Diversity, distribution and relative abundance of the mosquito fauna (Diptera: Culicidae) of Malakand and Dir Lower, Pakistan / Diversidade, distribuição e abundância relativa da fauna de mosquitos (Diptera: Culicidae) de Malakand e Dir Lower, Paquistão

The present study was conducted to evaluate the diversity, distribution (C) and relative abundance (RA) of the mosquito fauna (Diptera: Culicidae) of Malakand and Dir Lower, Pakistan. Collection of specimens (n = 1087) was made during September 2018 to July 2019 at six different habitats including freshwater bodies, rice fields, animal sheds, indoors, drains and sewage waters. Specimens were collected through light traps, pyrethrum spray, aspirators and nets and subsequently killed, preserved and then arranged in entomological boxes for identification. Three genera were identified namely Culex, Anopheles and Aedes. A total of fourteen species were identified namely: Cx. quinquefasciatus (Say, 1823), An. stephensi (Liston, 1901), Cx. tritaeniorhynchus (Giles, 1901), Ae. vittatus (Bigot, 1861), An. maculatus (Theobald, 1901), An. fluviatilis (James, 1902), Cx. vishnui (Theobald, 1901), Ae. aegypti (Linnaeus, 1762) An. subpictus (Grassi, 1899), An. dthali (Patton, 1905), An. culicifascies (Giles, 1901), An. pallidus (Theobald, 1901), Ae. albopictus (Skuse, 1894) and An. annularis (van der Wulp, 1884). Cx. quinquefasciatus was found constantly distributed in the study area with RA = 16.5% and C = 100%. An. annularis was found as a satellite species, sporadically distributed in the study area having RA = 0.9% and C = 17%. Diversity indices of mosquitoes in the studied habitats were found as, Shannon-Wiener Index (2.415), Simpson Index (9.919), Fisher's Index (2.269) and Margalef's Index (1.859). A statistically significant difference was recorded in mosquito diversity in the six habitats (Kruskal-Wallis, chi-squared, H = 17.5, df = 5, P = 0.003 at α = 0.05). The present study encompasses [...].

O presente estudo foi conduzido para avaliar a diversidade, distribuição (C) e abundância relativa (RA) da fauna de mosquitos (Diptera: Culicidae) de Malakand e Dir Lower, Paquistão. A coleta de espécimes (n = 1087) foi feita durante o período de setembro de 2018 a julho de 2019 em seis habitats diferentes, incluindo corpos d’água, campos de arroz, galpões de animais, ambientes internos, ralos e águas residuais. Os espécimes foram coletados por meio de armadilhas luminosas, spray de piretro, aspiradores e redes e posteriormente mortos, preservados e depois dispostos em caixas entomológicas para identificação. Três gêneros foram identificados, nomeadamente Culex, Anopheles e Aedes. Um total de 14 espécies foi identificado, a saber: Cx. quinquefasciatus (Say, 1823), An. stephensi (Liston, 1901), Cx. tritaeniorhynchus (Giles, 1901), Ae. vittatus (Bigot, 1861), An. maculatus (Theobald, 1901), An. fluviatilis (James, 1902), Cx. vishnui (Theobald, 1901), Ae. aegypti (Linnaeus, 1762), An. subpictus (Grassi, 1899), An. dthali (Patton, 1905), An. culicifascies (Giles, 1901), An. pallidus (Theobald, 1901), Ae. albopictus (Skuse, 1894) e An. annularis (Van der Wulp, 1884). Cx. quinquefasciatus foi encontrado constantemente distribuído na área de estudo com AR = 16,5% e C = 100%. A. annularis foi encontrada como espécie satélite, distribuída esporadicamente na área de estudo com RA = 0,9% e C = 17%. Os índices de diversidade de mosquitos nos habitats estudados foram encontrados como índice de Shannon-Wiener (2,415), índice de Simpson (9,919), índice de Fisher (2,269) e índice de Margalef (1,859). Uma diferença estatisticamente significativa foi registrada na diversidade de mosquitos nos seis habitats (Kruskal-Wallis, qui-quadrado, H = 17,5, df = 5, P = 0,003 em α = 0,05). O presente estudo abrange a fauna de mosquitos de Malakand, Paquistão, com respeito à diversidade, abundância relativa e distribuição em [...].

Gonotrophic discordance in Culex quinquefasciatus (Diptera: Culicidae) in the city of São Paulo, Brazil

Abstract INTRODUCTION: This study aimed to assess the occurrence of gonotrophic discordance in females of Culex quinquefasciatus in São Paulo, Brazil. METHODS: Resting females were collected monthly for 8 months. Females of Cx. quinquefasciatus were identified, and their midgut and ovaries were dissected. RESULTS: Two hundred females were dissected, out of which, 27.5% were nulliparous and 57% were parous. Most females had no blood in the midgut, but gonotrophic discordance was found in 21% females. CONCLUSIONS: Females of Cx. quinquefasciatus showed a high parity rate and gonotrophic discordance, which could favor the vector capacity of this species.

