Culicidae (Diptera) em área sob influência de construção de represa no Estado de São Paulo

OBJECTIVE: To describe the culicidae fauna in an area impacted by environmental changes caused by the construction of a dam. METHODS: The studied area was the Porto Primavera dam construction site in Southeastern Brazil. Monthly culicidae samples were taken in six exploratory sites in the pre-filling period and in one fi xed site, one year before (1997-1998) and after the first filling (1999-2000). Adult mosquitoes were captured in the morning with an aspirator and with Shannon and CDC traps during the evening twilight period. Immature stages were captured using a ladle in the larger breeding sites and with a pipette in the smaller ones. RESULTS: In the pre-filling period of the dam, a total of 944 immature culicidae specimens, from ten species, were captured. A total of 14,932 adults were captured, including 7,031 mosquitoes from ten species in the exploratory points and 7,901 specimens from eight genera in the fixed site. After the first stage of the dam filling, the immature stages total was 1,201, from four genera, and the captured mosquitoes total was 5,912, from nine genera. There was a population reduction of the genera Aedes and Psorophora and an increase of the following species populations: Aedeomyia, Anopheles, Culex (Melanoconion), Mansonia and Uranotaenia. CONCLUSIONS: The environmental changes caused due to the construction of the Porto Primavera Dam contributed to an increase in the population density of some culicidae vectors, causing a nuisance and the potential risk of the transmission of pathogens to humans.OBJETIVO: Descrever a fauna Culicidae em área sob impacto da modificação ambiental causada pela construção de represa. MÉTODOS: Foi estudada a área onde estava sendo construída a Represa Porto Primavera no município de Presidente Epitácio, SP. As capturas dos culicídeos foram realizadas mensalmente, em seis pontos exploratórios antes do seu enchimento e em um ponto fixo, um ano antes (1997-1998) e outro depois do primeiro enchimento (1999-2000). Mosquitos adultos foram capturados com aspirador, no período matutino, e com armadilhas de Shannon e CDC, no período crepuscular vespertino. Os imaturos foram coletados por meio de conchadas nos criadouros maiores e com pipeta, nos menores. RESULTADOS: No período anterior ao enchimento da represa foram coletados 944 exemplares de culicídeos imaturos, distribuídos em dez gêneros. O total de adultos foi de 14.932, dos quais 7.031 mosquitos (em dez gêneros) foram capturados nos pontos exploratórios e 7.901 espécimes, distribuídos em oito gêneros, no ponto fixo. Após a primeira etapa de enchimento da represa, o total de imaturos foi de 1.201 exemplares, distribuídos em quatro gêneros, e o total de mosquitos capturados foi de 5.912, distribuídos em nove gêneros. Houve redução populacional de espécies dos gêneros Aedes e Psorophora e aumento no número de espécimes dos gêneros Aedeomyia, Anopheles, Culex (Melanoconion), Mansonia e Uranotaenia. CONCLUSÕES: As mudanças ambientais decorrentes da construção da Represa Porto Primavera favoreceram o aumento da densidade de algumas populações de culicídeos vetores e que geram incômodo, com riscos potenciais de transmissão de patógenos para humanos

Ecology of Anopheles (Nyssorhynchus) darlingi Root in the installation area of a hydroelectric scheme on the border between the States of Mato Grosso do Sul and São Paulo

INTRODUÇÃO: Hidrelétricas alteram o fluxo das águas e provocam impactos sobre a composição de mosquitos, justificando-se essa pesquisa. O objetivo da pesquisa foi estudar anofelinos de área sob a influência de um novo lago e avaliar a vulnerabilidade relativa à malária. MÉTODOS: Foram feitas coletas de Anopheles nas margens da Represa Porto Primavera, durante as fases do alagamento até sua cota máxima. Utilizaram-se as técnicas: atrativa humana, de armadilha de Shannon e concha entomológica. Os indicadores Riqueza e Diversidade foram utilizados para medir o impacto. A análise das distribuições temporais foi realizada pelo teste Mann-Whitney, considerando localidade, cota e método de captura como variáveis independentes (α=0,05). RESULTADOS: A densidade de Anopheles darlingi oscilou entre as localidades A, B e C, sendo que os maiores picos foram para B e C. Com a estabilidade do lago, no último nível, evidenciou-se a tendência de redução da densidade de Anopheles darlingi. CONCLUSÕES: Sugere-se que o risco de autoctonia de malária nas proximidades do lago permanece inalterado, ficando o alerta para esporádicas infecções humanas.IINTRODUCTION: Hydroelectric schemes modify the water flow and cause an impact on mosquito composition, thus justifying investigations. The aim of this study was to study anophelines in the area under the influence of a new lake and to evaluate their relative vulnerability to malaria. METHODS: Anopheles specimens were collected from the edges of the Porto Primavera reservoir, during the phases of reservoir filling until its maximum level was reached. The techniques used were attraction to humans, Shannon traps and entomological scoops. The richness and diversity indexes were used to measure the impact. The temporal distribution analysis was performed using the Mann-Whitney test, taking the site, level and capture method as independent variables (α = 0.05). RESULTS: The density of Anopheles darlingi oscillated among the sites A, B and C, and the biggest peaks were located at B and C. After the lake reached its stable maximum level, there was a tendency for the density to decrease. CONCLUSIONS: It is suggested that the risk of autochthonous malaria in the vicinity of the lake remained unchanged, but it is necessary to remain alert regarding sporadic human infections.Brasil - Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Efeitos do alagamento do Rio Paraná na atividade horária de Anopheles (Nyssorhynchus) darlingi Root (Diptera: Culicidae), na divisa dos estados do Mato Grosso do Sul e São Paulo, Brasil

