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Sample records for superinfected aedes albopictus

  1. IDENTIFIKASI AEDES AEGYPTI DAN AEDES ALBOPICTUS

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    Diah Fitri Rahayu

    2013-09-01

    Full Text Available ABSTRAK. Demam Berdarah Dengue (DBD adalah penyakit yang disebabkan oleh virus Dengue yangditularkan oleh nyamuk . Kabupaten Banjarnegara merupakan daerah endemis reseptif DBD. Dari tahun ketahun kasus DBD cenderung meningkat, terutama di tahun 2009 - 2010. Vektor DBD di Kabupaten Banjarnegaraadalah Ae. aegypti dan Ae. albopictus. Ae. aegypti secara makroskopis terlihat sama seperti Ae. albopictus,namun perbedaannya terletak pada morfologi kepala (mesonotum di mana Ae. aegypti memiliki gambar garisseperti kepala kecapi berbentuk dengan dua garis lengkung dan dua garis lurus putih sementara Ae. albopictushanya memiliki satu garis putih di mesonotum tersebut.Kata kunci: identifikasi, Ae. aegypti, Ae. albopictusABSTRACT. Dengue hemorrhagic fever (DHF is a disease caused by the dengue virus transmitted by mosquito.Banjarnegara district is a Dengue receptive endemic area. From year to year the Dengue cases is likely toincrease, especially in 2009 - 2010. The main vector of dengue in Banjarnegara district is Aedes aegypti andAedes albopictus. Ae. aegypti morphologically look like with Ae. albopictus, but the difference lies in the headmorphology (mesonotum where A. aegypti has a picture of the line like a lyre-shaped head with two curved linesand two white straight line while A. albopictus has only one white stripe on the mesonotum.Key words:identification, Ae. aegypti, Ae. albopictus

  2. Superinfection interference between dengue-2 and dengue-4 viruses in Aedes aegypti mosquitoes.

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    Muturi, Ephantus J; Buckner, Eva; Bara, Jeffrey

    2017-04-01

    Dengue virus consists of four antigenically distinct serotypes (DENV 1-4) that are transmitted to humans by Aedes aegypti and Aedes albopictus mosquitoes. In many dengue-endemic regions, co-circulation of two or more DENV serotypes is fairly common increasing the likelihood for exposure of the two vectors to multiple serotypes. We used a model system of DENV-2 and DENV-4 to investigate how prior exposure of Aedes aegypti to one DENV serotype affects its susceptibility to another serotype. Aedes aegypti mosquitoes were sequentially infected with DENV-2 and DENV-4 and the infection and dissemination rates for each virus determined. We found that prior infection of Ae. aegypti mosquitoes with DENV-4 rendered them significantly less susceptible to secondary infection with DENV-2. Although the results were not statistically significant, mosquitoes infected with DENV-2 were also less susceptible to secondary infection with DENV-4. The midgut dissemination and population dissemination rates for DENV-2 were significantly higher than those of DENV-4 when either virus was administered 7 days after administration of either a non-infectious blood meal or a blood meal containing a heterologous dengue serotype. These results demonstrate that superinfection interference between DENV serotypes is possible within Ae. aegypti mosquitoes, but its effect on DENV epidemiology may be dependent on the fitness of interacting serotypes. © 2017 John Wiley & Sons Ltd.

  3. Aedes albopictus breeding in southern Germany, 2014.

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    Werner, Doreen; Kampen, Helge

    2015-03-01

    Larvae, pupae and eggs of the Asian tiger mosquito Aedes albopictus were found in Freiburg, southern Germany, after submission of an adult mosquito specimen from that area to the 'Mückenatlas', a German instrument of passive mosquito surveillance. While previously collected Ae. albopictus in Germany were trapped on, or close to, service stations on motorways, suggesting introduction by vehicles from southern Europe, these new specimens were out of flight distance from the motorway on the one hand and indicate local reproduction on the other. The findings call for a thorough active and passive surveillance in exposed geographic regions such as the relatively warm German Upper Rhine Valley to prevent Ae. albopictus from establishing.

  4. Successful overwintering of Aedes albopictus in Germany.

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    Pluskota, Björn; Jöst, Artur; Augsten, Xenia; Stelzner, Lilith; Ferstl, Ina; Becker, Norbert

    2016-08-01

    The Asian tiger mosquito (Aedes albopictus) is of great concern to public health authorities due to its vector competence and rapid spread across the globe. In 2015, two large local breeding populations of Ae. albopictus were discovered in southwest Germany. In spring 2016, we were able to demonstrate the first evidence of a successful overwintering in Germany of this originally tropical mosquito species in different research projects. Particularly noteworthy is the successful hatching of diapause eggs of an Italian strain (Calabria), which overwintered successfully in the field in St. Georgen im Schwarzwald (Baden-Wuerttemberg) at 820 m above sea level. Furthermore, within the scope of a larvae monitoring, the first larvae that hatched in the field were detected on the April 09, 2016 in a rain barrel within the Heidelberg population. Our first results show that self-extinction due to an unsuccessful overwintering cannot be assumed for populations of the Asian tiger mosquito which settled in Germany in previous years. The evidence of a successful overwintering of a large number of diapause eggs and the hatching of the first larvae in field conditions opens the control year against Ae. albopictus in southwest Germany.

  5. The phenetic structure of Aedes albopictus.

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    Morales Vargas, Ronald Enrique; Phumala-Morales, Noppawan; Tsunoda, Takashi; Apiwathnasorn, Chamnan; Dujardin, Jean-Pierre

    2013-01-01

    The large and recent migrations of the main vector of the Chikungunya virus, Aedes albopictus, raise questions about the epidemiological impact of possible microevolutionary changes in new territories. Quantitative traits are suitable to detect such changes as induced by environmental adaptations, local competition and founder effects. Using landmark-based geometric morphometrics, we compared the size and shape of 22 populations (1572 females) of Ae. albopictus. The collection sites covered five countries around the world, with special emphasis on Asia, which is assumed to be the origin of the vector. Some collections came from places where an important epidemic outbreak of Chikungunya has recently occurred. Quantitative comparisons were based on 18 anatomical landmarks on the wing. To contrast geographic and possible interspecific shape variation, close species were introduced in the sample, namely five Aedes riversi and nine Ae. flavopictus from Japan. The three species had similar size, but they were clearly separated by shape. Within Ae. albopictus, there was general agreement on size variation with the available climatic data. Shape variation was less related to climatic data than to either geography or a known itinerary of past territorial expansion. Thus, two main clusters were distinguished by wing shape variation: the first one composed of the Southeast Asian sample, the second one grouping Japan, Florida, Hawaii and the Reunion Island samples. The Southeast Asian countries, assumed to be at the origin of the geographic expansion of the mosquito, had similar wings and constituted a distinct group where localities clustered into northern and southern localities. Contrasting with this homogeneous group, very distant localities such as United States (US) and Japan shared a common shape pattern. The US Ae. albopictus samples (Hawaii and Florida) were indeed very similar to the Japanese samples, with Florida behaving exactly like a northern Japanese locality

  6. Truck-mounted Area-wide Application of Pyriproxyfen Targeting Aedes aegypti and Aedes albopictus in Northeast Florida

    Science.gov (United States)

    2014-12-01

    larval control , Aedes aegypti , Aedes albopictus INTRODUCTION Aedes albopictus (Skuse) (Asian tiger mosquito) and Ae. aegypti (L.) (yellow fever...Bull Fla Mosq Control Assoc 9:48– 52. Seng CM, Setha T, Nealon J, Socheat D, Nathan MB. 2008. Six months of Aedes aegypti control with a novel...TRUCK-MOUNTED AREA-WIDE APPLICATION OF PYRIPROXYFEN TARGETING AEDES AEGYPTI AND AEDES ALBOPICTUS IN NORTHEAST FLORIDA1 CARL W. DOUD,2,3 ANTHONY M

  7. The identification of Aedes albopictus in the Nearctic region.

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    Darsie, R F

    1986-09-01

    An introduced, breeding population of Aedes albopictus has been established in Harris County, Texas, and several parishes in Louisiana. The problem of its identification and separation from the indigenous Nearctic mosquito fauna is addressed. Using the keys of Darsie and Ward (1981), the author offers suggested inserts which will accomplish the identification of adult females and larvae in the Nearctic Region. Additional pointers are given for distinguishing albopictus from the 2 common container breeders, Ae. aegypti and Ae. triseriatus.

  8. Detection of Aedes aegypti, Aedes albopictus, and Aedes koreicus in the Area of Sochi, Russia.

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    Ganushkina, Ludmila A; Patraman, Ivan V; Rezza, Giovanni; Migliorini, Luigi; Litvinov, Serguei K; Sergiev, Vladimir P

    2016-01-01

    Following the identification of Aedes (Ae.) aegypti in the Sochi area in Russia at the beginning of 2000, entomological surveys were conducted during the summers of 2007, 2011, and 2012, leading to the identification of Ae. albopictus and Ae. koreicus. These findings highlight Russia as being the only country in the World Health Organization European Region with a documented presence of both Ae. aegypti and Ae. albopictus mosquitoes. Both mosquito species are found on the coasts of the Black Sea. Control measures are needed to reduce the possible risks of importing exotic vector-borne infections, such as dengue and chikungunya.

  9. Aedes aegypti and Aedes albopictus Habitat Preferences in South Texas, USA

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    Champion, Samantha R; Vitek, Christopher J.

    2014-01-01

    The South Texas region has a historical record of occasional dengue outbreaks. The recent introduction of chikungunya virus to the Caribbean suggests that this disease may be a concern as well. Six different cities and three field habitat types (residential, tire shops, and cemeteries) were examined for evidence of habitat and longitudinal preference of two vector species, Aedes aegypti and Aedes albopictus. A. aegypti was more prevalent in tire shop sites, while A. albopictus was more preval...

  10. Temporal patterns of abundance of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) and mitochondrial DNA analysis of Ae. albopictus in the Central African Republic

    National Research Council Canada - National Science Library

    Kamgang, Basile; Ngoagouni, Carine; Manirakiza, Alexandre; Nakouné, Emmanuel; Paupy, Christophe; Kazanji, Mirdad

    2013-01-01

    The invasive Asian tiger mosquito Aedes albopictus (Diptera: Culicidae) was first reported in central Africa in 2000, in Cameroon, with the indigenous mosquito species Ae. aegypti (Diptera: Culicidae...

  11. Distribution and dynamics of Wolbachia infection in Malaysian Aedes albopictus.

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    Joanne, Sylvia; Vythilingam, Indra; Yugavathy, Nava; Leong, Cherng-Shii; Wong, Meng-Li; AbuBakar, Sazaly

    2015-08-01

    Wolbachia are maternally transmitted bacteria found in most arthropods and nematodes, but little is known about their distribution and reproductive dynamics in the Malaysian dengue vector Aedes albopictus. In this study, polymerase chain reaction (PCR) was used to determine the presence of Wolbachia from field collected Ae. albopictus from various parts of the country using wsp specific primers. Ae. albopictus had Wolbachia infection ranging from 60 to 100%. No sequence diversity of wsp gene was found within all wAlbA and wAlbB sequences. Our findings suggest that Wolbachia infection amongst the Malaysian Ae. albopictus were not homogenously distributed in all districts in Malaysia. The presence of Wolbachia in different organs of Ae. albopictus was also determined. Wolbachia were only found in the ovaries and midguts of the mosquitoes, while absent in the salivary glands. The effects of Wolbachia on Ae. albopictus fecundity, longevity and egg viability were studied using infected and uninfected colonies. The removal of Wolbachia from Ae. albopictus resulted in reduced fecundity, longevity and egg viability, thus. Wolbachia seem to play a vital role in Ae. albopictus reproductive system.

  12. Asymmetric Mating Interference between Two Related Mosquito Species: Aedes (Stegomyia albopictus and Aedes (Stegomyia cretinus.

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    Athanassios Giatropoulos

    Full Text Available Aedes (Stegomyia albopictus (Skuse and Aedes (Stegomyia cretinus Edwards are closely related mosquito species with common morphological features and bio-ecological similarities. Recent mosquito surveillance in Athens, Greece, showed that they are sympatric mosquito species, with Ae. albopictus [corrected] developing quite higher population densities than Ae. cretinus [corrected] . The potential of mating interference between these species was investigated by reciprocal and homologous mating experiments in cages under laboratory conditions. In non-choice interspecific crosses (groups of males and females females of both species produced sterile eggs. Insemination rate was 58% for Ae. cretinus females and only 1% for Ae. albopictus [corrected] females. Aedes albopictus males were sexually aggressive and inseminated Ae. cretinus females (31% in choice experiments, where males of one species had access to mate with females of both species. Whereas, interspecific mating of Ae. albopictus [corrected] females with Ae. cretinus males in the co-occurrence of Ae. cretinus females was weaker (4%. Aedes cretinus females from non-choice crossing with Ae. albopictus [corrected] or Ae. cretinus males were paired individually with conspecific males. The percentage of fertile Ae. cretinus females was 17.5% when had encaged before with Ae. albopictus [corrected] males, compared to 100% when Ae. cretinus [corrected] females were encaged with conspecific males only. Probable ecological consequences of asymmetric mating between these ecologically homologous species in nature are discussed.

  13. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus

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    São Thiago André Iwersen de

    2002-01-01

    Full Text Available Software for pattern recognition of the larvae of mosquitoes Aedes aegypti and Aedes albopictus, biological vectors of dengue and yellow fever, has been developed. Rapid field identification of larva using a digital camera linked to a laptop computer equipped with this software may greatly help prevention campaigns.

  14. Software for pattern recognition of the larvae of Aedes aegypti and Aedes albopictus

    OpenAIRE

    São Thiago André Iwersen de; Kupek Emil; Ferreira Neto Joaquim Alves; São Thiago Paulo de Tarso

    2002-01-01

    Software for pattern recognition of the larvae of mosquitoes Aedes aegypti and Aedes albopictus, biological vectors of dengue and yellow fever, has been developed. Rapid field identification of larva using a digital camera linked to a laptop computer equipped with this software may greatly help prevention campaigns.

  15. Geographic distribution of Aedes aegypti and Aedes albopictus collected from used tires in Vietnam.

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    Higa, Yukiko; Yen, Nguyen Thi; Kawada, Hitoshi; Son, Tran Hai; Hoa, Nguyen Thuy; Takagi, Masahiro

    2010-03-01

    The spatial distribution of Aedes aegypti and Aedes albopictus in environmental and geographical zones, e.g., urban-rural, coastal-mountainous, and north-south, was investigated throughout Vietnam. Immature stages were collected from used tires along roads. The effects of regions, seasons, and the degree of urbanization on the density and the frequency were statistically analyzed. Aedes aegypti predominated in the southern and central regions, while Ae. albopictus predominated in the northern region, which may be related to climatic conditions (temperature and rainfall). Larval collection from used tires may be suitable to assess rapidly the current distribution of dengue mosquitoes for estimating health risks and implementing vector control measures.