Field evaluation of sticky BR-OVT traps to collect culicids eggs and adult mosquitoes inside houses

Abstract INTRODUCTION: Culex quinquefasciatus is a mosquito of importance to public health, as it represents a real and/or potential risk for the transmission of pathogens to humans, such as some arthropod-borne viruses and nematodes that cause filariasis. In Brazil, three municipalities in the Metropolitan Region of Recife (RMR) that are endemic for lymphatic filariasis conducted control actions targeting this vector. With the goal of contributing novel C. quinquefasciatus collection strategies, a sticky trap capable of collecting eggs and imprisoning mosquitoes was investigated. METHODS: To evaluate the performance of the sticky BR-OVT trap, tests were carried out in the neighborhoods of Caixa d'Água and Passarinho (Olinda-PE-Brasil) between August 2011 and June 2012. Sixty traps were installed in the indoor areas of residences in the two districts. RESULTS: During the 11-month study, 0.52 [standard deviation (SD) = 1.52] Culex egg rafts, 2.16 (SD = 4.78) C. quinquefasciatus/trap/month, and 0.55 (SD = 1.28) Aedes/trap/month were caught. Female specimens predominated the traps (59% of C. quinquefasciatus and 96% of Aedes spp.). CONCLUSIONS The results demonstrated that the sticky BR-OVT trap is a useful tool for the collection of adult culicids of medical importance and offers an innovative way to collect C. quinquefasciatus eggs and adults in a single trap.

Larvicidal effect of Clinopodium macrostemum essential oil extracted by microwave-assisted hydrodistillation against Culex quinquefasciatus (Diptera: Culicidae)

Abstract INTRODUCTION: In the present study, we determined the chemical composition of Clinopodium macrostemum essential oil obtained by microwave-assisted hydrodistillation and its effect on the growth and development of Culex quinquefasciatus mosquito larvae. METHODS: The essential oil compounds were identified by gas chromatography-mass spectrometry analysis, and bioassays were conducted to evaluate the influence on the developmental stages of early second instar larvae of Cx. quinquefasciatus until the emergence of adults, using essential oil concentrations of 50, 100, 200, 400, and 800mg/L. RESULTS: The gas chromatography-mass spectrometry analyses revealed that the leaf essential oil of C. macrostemum contained 32 compounds and the major chemical compounds identified were linalool (55.4%), nerol (6.4%), caryophyllene (6.25%), menthone (5.8%), geraniol acetate (4.1%), terpineol (3.7%), and pulegone (2.8%). The essential oil yield obtained by microwave-assisted hydrodistillation was 0.8% at 20 min. The treatments showed lethal concentrations (LC50 and LC90) of 22.49 and 833.35mg/L, respectively, after the final measurement of the total number of dead larvae (second, third, and fourth instars), and LC50 and LC90 of 6.62 and 693.35mg/L, respectively, at the end of the experimental period. The essential oil inhibited the growth and development of the mosquito larvae by 32% (relative growth index = 0.68) at 50mg/L, and up to 47% (relative growth index = 0.53) at 800mg/L. CONCLUSION: The present study demonstrated the larvicidal effect of C. macrostemum essential oil on Cx. quinquefasciatus, which can be attributed to the oxygenate compounds obtained by the extraction method.

Distribution of the members of the Pipiens Assemblage in the sympatric area from Argentina: which is where and when?

Given their medical and veterinary relevance, the members of the Pipiens Assemblage are a worldwide target of ecological research. The distribution of Culex pipiens s.s. and Cx. quinquefasciatus converge in Buenos Aires, Argentina, where hybrids have been detected. Each member of the assemblage exhibits a distinct eco-physiological behaviour that can affect its efficiency in pathogen transmission. Our aim was to identify the environmental drivers for the spatio-temporal distribution of each member, focusing on latitudinal and urbanisation gradients. Immatures of mosquitoes were surveyed in artificial containers found within 11 public cemeteries, raised up to the adult stage and identified by their male genitalia. The distribution of each member was associated with the environment in a Generalized Linear Model. The variable accounting for most of the heterogeneity was latitude; Cx. quinquefasciatus was collected more frequently at northern cemeteries, whereas Cx. pipiens and hybrids were more likely at the southern extreme. The urbanisation gradient was also associated with the occurrence of Cx. quinquefasciatus and hybrids at the high and low end, respectively. Other relevant variables were cemetery total area, the proportion with graves and the presence of plastic flowers in the containers. The spatial distribution of the members of the Pipiens Assemblage within the sympatric region in South America is driven by environmental features. The information presented herein provides essential baseline data for surveillance programs and control activities.