INTRODUCTION: Study of the temporal activity of malaria vectors during the implantation of a hydroelectric power station on the River Paraná, intended to generate electrical energy. The river separates the States of São Paulo and Mato Grosso do Sul, in Brazil. The objective was to verify whether alterations occurred in the wealth and diversity indices of Anopheles, following two successive floods, extended to the temporal activity and nycthemeral rhythm followed over a five year period. METHODS: Mosquito capture was performed monthly using the Human Attraction Technique and Shannon Traps. The first, executed for 24h, provided the nycthemeral rhythm and the second, lasting 15h, permitted the tracking of Anopheles during the two floods. RESULTS: The bimodal pattern of Anopheles darlingi defined before these floods was modified throughout the environment interventions. The same effect had repercussions on the populations of An albitarsis s.l., An triannulatus and An galvaoi. Activity prior to twilight was less affected by the environment alterations. CONCLUSIONS: The dam construction provoked changes in Anopheles temporal activity patterns, permitting classification of the area as an ecologically steady and unstable situation. Differences observed in Anopheles behavior due to the capture methods revealed the influence of solo and multiple attractiveness inside the populations studied.INTRODUÇÃO: Estudo da atividade horária de vetores da malária durante a implantação de uma represa no Rio Paraná, destinada à geração de energia elétrica. O rio separa os Estados de São Paulo e Mato Grosso do Sul, no Brasil. O objetivo foi verificar se as alterações na riqueza e diversidades de Anopheles diante de duas inundações sucessivas se estendiam à atividade horária e ritmo nictimeral numa série temporal de cinco anos. MÉTODOS: A captura de mosquito foi mensal, por meio dos métodos Técnica Atrativa Humana e Armadilha de Shannon. A primeira, executada durante 24 horas, forneceu o ritmo nictimeral e a segunda, com duração de 15 horas, para acompanhar os anofelinos durante as duas inundações. RESULTADOS: O padrão bimodal de Anopheles darlingi definido antes dessas inundações foi alterado ao longo das intervenções ambientais. O mesmo efeito repercutiu nas populações de An albitarsis s.l., An triannulatus e An galvaoi. A atividade pré-crepuscular foi a menos afetada pelas alterações ambientais. CONCLUSÕES: As barragens provocam mudanças no padrão de atividade horária dos anofelinos permitindo classificar a área em situação ecologicamente estável e instável. Diferenças observadas no comportamento dos anofelinos pelos métodos de captura mostram a influência da uni e múltipla atratividade dentro das populações estudadas.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Companhia Energética de São Paul

Effects of Artificial Flooding for Hydroelectric Development on the Population of Mansonia humeralis (Diptera: Culicidae) in the Paraná River, São Paulo, Brazil

The closure of two phases of the dam at the Porto Primavera Hydroelectric Plant on the Paraná River flooded a flawed system located in the Municipality of Presidente Epitácio, São Paulo state, favoring the proliferation of aquatic weeds. This study aimed to observe the population of Mansonia humeralis in the area, monitoring the richness, diversity, and dominance of this species both before and during different phases of reservoir flooding as well as evaluate its possible consequences concerning human and animal contact. Adult mosquitoes were collected monthly in the following periods: at the original level, after the first flood, and after the maximum level had been reached between 1997 and 2002. Collection methods used were an aspirator, a Shannon trap, and the Human Attractive Technique. A total of 30,723 mosquitoes were collected, Ma. humeralis accounting for 3.1% in the preflood phase, 59.6% in the intermediate, and 53.8% at maximum level. This species is relevant to public health, since the prospect of continued contact between Ma. humeralis and the human population enhances the dam's importance in the production of nuisance mosquitoes, possibly facilitating the transmission of arboviruses. Local authorities should continue to monitor culicid activity through sustainable entomological surveillance