  16. Key characters for identifying Aedes bahamensis and Aedes albopictus in North America, north of Mexico.

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    Darsie, R F

    1992-09-01

    Aedes bahamensis, a species recently introduced into southern Florida represents the first member of the subgenus Howardina to be found in the United States. Its separation from all other Nearctic Aedes is the subject of this work, integrating it into the North American mosquito keys (Darsie and Ward 1981). The key revisions presented are expanded to include the other exotic species now found in the United States, Aedes albopictus.

  17. Role of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) in local dengue epidemics in Taiwan.

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    Tsai, Pui-Jen; Teng, Hwa-Jen

    2016-11-09

    Aedes mosquitoes in Taiwan mainly comprise Aedes albopictus and Ae. aegypti. However, the species contributing to autochthonous dengue spread and the extent at which it occurs remain unclear. Thus, in this study, we spatially analyzed real data to determine spatial features related to local dengue incidence and mosquito density, particularly that of Ae. albopictus and Ae. aegypti. We used bivariate Moran's I statistic and geographically weighted regression (GWR) spatial methods to analyze the globally spatial dependence and locally regressed relationship between (1) imported dengue incidences and Breteau indices (BIs) of Ae. albopictus, (2) imported dengue incidences and BI of Ae. aegypti, (3) autochthonous dengue incidences and BI of Ae. albopictus, (4) autochthonous dengue incidences and BI of Ae. aegypti, (5) all dengue incidences and BI of Ae. albopictus, (6) all dengue incidences and BI of Ae. aegypti, (7) BI of Ae. albopictus and human population density, and (8) BI of Ae. aegypti and human population density in 348 townships in Taiwan. In the GWR models, regression coefficients of spatially regressed relationships between the incidence of autochthonous dengue and vector density of Ae. aegypti were significant and positive in most townships in Taiwan. However, Ae. albopictus had significant but negative regression coefficients in clusters of dengue epidemics. In the global bivariate Moran's index, spatial dependence between the incidence of autochthonous dengue and vector density of Ae. aegypti was significant and exhibited positive correlation in Taiwan (bivariate Moran's index = 0.51). However, Ae. albopictus exhibited positively significant but low correlation (bivariate Moran's index = 0.06). Similar results were observed in the two spatial methods between all dengue incidences and Aedes mosquitoes (Ae. aegypti and Ae. albopictus). The regression coefficients of spatially regressed relationships between imported dengue cases and Aedes mosquitoes

  18. Globally invasive, withdrawing at home: Aedes albopictus and Aedes japonicus facing the rise of Aedes flavopictus

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    Chaves, Luis Fernando

    2016-11-01

    It has been suggested that climate change may have facilitated the global expansion of invasive disease vectors, since several species have expanded their range as temperatures have warmed. Here, we present results from observations on two major global invasive mosquito vectors (Diptera: Culicidae), Aedes albopictus (Skuse) and Aedes japonicus (Theobald), across the altitudinal range of Mt. Konpira, Nagasaki, Japan, a location within their native range, where Aedes flavopictus Yamada, formerly a rare species, has now become dominant. Spatial abundance patterns of the three species suggest that temperature is an important factor influencing their adult distribution across the altitudinal range of Mt. Konpira. Temporal abundance patterns, by contrast, were associated with rainfall and showed signals of density-dependent regulation in the three species. The spatial and temporal analysis of abundance patterns showed that Ae. flavopictus and Ae. albopictus were negatively associated, even when accounting for differential impacts of weather and other environmental factors in their co-occurrence patterns. Our results highlight a contingency in the expansion of invasive vectors, the potential emergence of changes in their interactions with species in their native communities, and raise the question of whether these changes might be useful to predict the emergence of future invasive vectors.

  19. Population genetic structure of Aedes albopictus in Penang, Malaysia.

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    Zawani, M K N; Abu, H A; Sazaly, A B; Zary, S Y; Darlina, M N

    2014-10-07

    The mosquito Aedes albopictus is indigenous to Southeast Asian and is a vector for arbovirus diseases. Studies examining the population genetics structure of A. albopictus have been conducted worldwide; however, there are no documented reports on the population genetic structure of A. albopictus in Malaysia, particularly in Penang. We examined the population genetics of A. albopictus based on a 445-base pair segment of the mitochondrial DNA cytochrome oxidase 1 gene among 77 individuals from 9 localities representing 4 regions (Seberang Perai Utara, Seberang Perai Tengah, Northeast, and Southwest) of Penang. A total of 37 haplotypes were detected, including 28 unique haplotypes. The other 9 haplotypes were shared among various populations. These shared haplotypes reflect the weak population genetic structure of A. albopictus. The phylogenetic tree showed a low bootstrap value with no genetic structure, which was supported by minimum spanning network analysis. Analysis of mismatch distribution showed poor fit of equilibrium distribution. The genetic distance showed low genetic variation, while pairwise FST values showed no significant difference between all regions in Penang except for some localities. High haplotype diversity and low nucleotide diversity was observed for cytochrome oxidase 1 mtDNA. We conclude that there is no population genetic structure of A. albopictus mosquitoes in the Penang area.

  20. The global distribution of the arbovirus vectors Aedes aegypti and Ae. albopictus

    National Research Council Canada - National Science Library

    Kraemer, Moritz U G; Sinka, Marianne E; Duda, Kirsten A; Mylne, Adrian Q N; Shearer, Freya M; Barker, Christopher M; Moore, Chester G; Carvalho, Roberta G; Coelho, Giovanini E; Van Bortel, Wim; Hendrickx, Guy; Schaffner, Francis; Elyazar, Iqbal R F; Teng, Hwa-Jen; Brady, Oliver J; Messina, Jane P; Pigott, David M; Scott, Thomas W; Smith, David L; Wint, G R William; Golding, Nick; Hay, Simon I

    2015-01-01

    .... Knowledge of the contemporary distribution of their shared vectors, Aedes aegypti and Aedes albopictus remains incomplete and is complicated by an ongoing range expansion fuelled by increased global trade and travel...

  1. On the analysis of parasite effect for Aedes aegypti and Aedes albopictus population

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    Kallista, Meta; Aldila, Dipo; Nuraini, Nuning; Soewono, Edy

    2014-03-01

    It has been reported in some countries that the population of Aedes aegypti has been significantly reduced by the invasion of Aedes albopictus. There has been a hypothesis explaining this phenomenon of which investigated the influence of parasites pathogenesis to the competition between these two mosquito species in the fields. Ascogregarina taiwanensis and Ascogregarina culicis are known as parasites that infect Aedes albopictus and Aedes aegypti, respectively. Several studies have concluded that Ascogregarina taiwanensis caused high fatality for Aedes aegypti larvae, but Ascogregarina culicis was not pathogenic to Aedes albopictus larvae. Therefore, Ascogregarina taiwanensis may contribute to reduce the number of populations Aedes aegypti in the fields. Inspired by these facts, a mathematical model depicting interaction between parasites and mosquitoes is constructed in this paper. In this model are included six dynamic mosquito compartments, i.e. egg, larvae, infected larvae, adult, infected adult and one dynamic compartment for parasite. Derivation of the existence criteria and the stability analysis of parasite-free equilibrium as well as the basic offspring for the model are presented. Numerical simulations for sensitivity analysis indicating the invasive species for variation parameters are shown.

  2. The global compendium of Aedes aegypti and Ae. albopictus occurrence

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    Kraemer, Moritz U. G.; Sinka, Marianne E.; Duda, Kirsten A.; Mylne, Adrian; Shearer, Freya M.; Brady, Oliver J.; Messina, Jane P.; Barker, Christopher M.; Moore, Chester G.; Carvalho, Roberta G.; Coelho, Giovanini E.; van Bortel, Wim; Hendrickx, Guy; Schaffner, Francis; Wint, G. R. William; Elyazar, Iqbal R. F.; Teng, Hwa-Jen; Hay, Simon I.

    2015-07-01

    Aedes aegypti and Ae. albopictus are the main vectors transmitting dengue and chikungunya viruses. Despite being pathogens of global public health importance, knowledge of their vectors’ global distribution remains patchy and sparse. A global geographic database of known occurrences of Ae. aegypti and Ae. albopictus between 1960 and 2014 was compiled. Herein we present the database, which comprises occurrence data linked to point or polygon locations, derived from peer-reviewed literature and unpublished studies including national entomological surveys and expert networks. We describe all data collection processes, as well as geo-positioning methods, database management and quality-control procedures. This is the first comprehensive global database of Ae. aegypti and Ae. albopictus occurrence, consisting of 19,930 and 22,137 geo-positioned occurrence records respectively. Both datasets can be used for a variety of mapping and spatial analyses of the vectors and, by inference, the diseases they transmit.

  3. Aedes albopictus in an area of Misiones, Argentina.

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    Schweigmann, Nicolás; Vezzani, Darío; Orellano, Pablo; Kuruc, Jorge; Boffi, Rolando

    2004-02-01

    Until early 1998 the presence of Aedes albopictus had never been detected in Argentina. During April of the same year, few individuals of this species were recorded in 33 breeding sites found in 25 out of 161 inspected houses in the city of Eldorado, Province of Misiones. The homogeneous spatial distribution of the proliferation foci suggests the existence of a generalized infestation in this locality during the study period.

  4. Emergência de Aedes albopictus em recipientes artificiais Emergence of Aedes albopictus in artificial containers

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    Oswaldo Paulo Forattini

    2001-10-01

    Full Text Available OBJETIVO: Estimar o potencial de emergência média diária de adultos fêmeas de Aedes albopictus, espécie que, embora não tenha sido incriminada, até o momento, como vetora de dengue no Brasil, é muito próxima de Aedes aegypti. MÉTODOS: As observações foram realizadas quinzenalmente e de maneira ininterrupta na localidade de Pedrinhas, Estado de São Paulo, no período de 1996 a 2000. Para estimar a produtividade dos criadouros, mediu-se o índice de emergência (E. Foram utilizados dois reservatórios grandes e permanentes com mais de 10 litros de água, para que o líquido faltante fosse reposto a cada coleta. Os demais reservatórios (seis foram representados por cubas com capacidade de 1 litro, sendo que, a cada cuba, foi adicionado 1 litro de água destilada. Posteriormente, a cada coleta, o volume de água foi reposto independentemente da pluviosidade. As associações foram estudadas pelo índice de correlação de Pearson. RESULTADOS: A emergência (E do reservatório mantido descoberto foi de 66,5, maior do que a emergência da caixa d'água coberta, que foi de 12,2. Ambos os criadouros tiveram o caráter de "permanente" assegurado pela reposição do líquido, caso o volume diminuísse ao longo do tempo de observação. Não houve associação importante com as condições de pluviosidade e de temperatura. Os recipientes menores foram representados por cubas, em número de seis. Algumas delas mostraram associação com as condições meteorológicas e os índices de emergência (E, indicando os meses de menor pluviosidade como menos produtivos. Esses meses, de junho a novembro, seriam o lapso de tempo mais propício para realizar a operação de remoção mecânica de recipientes. CONCLUSÃO: As diferenças encontradas na produtividade dos dois reservatórios permanentes poderão, ao menos parcialmente, ser explicadas pela presença de matéria orgânica que serviria para a alimentação larval. Quanto aos recipientes transit

  5. Insecticide susceptibility of Aedes aegypti and Aedes albopictus in Central Africa

    OpenAIRE

    Nwane Philippe; Nchoutpouen Elysée; Chandre Fabrice; Marcombe Sébastien; Kamgang Basile; Etang Josiane; Corbel Vincent; Paupy Christophe

    2011-01-01

    Abstract Background Aedes aegypti (Linnaeus, 1762) and Aedes albopictus (Skuse, 1894) are the main vectors of dengue (DENV) and chikungunya (CHIKV) viruses worldwide. As there is still no vaccine or specific treatment for DENV and CHIKV, vector control remains the cornerstone of prevention and outbreak control. Unfortunately, vector control programs are facing operational challenges with mosquitoes becoming resistant to commonly used insecticides in several areas through the world. Throughout...

  6. Comparison of BG-Sentinel Trap and Oviposition Cups for Aedes aegypti and Aedes albopictus Surveillance in Jacksonville, Florida, USA

    Science.gov (United States)

    2015-03-01

    COMPARISON OF BG-SENTINELH TRAP AND OVIPOSITION CUPS FOR AEDES AEGYPTI AND AEDES ALBOPICTUS SURVEILLANCE IN JACKSONVILLE, FLORIDA, USA JENNIFER A...tropical and subtropical areas around the world (WHO 2009, Bhatt et al. 2013). In the USA , the principal mosquito vector, Aedes aegypti (L.), has been...virus is well known, the importance of Ae. albopictus in the transmission of arboviruses in the USA , including dengue, is not clear. Specifically, Cache

  7. [Ecology of Aedes aegypti and Aedes albopictus in the Americas and disease transmission].

    Science.gov (United States)

    Rey, Jorge R; Lounibos, Philip

    2015-01-01

    The recent range expansion of the mosquito Aedes albopictus has been associated in some areas by declines in abundance or local elimination of Aedes aegypti, but the two species still coexist in large regions of the Americas. We offer a summary of the possible mechanisms responsible for the abundance and displacement pattern observed and of their significance in terms of disease transmission. Among these mechanisms we may mention the competition for limiting resources, the differences in the ability to withstand starvation, the apparent competition through differential effects of the parasite Ascogregarina taiwanensis, and the inhibition of Ae. aegypti egg development by Ae. albopictus larvae. Habitat segregation has been proposed as a mechanism promoting the coexistence of the two species through avoidance of direct competition. Aedes aegypti predominates in urban areas, Ae. albopictus in rural ones, and both species coexist in the suburbs. There is also evidence that in certain areas, habitat segregation in terms of distance from the coast can influence the distribution of both species. Another possible cause of the rapid disappearance of Ae. aegypti is reproductive interference between the species. According to this hypothesis, asymmetric effects of interspecific mating favor Ae. albopictus. This type of reproductive interference can result in the elimination of sympatric populations of the affected species and can be one of the major causes for the swiftness with which Ae. aegypti disappeared from some places in the Americas following invasions by Ae. albopictus.