Detection of Oropouche virus segment S in patients and inCulex quinquefasciatus in the state of Mato Grosso, Brazil

This study aimed to investigate the circulation of Orthobunyavirus species in the state of Mato Grosso (MT) Brazil. During a dengue outbreak in 2011/2012, 529 serum samples were collected from patients with acute febrile illness with symptoms for up to five days and 387 pools of female Culex quinquefasciatuscaptured in 2013 were subjected to nested-reverse transcription-polymerase chain reaction for segment S of the Simbu serogroup followed by nucleotide sequencing and virus isolation in Vero cells. Patients (5/529; 0.9%) from Cuiabá (n = 3), Várzea Grande (n = 1) and Nova Mutum (n = 1) municipalities were positive for the S segment of Oropouche virus (OROV). Additionally, eight/387 Cx. quinquefasciatuspools were positive for the segment, with a minimum infection rate of 2.3. Phylogenetic analysis indicated that all the samples belong to the subgenotype Ia, presenting high homology with OROV strains obtained from humans and animals in the Brazilian Amazon. The present paper reports the first detection of an Orthobunyavirus, possibly OROV, in patients and in Cx. quinquefasciatus mosquitoes in MT. This finding reinforces the notion that arboviruses frequently reported in the Amazon Region circulate sporadically in MT during dengue outbreaks.

O subgênero Culex na América do Sul (Diptera: Culicidade) / The subgenus Melanoconion of Culex (Diptera: Culicidae) in South America

Introdução - Algumas espécies de Culex (Melanoconion) são consideradas vetores de vírus do complexo da Encefalite Equina Venezuelana e do Vírus do Nilo Ocidental. O subgênero Melanoconion é considerado grupo taxonômico diverso, amplamente distribuído nos países do continente americano, com exceção do Chile e Canadá. A diferenciação das espécies implica grande dificuldade taxonômica, dependendo de estudos dos caracteres morfológicos da genitália dos machos. Contudo o estudo da genitália masculina demanda destreza na dissecção das respectivas estruturas. A classificação atual do subgênero inclui 160 espécies distribuídas em dois grupos principais, a Seção Melanoconion e a Seção Spissipes. Estas seções estão subdivididas em agrupamentos não formais que foram propostos de maneira a englobar as espécies morfologicamente semelhantes, em especial por caracteres da genitália masculina. Objetivos - Investigar as relações filogenéticas entre as espécies do subgênero, e testar a classificação atual proposta por Sirivanakarn (1983). O estudo avaliou o monofiletismo das seções Melanoconion e Spissipes, e de alguns agrupamentos incluídos em cada uma. Métodos - A partir de amostra composta por 106 espécimes do subgênero (46 espécies) e empregando fragmentos de dois genes nucleares de cópia única (CAD, HB), e do gene mitocondrial (COI), foram propostas hipóteses sobre relações filogenéticas. As análises filogenéticas empregaram os métodos estatísticos de Máxima Verossimilhança e de análise Bayesiana. Resultados e Discussão - Apresenta-se a primeira hipótese filogenética de espécies do subgênero Melanoconion baseada informações de três genes. Os resultados obtidos corroboram o monofiletismo das duas seções. As espécies incluídas na Seção Spissipes estão subdivididas em grupos que refletem a história evolutiva e, portanto, correspondem a grupos naturais que compartilham ancestral comum. Portanto, propomos a revalidação do subgênero Helcoporpa Dyar transferindo para ele todas as espécies até agora incluídas na Seção Sipissipes, com exceção do Culex nicaroensis. Por outro lado, a Seção Melanoconion é formada por grupos monofiléticos e outros grupos polifiléticos ou parafiléticos. Este fato sugere que serão necessários rearranjos taxonômicos na Seção Melanoconion, além de estudos mais abrangentes tanto em relação à amostra de espécies como outros genes. Os resultados aqui descritos mostram que o gene COI pode ser utilizado como ferramenta complementar para facilitar a identificação taxonômica das espécies de Melanoconion. Adicionalmente, os genes nucleares, quando analisados em conjunto, proporcionaram informação suficiente na diferenciação de seções, grupos não formais e espécies do subgênero. O uso dos três marcadores moleculares é recomendado para estudo da filogenia de Culex (Melanoconion). Este estudo contribui com informação nova e útil para melhor compreender a classificação de Melanoconion e auxiliar na identificação das espécies.