Duration of larval and pupal development stages of Aedes albopictus in natural and artificial containers

Aedes albopictus were reared in different containers: a tree hole, a bamboo stump and an auto tire. The total times from egg hatching to adult emergence were of 19.6,27.3 and 37.5 days, respectively, according to the container. The first, second and third-instar larvae presented growth periods with highly similar durations. The fourth-instar larvae was longer than the others stages. The pupation time was longer than the fourth-instar larvae growth period. The temperature of the breeding sites studied, which was of 18&deg; C to 22&deg; C on average, was also taken into consideration. The mortality of the immature stages was analysed and compared as between the experimental groups; it was lower in the natural containers than in the discarded tire. The average wing length of adult females emerging from tree hole was significantly larger (p < 0.05) than that of those emerging from the tire.Ae. albopictus foi criado em oco de árvore, internódio de bambu e pneu de carro descartável, sob condições de campo. O resultado obtido a partir de larvas recém-nascidas até alado foi de 19,6,27,3 e 37,5 dias. As larvas dos três primeiros estádios tiveram tempo de crescimento similar, não obstante tratar-se de diferentes micro-habitats estudados. Contudo, larvas de 4º estádio apresentaram tempo de duração mais longo e crescente do oco de árvore para o pneu. A temperatura média dos três micro-habitats variou de 18&deg; Ca 22&deg; C. O resultado da taxa de mortalidade encontrada foi menor para larva e pupa do oco de árvore e maior para o pneu. A medida do comprimento médio de asa das fêmeas emergidas do oco de árvore foi maior em relação àquela do pneu

New records and epidemiological potential of certain species of mosquito (Diptera, Culicidae) in the State of Rio Grande do Sul, Brazil

INTRODUÇÃO: A vigilância entomológica tem se mostrado uma importante estratégia de monitoramento da fauna de culicídeos com vistas a predizer o risco de exposição a espécies vetoras de patógenos. Esse trabalho apresenta uma lista de mosquitos identificados pela primeira vez no Rio Grande do Sul e discute o potencial epidemiológico de algumas espécies ocorrentes no Município de Maquiné com registros em outras regiões do Estado. MÉTODOS: Os mosquitos foram coletados com aspirador de Nasci e armadilhas CDC, entre dezembro de 2006 e dezembro de 2008, em área silvestre, rural e urbana do Município de Maquiné. RESULTADOS: Foram verificadas 55 espécies, das quais 22 são registradas pela primeira vez no estado e 10 são potencialmente vetoras do vírus Saint Louis, Oropouche, Aura, Trocara, Ilhéus, Rocio, Una, West Nile e encefalite equina do leste. CONCLUSÕES: Esses dados demonstram a importância da Vigilância Entomológica como ferramenta de informação e ação para a Vigilância em Saúde.INTRODUCTION: Entomological surveillance has proven to be an important strategy for monitoring culicidae fauna, aimed at predicting the risk of exposure to pathogen vector species. The present work reports species identified for the first time in the State Rio Grande do Sul and discusses the epidemiological potential displayed by mosquito species occurring in Maquiné municipality and in other regions of the State. METHODS: Mosquitoes were collected with Nasci vacuum and CDC light traps between December 2006 and December 2008, in the wild, rural and urban areas of Maquiné. RESULTS: Fifty-five species were verified, of which 22 were registered for the first time in the state and 10 are potential vector species for the Saint Louis, Oropouche, Aura, Trocara, Ilhéus, Rocio, Una, West Nile, and eastern equine encephalitis viruses. CONCLUSIONS: These data demonstrate the importance of entomological surveillance as a tool for gathering information and promoting Health Surveillance actions.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Técnico e Científico (CNPq

Riqueza e abundância de Culicidae (Diptera) em área impactada, Mato Grosso do Sul, Brasil