  8. Susceptibility of Florida Aedes aegypti and Aedes albopictus to dengue viruses from Puerto Rico.

    Science.gov (United States)

    Alto, Barry W; Smartt, Chelsea T; Shin, Dongyoung; Bettinardi, David; Malicoate, Jolene; Anderson, Sheri L; Richards, Stephanie L

    2014-12-01

    Locally acquired dengue cases in the continental U.S. are rare. However, outbreaks of dengue-1 during 2009, 2010, and 2013 in Florida and dengue-1 and -2 in Texas suggest vulnerability to transmission. Travel and commerce between Puerto Rico and the U.S. mainland is common, which may pose a risk for traveler-imported dengue cases. Mosquitoes were collected in Florida and used to evaluate their susceptibility to dengue viruses (DENV) from Puerto Rico. Aedes aegypti and Ae. albopictus were susceptible to virus infection with DENV-1 and -2. No significant differences were observed in rates of midgut infection or dissemination between Ae. aegypti or Ae. albopictus for DENV-1 (6-14%). Aedes aegypti was significantly more susceptible to midgut infection with DENV-2 than Ae. albopictus (Ae. aegypti, ∼28%; Ae. albopictus, ∼9%). The dissemination rate with dengue-2 virus for Ae. aegypti (23%) was greater than Ae. albopictus (0%), suggesting that Ae. albopictus is not likely to be an important transmitter of the DENV-2 isolate from Puerto Rico. These results are discussed in light of Florida's vulnerability to DENV transmission.

  9. Aedes albopictus emergency. Mosquito control in the area of U.S.L. 16; L` emergenza aedes albopictus: il controllo delle zanzare nel territorio dell`ULSS 19

    Energy Technology Data Exchange (ETDEWEB)

    Dalla Pozza, G. [DPM, Bologna (Italy); Galuppo, M.; Magagni, A. [AMNIUP, Padova (Italy)

    1995-03-01

    The presented paper deal with the mosquito control in the Padova district (Italy). Control strategies and operative planning are reported, together with an example of census schedule. Further development in aedes albopictus control are pointed out.

  10. Dominância de Aedes aegypti sobre Aedes albopictus no litoral sudeste do Brasil Dominance of Aedes aegypti over Aedes albopictus in the southeastern coast of Brazil

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    Ricardo A Passos

    2003-12-01

    Full Text Available OBJETIVO: Analisar a infestação de Aedes aegypti e Aedes albopictus e verificar sua associação com fatores climáticos e com a sua freqüência em recipientes de área urbana. MÉTODOS: Foi selecionado o município de São Sebastião, localizado no litoral Sudeste do Brasil. Foram utilizados os dados do "Programa de Controle de Vetores de Dengue e Febre Amarela no Estado de São Paulo" que realiza a vigilância entomológica em pontos estratégicos, armadilhas e delimitação de focos. Os pontos estratégicos são imóveis onde existem recipientes em condições favoráveis à proliferação de larvas. Para análise dos dados, foram utilizados os testes de significância estatística: Kruskal-Wallis, Dwass-Steel-Chritchlow-Fligne e Mann-Whitney. RESULTADOS: Verificou-se crescimento anual da positividade de armadilhas e pontos estratégicos para Ae. aegypti e diminuição para Ae. albopictus. Observou-se aumento do número de imaturos de Ae. aegypti e diminuição da outra espécie. Na positividade de imóveis para a presença de larvas, verificou-se aumento gradativo do número de imóveis com Ae. Aegypti, superando a positividade para Ae. albopictus. Houve uma fraca correlação das espécies com os fatores abióticos. As maiores freqüências de imaturos de ambas espécies foram em recipientes artificiais passíveis de remoção. CONCLUSÕES: Os resultados evidenciaram no período de estudo a predominância de Ae. aegypti sobre Ae. albopictus em área urbana, indicando que o crescimento populacional do primeiro parece ter afetado a chance de sua coexistência. Sugere-se que algum processo de seleção natural possa estar operando e desse modo contribuindo para levar à separação das duas espécies.OBJECTIVE: To assess infestation of Aedes aegypti and Aedes albopiticus and describe their association with weather conditions and container colonization in urban areas. METHODS: The town of São Sebastião in the southeastern coast of Brazil

  11. Evaluation of Bifenthrin and Acorus calamus Linn. Extract against Aedes aegypti L. and Aedes albopictus (Skuse

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    S Sulaiman

    2008-12-01

    Full Text Available "nBackground: Bifenthrin and Acorus calamus Linn extract were evaluated against dengue vectors in the laboratory."nMethods: Both Bifenthrin and Acorus calamus Linn crude hexane extract were bioassayed against the adults and larval stages of dengue vectors Aedes aegypti L. and Aedes albopictus(Skuse in the laboratory."nResults: The A. calamus crude hexane extract exhibited a larvicidal activity against 4th-instar Ae. aegypti larvae with LC50 and LC90 values of 0.4418 and 11.3935 ppm respectively. The plant crude extract exhibited against Ae. albopictus larvae with a higher LC50 and LC90 values of 21.2555 ppm and 36.1061 ppm, respectively. There was a significant difference on the effect of A. calamus extract on both Aedes spp. Larvae (P< 0.05. However, bifenthrin showed a significant difference on larvicidal effect to that of A. calamus hexane extract on both Aedes spp (P< 0.05. In testing the adulticidal activity, this plant extract exhibited the LC50 and LC90 values of 17.4075 and 252.9458 ppm against Ae .aegypti and a higher LC50 and LC90 values of 43.9952 and 446.1365 ppm respectively on Ae. albopictus. There was no significant difference on the effect of A. calamus extract on both Aedes spp adults (P> 0.05."nConclusion: Bifenthrin however showed a significant difference on both Aedes spp adults (P< 0.05. With the wide availability of A. calamus in Malaysia, it could be utilized for controlling dengue vectors. "n 

  12. Peridomestic Aedes malayensis and Aedes albopictus are capable vectors of arboviruses in cities.

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    Ian H Mendenhall

    2017-06-01

    Full Text Available Dengue and chikungunya are global re-emerging mosquito-borne diseases. In Singapore, sustained vector control coupled with household improvements reduced domestic mosquito populations for the past 45 years, particularly the primary vector Aedes aegypti. However, while disease incidence was low for the first 30 years following vector control implementation, outbreaks have re-emerged in the past 15 years. Epidemiological observations point to the importance of peridomestic infection in areas not targeted by control programs. We investigated the role of vectors in peri-domestic areas.We carried out entomological surveys to identify the Aedes species present in vegetated sites in highly populated areas and determine whether mosquitoes were present in open-air areas frequented by people. We compared vector competence of Aedes albopictus and Aedes malayensis with Ae. aegypti after oral infection with sympatric dengue serotype 2 and chikungunya viruses. Mosquito saliva was tested for the presence of infectious virus particles as a surrogate for transmission following oral infection.We identified Aedes albopictus and Aedes malayensis throughout Singapore and quantified their presence in forested and opened grassy areas. Both Ae. albopictus and Ae. malayensis can occupy sylvatic niches and were highly susceptible to both arboviruses. A majority of saliva of infected Ae. malayensis contained infectious particles for both viruses.Our study reveals the prevalence of competent vectors in peri-domestic areas, including Ae. malayensis for which we established the vector status. Epidemics can be driven by infection foci, which are epidemiologically enhanced in the context of low herd immunity, selective pressure on arbovirus transmission and the presence of infectious asymptomatic persons, all these conditions being present in Singapore. Learning from Singapore's vector control success that reduced domestic vector populations, but has not sustainably reduced

  13. Peridomestic Aedes malayensis and Aedes albopictus are capable vectors of arboviruses in cities.

    Science.gov (United States)

    Mendenhall, Ian H; Manuel, Menchie; Moorthy, Mahesh; Lee, Theodore T M; Low, Dolyce H W; Missé, Dorothée; Gubler, Duane J; Ellis, Brett R; Ooi, Eng Eong; Pompon, Julien

    2017-06-01

    Dengue and chikungunya are global re-emerging mosquito-borne diseases. In Singapore, sustained vector control coupled with household improvements reduced domestic mosquito populations for the past 45 years, particularly the primary vector Aedes aegypti. However, while disease incidence was low for the first 30 years following vector control implementation, outbreaks have re-emerged in the past 15 years. Epidemiological observations point to the importance of peridomestic infection in areas not targeted by control programs. We investigated the role of vectors in peri-domestic areas. We carried out entomological surveys to identify the Aedes species present in vegetated sites in highly populated areas and determine whether mosquitoes were present in open-air areas frequented by people. We compared vector competence of Aedes albopictus and Aedes malayensis with Ae. aegypti after oral infection with sympatric dengue serotype 2 and chikungunya viruses. Mosquito saliva was tested for the presence of infectious virus particles as a surrogate for transmission following oral infection. We identified Aedes albopictus and Aedes malayensis throughout Singapore and quantified their presence in forested and opened grassy areas. Both Ae. albopictus and Ae. malayensis can occupy sylvatic niches and were highly susceptible to both arboviruses. A majority of saliva of infected Ae. malayensis contained infectious particles for both viruses. Our study reveals the prevalence of competent vectors in peri-domestic areas, including Ae. malayensis for which we established the vector status. Epidemics can be driven by infection foci, which are epidemiologically enhanced in the context of low herd immunity, selective pressure on arbovirus transmission and the presence of infectious asymptomatic persons, all these conditions being present in Singapore. Learning from Singapore's vector control success that reduced domestic vector populations, but has not sustainably reduced arboviral incidence

  14. Modified technique of Wolbachia removal from Malaysian Aedes albopictus

    Institute of Scientific and Technical Information of China (English)

    Sylvia; Joanne; Indra; Vythilingam; Nava; Yugavathy; Jonathan; Inbaraj; Doss

    2014-01-01

    Objective:To develop an artificial and modified Wolbaehia removal technique using tetracycline from naturally Wolbachia infected Aedes albopictus(Ae.albopictus)so as to be able to produce generations of Wolbaehia free offsprings.Methods:In this study,seven different tetracycline treatment methods were conducted to obtain the best removal method.Four methods focused on larvae tetracycline treatment,one method on both larvae and adult tetracycline treatment and the last two methods on adult mosquito sucrose treatment.Results:All larval tetracycline treatments resulted in either high larvae mortality,sterile F_o adult mosquitoes or unsuccessful Wolbaehia removal.Treatment of both larvae and adults resulted in reduced larvae mortality,successful Wolbachia removal but slow mosquito fecundity.As for the adult treatment,1.0 mg/mL as previously published was not aisle to completely remove Wolbaehia in F,generation whereas 1.25 mg/mL successfully removed Wolbachia from F,and F,mosquitoes in 2 weeks.Conclusions:This method is different from the previously published methods as it provides an improved Watbachia removal technique from Ae.albopictus with high egg hatchability.low larvae mortality,increased fecundity and better Wolbaehia removal rate.

  15. Modified technique of Wolbachia removal from Malaysian Aedes albopictus

    Institute of Scientific and Technical Information of China (English)

    Sylvia Joanne; Indra Vythilingam; Nava Yugavathy; Jonathan Inbaraj Doss

    2014-01-01

    Objective: To develop an artificial and modified Wolbachia removal technique using tetracycline from naturally Wolbachia infected Aedes albopictus (Ae. albopictus) so as to be able to produce generations of Wolbachia free offsprings.Methods:In this study, seven different tetracycline treatment methods were conducted to obtain the best removal method. Four methods focused on larvae tetracycline treatment, one method on both larvae and adult tetracycline treatment and the last two methods on adult mosquito sucrose treatment.Results:All larval tetracycline treatments resulted in either high larvae mortality, sterile F0 adult mosquitoes or unsuccessful Wolbachia removal. Treatment of both larvae and adults resulted in reduced larvae mortality, successful Wolbachia removal but slow mosquito fecundity. As for the adult treatment, 1.0 mg/mL as previously published was not able to completely remove Wolbachia in F1 generation whereas 1.25 mg/mL successfully removed Wolbachia from F1 and F2 mosquitoes in 2 weeks. Conclusions: This method is different from the previously published methods as it provides an improved Wolbachia removal technique from Ae. albopictus with high egg hatchability, low larvae mortality, increased fecundity and better Wolbachia removal rate.

  16. Primeiro registro de Aedes (Stegomyia albopictus no Estado do Ceará, Brasil First report of Aedes (Stegomyia albopictus in the state of Ceará, Brazil

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    Víctor Emanuel Pessoa Martins

    2006-08-01

    Full Text Available Pela primeira vez é registrada a ocorrência de Aedes (Stegomyia albopictus em área urbana da cidade de Fortaleza, no Estado do Ceará, Brasil. De janeiro a julho de 2005 foram utilizadas ovitrampas para a coleta de ovos de Aedes spp., os quais foram mantidos em laboratório para desenvolvimento até a fase adulta. Os mosquitos resultantes foram identificados e submetidos a testes para o isolamento dos vírus da dengue. Foram identificados 13 espécimes de Aedes albopictus, todos fêmeas. Não foi isolado vírus da dengue em nenhum dos pools de mosquitos. Apesar de o Aedes albopictus não ter sido incriminado por surtos de dengue no Brasil, não se pode descartar a possibilidade da transmissão dos vírus da dengue por tais mosquitos.For the first time, the occurrence of Aedes (Stegomyia albopictus in an urban area of the city of Fortaleza, Northeastern, Brazil, is reported. From January to July 2005, ovitraps were used to collect eggs from Aedes spp., which were kept under laboratory conditions to develop into the adult phase. The resultant mosquitoes were identified and subjected to dengue virus isolation tests. Thirteen specimens of Aedes albopictus, all females, were identified. No dengue virus was isolated in any of the mosquito pools. Even though Aedes albopictus has not been incriminated in Brazilian dengue outbreaks, the possibility of dengue virus transmission by these mosquitoes cannot be dismissed.

  17. Larvicidal Activity of Citrus Limonoids against Aedes albopictus Larvae

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    Hazrat Bilal

    2012-12-01

    Full Text Available Background: Development of insecticide resistance occurred due to the continuous and misuse of synthetic insecticidestherefore, the recent study was conducted to explore eco-friendly plant extracts that have some potential to suppressmosquito larval population.Methods: WHO recommended mosquito larval bioassay method for insecticide was used while for the analysis of citrus oils for limonin and nomilin content HPLC was used.Results: Among the two citrus cultivars tested as larvicide against Aedes albopictus, valencia late (Citrus sinensis wasthe best in terms of LC50 (297 ppm, % mortality (97% and LT50 (18.49 hours then freutrall early (Citrus reticulatewith LC50 (377.4 ppm, % mortality (88% and LT50 (31 hours, While nomilin gave lowest LC50 (121.04 ppm than limonin (382.22 ppm after 72 hours of exposure. Valencia late also had more limonin and nomilin (377 μg/ml and 21.19 μg/ml than freutrall early (5.29 μg/ml and 3.89 μg/ml respectively.Conclusion: Valencia late showed best results in term of LC50, LT50 and percentage mortality against Aedes albopictus as it has more amount of nomilin then freutrall early, however further evaluation in the field conditions is required.