Introduction - Some of the species of Culex (Melanoconion) Theobald are recognized as vectors of arboviruses such as Venezuelan Equine Encephalitis Virus complex and West Nile Virus. Melanoconion is considered taxonomically diverse and widely distributed in the Americas, with the exception of Chile and Canada. The species of this subgenus pose a real taxonomical challenge as the identification based on morphological traits focuses mainly on the male genitalia that require well-trained skills for dissection of the structures. The current classification of the subgenus recognizes 160 species divided in two major groups, Melanoconion Section and Spissipes Section. Each one of these sections are further divided into non-formal groupings proposed to include morphologically similar species, mainly based on male genitalia characters. Research objectives - To investigate phylogenetic relationships between species of the subgenus Melanoconion of Culex by testing the current classification by Sirivanakarn (1983). We intended to evaluate the monophyly of the two major sections of the subgenus and some of the non-formal groups included in each section. Methods - Our sample taxa included 106 specimens of Melanoconion (46 species), from which we used fragments of two single-copy nuclear genes (CAD, HB) and the mitochondrial gene COI. We raised phylogenetic hypotheses about the subgenus Melanoconion based on analyses that used statistical methods such as Maximum likelihood and Bayesian inference. Results and Discussion - We present the first molecular phylogeny of Melanoconion based on information provided by three genes. The obtained phylogenetic trees strongly support that both sections, Melanoconion and Spissipes, are monophyletic groups. Furthermore the Spissipes Section showed phylogenetic lineages consistent with morphological classification. Thus we strongly recommend the resurrection of subgenus Helcoporpa Dyar to include species until now considered as Spissipes Section, with the exception of Culex nicaroensis. As for the Melanoconion Section, several non-formal groupings corresponded to polyphyletic or paraphyletic groups, with only a few having monophyletic origins. This fact suggests that future taxonomic rearrangements should be consider for Melanoconion Section, as well as a wider sampling of species and molecular markers. Our results confirmed the use of COI gene as a complementary tool for taxonomical identifications. Additionally, the performance of nuclear genes, when analyzed together, was highly informative, showing resolution between the two sections and also for species level. As for tools to infer phylogeny, our data are in agreement with the use of multi loci approach, in order to propose a phylogenetic hypothesis. Our results contribute with new information that improves the classification of subgenus Melanoconion and provides useful data to help with the identification tasks.

Caracterização de populações de Culex coronator (Diptera: Culicidae) e distinção de fêmeas adultas de Culex coronator e Culex usquatus por meio da análise da morfometria geométrica de asa e de sequências gênicas / Characterization of populations of Culex coronator (Diptera: Culicidae) and differentiation of adult females of Culex coronator and Culex usquatus using wing geometric morphometry and gene sequences

Culex coronator Dyar & Knab e Culex usquatus Dyar são duas espécies irmãs, que fazem parte do Complexo Coronator, composto por mais quatro espécies (Culex usquatissimos Dyar, Culex ousqua Dyar, Culex camposi Dyar, Culex covagarciai Forattini). As fêmeas deste grupo são indistinguíveis por caracteres morfológicos, sendo a identificação possível somente através da distribuição e tamanho das cerdas apicais que ornamentam o gonocoxito da genitália masculina. Cx. coronator, é a espécie com maior distribuição geográfica, ocupando as Américas do Norte, Central e Sul. Já Cx. usquatus só foi registrado nas Américas Central e do Sul, ocorrendo em simpatria no Brasil com Cx. coronator. Apesar da semelhança morfológica das fêmeas das duas espécies, até o momento, somente Cx. coronator foi encontrado naturalmente infectado por diversas arboviroses. Considerando que estudos populacionais são importantes para compreender a evolução e a dinâmica de populações de pontencias vetores, e que a correta identificação de fêmeas é fundamental para estudos de competência vetorial, os objetivos deste trabalho foram: (1) distinguir fêmeas adultas de Cx. coronator de Cx. usquatus (2) obter conhecimento da estrutura populacional de Culex coronator nas regiões Sul e Sudeste (3) examinar a possível existência de outras espécies não descritas e/ou incorretamente identificadas sob o epíteto de Cx. coronator. Para tanto foram utilizadas duas ferramentas: uma morfológica (morfometria de asa), e outra genética...

Culex coronator and Culex usquatus are sibling species belonging to Coronator Group, which comprises five other species (Culex usquatissimos Dyar, Culex ousqua Dyar, Culex camposi Dyar, Culex covagarciai Forattini). Except by Cx. yojae, the females of this group are indistinguishable, being the identification only possible by the analysis of the arrangement and number of appendicles on the apical lobe of the gonocoxite of the male genitalia. Cx. coronator is the most widely distributed species in the complex, occupying North, Central and South America, while Cx. usquatus was recorded only in Central and South America. Therefore, these species are sympatric in Brazil. Despite the morphological similarity of the females of both species, only Cx. coronator has epidemiological importance, being found infected with many arboviruses. Since studies focusing in population structure are important to understand the evolution and dynamics of potencial vectors and that the correct female identification is critical for development of vectorial competence studies, the aims of this study were to: (1) distinguish adult females of Cx. coronator from Cx. usquatus (2) obtain knowledge of the population structure of Culex coronator in Southern and Southeastern areas (3) examine the presence of undescribed and/or incorrectly identified species under Cx. coronator. Thereby, a survey was carried out using morphological (wing geometry) and genetic (4 microsatellite loci and barcode region...

