval habitat, nature of the habitat (artificial or natural), size, depth, location related to sunlight, distance to the neighbouring houses, type of substrate, organic material, vegetation and algae type and their presence were collected. Data on the permanence, temperature, pH, turbidity, colour, odour and movement of the larval habitat's water were also collected. From the cluster analysis, three groups of species associated by their degree of habitat similarity were obtained and are listed below. Group 1 consisted of Aedes aegypti. Group 2 consisted of Culex imitator, Culex davisi, Wyeomyia muehlensi and Toxorhynchites haemorrhoidalis separatus. Within group 3, two subgroups are distinguished: A (Psorophora ferox, Psorophora cyanescens, Psorophora varinervis, Psorophora confinnis, Psorophora cingulata, Ochlerotatus hastatus-oligopistus, Ochlerotatus serratus, Ochlerotatus scapularis, Culex intrincatus, Culex quinquefasciatus, Culex pilosus, Ochlerotatus albifasciatus, Culex bidens) and B (Culex maxi, Culex eduardoi, Culex chidesteri, Uranotaenia lowii, Uranotaenia pulcherrima, Anopheles neomaculipalpus, Anopheles triannulatus, Anopheles albitarsis, Uranotaenia apicalis, Mansonia humeralis and Aedeomyia squamipennis). Principal component analysis indicates that the size of the larval habitats and the presence of aquatic vegetation are the main characteristics that explain the variation among different species. In contrast, water permanence is second in importance. Water temperature, pH and the type of larval habitat are less important in explaining the clustering of species.
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Animals , Culicidae , Ecosystem , Argentina , Culicidae/physiology , Larva/physiology , Seasons , Tropical ClimateABSTRACT
Background & objectives: Larval control is an integral part of malaria vector management in Ethiopia and elsewhere. For effective larval control, a sound understanding of the factors responsible for spatio-temporal variation in larval production is essential. A study was thus conducted to characterize larval habitats of anopheline mosquitoes in irrigation and major drainage areas between Adami Tulu and Meki towns, in the middle course of the Ethiopian Rift Valley. Methods: Aquatic habitats were sampled for anopheline larvae and the associated environmental variables (water temperature, turbidity, water current, water pH and other variables) were measured, characterized and analyzed. Results: Microscopic identification of the late instars (III and IV) of anopheline larvae collected throughout the study period yielded nearly 47.6% Anopheles pharoensis, 32.1% An. arabiensis, 17.1% An. squamosus and only 3.2% of other species (An. coustani and An. cinereus). Larvae of the local malaria vectors, An. arabiensis and An. pharoensis were most abundantly sampled from sand pools and natural swamps, respectively. Logistic regression analysis detected four best predictor variables associated with larval abundance of malaria vector species. Thus, relative abundance of An. arabiensis larvae was significantly and inversely associated with aquatic vegetation and water current, whereas the relative abundance of An. pharoensis larvae was significantly and positively associated with water temperature and the presence of algae in the water bodies. Conclusion: Dry season anopheline larval habitats such as riverine sand pools that are created and maintained by perennial water bodies and their associated water development projects need to be considered in vector control operations.
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Se reporta por primera vez una lista de especies de anofelinos y culicinos presentes en el territorio indígena del Bajo Caura, estado Bolívar. Entre larvas y adultos se colectaron en total ocho especies de anofelinos pertenecientes a los subgéneros Anopheles Meigen, Lophopodomyia Antunes, Stethomyia Theobald, Nyssorhynchus Blanchard del género Anopheles Meigen y Chagasia bathana Dyar y 10 géneros de culicinos entre los cuales se identificaron siete especies. Se identificaron y caracterizaron los criaderos con base a la hidrología en arroyo, caño, manantial, laguna, pantano y charco. En colectas de estadíos inmaduros la especie más abundante fue Anopheles triannulatus (Neiva & Pinto), mientras que en colectas de adultos con cebos humanos y trampas CDC la especie más abundante fue el vector de malaria An. darlingi Root. Las trampas de luz ultravioleta resultaron ineficientes para capturar anofelinos y culicinos. Se reporta por primera vez para el estado Bolívar los géneros Coquillettidia Dyar y Johnbelkinia Zavortink, así como las especies Aedes (Ochlerotatus) fulvus (Wiedemann) y Ae. (Och.) serratus (Theobald)
This is the first report of anophelines and culicines species in the indigenous territory of the Lower Caura River, Bolívar State. A total of 8 species of anophelines belonging to the subgenus Anopheles Meigen, Lophopodomyia Antunes, Stethomyia Theobald, Nyssorhynchus Blanchard of the genus Anopheles Meigen and Chagasia bathana Dyar and 10 genera of culicines were collected and 7 species identified. Larval habitats were identified and characterized based on the hidrology in stream, small river, spring, lagoon, swamp and pool. Culicines were also collected in artificial and natural containers. The most abundant species in collections of inmature stages was Anopheles triannulatus (Neiva & Pinto), while in adult collections on human landing catches and CDC light traps the most abundant species was the malaria vector An. darling Root. Ultra violet up draft light traps were inefficient to collect anophelines and culicines. It is reported for the first time the presence in Bolívar State of the genus Coquillettidia Dyar and Johnbelkinia Zavortink, and the species Aedes (Ochlerotatus) fulvus (Wiedemann) and Ae. (Och.) serratus (Theobald)
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Humans , Adult , Anopheles/physiology , Anopheles/genetics , Anopheles/immunology , Anopheles/virology , Epidemiology/classification , Epidemiology/history , Epidemiology/trends , Malaria , Public HealthABSTRACT
Culicoides paraensis (Goeldi), a common and widespread American bloodsucking midge that has been incriminated in the transmission of Mansonellosis and Oropouche Fever of humans in South America, is redescribed and figured. All published records are listed and new distribution is based on examination of extensive collections from throughout its range. Three closely related species of the subgenus Haematomyidium that have been confused with C. paraensis are briefly redescribed and figured, and a key is presented for their identification.