  18. Larvicidal Activity of Citrus Limonoids against Aedes Albopictus Larvae

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    Hazrat Bilal

    2012-12-01

    Full Text Available Background: Development of insecticide resistance occurred due to the continuous and misuse of synthetic insecti­cides therefore, the recent study was conducted to explore eco-friendly plant extracts that have some potential to sup­press mosquito larval population.Methods: World Health Organization recommended mosquito larval bioassay method for insecticide was used while for the analysis of citrus oils for limonin and nomilin content HPLC was used.Results: Among the two citrus cultivars tested as larvicide against Aedes albopictus, valencia late (Citrus sinensis was the best in terms of LC50 (297 ppm, % mortality (97% and LT50 (18.49 hours then freutrall early (Citrus reticulate with LC50 (377.4 ppm, % mortality (88% and LT50 (31 hours, While nomilin gave lowest LC­­50 (121.04 ppm than limonin (382.22 ppm after 72 hours of exposure. Valencia late also had more limonin and nomilin (377 µg/ml and 21.19 µg/ml than freutrall early (5.29 µg/ml and 3.89 µg/ml respectively.Conclusion: Valencia late showed best results in term of LC50, LT50 and percentage mortality against Aedes albopictus as it has more amount of nomilin then freutrall early, however further evaluation in the field conditions is required

  19. A new tent trap for monitoring the daily activity of Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Casas Martínez, Mauricio; Orozco Bonilla, Arnoldo; Muñoz Reyes, Miguel; Ulloa García, Armando; Bond, J Guillermo; Valle Mora, Javier; Weber, Manuel; Rojas, Julio C

    2013-12-01

    In this study, we designed a new tent trap; the BioDiVector (BDV) tent trap, consisting of two rectangular tents that use human bait without endangering the technical personnel. The daily activity pattern of Aedes aegypti and Aedes albopictus in intra, peri, and extradomiciliary sites was studied in an endemic area of dengue in southern Mexico by using the BDV tent trap. Totals of 3,128 individuals of Ae. aegypti and 833 Ae. albopictus were captured. More Ae. aegypti males than females were caught, while the opposite was true with Ae. albopictus. The activity of both mosquito species was affected by the interaction between the collection site and time of day. In general, more individuals of both mosquito species were captured at the extradomicillary sites than at the peri and intradomicillary sites. Mosquitoes showed two peaks of activity, one in the morning and the other in the afternoon, but in general this only occurred at the extradomicillary sites, whereas no peak of activity was observed at the intra and peridomicillary sites. Overall, Ae. aegypti had a higher indirect biting rate than Ae. albopictus. Finally, due to its efficiency, simplicity, and low cost, we suggest the use of this innovative tool for entomological surveillance, bionomics and vector incrimination studies in geographical areas where dengue and other arboviruses are present.

  20. Male accessory gland substances from Aedes albopictus affect the locomotor activity of Aedes aegypti females

    Science.gov (United States)

    Lima-Camara, Tamara Nunes; Codeço, Claudia Torres; Honório, Nildimar Alves; Bruno, Rafaela Vieira; Peixoto, Alexandre Afranio; Lounibos, Leon Philip

    2013-01-01

    Dengue is one of the world’s most important mosquito-borne diseases and is usually transmitted by one of two vector species: Aedes aegypti or Aedes albopictus . These two diurnal mosquitoes are frequently found coexisting in similar habitats, enabling interactions between adults, such as cross-mating. The objective of this study was to assess cross-mating between Ae. aegypti females and Ae. albopictus males under artificial conditions and evaluate the locomotor activity of Ae. aegypti virgin females injected with male accessory gland (MAG) homogenates to infer the physiological and behavioural responses to interspecific mating. After seven days of exposure, 3.3-16% of Ae. aegypti females mated with Ae. albopictus males. Virgin Ae. aegypti females injected with conspecific and heterospecific MAGs showed a general decrease in locomotor activity compared to controls and were refractory to mating with conspecific males. The reduction in diurnal locomotor activity induced by injections of conspecific or heterospecific MAGs is consistent with regulation of female reproductive activities by male substances, which are capable of sterilising female Ae. aegypti through satyrisation by Ae. albopictus . PMID:24473799

  1. EKSISTENSI DAN SEBARAN NYAMUK AEDES AEGYPTI DAN AEDES ALBOPICTUS DI KAMPUS UNIVERSITAS HASANUDDIN MAKASSAR

    Directory of Open Access Journals (Sweden)

    Yosefina Dota T

    2015-03-01

    Full Text Available Penelitian yang bertujuan untuk mengetahui eksistensi dan sebaran nyamuk Aedes aegypti dan Aedes albopictus telah dilakukan di Kampus Universitas Hasanuddin, Kec. Tamalanrea, Makassar. Penelitian bersifat eksploratif dengan melakukan sampling terhadap lima lokasi yaitu : a Fak. Peternakan (Utara, b Fak. Hukum (Timur, c Pusat Kegiatan Penelitian/PKP (Selatan, d Workshop/Dekat Pondokan mahasiswa (Barat dan e Fak. MIPA (Tengah. Sampling nyamuk menggunakan metode ovitrap (menggunakan attraktan Eluisine Indica L. dan survei terhadap berbagai tempat penampungan air. Sampel telur dan larva nyamuk yang diperoleh disimpan dalam microtube berisi alkohol 70% kemudian diidentifikasi berdasarkan Rueda (2004. Hasil penelitian menunjukkan bahwa Nyamuk Ae. aegypti dan Ae. albopictus ditemukan hidup dan berkembang biak di kampus Universitas Hasanuddin, Makassar. Eksistensi dan sebaran kedua jenis nyamuk tersebut dipengaruhi oleh faktor adanya manusia/masyarakat kampus yang beraktivitas baik di dalam ruangan (indoor maupun di luar ruangan (outdoor, adanya berbagai tempat penampungan air baik buatan (bak mandi, ember maupun barang bekas (botol/kaleng bekas, tempurung kelapa, vegetasi/tanaman dan berbagai macam hewan yang berada di sekitaran kampus. Hasil penelitian dalam ruangan (indoor menunjukkan bahwa nyamuk Ae. aegypti lebih banyak ditemukan hidup di dalam ruangan gedung PKP sedangkan Ae.albopictus lebih banyak di Fak. Hukum. Hasil penelitian di luar ruangan (outdoor menunjukkan bahwa nyamuk Ae. aegypti lebih banyak ditemukan hidup di area Workshop sedangkan Ae.albopictus lebih banyak di area PKP.

  2. Diversidade de criadouros e tipos de imóveis freqüentados por Aedes albopictus e Aedes aegypti Diversity of oviposition containers and buildings where Aedes albopictus and Aedes aegypti can be found

    Directory of Open Access Journals (Sweden)

    Vanderlei C da Silva

    2006-12-01

    Full Text Available OBJETIVOS: Verificar a diversidade de criadouros e tipos de imóveis freqüentados por fêmeas de Aedes albopictus e Aedes aegypti. MÉTODOS: O estudo foi realizado nos anos de 2002 e 2003 no bairro de Campo Grande, Rio de Janeiro, RJ. Realizou-se pesquisa larvária em diferentes tipos de imóveis. As larvas encontradas foram identificadas em laboratório. A freqüência de larvas dessas duas espécies foi computada nos diversos criadouros disponíveis. Foram calculados os índices de infestação predial e de Breteau, as diferenças foram testadas pelo qui-quadrado. RESULTADOS: Os tipos de imóveis positivos para os aedinos foram: residências (83,9% do total; igrejas, escolas, clubes (6,8%; terrenos baldios (6,4%; e comércios (2,8%. Das 9.153 larvas, 12,0% eram de Aedes albopictus e 88,0% de Aedes aegypti. Para aquela espécie, os recipientes onde foram mais encontradas foram ralos (25,4%, latas, garrafas, vasilhames (23,9% e vasos com plantas (16,2%. Aedes aegypti mostrou-se mais freqüente nos criadouros que Aedes albopictus (chi2=145,067, pOBJECTIVE: To assess the diversity of oviposition containers and buildings where females of Aedes albopictus and Aedes aegypti can be found. METHODS: A study was carried out in the city of Rio de Janeiro, Southern Brazil, between 2002 and 2003. Larvae in different types of buildings were investigated, and immature forms found were then sent to the laboratory for identification. The larval frequency for both mosquitoes was estimated in the oviposition containers available. The Breteau index and the building infestation index were calculated and differences were tested using the Chi-square test. RESULTS: The types of buildings that were positive for Aedes albopictus and Aedes aegypti were: dwellings (83.9%; churches, schools, clubs (6.8%; vacant land (6.4%; and businesses (2.8%. Of 9,153 larvae collected, 12.0% were Aedes albopictus and 88.0% were Aedes aegypti. Aedes albopictus were mostly found in drains

  3. Aedes albopictus in Lebanon, a potential risk of arboviruses outbreak

    Science.gov (United States)

    2012-01-01

    Background The mosquito Aedes albopictus is undergoing a worldwide expansion with potential consequences on transmission of various arboviruses. This species has been first detected in Lebanon in 2003. Methods We performed a phylogenetic study of Lebanese specimens and assessed their host preference by detecting human, cat, dog and chicken immunoglobulins in mosquito blood-meals. Their capacity to transmit arboviruses was investigated by providing infectious blood-meals using an artificial feeding system followed by detection of viral particles in mosquito saliva. Results Our results suggest that Lebanese strains are part of the recent wave of Ae. albopictus expansion and are related to some European, African and North American strains. They exhibited a host preference towards humans and an important capacity to transmit arboviruses. Indeed, we showed that Ae. albopictus was able to transmit chikungunya (CHIKV), dengue (DENV) and West-Nile (WNV) viruses. At day 10 after an infectious blood-meal at a titer of 108 MID50/ml, 30% of mosquitoes delivered an average of 515 ± 781 viral particles of CHIKV in saliva collected using a forced salivation technique and 55% with an average of 245 ± 304 viral particles when infected with WNV. Whereas DENV was not found in saliva at day 10 post-infection (pi), an average of 174 ± 455 viral particles was detected in 38.1% of mosquitoes tested at day 21 after an infectious blood-meal at a higher titer of 109 MID50/ml. Conclusion These observations suggest that Ae. albopictus around Beirut is a potential vector of the three tested arboviruses. PMID:23151056

  4. Insecticide susceptibility of Aedes aegypti and Aedes albopictus in Central Africa

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    Nwane Philippe

    2011-05-01

    Full Text Available Abstract Background Aedes aegypti (Linnaeus, 1762 and Aedes albopictus (Skuse, 1894 are the main vectors of dengue (DENV and chikungunya (CHIKV viruses worldwide. As there is still no vaccine or specific treatment for DENV and CHIKV, vector control remains the cornerstone of prevention and outbreak control. Unfortunately, vector control programs are facing operational challenges with mosquitoes becoming resistant to commonly used insecticides in several areas through the world. Throughout Central Africa no recent data are available susceptible/resistant status of either vector species since the introduction/arrival of Ae. albopictus in this area. We therefore studied the level of resistance of these two major vectors to insecticides commonly used in Africa for mosquito control. Results Aedes aegypti and Ae. albopictus were sampled in six urban localities of Cameroon (Garoua, Bertoua, Yaoundé, Bafia, Buea and Gabon (Libreville. Larval bioassays, carried out to determine the lethal concentrations (LC50 and LC95 and resistance ratios (RR50 and RR95 suggested that both vector species were susceptible to Bti (Bacillus thuringiensis var israeliensis and temephos. Bioassays were also performed on adults using WHO diagnostic test kits to assess phenotypic resistance to deltamethrin, DDT, fenitrothion and propoxur. These experiments showed that one population of Ae. aegypti (Libreville and two populations of Ae. albopictus (Buea and Yaoundé were resistant to DDT (mortality 36% to 71%. Resistance to deltamethrin was also suspected in Ae. albopictus from Yaoundé (83% mortality. All other field mosquito populations were susceptible to deltamethrin, DDT, fenitrothion and propoxur. No increase in the knockdown times (Kdt50 and Kdt95 was noted in the Yaoundé resistant population compared to other Ae. albopictus populations, suggesting the possible involvement of metabolic resistance to deltamethrin and DDT. Conclusion In view of the recent increase in

  5. Characterization of Tolypocladium cylindrosporum (Hypocreales: Ophiocordycipitacea) and its impact against Aedes aegypti and Aedes albopictus eggs at low temperature

    Science.gov (United States)

    We examined the growth characteristics of Tolypocladium cylindrosporum IBT 41712 and its potential to infect eggs of Aedes aegypti Linnaeus and Aedes albopictus (Skuse) mosquitoes at low temperature (15 deg C). When grown on sabouraud dextrose agar supplemented with yeast extract, IBT 41712 formed w...

  6. Updated Distribution of Aedes albopictus in Oklahoma, and Implications in Arbovirus Transmission.

    Science.gov (United States)

    Noden, Bruce H; Coburn, Lisa; Wright, Russell; Bradley, Kristy

    2015-03-01

    A series of statewide surveys were conducted in Oklahoma in the summers between 1991 and 2004 to identify the distribution of Aedes albopictus. Adult mosquitoes were identified in 63 counties, bringing the currently known distribution of Ae. albopictus in the state to 69 of 77 counties. The widespread presence of Ae. albopictus in Oklahoma has important current and future public and veterinary health implications for surveillance and control efforts.

  7. Evaluation of different formulations of IGRs against Aedes albopictus and Culex quinquefasciatus (Diptera: Culicidae)

    OpenAIRE

    Gul Zamin Khan; Inamullah Khan; Imtiaz Ali Khan; Alamzeb; Muhammad Salman; Kalim Ullah

    2016-01-01

    Objective: To test the relative efficacy of pyriproxyfen and methoprene on mortality, deformity, inhibition and emergence to adult stages of Culex quinquefasciatus and Aedes albopictus. Methods: Serial dilutions (0.01–0.05 mg/L) of methoprene, pyriproxyfen 0.5 water dispersible granules (WDG) and pyriproxyfen 1.0 WDG were used to assess mortality and inhibition of 3rd instar larvae of Aedes albopictus and Culex quinquefasciatus. Each concentration and control was replicated four times in c...

  8. Fipronil as a larvicide against container-inhabiting mosquito, Aedes albopictus.

    Science.gov (United States)

    In the laboratory, Fipronil was tested against laboratory-reared and field-collected early 4th instar Aedes albopictus larvae. The insecticide was also bioassayed for activity against natural field populations of Ae. albopictus inhabiting one-liter capacity stone-made containers in a cemetery, St. A...