COI barcode versus morphological identification of Culex ( Culex ) (Diptera: Culicidae) species: a case study using samples from Argentina and Brazil

Sequences of the cytochrome c oxidase subunit I (COI) mitochondrial gene from adults of 22 Culex ( Culex ) species from Argentina and Brazil were employed to assess species identification and to test the usefulness of COI for barcoding using the best close match (BCM) algorithm. A pairwise Kimura two-parameter distance matrix including the mean intra and interspecific distances for 71 COI barcode sequences was constructed. Of the 12 COI lineages recovered in the Neighbour-joining topology, five confirmed recognised morphological species ( Cx. acharistus , Cx. chidesteri , Cx. dolosus , Cx. lygrus and Cx. saltanensis ) with intraspecific divergences lower than 1.75%. Cx. bilineatus is formally resurrected from the synonymy of Cx. dolosus . Cx. maxi , Cx. surinamensis and the Coronator group species included were clustered into an unresolved lineage. The intraspecific distance of Cx. pipiens (3%) was almost twice the interspecific between it and Cx. quinquefasciatus (1.6%). Regarding the BCM criteria, the COI barcode successfully identified 69% of all species. The rest of the sequences, approximately 10%, 18% and 3%, remained as ambiguously, mis and unidentified, respectively. The COI barcode does not contain enough information to distinguish Culex ( Cux. ) species.

Toxicity of saponin isolated from Gymnema sylvestre R. Br. (Asclepiadaceae) against Culex tritaeniorhynchus Giles (Diptera: Culicidae) Japanese encephalitis vector mosquito in India / Toxicidade da saponina isolada de Gymnema sylvestre R. Br. (Asclepiadaceae) contra Culex tritaeniorhynchus Giles (Diptera: Culicidae) mosquito vetor da encefalite japonesa na Índia

To determine the larvicidal activity of various extracts of Gymnema sylvestre against the Japanese Encephalitis vector, Culex tritaeniorynchus in Tamilnadu, India. To identify the active principle present in the promising fraction obtained in Chlorofom:Methanol extract of Fraction 2. The G. sylvestre leaf extracts were tested, employing WHO procedure against fourth instar larvae of C. tritaeniorhynchus and the larval mortalities were recorded at various concentrations (6.25, 12.5, 25.0, 50 and 100 µg/mL); the 24h LC50 values of the G. Sylvestre leaf extracts were determined following Probit analysis. It was noteworthy that treatment level 100 µg/mL exhibited highest mortality rates for the three different crude extracts and was significantly different from the mean mortalities recorded for the other concentrations. The LC50 values of 34.756 µg/mL (24.475-51.41), 31.351 µg/mL (20.634-47.043) and 28.577 µg/mL (25.159-32.308) were calculated for acetone, chloroform and methanol extract with the chi-square values of 10.301, 31.351 and 4.093 respectively. The present investigation proved that G. Sylvestre could be possibly utilized as an important component in the Vector Control Program.

O presente trabalho é para identificar a atividade larvicida de vários extratos da Gymnema sylvestre contra o vetor da encefalite japonesa, Culex tritaeniorhynchus em Tamilnadu, Índia. Com este propósito o princípio ativo presente na fração mais promissora foi obtida através de um extrato clorofórmio:metanol da fração 2. Os extratos das folhas do G. sylvestre foram testados empregando o procedimento da WHO contra estágios quaternários da larva do C. tritaeniorhynchus e as mortalidades larvais foram registradas após várias concentrações (6,25, 12,5, 25,0 e 100; 34,756 µg/mL (24,475-51,41), 31,351 µg/mL (20,634-47,043) e 28,577 µg/mL (25,159-32,308) g/mL); os valores de LC50 de 24 horas dos extratos das folhas de G. sylvestre foram determinados seguindo a análise Probit. Foi notado que o nível de tratamento de 100 µg/mL exibiu a mortalidade mais alta para os três diferentes extratos crus e foi significantemente diferente das mortalidades médias registradas para as outras concentrações. Os valores de LC50 de 34,756 µg/mL (24,475-51,41), 31,351 µg/mL (20,634-47,043) e 28,577 µg/mL (25,159-32,308) foram calculados para os extratos de acetona, clorofórmio e metanol com os valores de qui-quadrado de 10,301, 31,351 e 4,093 respectivamente. A presente investigação mostra que o G. sylvestre pode ser usado como componente importante no programa de controle do vetor.