The damming of Paraná River for the construction of Porto Primavera Hydroelectric Power Plant, between the states of Mato Grosso do Sul, Midwestern Brazil and São Paulo, Southeastern Brazil, has changed the ecological relationships in the area. The objective of the study was to describe the fauna that can be potential vectors in this reservoir, 2 km away from its right bank, in Bataguassu, Mato Grosso do Sul, before flooding. Mosquitoes were monthly captured in different environments from July 1997 to November 1999. During this period 16,553 adult specimens and 1,795 immature forms were collected with richness of 86 different species of adults and 44 different species of immature forms. The fauna presented a richness that included species of epidemiological importance, as Anopheles darlingi and other mosquitoes with potential for arbovirus transmission.O represamento do Rio Pananá para construção da hidrelétrica de Porto Primavera, entre os Estados do Mato Grosso do Sul e São Paulo, alterou as relações ecológicas na região. O objetivo do estudo foi descrever a fauna de culicídeos potencialmente vetores nesse reservatório, a 2km da margem direita, em Bataguassu, Mato Grosso do Sul, na fase anterior à inundação. Os culicídeos foram capturados em ambientes distintos mensalmente, de julho de 1997 a novembro de 1999. Foram calculados índices de riqueza e abundância. Obtiveram-se 16.553 exemplares adultos e 1.795 imaturos, com riqueza de 86 e 44 espécies, respectivamente. A fauna culicídea da área de estudo apresentava relativa riqueza, com espécies de valor epidemiológico, como o Anopheles darlingi, além de outras com potencial na veiculação de arbovírus

Feeding habits of mosquitoes (Diptera: Culicidae) in an area of sylvatic transmission of yellow fever in the state of São Paulo, Brazil

Abstract\ud \ud Background\ud The reintroduction of sylvatic yellow fever in the state of São Paulo after about six decades was confirmed in the Northwestern region in 2000, where in 2008 there also occurred an important epizootic. The purpose of this study was to investigate the feeding habits of culicids potentially involved in the sylvatic transmission of the virus in this region.\ud \ud \ud Methods\ud Specimens were collected in 24 forested localities at ground level with hand nets and mouth aspirators. Collections were made quarterly between October 2006 and July 2008 during daylight hours. Blood-meal identification was carried out in mosquitoes of the tribes Aedini, Mansoniini and Sabethini. The biotin/avidin sandwich ELISA was employed to determine six source types: bird, bovine, equine, rat, human and monkey.\ud \ud \ud Results\ud A total of 24,879 females of the three tribes were obtained, 245 (0.98%) of which were engorged. The presence of three different blood sources per engorged female was the predominant situation, and included 35.10% of the total of samples processed. Samples with two or four different sources were represented by 25.31% and 25.71%, of the specimens, respectively, while just 9.39% had only one type and 1.22%, five different sources. Aedes scapularis, Ae. serratus (Group), Psorophora albigenu and Ps. ferox were the most abundant species and accounted for about 95% of the engorged specimens. Of the principal vector species, Haemagogus janthinomys/capricornii was found with bird, bovine and primate blood. These sources were predominant and alternated top ranking as the most frequent source according to the mosquito species and collection site. In general, primate blood was the most prevalent source.\ud \ud \ud Conclusions\ud The human population of the region visits this ecotone frequently, which indicates the need for the periodical assessment of vaccination coverage against yellow fever. The frequency of non-human primate blood source in mosquito species that show minor vector importance in yellow fever virus transmission deserves attention. The eclectic feeding habits and some aspects of the interactions between potential vectors and reservoirs of yellow fever may be associated with the habitat fragmentation characteristic of the region. We recommend that further studies on the capacity and vector competence be performed on secondary vectors in extra-Amazonian region

Descripción de la hembra de Pintomyia (Pifanomyia) deorsa (Diptera, Psychodidae, Phlebotominae)

Pintomyia (Pifanomyia) deorsa (Pérez, Ogusuku, Monje &amp; Young, 1991) was described on the basis of a single male; the female is being described here from specimens collected in Ollantaytambo, Cusco, Peru. Diagnoses for the Pintomyia genus, Pifanomyia subgenus, Verrucarum series and both sexes of Pi. deorsa are presented, as well as an identification key to distinguish the females of the Verrucarum series.Pintomyia (Pifanomyia) deorsa (Pérez, Ogusuku, Monje &amp; Young, 1991) fue descrita en base a un solo espécimen macho; la hembra es descrita aquí a partir de especímenes colectados en Ollantaytambo, Cusco, Perú. El diagnóstico para en género Pintomyia, el subgénero Pifanomyia, la série Verrucarum y ambos sexos de Pi. deorsa son presentados, así como claves para la identificación y separación de las hembras de la serie Verrucarum

First official record of Aedes (Stegomyia) albopictus (Diptera: Culicidae) in the Acre State, Northern Brazil

Aedes (Stegomyia) albopictus (Skuse, 1854) was reported in Brazil for the first time in 1986 and has shown marked expansion throughout the Brazilian territory. During a routine activity to control dengue fever conducted by the Division of Entomology of the Municipal Health Department in Rio Branco city, adults and immatures of Culicidae were collected in a peri-urban area. The identified Culicidae forms indicated that they belonged to the species Ae. albopictus. This is the first official record of the presence of Ae. albopictus in the Acre State, confirming its current presence in all Brazilian states