  9. Low oral receptivity for dengue type 2 viruses of Aedes albopictus from Southeast Asia compared with that of Aedes aegypti.

    Science.gov (United States)

    Vazeille, Marie; Rosen, Leon; Mousson, Laurence; Failloux, Anna-Bella

    2003-02-01

    Dengue hemorrhagic fever has been a major health problem in Asia since the 1950s. During this period, the former principal vector of dengue viruses in Asia, Aedes albopictus, was replaced by Aedes aegypti in most major cities of the area. Ae. aegypti is now considered the main vector of dengue viruses in Asia. Surprisingly, however, this mosquito has been described as having a relatively low oral receptivity for dengue viruses compared with Ae. albopictus. In the present study, we compared the relative oral receptivities of Ae. aegypti and Ae. albopictus collected in southeast Asia from both sympatric and allopatric breeding sites. In all instances, the oral receptivity of Ae. aegypti to the dengue type 2 virus used was significantly higher than that of Ae. albopictus. We also compared the relative oral receptivity of Ae. aegypti and Ae. albopictus for two other low-passage strains of dengue 2. In all instances, Ae. aegypti was significantly more receptive than Ae. albopictus. It should be noted, however, that the difference was found only for Ae. albopictus recently collected from the field (Ta Promh strain, Cambodia, 2001) and not for an Ae. albopictus strain that had been colonized for many years (Oahu strain, Hawaii, 1971). We also observed a significant increase in the infection rate of Ae. albopictus of the Ta Promh strain with increasing generations in the laboratory. These observations demonstrate the importance of considering the colonization history of mosquitoes when assessing their susceptibility to infection with dengue viruses and, perhaps, other arboviruses.

  10. Aedes albopictus et Aedes aegypti à l'île de La Réunion

    OpenAIRE

    Salvan, M; Mouchet,Jean

    1994-01-01

    #Aedes albopictus$ et #Aedes aegypti$ (forme #typicus$) cohabitent à l'île de la Réunion. La première espèce, vecteur probable de la dengue, très anthropophile, occupe une aire de distribution beaucoup plus grande que la seconde et se développe dans les gîtes domestiques aussi bien que sauvages. La seconde ne pique pas l'homme et ses gîtes sont toujours sauvages : elle y est toujours associée à la première mais en faible proportion. La forme #typicus$ d'#Aedes aegypti$ étant généralement anth...

  11. Prevalence of Aedes aegypti Linnaeus and Aedes albopictus Skuse in Koderma, Jharkhand.

    Science.gov (United States)

    Singh, R K; Dhiman, R C; Dua, V K

    2011-09-01

    Entomological survey was carried out in different localities of Koderma district of Jharkhand with a view to study the prevalence, distribution and stratification of areas for Aedes mosquito species. A total of 233 houses were covered during house to house larval and adult survey. Aedes breeding could be detected in 157 houses. In all, a total of 942 domestic water containers were searched, out of which 461 were found positive. The overall house index(HI) container index(CI) breteau index(B1) and pupal index(PI) were 67.38%, 48.94%, 197.85% and 79.4%, respectively. The survey revealed that Aedes aegypti Linnaeus and Aedes albopictus Skuse are well established in Koderma with most of the areas showing high adult and larval indices. The preventive strategy needs to be directed towards minimizing the breeding potential of Aedes and water management practice by individuals along with implementation of urban bye-laws as well as IEC activities to contain Aedes breeding in future.

  12. Characterising the spatial dynamics of sympatric Aedes aegypti and Aedes albopictus populations in the Philippines

    Directory of Open Access Journals (Sweden)

    Jennifer Duncombe

    2013-11-01

    Full Text Available Entomological surveillance and control are essential to the management of dengue fever (DF. Hence, understanding the spatial and temporal patterns of DF vectors, Aedes (Stegomyia aegypti (L. and Ae. (Stegomyia albopictus (Skuse, is paramount. In the Philippines, resources are limited and entomological surveillance and control are generally commenced during epidemics, when transmission is difficult to control. Recent improvements in spatial epidemiological tools and methods offer opportunities to explore more efficient DF surveillance and control solutions: however, there are few examples in the literature from resource-poor settings. The objectives of this study were to: (i explore spatial patterns of Aedes populations and (ii predict areas of high and low vector density to inform DF control in San Jose village, Muntinlupa city, Philippines. Fortnightly, adult female Aedes mosquitoes were collected from 50 double-sticky ovitraps (SOs located in San Jose village for the period June-November 2011. Spatial clustering analysis was performed to identify high and low density clusters of Ae. aegypti and Ae. albopictus mosquitoes. Spatial autocorrelation was assessed by examination of semivariograms, and ordinary kriging was undertaken to create a smoothed surface of predicted vector density in the study area. Our results show that both Ae. aegypti and Ae. albopictus were present in San Jose village during the study period. However, one Aedes species was dominant in a given geographic area at a time, suggesting differing habitat preferences and interspecies competition between vectors. Density maps provide information to direct entomological control activities and advocate the development of geographically enhanced surveillance and control systems to improve DF management in the Philippines.

  13. Pyrethroid resistance in Aedes aegypti and Aedes albopictus: Important mosquito vectors of human diseases.

    Science.gov (United States)

    Smith, Letícia B; Kasai, Shinji; Scott, Jeffrey G

    2016-10-01

    Aedes aegypti and A. albopictus mosquitoes are vectors of important human disease viruses, including dengue, yellow fever, chikungunya and Zika. Pyrethroid insecticides are widely used to control adult Aedes mosquitoes, especially during disease outbreaks. Herein, we review the status of pyrethroid resistance in A. aegypti and A. albopictus, mechanisms of resistance, fitness costs associated with resistance alleles and provide suggestions for future research. The widespread use of pyrethroids has given rise to many populations with varying levels of resistance worldwide, albeit with substantial geographical variation. In adult A. aegypti and A. albopictus, resistance levels are generally lower in Asia, Africa and the USA, and higher in Latin America, although there are exceptions. Susceptible populations still exist in several areas of the world, particularly in Asia and South America. Resistance to pyrethroids in larvae is also geographically widespread. The two major mechanisms of pyrethroid resistance are increased detoxification due to P450-monooxygenases, and mutations in the voltage sensitive sodium channel (Vssc) gene. Several P450s have been putatively associated with insecticide resistance, but the specific P450s involved are not fully elucidated. Pyrethroid resistance can be due to single mutations or combinations of mutations in Vssc. The presence of multiple Vssc mutations can lead to extremely high levels of resistance. Suggestions for future research needs are presented. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Seasonal monitoring of Aedes albopictus: practical applications and outcomes

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    Stefano Gavaudan

    2014-06-01

    Full Text Available The introduction of the Asian tiger mosquito Aedes (Stegomya albopictus (Diptera: Culicidae into temperate regions poses serious concerns for the risk of the spreading of arboviral epidemics, as confirmed by the Chikungunya fever outbreak in Italy. This article describes the implementation and the results of a strategy for the pest management implemented over 4 years in Pesaro (a city in the Marche region, Italy. The strategy used 60 integrated wide‑sized ovitraps for monitoring purposes. Twenty-day larvicide-based treatment cycles were implemented for the manholes of the urban area and also the inhabitants were involved in pest control relating to their own properties. It was observed that the weekly median of eggs laid decreased consistently from 2008 to 2011, indicating the good performance of the vector control and a reduction in the related epidemics risk.

  15. Modelling the Dynamics of an Aedes albopictus Population

    CERN Document Server

    Basuki, Thomas Anung; Barbuti, Roberto; Maggiolo-Schettini, Andrea; Milazzo, Paolo; Rossi, Elisabetta; 10.4204/EPTCS.33.2

    2010-01-01

    We present a methodology for modelling population dynamics with formal means of computer science. This allows unambiguous description of systems and application of analysis tools such as simulators and model checkers. In particular, the dynamics of a population of Aedes albopictus (a species of mosquito) and its modelling with the Stochastic Calculus of Looping Sequences (Stochastic CLS) are considered. The use of Stochastic CLS to model population dynamics requires an extension which allows environmental events (such as changes in the temperature and rainfalls) to be taken into account. A simulator for the constructed model is developed via translation into the specification language Maude, and used to compare the dynamics obtained from the model with real data.

  16. Modelling the Dynamics of an Aedes albopictus Population

    Directory of Open Access Journals (Sweden)

    Thomas Anung Basuki

    2010-08-01

    Full Text Available We present a methodology for modelling population dynamics with formal means of computer science. This allows unambiguous description of systems and application of analysis tools such as simulators and model checkers. In particular, the dynamics of a population of Aedes albopictus (a species of mosquito and its modelling with the Stochastic Calculus of Looping Sequences (Stochastic CLS are considered. The use of Stochastic CLS to model population dynamics requires an extension which allows environmental events (such as changes in the temperature and rainfalls to be taken into account. A simulator for the constructed model is developed via translation into the specification language Maude, and used to compare the dynamics obtained from the model with real data.

  17. Chikungunya virus transmission between Aedes albopictus and laboratory mice.

    Science.gov (United States)

    Hugo, Leon E; Prow, Natalie A; Tang, Bing; Devine, Greg; Suhrbier, Andreas

    2016-10-19

    Chikungunya virus (CHIKV) is a mosquito-borne alphavirus associated with epidemics of acute and chronic arthritic disease in humans. Aedes albopictus has emerged as an important new natural vector for CHIKV transmission; however, mouse models for studying transmission have not been developed. Aedes albopictus mosquitoes were infected with CHIKV via membrane feeding and by using infected adult wild-type C57BL/6 mice. Paraffin sections of infected mosquitoes were analysed by immunofluorescent antibody staining using an anti-CHIKV antibody. CHIKV-infected mosquitoes were used to infect adult C57BL/6 and interferon response factor 3 and 7 deficient (IRF3/7(-/-)) mice. Feeding mosquitoes on blood meals with CHIKV titres > 5 log10CCID50/ml, either by membrane feeding or feeding on infected mice, resulted in  ≥ 50 % of mosquitoes becoming infected. However, CHIKV titres in blood meals  ≥ 7 log10CCID50/ml were required before salivary glands showed significant levels of immunofluorescent staining with an anti-CHIKV antibody. Mosquitoes fed on blood meals of 7.5 (but not 5.9) log10CCID50/ml were able efficiently to transmit virus to adult C57BL/6 and IRF3/7(-/-) mice, with the latter mice showing overt signs of arthritis post-infection. The results provide a simple in vivo model for studying transmission of CHIKV from mosquitoes to mammals and also argue against a resistance barrier to CHIKV infection in adult mice.

  18. Discriminable roles of Aedes aegypti and Aedes albopictus in establishment of dengue outbreaks in Taiwan.

    Science.gov (United States)

    Yang, Chao-Fu; Hou, Jion-Nun; Chen, Tien-Huang; Chen, Wei-June

    2014-02-01

    Aedes aegypti and Aedes albopictus were reported to be significant as vectors of dengue fever. In Taiwan, the latter is distributed throughout the island while the former appears only south of the Tropic of Cancer; i.e., 23.5°N. In the past decade, there were five outbreaks with over 1000 cases of dengue fever in Taiwan. Without exception, these outbreaks all occurred in the south where the two Aedes mosquitoes are sympartic. According to the Center for Disease Control of Taiwan, imported cases are thought to provide the seeds of dengue outbreaks every year. Mostly, the number of imported cases is greater in northern island, probably due to a larger population of travelers and imported workers from endemic countries. Looking at the example in 2002, northern, central, and southern parts of Taiwan reported 28, 11, and 13 imported cases, respectively. However, 54, 21, and 5309 total cases were confirmed in the corresponding regions over the entire year, indicating a significant skew of case distributions. A hypothesis is thus inspired that the existence of Ae. aegypti is a prerequisite to initiate a dengue outbreak, while participation of Ae. albopictus expands or maintains the scale until the de novo herd immunity reaches high level.

  19. Wolbachia strain wPip yields a pattern of cytoplasmic incompatibility enhancing a Wolbachia-based suppression strategy against the disease vector Aedes albopictus

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    Calvitti Maurizio

    2012-11-01

    Full Text Available Abstract Background Cytoplasmic incompatibility (CI is induced in nature by Wolbachia bacteria, resulting in conditional male sterility. Previous research demonstrated that the two Wolbachia strains (wAlbA and wAlbB that naturally co-infect the disease vector mosquito Aedes albopictus (Asian tiger mosquito can be replaced with the wPip Wolbachia strain from Culex pipiens. Since Wolbachia-based vector control strategies depend upon the strength and consistency of CI, a greater understanding is needed on the CI relationships between wPip, wAlbA and wAlbB Wolbachia in Ae. albopictus. Methods This work consisted of a collaborative series of crosses carried out in Italy and in US to study the CI relationships between the “wPip” infected Ae. albopictus strain (ARwP and the superinfected SR strain. The Ae. albopictus strains used in Italian tests are the wPip infected ARwP strain (ARwPIT, the superinfected SR strain and the aposymbiotic AR strain. To understand the observed pattern of CI, crossing experiments carried out in USA focused on the study of the CI relationships between ARwP (ARwPUS and artificially-generated single infected lines, in specific HTA and HTB, harbouring only wAlbA and wAlbB Wolbachia respectively. Results The paper reports an unusual pattern of CI observed in crossing experiments between ARwP and SR lines. Specifically, ARwP males are able to induce full sterility in wild type females throughout most of their lifetime, while crosses between SR males and ARwP females become partially fertile with male aging. We demonstrated that the observed decrease in CI penetrance with SR male age, is related to the previously described decrease in Wolbachia density, in particular of the wAlbA strain, occurring in aged superinfected males. Conclusions The results here reported support the use of the ARwP Ae. albopictus line as source of “ready-made sterile males”, as an alternative to gamma radiation sterilized males, for autocidal

  20. Oviposition preferences of dengue vectors; Aedes aegypti and Aedes albopictus in Sri Lanka under laboratory settings.