Bionomics of Culex quinquefasciatus within urban areas of Rio de Janeiro, Southeastern Brazil / Bionomia de Culex quinquefasciatus em áreas urbanas no Rio de Janeiro, RJ / Bionomía de Culex quinquefasciatus en áreas urbanas en Rio de Janeiro, Brasil

OBJECTIVE: To evaluate density, parity rates, daily survival and longevity of natural populations of Culex quinquefasciatus in three neighborhoods with distinct socio-economic and infrastructure profiles. METHODS: Mosquito collections of the Culex quinquefasciatus species were performed weekly during two four month periods, from August to November 2008 (spring) and March to June 2009 (fall), in a favela (slum), a suburban area and a middle class area of Rio de Janeiro, Southeastern Brazil. Collections were performed with backpack aspirators, in 20 randomly selected houses in each area per week, during 15-20 minutes per house. Ovaries were removed from captured females and classified as initial, intermediary or final stage. Furthermore, females were dissected for determination of parity based on the condition of the tracheal system. Mosquito survival rate and longevity were estimated on a per month basis for each neighborhood. RESULTS: We collected a total of 2,062 Culex quinquefasciatus, but monthly vector density was not correlated with temperature and rainfall. We dissected the ovaries of 625 Culex quinquefasciatus, and overall, there was a higher proportion of nulliparous females during the dryer months, while gravid females were more frequent in rainy months. In the middle class neighborhood, the parity rate reached up to 93.75% with survivorship of 0.979. Lower parity and survival rates were obtained in the suburban area (as low as 36.4% parity and 0.711 daily survival). Up to 84.7% of Culex quinquefasciatus females could survive the eight day period needed to complete West Nile Virus incubation. CONCLUSIONS: The survival rate of Culex quinquefasciatus varied significantly between the neighborhoods. This suggests that vectorial capacity and disease transmission risk may vary greatly between different urban areas, which is potentially useful information for vector control programs.

OBJETIVO: Avaliar densidade, taxa de paridade, sobrevivência diária e longevidade de populações naturais de Culex quinquefasciatus de três localidades com diferentes perfis socioeconômicos e de infraestrutura. MÉTODOS: Mosquitos da espécie Culex quinquefasciatus foram coletados semanalmente em dois períodos de quatro meses, de agosto a novembro de 2008 e de março a junho de 2009, em uma comunidade, uma área de subúrbio e um bairro de classe média no Rio de Janeiro, RJ. As coletas foram realizadas com o auxílio de aspiradores costais em 20 domicílios, aleatoriamente selecionados por semana e por área, durante 15-20 minutos por domicílio. As fêmeas capturadas tiveram os ovários removidos e classificados em estágios inicial, intermediário e final. Adicionalmente, as fêmeas foram dissecadas para determinação da paridade de acordo com as condições do sistema traqueal. A taxa de sobrevivência e a longevidade das fêmeas foram estimadas por mês, para cada localidade. RESULTADOS: Foram coletados 2.062 Culex quinquefasciatus, porém a densidade mensal deste vetor não apresentou correlação com temperatura e precipitação. Dissecamos os ovários de 625 Culex quinquefasciatus e obtivemos maior proporção de fêmeas nulíparas durante os meses mais secos, enquanto fêmeas grávidas foram mais frequentes nos meses chuvosos. A taxa de paridade foi de até 93,75% no bairro de classe média, com sobrevivência de 0,979. Menores valores de paridade e sobrevivência foram obtidos no subúrbio (começando em 36,4% de paridade e 0,711 de sobrevivência diária). Até 84,7% das fêmeas de Culex quinquefasciatus poderiam sobreviver ao período de oito dias, necessário para completar o período de incubação do vírus da febre do Nilo Ocidental. CONCLUSÕES: A taxa de sobrevivência de Culex quinquefasciatus variou significativamente entre os bairros, o que sugere que a capacidade vetorial e o risco de transmissão de doenças podem variar entre diferentes áreas urbanas, informação relevante para o planejamento dos programas de controle de vetores.

OBJETIVO: Evaluar densidad, tasa de paridad, sobrevivencia diaria y longevidad de poblaciones naturales de Culex quinquefasciatus de tres localidades con diferentes perfiles socioeconómicos y de infraestructura. MÉTODOS: Mosquitos de la especie Culex quinquefasciatus fueron colectados semanalmente en dos períodos de cuatro meses, de agosto a noviembre de 2008 y de marzo a junio de 2009, en un barrio, un área de suburbio y una urbanización de clase media en Rio de Janeiro, Litoral Sudeste de Brasil. Las colectas se realizaron con ayuda de aspiradores costales en 20 domicilios, aleatoriamente seleccionados por semana y por área, durante 15-20 minutos por domicilio. A las hembras capturadas se les retiraron los ovarios y clasificaron en fases inicial, intermediario y final. Adicionalmente, las hembras fueron diseccionadas para determinar la paridad de acuerdo con las condiciones del sistema traqueal. La tasa de sobrevivencia y la longevidad de las hembras fueron estimadas por mes para cada localidad. RESULTADOS: Se colectaron 2.062 Culex quinquefasciatus, sin embargo, la densidad mensual del vector no presentó correlación con la temperatura y precipitación. Se diseccionaron los ovarios de 625 Culex quinquefasciatus y se obtuvo mayor proporción de hembras nulíparas durante los meses más secos, mientras que las hembras grávidas fueron más frecuentes en los meses de lluvia. La tasa de paridad alcanzó el 93,75% en la urbanización de clase media, con sobrevivencia de 0,979. Menores valores de paridad y sobrevivencia se obtuvieron en el suburbio (comenzando en 36,4% de paridad y 0,711 de sobrevivencia diaria). El 84,7% de las hembras de Culex quinquefasciatus podrían sobrevivir al período de ocho días, necesario para completar el período de incubación del virus de la fiebre del Oeste del Nilo. CONCLUSIONES: La tasa de sobrevivencia de Culex quinquefasciatus varió significativamente entre las urbanizaciones, sugiriendo que la capacidad vectorial y el riesgo de transmisión de enfermedades pueden variar entre diferentes áreas urbanas, información relevante para la planificación de los programas de control de vectores.

Anopheles (Nyssorhynchus) lanei e Culex (Culex) dolosus (Diptera: Culicidae): duas espécies que ocorrem na região de Campos do Jordão, Serra da Mantiqueira, São Paulo, Brasil / Anopheles (Nyssorhynchus) lanei and Culex (Culex) dolosus (Diptera: Culicidae): two species that occur in Campos do Jordão region, Serra da Mantiqueira, São Paulo, Brazil

Introdução: Anopheles (Nyssorhynchus) lanei foi descrito por Galvão e Amaral em 1938, a partir de espécimes coletados em Campos de Jordão, na Serra da Mantiqueira, Estado de São Paulo, sendo provável espécie endêmica desta região.Linthicum (1988) redescreveu An. lanei baseando-se em um espécime adulto fêmea e duas genitálias masculinas de Campos do Jordão; porém, a ilustração de genitália masculina foi feita a partir de um espécime coletado na cidade de Estância, Estado de Sergipe, Brasil. Evidências morfológicas somadas a diferenças ambientais entre estas localidades indicam que os espécimes analisados por Linthicum não correspondem a An. lanei. Culex (Culex) dolosus foi descrito por Lynch Arribálzaga em 1891 com base em espécimes coletados na Província de Buenos Aires, Argentina. O último trabalho a tratar de aspectos da morfologia de Cx. dolosus é anterior à descrição de Culex eduardoi Casal & García, espécie similar a esta. Dados de literatura apontam para a existência de formas morfológicas diferenciadas em populações de Cx. dolosus, o que parece ser o caso dos espécimes que ocorrem na região de Campos do Jordão. Objetivos: Este estudo visa contribuir para o conhecimento taxonômico de espécies pertencentes aos subgêneros Nyssorhynchus e Culex, que ocorrem na Serra da Mantiqueira, por meios da redescrição de An. lanei e Cx. dolosus, e também da identificação de fauna de Culicidae associada. Métodos: As redescrições foram baseadas na análise de exemplares coletados na região de Campos do Jordão e implicaram em etapas de quetotaxia das larvas e pupas, biometria dos adultos e formas imaturas e elaboração de ilustrações das estruturas anatômicas da morfologia externa. Resultados: Deste trabalho resultaram redescrições morfológicas detalhadas, tabelas de quetotaxia das formas imaturas e ilustrações das larvas, pupas e estruturas das genitálias masculinas. Considerações Finais: Espera-se que os resultados alcançados possam ampliar e dar continuidade a estudos t...

Habitat biodiversity of mosquito richness in certain parts of Garhwal (Uttaranchal), India.

The present study gives an overview of data on the habitat biodiversity of mosquitoes occurring in certain parts (viz, Pauri, Tehri and Uttarkashi) of Garhwal (Uttaranchal), India. The study was based on the mosquito sampling in 450 sites/spots in all the 3 districts, each spot having an area of 25 km2 and geographically located at varying altitudes between 300 to 3,000 m. While compiling the data, published sources in the recent past were also considered. The species richness was categorized as most species and least species by estimating the top and least 5 percentile of species density in each grid cells/spots, respectively. Our database showed that the area harbors 45 species from 3 genera. As many as 17 species of Anopheles and 15 species of the genus Aedes were recorded during November 2000 to October 2002. Further, there were 13 species of Culex, besides few specimens that could not be identified correctly because of damage body parts. Collected species of Anophelines were grouped as common, uncommon, and rare species depending to their percentage of occupying in grid cells/spots. There were 9 common species, while the number of rare species and uncommon species were 3 and 5, respectively. The sites/ spots nearer to riverine areas or thick-forested areas showed more diversity of mosquitoes than those nearer to non-forested or thin-forested areas. However, the biodiversity rich spots were up to 1,200 m altitudes.

protection of permethrin-treated military uniforms against natural population of Culex bitaeniohynchus, Culex ritaeniorhynchus and Culex perexiguus [Diptera: Culicidae]