    Science.gov (United States)

    Gunathilaka, N; Ranathunge, T; Udayanga, L; Wijegunawardena, A; Abeyewickreme, W

    2017-09-27

    Investigations on oviposition behaviour of dengue vectors are critical for effective controlling of vector breeding. Therefore, the aim of the present study was to determine the oviposition behaviour of dengue vectors, Aedes aegypti and Aedes albopictus in Sri Lanka. Batches of 1000 adult mosquitoes (1 : 1, male: female ratio) housed in rearing cages were used for each experimental setup from Ae. aegypti and Ae. albopictus. Oviposition responses with respect to the size of the ovitrap, colours of the ovitrap, water source, sodium chloride (NaCl) concentration and presence/absence of larvae were evaluated by enumerating the number of eggs laid in the ovitraps. The analysis of variance and cluster analysis were used to investigate the significance in the variations among oviposition. The number of eggs laid by both species were improved with the increasing size of ovitraps. Ae. albopictus indicated the highest mean number of eggs in 0.2% of NaCl than in the ovitraps filled with distilled water. However, the egg laying preference was reduced with increasing salinity in both species. Drain water with low dissolved oxygen (DO) level (0.43 ± 0.12 mg l-1) was the preferred water source for both species, while a significantly high oviposition rate was observed in ovitraps with larvae. Black colour ovitraps attracted the majority of gravid females, while white was least preferred. There were no significant variations among oviposition behaviours of Ae. albopictus and Ae. aegypti. The ability of these vectors to breed in waste water with low DO levels may lead them to attain wide dissemination in the natural environment, enhancing their potential threat to human life.

  1. Freqüência de larvas e pupas de Aedes aegypti e Aedes albopictus em armadilhas, Brasil Frequency of Aedes aegypti and Aedes albopictus larvae and pupae in traps, Brazil

    Directory of Open Access Journals (Sweden)

    Nildimar Alves Honório

    2001-08-01

    Full Text Available OBJETIVO: Avaliar a freqüência mensal de larvas e pupas de Ae. albopictus, Ae. aegypti e de outras espécies de mosquitos e verificar a influência de fatores ambientais dessas espécies em pneus. MÉTODOS: A pesquisa foi desenvolvida no município de Nova Iguaçu, Estado do Rio de Janeiro, Brasil. Efetuaram-se coletas mensais de formas imaturas, em quatro pneus, no período de novembro de 1997 a outubro de 1998. Os pneus foram numerados e dispostos em forma de pirâmide, um na base (pneu 1 e os três restantes (2, 3 e 4 inclinados sobre o primeiro. Os pneus 1 e 4 eram mais sombreados, e 2 e 3 eram expostos ao sol, já que não eram alcançados, como os demais, pela sombra de árvores e de um galinheiro próximos a esses pneus. Foram estudadas as variáveis: pluviosidade; temperatura ambiente; volume; pH da água; e condições de isolamento de água em pneus. RESULTADOS: Coletaram-se 10.310 larvas e 612 pupas. Ae. albopictus foi a espécie predominante tanto na fase larvar quanto na de pupa; Ae. aegypti e Ae. albopictus foram coletados em todos os meses, sendo mais freqüentes naqueles de maior pluviosidade. A temperatura, a pluviosidade e o volume de água apresentaram diferenças significativas, quando correlacionados ao número de larvas de Ae. aegypti. Não houve diferença significativa na freqüência de larvas quanto ao pH da água. Registrou-se maior número de larvas de Ae. albopictus em pneus mais sombreados. CONCLUSÕES: Ae. albopictus instala-se muito mais freqüentemente em pneus do que Ae. aegypti. Pneus descartados parecem representar importantes focos de manutenção de ambos os Aedes, durante todo o ano. Mesmo próximo uns ao outros, os pneus podem oferecer diferentes condições para a colonização desses mosquitos, de acordo com o volume d'água e a exposição ao sol.OBJECTIVE: To evaluate the monthly frequency of larvae and pupae of Aedes albopictus, Aedes aegypti and other mosquitoe species in tires, and the influence

  2. Evaluation of Sumithion L-40 against Aedes aegypti (L.) and Aedes albopictus Skuse.

    Science.gov (United States)

    Loke, S R; Sing, K W; Teoh, G N; Lee, H L

    2015-03-01

    Space spraying of chemical insecticides is still an important mean of controlling Aedes mosquitoes and dengue transmission. For this purpose, the bioefficacy of space-sprayed chemical insecticide should be evaluated from time to time. A simulation field trial was conducted outdoor in an open field and indoor in unoccupied flat units in Kuala Lumpur, to evaluate the adulticidal and larvicidal effects of Sumithion L-40, a ULV formulation of fenitrothion. A thermal fogger with a discharge rate of 240 ml/min was used to disperse Sumithion L-40 at 3 different dosages (350 ml/ha, 500 ml/ha, 750 ml/ha) against lab-bred larvae and adult female Aedes aegypti and Aedes albopictus. An average of more than 80% adult mortality was achieved for outdoor space spray, and 100% adult mortality for indoor space spray, in all tested dosages. Outdoor larvicidal effect was noted up to 14 days and 7 days at a dosage of 500 and 750 ml/ha for Ae. aegypti and Ae. albopictus, respectively. Indoor larvicidal effect was up to 21 days (500 ml/ha) and 14 days (750 ml/ha), respectively, after spraying with larval mortality > 50% against Ae. aegypti. This study concluded that the effective dosage of Sumithion L-40 thermally applied against adult Ae. aegypti and Ae. albopictus indoor and outdoor is 500 and 750 ml/ha. Based on these dosages, effective indoor spray volume is 0.4 - 0.6 ml/m³. Additional indoor and outdoor larvicidal effect will be observed at these application dosages, in addition to adult mortality.

  3. Seasonal abundance of Aedes albopictus in selected urban and suburban areas in Penang, Malaysia.

    Science.gov (United States)

    Rozilawati, H; Zairi, J; Adanan, C R

    2007-06-01

    Ovitrap surveillance was conducted in a selected urban area and suburban area, ie. Taman Permai Indah(TPI) and Kampung Pasir Gebu (KPG) in Penang for 14 months. It was found that Aedes albopictus was the most abundant Aedes species in both study areas, even though a small percentage of Aedes aegypti and Culex quinquefasciatus were found to breed simultaneously in the same ovitrap. This study indicated that the main dengue vector was Ae. albopictus. A strong correlation was found between rainfall and egg population in both of the study sites (r = 0.982 and r = 0.918).

  4. Aedes albopictus and Aedes japonicus - two invasive mosquito species with different temperature niches in Europe.

    Science.gov (United States)

    Cunze, Sarah; Koch, Lisa K; Kochmann, Judith; Klimpel, Sven

    2016-11-04

    Aedes albopictus and Ae. japonicus are two of the most widespread invasive mosquito species that have recently become established in western Europe. Both species are associated with the transmission of a number of serious diseases and are projected to continue their spread in Europe. In the present study, we modelled the habitat suitability for both species under current and future climatic conditions by means of an Ensemble forecasting approach. We additionally compared the modelled MAXENT niches of Ae. albopictus and Ae. japonicus regarding temperature and precipitation requirements. Both species were modelled to find suitable habitat conditions in distinct areas within Europe: Ae. albopictus within the Mediterranean regions in southern Europe, Ae. japonicus within the more temperate regions of central Europe. Only in few regions, suitable habitat conditions were projected to overlap for both species. Whereas Ae. albopictus is projected to be generally promoted by climate change in Europe, the area modelled to be climatically suitable for Ae. japonicus is projected to decrease under climate change. This projection of range reduction under climate change relies on the assumption that Ae. japonicus is not able to adapt to warmer climatic conditions. The modelled MAXENT temperature niches of Ae. japonicus were found to be narrower with an optimum at lower temperatures compared to the niches of Ae. albopictus. Species distribution models identifying areas with high habitat suitability can help improving monitoring programmes for invasive species currently in place. However, as mosquito species are known to be able to adapt to new environmental conditions within the invasion range quickly, niche evolution of invasive mosquito species should be closely followed upon in future studies.

  5. Spatial and temporal patterns of abundance of Aedes aegypti L. (Stegomyia aegypti) and Aedes albopictus (Skuse) [Stegomyia albopictus (Skuse)] in southern Florida.

    Science.gov (United States)

    Reiskind, M H; Lounibos, L P

    2013-12-01

    Invasion by mosquito vectors of disease may impact the distribution of resident mosquitoes, resulting in novel patterns of vectors and concomitant risk for disease. One example of such an impact is the invasion by Aedes albopictus (Skuse) [Stegomyia albopictus (Skuse)] (Diptera: Culicidae) of North America and this species' interaction with Aedes aegypti L. (Stegomyia aegypti L). We hypothesized that Ae. aegypti would be found in urban, coastal areas that experience hotter and drier conditions, whereas Ae. albopictus would be more commonly found in suburban and rural areas that are cooler and wetter. In addition, we hypothesized that Ae. aegypti would be more abundant early in the wet season, whereas Ae. albopictus would be more abundant later in the wet season. Urban areas were drier, hotter and contained more Ae. aegypti than suburban or rural areas. Aedes aegypti was relatively more abundant early in the wet season, whereas Ae. albopictus was more abundant in both the late wet season and the dry season. The spatial patterns of inter- and intraspecific encounters between these species were also described. The distribution of these mosquitoes is correlated with abiotic conditions, and with temperature, humidity and the relative availability of rain-filled containers. Understanding the ecological determinants of species distribution can provide insight into the biology of these vectors and important information for their appropriate control.

  6. Estimates of public health risks through import of Aedes albopictus via Dracaena's in the Netherlands : Investigation in the establlishment of Aedes albopictus : final report

    NARCIS (Netherlands)

    Takken, W.; Jacobs, F.H.H.

    2008-01-01

    Between September 2005 and October 2007 studies were done in six horticultural companies in the Netherlands to assess the presence of the exotic Aedes albopictus and to determine whether the species had become established. Adult mosquitoes were sampled with liberty plus carbon dioxide traps. The pre

  7. Encontro de Aedes albopictus no Estado do Pará, Brasil Occurrence of Aedes albopictus in the state of Pará, Brazil

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    Maria de Nazaré de Oliveira Segura

    2003-06-01

    Full Text Available Pela primeira vez é registrada a presença do Aedes (Stg albopictus no Estado do Pará, Brasil, em área urbana no município de Medicilândia distante cerca de 90 km de Altamira, onde foram capturados por meio de isca humana 42 exemplares de mosquitos adultos. Estes foram inoculados em C6/36 e em camundongos recém-nascidos na tentativa de isolamento viral, não tendo sido isolado nenhum vírus. A presença de Aedes albopictus em áreas da Amazônia onde circulam os vírus de dengue e de febre amarela é preocupante e representa um risco potencial desta espécie de mosquito se tornar infectada com tais vírus.It is first reported the detection of Aedes (Stg albopictus mosquitoes in state of Pará, Brazil, in the urban area of Medicilândia, a municipality far 90 km from Altamira, where 42 adult mosquitoes were baited using human attraction. All mosquitoes were pooled and inoculated into C6/36 and suckling mice in attempts for virus isolation. No virus was isolated. The occurrence of Aedes albopictus in urban areas of the Amazon region is of concern since dengue and yellow fever viruses are endemic in the Amazon and thus there is a potential risk for this mosquito species to become infected with both viruses.

  8. [Aedes aegypti and Aedes albopictus in bromeliads grown in the Bauru Municipal Botanical Gardens, São Paulo, Brazil].

    Science.gov (United States)

    Oliveira, Viviane Camila de; Almeida, Luiz Carlos de

    2017-01-23

    The aim of this study was to observe the occurrence of mosquito larvae, especially Aedes aegypti and Aedes albopictus, in the tanks and axillae of bromeliads at the Bauru Municipal Botanical Gardens, São Paulo, Brazil, highlighting the epidemiological implications for the use of these plants. The majority of the larvae belonged to mosquitos from genus Culex, with only occasional findings of A. aegypti and A. albopictus. The use of screens for protection of the plants, exposure to sunlight, and larger amounts of water in the tanks may have influenced the occurrence and grouping of larvae.

  9. Breeding sites of Aedes albopictus in Jesús Menéndez municipality

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    Marco Antonio Cruz Cruz

    2015-10-01

    Full Text Available Introduction: aedes albopictus is a vector mosquito of dengue, yellow fever, chikungunya virus, and other arboviruses that has been increasing its spread in Jesús Menéndez municipality, Las Tunas, during the last years.Objectives: to identify the breeding sites of the Aedes albopictus in Jesús Menéndez municipality.Methods: the houses were entirely inspected between January and December, 2014, in work cycles of 44 days according to planning. During the inspections all the available probable tanks for Aedes albopictus were checked and treated by the personnel in charge of the integrated management of vectors. In each visit all the water containers were checked, looking for larvae of this species. Samples were taken from each kind of container where there were larvae.Results: presence of Aedes albopictus was identified in 11 of the Popular Councils mainly in the three urban areas during the whole year. It was observed that the breeding places are diverse; the artificial tanks were the ones that prevailed.Conclusions: the variety of breeding places used by the Aedes albopictus was demonstrated in Jesús Menéndez municipality during every month of the year.

  10. Widespread evidence for interspecific mating between Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in nature.

    Science.gov (United States)

    Bargielowski, I E; Lounibos, L P; Shin, D; Smartt, C T; Carrasquilla, M C; Henry, A; Navarro, J C; Paupy, C; Dennett, J A

    2015-12-01

    Aedes aegypti and Aedes albopictus, two important vectors of the dengue and chikungunya viruses to humans, often come in contact in their invasive ranges. In these circumstances, a number of factors are thought to influence their population dynamics, including resource competition among the larval stages, prevailing environmental conditions and reproductive interference in the form of satyrization. As the distribution and abundance of Ae. aegypti and Ae. albopictus have profound epidemiological implications, understanding the competitive interactions that influence these patterns in nature is important. While evidence for resource competition and environmental factors had been gathered from the field, the evidence for reproductive interference, though strongly inferred through laboratory trials, remained sparse (one small-scale field trial). In this paper we demonstrate that low rates (1.12-3.73%) of interspecific mating occur in nature among populations of these species that have co-existed sympatrically from 3 to 150yrs. Finally this report contributes a new species-specific primer set for identifying the paternity of sperm extracted from field collected specimens.

  11. Invasiveness of Aedes aegypti and Aedes albopictus and Vectorial Capacity for Chikungunya Virus.

    Science.gov (United States)

    Lounibos, Leon Philip; Kramer, Laura D

    2016-12-15

    In this review, we highlight biological characteristics of Aedes aegypti and Aedes albopictus, 2 invasive mosquito species and primary vectors of chikungunya virus (CHIKV), that set the tone of these species' invasiveness, vector competence, and vectorial capacity (VC). The invasiveness of both species, as well as their public health threats as vectors, is enhanced by preference for human blood. Vector competence, characterized by the efficiency of an ingested arbovirus to replicate and become infectious in the mosquito, depends largely on vector and virus genetics, and most A. aegypti and A. albopictus populations thus far tested confer vector competence for CHIKV. VC, an entomological analog of the pathogen's basic reproductive rate (R0), is epidemiologically more important than vector competence but less frequently measured, owing to challenges in obtaining valid estimates of parameters such as vector survivorship and host feeding rates. Understanding the complexities of these factors will be pivotal in curbing CHIKV transmission. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  12. Temporal Patterns of Abundance of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) and Mitochondrial DNA Analysis of Ae. albopictus in the Central African Republic

    Science.gov (United States)

    Kamgang, Basile; Ngoagouni, Carine; Manirakiza, Alexandre; Nakouné, Emmanuel; Paupy, Christophe; Kazanji, Mirdad

    2013-01-01

    The invasive Asian tiger mosquito Aedes albopictus (Diptera: Culicidae) was first reported in central Africa in 2000, in Cameroon, with the indigenous mosquito species Ae. aegypti (Diptera: Culicidae). Today, this invasive species is present in almost all countries of the region, including the Central African Republic (CAR), where it was first recorded in 2009. As invasive species of mosquitoes can affect the distribution of native species, resulting in new patterns of vectors and concomitant risk for disease, we undertook a comparative study early and late in the wet season in the capital and the main cities of CAR to document infestation and the ecological preferences of the two species. In addition, we determined the probable geographical origin of invasive populations of Ae. albopictus with two mitochondrial DNA genes, COI and ND5. Analysis revealed that Ae. aegypti was more abundant earlier in the wet season and Ae. albopictus in the late wet season. Used tyres were the most heavily colonized productive larval habitats for both species in both seasons. The invasive species Ae. albopictus predominated over the resident species at all sites in which the two species were sympatric. Mitochondrial DNA analysis revealed broad low genetic diversity, confirming recent introduction of Ae. albopictus in CAR. Phylogeographical analysis based on COI polymorphism indicated that the Ae. albopictus haplotype in the CAR population segregated into two lineages, suggesting multiple sources of Ae. albopictus. These data may have important implications for vector control strategies in central Africa. PMID:24349596

  13. Temporal patterns of abundance of Aedes aegypti and Aedes albopictus (Diptera: Culicidae and mitochondrial DNA analysis of Ae. albopictus in the Central African Republic.

    Directory of Open Access Journals (Sweden)

    Basile Kamgang

    Full Text Available The invasive Asian tiger mosquito Aedes albopictus (Diptera: Culicidae was first reported in central Africa in 2000, in Cameroon, with the indigenous mosquito species Ae. aegypti (Diptera: Culicidae. Today, this invasive species is present in almost all countries of the region, including the Central African Republic (CAR, where it was first recorded in 2009. As invasive species of mosquitoes can affect the distribution of native species, resulting in new patterns of vectors and concomitant risk for disease, we undertook a comparative study early and late in the wet season in the capital and the main cities of CAR to document infestation and the ecological preferences of the two species. In addition, we determined the probable geographical origin of invasive populations of Ae. albopictus with two mitochondrial DNA genes, COI and ND5. Analysis revealed that Ae. aegypti was more abundant earlier in the wet season and Ae. albopictus in the late wet season. Used tyres were the most heavily colonized productive larval habitats for both species in both seasons. The invasive species Ae. albopictus predominated over the resident species at all sites in which the two species were sympatric. Mitochondrial DNA analysis revealed broad low genetic diversity, confirming recent introduction of Ae. albopictus in CAR. Phylogeographical analysis based on COI polymorphism indicated that the Ae. albopictus haplotype in the CAR population segregated into two lineages, suggesting multiple sources of Ae. albopictus. These data may have important implications for vector control strategies in central Africa.

  14. Differential Susceptibilities of Aedes aegypti and Aedes albopictus from the Americas to Zika Virus.

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    Thais Chouin-Carneiro

    2016-03-01

    Full Text Available Since the major outbreak in 2007 in the Yap Island, Zika virus (ZIKV causing dengue-like syndromes has affected multiple islands of the South Pacific region. In May 2015, the virus was detected in Brazil and then spread through South and Central America. In December 2015, ZIKV was detected in French Guiana and Martinique. The aim of the study was to evaluate the vector competence of the mosquito spp. Aedes aegypti and Aedes albopictus from the Caribbean (Martinique, Guadeloupe, North America (southern United States, South America (Brazil, French Guiana for the currently circulating Asian genotype of ZIKV isolated from a patient in April 2014 in New Caledonia.Mosquitoes were orally exposed to an Asian genotype of ZIKV (NC-2014-5132. Upon exposure, engorged mosquitoes were maintained at 28° ± 1 °C, a 16h:8h light:dark cycle and 80% humidity. 25-30 mosquitoes were processed at 4, 7 and 14 days post-infection (dpi. Mosquito bodies (thorax and abdomen, heads and saliva were analyzed to measure infection, dissemination and transmission, respectively. High infection but lower disseminated infection and transmission rates were observed for both Ae. aegypti and Ae. albopictus. Ae. aegypti populations from Guadeloupe and French Guiana exhibited a higher dissemination of ZIKV than the other Ae. aegypti populations examined. Transmission of ZIKV was observed in both mosquito species at 14 dpi but at a low level.This study suggests that although susceptible to infection, Ae. aegypti and Ae. albopictus were unexpectedly low competent vectors for ZIKV. This may suggest that other factors such as the large naïve population for ZIKV and the high densities of human-biting mosquitoes contribute to the rapid spread of ZIKV during the current outbreak.

  15. Bioefficacy of crude extract of Cyperus aromaticus (Family:Cyperaceae) cultured cells, against Aedes aegypti and Aedes albopictus mosquitoes

    Institute of Scientific and Technical Information of China (English)

    Fatemeh Kamiabi; Zairi Jaal; Chan Lai Keng

    2013-01-01

    Objective:To evaluate the growth inhibition activity of the crude extract of Cyperus aromaticus (C. aromaticus) cultured cells against the 3rd instar larvae of Aedes aegypti (Linn.) and Aedes albopictus Skuse (Ae. albopictus) under laboratory conditions, and determine the sublethal effects (EI50) of the crude extract of C. aromaticus cultured cells on some biological and morphological parameters of both Aedes mosquito species during two generations as well. Methods:The cell suspension cultures of C. aromaticus were activated from five callus lines (P4, Pa, Z1, Z6 and Ml) derived from the root explants of in vitro plantlets. The cultured cells were extracted in chloroform and used as plant material for the present study. For detection of juvenile hormone III, the crude extracts were analyzed by HPLC. Then the crude extracts of the three C. aromaticus cultured cell lines which contained varied amounts of juvenile hormone III [high level (P4 cell line), medium level (Z1 cell line) and low level (Ml cell line)] were tested against Aedes mosquito species. Laboratory evaluation was performed against late third instar larvae of the Vector Control Research Unit strains of Ae. aegypti and Ae. albopictus using the standard WHO method. The effects of EI50 of the C. aromaticus cultured P4 cells on fecundity, fertility, growth period, sex ratio, adult size and longevity of Aedes mosquitoes were assessed. Results:Bioassay tests presented the remarkable growth inhibition activity of the crude extracts of C. aromaticus cultured cells against the two Aedes mosquitoes. Between the two mosquito species, Ae. albopictus was more susceptible to the crude extracts with lower EI50 values. EI50 of the crude extract of C. aromaticus cultured cells (P4) increased the sterility indices in the parental generation females in both Aedes mosquito species. A significant delay in the pupal formation and adult emergence were observed in the parental generation of the both mosquito species. The sex

  16. Effects of density dependent larval competition on the life history traits of Aedes aegypti and Aedes albopictus (Diptera: Culicidae)

    OpenAIRE

    Sampa Banerjee; Soujita Pramanik; Soumyajit Banerjee; Goutam K Saha; Gautam Aditya

    2017-01-01

    Consequences of larval competition at the population level provide explanation for the differences in relative abundance of Aedes aegypti and Aedes albopictus in different geographical regions. The outcome of competition is assessed through the estimates of the life history traits as a response to varying density and resource available for larval development. In the present study, variations in the life history traits due to density-dependent intra- and inter- specific competition involving A...

  17. Wolbachia Modulates Lipid Metabolism in Aedes albopictus Mosquito Cells

    Science.gov (United States)

    Molloy, Jennifer C.; Sommer, Ulf; Viant, Mark R.

    2016-01-01

    ABSTRACT Certain strains of the intracellular endosymbiont Wolbachia can strongly inhibit or block the transmission of viruses such as dengue virus (DENV) by Aedes mosquitoes, and the mechanisms responsible are still not well understood. Direct infusion and liquid chromatography-Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry-based lipidomics analyses were conducted using Aedes albopictus Aa23 cells that were infected with the wMel and wMelPop strains of Wolbachia in comparison to uninfected Aa23-T cells. Substantial shifts in the cellular lipid profile were apparent in the presence of Wolbachia. Most significantly, almost all sphingolipid classes were depleted, and some reductions in diacylglycerols and phosphatidylcholines were also observed. These lipid classes have previously been shown to be selectively enriched in DENV-infected mosquito cells, suggesting that Wolbachia may produce a cellular lipid environment that is antagonistic to viral replication. The data improve our understanding of the intracellular interactions between Wolbachia and mosquitoes. IMPORTANCE Mosquitoes transmit a variety of important viruses to humans, such as dengue virus and Zika virus. Certain strains of the intracellular bacterial genus called Wolbachia found in or introduced into mosquitoes can block the transmission of viruses, including dengue virus, but the mechanisms responsible are not well understood. We found substantial shifts in the cellular lipid profiles in the presence of these bacteria. Some lipid classes previously shown to be enriched in dengue virus-infected mosquito cells were depleted in the presence of Wolbachia, suggesting that Wolbachia may produce a cellular lipid environment that inhibits mosquito-borne viruses. PMID:26994075

  18. First Record of the Asian Tiger Mosquito Aedes albopictus in Hidalgo State, Mexico.

    Science.gov (United States)

    Ortega-Morales, Aldo I; Cueto-Medina, Sarai M; Rodríguez, Quetzaly K Siller

    2016-09-01

    The occurrence of the Asian tiger mosquito, Aedes albopictus , has been reported in the Mexican states of Tamaulipas, Nuevo León, Coahuila (northeastern), Veracruz, Chiapas, Quintana Roo (southeastern), Morelos, San Luis Potosí (middle), and Sinaloa (northwestern). In April and September 2012, Ae. albopictus was collected in a variety of habitats and landing/biting on the collecting personnel in 12 counties of Hidalgo state (middle). This is the first record of the occurrence of this species in Hidalgo state.

  19. Effect of monensin on Mayaro virus replication in monkey kidney and Aedes albopictus cells.

    Science.gov (United States)

    De Campos, R M; Ferreira, D F; Da Veiga, V F; Rebello, M A; Rebello, M C S

    2003-01-01

    The effect of a cationic ionophore, monensin, on the replication of Mayaro virus in monkey kidney TC7 and Aedes albopictus cells has been studied. Treatment of these cells with 1 micromol/l monensin during infection did not affect the virus protein synthesis but inhibited severely the virus replication. Electron microscopy of the cells infected with Mayaro virus and treated with monensin revealed that the morphogenesis of Mayaro virus was impaired in TC7 but not in A. albopictus cells.

  20. Chikungunya Virus Replication in Salivary Glands of the Mosquito Aedes albopictus

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    Anubis Vega-Rúa

    2015-11-01

    Full Text Available Chikungunya virus (CHIKV is an emerging arbovirus transmitted to humans by mosquitoes such as Aedes albopictus. To be transmitted, CHIKV must replicate in the mosquito midgut, then disseminate in the hemocele and infect the salivary glands before being released in saliva. We have developed a standardized protocol to visualize viral particles in the mosquito salivary glands using transmission electron microscopy. Here we provide direct evidence for CHIKV replication and storage in Ae. albopictus salivary glands.

  1. Chikungunya Virus Replication in Salivary Glands of the Mosquito Aedes albopictus.

    Science.gov (United States)

    Vega-Rúa, Anubis; Schmitt, Christine; Bonne, Isabelle; Krijnse Locker, Jacomine; Failloux, Anna-Bella

    2015-11-17

    Chikungunya virus (CHIKV) is an emerging arbovirus transmitted to humans by mosquitoes such as Aedes albopictus. To be transmitted, CHIKV must replicate in the mosquito midgut, then disseminate in the hemocele and infect the salivary glands before being released in saliva. We have developed a standardized protocol to visualize viral particles in the mosquito salivary glands using transmission electron microscopy. Here we provide direct evidence for CHIKV replication and storage in Ae. albopictus salivary glands.

  2. Experimental studies of susceptibility of Italian Aedes albopictus to Zika virus.

    Science.gov (United States)

    Di Luca, Marco; Severini, Francesco; Toma, Luciano; Boccolini, Daniela; Romi, Roberto; Remoli, Maria Elena; Sabbatucci, Michela; Rizzo, Caterina; Venturi, Giulietta; Rezza, Giovanni; Fortuna, Claudia

    2016-05-05

    We report a study on vector competence of an Italian population of Aedes albopictus for Zika virus (ZIKV). Ae. albopictus was susceptible to ZIKV infection (infection rate: 10%), and the virus could disseminate and was secreted in the mosquito's saliva (dissemination rate: 29%; transmission rate: 29%) after an extrinsic incubation period of 11 days. The observed vector competence was lower than that of an Ae. aegypti colony tested in parallel.

  3. Differential responses of the mosquito Aedes albopictus from the Indian Ocean region to two chikungunya isolates

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    Failloux Anna-Bella

    2010-03-01

    Full Text Available Abstract Background Aedes aegypti and Aedes albopictus are both vectors of chikungunya virus (CHIKV. The two Aedes species co-exist in the Indian Ocean region and were involved in the 2005-2006 CHIKV outbreaks. In the Reunion Island, a single mutation in the viral envelope has been selected that leads to high levels of replication in Ae. albopictus, and a short extrinsic incubation period as the virus could be found in saliva as early as two days after infection. An important question is whether this variant is associated with adverse effects impacting some mosquito life-history traits such as survival and reproduction. Results We performed experimental infections using three mosquito strains of Ae. aegypti Mayotte and Ae. albopictus (Mayotte and Reunion, and two CHIKV strains (E1-226A and E1-226V. Ae. aegypti Mayotte were similarly susceptible to both viral strains, whereas Ae. albopictus Mayotte and Ae. albopictus Reunion were more susceptible to CHIKV E1-226V than to E1-226A. In terms of life-history traits measured by examining mosquito survival and reproduction, we found that: (1 differences were observed between responses of mosquito species to the two viruses, (2 CHIKV infection only affected significantly some life-history traits of Ae. albopictus Reunion and not of the other two mosquito strains, and (3 CHIKV reduced the lifespan of Ae. albopictus Reunion and shortened the time before egg laying. Conclusion We demonstrated that CHIKV only reduces the survival of Ae. albopictus from the Reunion Island. By laying eggs just before death, reproduction of Ae. albopictus from the Reunion Island is not reduced since other parameters characterizing oviposition and hatching were not affected.