Personnel of military forces have close contact with the environment and can be bitten by insects and exposed to the related diseases, more than other people. The importance of Culex mosquitoes for mankind is in fact, its biting and nuisance, especially at sleeping time. In recent years, great progresses have occurred in protecting people, especially military personnel, against arthropod bites and vector-borne disease, using treated clothes with permethrin. In this study, the protection of permethrin-treated military uniforms against 3 species of Culex in a rural field of Iran has been examined. In this study, six types of current military uniforms of Iran were treated by permethrin [0.125mg permethrin [Al]/cm[2] and examined against the biting of natural population mosquitoes of rural areas of Kazeroon, Fars Province, south of Iran, namely Culex. Eight volunteers were selected for this study. Six of them put on the treated uniforms and the other two wore the untreated uniforms. All the subjects participated in the night biting test for eight active nights of July 2004. There was no significant difference in the protection of different treated uniforms against mosquitoes biting. The relative protection level of treated uniforms, in comparison with untreated ones, was about 88/2%. The protection percentage of treated uniforms for different species of mosquitoes, in comparison with untreated ones, was calculated through determining the species of captured mosquitoes, separately from case and control subjects. The results showed that the relative protection percent of treated uniforms against species of Culex bitaeniohynchus, Cx. tritaeniorhynchus and Cx.perexiguus were 72.7, 87 and 89.8, respectively. The results of chemical analysis with High performance Thin Layer Chromatography [HPTLC] method, before and after field test, showed that in two weeks of study, there hasn't been any significant decrease in the amount of uniforms' permethrin. According to this study, using of permethrin-treated clothing is a useful technique, which makes a considerable protection against insects biting. Therefore using this technique is recommended for protecting military personnel or civilians, as an effective method against hematophagous insects

Feeding pattern of anopheline and culicine mosquitoes in relation to biotopes and seasons in Delhi and environs.

In the studies to know the feeding pattern of various species of mosquitoes, a total of 7461 specimens comprising of Anopheles culicifacies (150), An. stephensi (61), An. subpictus (990), An. annularis (572), Culex quinquefasciatus (5217) and C. vishnui group (471) of mosquitoes were collected from different biotopes of selected localities in Delhi and environs during all the months of the year. The mosquito blood samples were processed by Gel diffusion technique to know the source of blood meal. Results of study revealed that the mosquito species tested in the study were by and large zoophilic and opportunistic feeders. The feeding behaviour was found to be highly influenced by biotopes from where the mosquitoes were collected, village and areas, different climatic seasons, sleeping behaviour of human beings and availability of alternative hosts particularly animal population. Overall anthropophilic index was found to be 24.66% for An. culicifacies, 20.96% for An. stephensi, 16.93% for An. subpictus, 9.96% for An. annularis, 26.33% for C. quinquefasciatus and 36.39% for C. vishnui group of mosquitoes. Feeding behaviour towards other animals viz: bovine, goat, dog, pig and bird for all these mosquito species in different months and biotopes e.g. human dwellings, cattle sheds and mixed dwellings; in different months and seasons of the year have been presented.

Antigen distribution pattern of West Nile virus in Culex tritaeniorhynchus, Culex vishnui and Culex pseudovishnui mosquitoes.

Distribution of West Nile (WN) virus antigen in different tissues of mosquitoes was studied in three species viz., Culex tritaeniorhynchus, C. vishnui and C. pseudovishnui. Overall per cent positivity was higher in the intra thoracically inoculated as compared to the orally infected mosquitoes, suggesting the existence of a midgut barrier. In a small number of mosquitoes salivary glands were found negative even though fluorescence was seen in the respective head squashes, suggesting salivary gland barrier in these mosquitoes. There was no difference in the per cent salivary gland and salivary gland area positivity between these three species. Presence of virus antigen in the ovaries of these three species on the 3rd post infection day suggests the possibility of transovarial transmission of virus even in the first gonotrophic cycle, which is of epidemiological importance.

Revisäo das espécies do grupo atratus de Culex (Melanoconion) (Diptera: Culicidae) / Revision of the atratus group of Culex (Melanoconion) (Diptera: Culicidae)

Descreve as espécies Cx. atratus, Cx. dunni, Cx. ensiformis, Cx. zeteki, Cx. commevynensis, Cx. trigeminatus e Cx. caribeanus em suas formas imaturas e adulta, inclusive genitália masculina e cibário feminino. Além dos sete taxa conhecidos, säo apresentadas três espécies pertencentes ao grupo, uma delas descrita em suas formas imaturas e outras duas, pela morfologia da genitália masculina. Apresenta histórico da sistemática do grupo, importância médica, distribuiçäo geográfica e dados bionômicos. Fornece chaves de identificaçäo específica e ilustraçöes das espécies estudadas