  4. Differential responses of the mosquito Aedes albopictus from the Indian Ocean region to two chikungunya isolates.

    Science.gov (United States)

    Martin, Estelle; Moutailler, Sara; Madec, Yoann; Failloux, Anna-Bella

    2010-03-12

    Aedes aegypti and Aedes albopictus are both vectors of chikungunya virus (CHIKV). The two Aedes species co-exist in the Indian Ocean region and were involved in the 2005-2006 CHIKV outbreaks. In the Reunion Island, a single mutation in the viral envelope has been selected that leads to high levels of replication in Ae. albopictus, and a short extrinsic incubation period as the virus could be found in saliva as early as two days after infection. An important question is whether this variant is associated with adverse effects impacting some mosquito life-history traits such as survival and reproduction. We performed experimental infections using three mosquito strains of Ae. aegypti Mayotte and Ae. albopictus (Mayotte and Reunion), and two CHIKV strains (E1-226A and E1-226V). Ae. aegypti Mayotte were similarly susceptible to both viral strains, whereas Ae. albopictus Mayotte and Ae. albopictus Reunion were more susceptible to CHIKV E1-226V than to E1-226A. In terms of life-history traits measured by examining mosquito survival and reproduction, we found that: (1) differences were observed between responses of mosquito species to the two viruses, (2) CHIKV infection only affected significantly some life-history traits of Ae. albopictus Reunion and not of the other two mosquito strains, and (3) CHIKV reduced the lifespan of Ae. albopictus Reunion and shortened the time before egg laying. We demonstrated that CHIKV only reduces the survival of Ae. albopictus from the Reunion Island. By laying eggs just before death, reproduction of Ae. albopictus from the Reunion Island is not reduced since other parameters characterizing oviposition and hatching were not affected.

  5. Structure comparisons of Aedes albopictus densovirus with other parvoviruses

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Parvoviridae is a family of the smallest viruses known with a wide variety of hosts. The capsid structure of the Aedes albopictus C6/36 cell densovirus (C6/36 DNV) at 1.2-nm resolution was obtained by elec-tron cryomicroscopy (cryoEM) and three-dimensional (3D) image reconstruction. Structure compari-sons between the C6/36 DNV and other parvoviruses reveal that the degree of structural similarity be-tween C6/36 DNV and the human parvovirus B19 is higher than that between C6/36 DNV and other in-sect parvoviruses. The amino acid sequence comparisons of structural and non-structural proteins also reveal higher levels of similarity between C6/36 DNV and parvovirus B19 than those between C6/36 DNV and other parvoviruses. These findings indicate that C6/36 DNV is closely related to the human virus B19, and the former might evolve from the human species other than from other insect viruses.

  6. Structure comparisons of Aedes albopictus densovirus with other parvoviruses

    Institute of Scientific and Technical Information of China (English)

    CHENG LingPeng; CHEN SenXiong; Z. H. ZHOU; ZHANG JingQiang

    2007-01-01

    Parvoviridae is a family of the smallest viruses known with a wide variety of hosts. The capsid structure of the Aedes albopictus C6/36 cell densovirus (C6/36 DNV) at 1.2-nm resolution was obtained by electron cryomicroscopy (cryoEM) and three-dimensional (3D) image reconstruction. Structure comparisons between the C6/36 DNV and other parvoviruses reveal that the degree of structural similarity between C6/36 DNV and the human parvovirus B19 is higher than that between C6/36 DNV and other insect parvoviruses. The amino acid sequence comparisons of structural and non-structural proteins also reveal higher levels of similarity between C6/36 DNV and parvovirus B19 than those between C6/36 DNV and other parvoviruses. These findings indicate that C6/36 DNV is closely related to the human virus B19, and the former might evolve from the human species other than from other insect viruses.

  7. Sodium channel gene expression in mosquitoes, Aedes albopictus (S.)

    Institute of Scientific and Technical Information of China (English)

    NANNAN LIU; QIANG XU; LEE ZHANG

    2006-01-01

    A mosquito strain of Aerdes albopictus,HAmAalG0,from Huntsville,Alabama,USA,showed a normal susceptibility and low tolerance to permethrin and resmethrin (pyrethroid insecticides) compared to a susceptible Ikaken strain,even though these pyrethroid insecticides have been used in the field for a long period of time in Alabama.Recently,we treated HAmAalG0 in the laboratory with permethrin for five generations and detected no significant change in the level of resistance to permethrin in the selected mosquitoes,HAmAalG5,compared with the parental strain HAmAalG0. We then examined the allelic expression at the L-to-F kdr site of the sodium channel gene in the Aedes mosquitoes to address our hypothesis that the L-to-F kdr mutation was not present in HAmAalG0 and HAmAalG5 mosquitoes. We found that every tested individual in Ikaken,HAmAalG0,and HAmAalG5 populations expressed a codon of CTA at the L-to-F kdr site encoding Leu,strongly corresponding to their susceptibility to insecticides.

  8. Olfactory Ionotropic Receptors in Mosquito Aedes albopictus (Diptera: Culicidae).

    Science.gov (United States)

    Chen, Qian; Man, Yahui; Li, Jianyong; Pei, Di; Wu, Wenjian

    2017-09-01

    Ionotropic glutamate receptors (iGluRs) are a conserved family of ligand-gated ion channels that primarily function to mediate neuronal communication at synapses. A variant subfamily of iGluRs, the ionotropic receptors (IRs), was recently identified in insects and proved with the function in odorant recognition. Ionotropic receptors participate in a distinct olfactory signaling pathway that is independent of olfactory receptors activity. In the present study, we identify 102 putative IR genes, dubbed as AalbIr genes, in mosquito Aedes albopictus (Skuse) by in silico comparative sequence analysis. Among AalbIr genes, 19 show expression in the female antenna by RT-PCR. These putative olfactory AalbIRs share four conservative hydrophobic domains of amino acids, similar to the transmembrane and ion channel pore regions found in conventional iGluRs. To determine the potential function of these olfactory AalbIRs in host-seeking, we compared their transcript expression levels in the antennae of blood-fed females with that of non-blood-fed females by quantitative real-time RT-PCR. Three AalbIr genes showed downregulation when the mosquito finished a bloodmeal. These results may help to improve our understanding of the IR-mediated olfactory signaling in mosquitoes. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. PENGARUH EKSTRAK DAUN LEGUNDI (Vitex trifolia Linn TERHADAP KEMATIAN LARVA Aedes albopictus

    Directory of Open Access Journals (Sweden)

    Nia Sari Nastiti

    2013-09-01

    Full Text Available ABSTRAKPengendalian Aedes albopictus penting dilakukan karena merupakan salah satu vektor penyakit yang mampumembawa dan menularkan virus Chikungunya. Di antara cara pengendalian yang perlu dikembangkan adalahpengendalian secara hayati, karena aman bagi manusia dan organisme lain serta ramah lingkungan. Pengendalian hayatiyang dapat digunakan adalah daun Legundi (Vitex trifolia linn. Vitex trifolia linn telah diketahui mengandung bahan aktifalkaloid, saponin, flafonoid. Tujuan penelitian ini adalah untuk mengetahui pengaruh ekstrak daun Vitex trifolia linnterhadap kematianlarva Aedes albopictus.Jenis penelitian ini adalah quasi experiment, menggunakan Post Test OnlyControl Group Design. Obyekpenelitian ini adalah 750 ekor larva Aedes albopictus instar IV yang berasal dari hasil penangkaran di Balai BesarPenelitian dan Pengembangan Vektor dan Reservoir Penyakit (B2P2VRP Salatiga, Jawa Tengah. Ekstrak etanol daunVitex trifolia linn dibuat dari daun Legundi segar yang didestilasi dengan suhu 100oC sampai pekat. Setiap kelompokmedia (gelas penelitian diisi 100 ml air sumur, dan ekstrak etanol daun Vitex trifolia linn dengan konsentrasi 2,5 %, 5 %,7,5 %, 10 %, 12,5 % dan 0 % (kontrol. Selanjutnya pada setiap media dimasukkan 25 ekor larva Aedes albopictus,penghitungan kematian larva dilakukan setiap jam ke 1, 2, 4, dan 24. Replikasi dilakukan sebanyak 5 kali.Hasil uji statistik dengan Oneway Anova diperoleh p=0,000, sehingga (p<0,05 artinya ada perbedaan yangbermakna, yaitu ekstrak daun Vitex trifolia linn dapat mematikan larva Aedes albopictus. Kesimpulan penelitian ini adalahpenggunaan ekstrak daun Vitex trifolia linn dengan konsentrasi 12,5 % paling efektif terhadap kematian larva Aedesalbopictus.Kata Kunci: Ekstrak, daun legundi (Vitex trifolia linn, Aedes albopictus

  10. Age-Stage, Two-Sex Life Table Characteristics of Aedes albopictus and Aedes Aegypti in Penang Island, Malaysia.

    Science.gov (United States)

    Maimusa, Hamisu A; Ahmad, Abu Hassan; Kassim, Nur Faeza A; Rahim, Junaid

    2016-03-01

    The life table developmental attributes of laboratory colonies of wild strains of Aedes albopictus and Aedes aegypti were analyzed and compared based on the age-stage, two-sex life table. Findings inclusive in this study are: adult preoviposition periods, total preoviposition period, mean intrinsic rate of increase (r), mean finite rate of increase (λ), net reproductive rates (R0), and mean generation time (T). The total preadult development time was 9.47 days for Ae. albopictus and 8.76 days for Ae. aegypti. The life expectancy was 19.01 days for Ae. albopictus and 19.94 days for Ae. aegypti. Mortality occurred mostly during the adult stage. The mean development time for each stage insignificantly correlated with temperature for Ae. albopictus (r  =  -0.208, P > 0.05) and (r  =  -0.312, P > 0.05) for Ae. aegypti. The population parameters suggest that Ae. albopictus and Ae. aegypti populations are r-strategists characterized by a high r, a large R0, and short T. This present study provides the first report to compare the life parameters of Ae. albopictus and Ae. aegypti strains from Penang island, Malaysia.

  11. Truck-mounted area-wide application of pyriproxyfen targeting Aedes aegypti and Aedes albopictus in northeast Florida

    Science.gov (United States)

    This study was conducted to determine the efficacy of truck-mounted ULV applications of pyriproxyfen against Aedes aegypti larvae in artificial water containers and wild adult Ae. albopictus populations in an urban setting. The study was conducted over a 3 ½ month period (Jun – Oct 2012), during wh...

  12. Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae, in Madagascar

    Directory of Open Access Journals (Sweden)

    Raharimalala Fara

    2012-03-01

    Full Text Available Abstract Background In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of this work was to update the entomological survey of the two Aedes species in the island of Madagascar which has to face these arboviroses. Methods The sampling of Aedes mosquitoes was conducted during two years, from October 2007 to October 2009, in fifteen localities from eight regions of contrasting climates. Captured adults were identified immediately whereas immature stages were bred until adult stage for determination. Phylogenetic analysis was performed using two mtDNA genes, COI and ND5 and trees were constructed by the maximum likelihood (ML method with the gene time reversible (GTR model. Experimental infections with the chikungunya virus strain 06.21 at a titer of 107.5 pfu/mL were performed to evaluate the vector competence of field-collected mosquitoes. Disseminated infection rates were measured fourteen days after infection by immunofluorescence assay performed on head squashes. Results The species Aedes aegypti was detected in only six sites in native forests and natural reserves. In contrast, the species Aedes albopictus was found in 13 out of the 15 sites sampled. Breeding sites were mostly found in man-made environments such as discarded containers, used tires, abandoned buckets, coconuts, and bamboo cuts. Linear regression models showed that the abundance of Ae. albopictus was significantly influenced by the sampling region (F = 62.00, p -16 and period (F = 36.22, p = 2.548 × 10-13, that are associated with ecological and climate variations. Phylogenetic analysis of the invasive Ae. albopictus distinguished haplotypes from South Asia and South America from those of Madagascar, but the markers used were not discriminant enough

  13. Evaluation of Insect Growth Regulators Against Field-Collected Aedes aegypti and Aedes albopictus (Diptera: Culicidae) from Malaysia.

    Science.gov (United States)

    Lau, Koon Weng; Chen, Chee Dhang; Lee, Han Lim; Norma-Rashid, Yusoff; Sofian-Azirun, Mohd

    2015-03-01

    Susceptibility status of Aedes aegypti (L.) and Aedes albopictus Skuse larvae obtained from 12 states in Malaysia were evaluated against five insect growth regulators (IGRs), namely, pyriproxyfen, methoprene, diflubenzuron, cyromazine, and novaluron under laboratory conditions. Field populations of Ae. aegypti exhibited moderate resistance toward methoprene and low resistance toward pyriproxyfen, with resistance ratios of 12.7 and 1.4, respectively, but susceptibility to diflubenzuron, cyromazine, and novaluron. On the other hand, field populations of Ae. albopictus exhibited low resistance against diflubenzuron and novaluron, with resistance ratio of 2.1 and 1.0, respectively, but susceptibility to other tested IGRs. Our study concluded that the tested IGRs provide promising results and can be used to control field population of Ae. aegypti and Ae. albopictus, especially cyromazine. The use of IGR should be considered as an alternative when larvae develop resistance to conventional insecticides.

  14. Interspecific Cross-Mating Between Aedes aegypti and Aedes albopictus Laboratory Strains: Implication of Population Density on Mating Behaviors.

    Science.gov (United States)

    Marcela, P; Hassan, A Abu; Hamdan, A; Dieng, H; Kumara, T K

    2015-12-01

    Mating behavior between Aedes aegypti and Ae. albopictus, established colony strains were examined under laboratory conditions (30-cm(3) screened cages) for 5 consecutive days. The effect of selected male densities (30, 20, 10) and female density (20) on the number of swarming, mating pairs, eggs produced, and inseminated females were evaluated. Male densities significantly increased swarming behavior, mating pairs, and egg production of heterospecific females, but female insemination was reduced. Aedes aegypti males mate more readily with heterospecific females than do Ae. albopictus males. The current study suggests that Ae. aegypti males were not species-specific in mating, and if released into the field as practiced in genetically modified mosquito techniques, they may mate with both Ae. aegypti and Ae. albopictus females, hence reducing populations of both species by producing infertile eggs.

  15. Prostaglandin A1 inhibits replication of Mayaro virus in Aedes albopictus cells.

    Science.gov (United States)

    Barbosa, J A; Rebello, M A

    1995-01-01

    Prostaglandin A1 (PGA1) reduced Mayaro virus replication in Aedes albopictus (mosquito) cells in culture. The highest nontoxic dose of PGA1, 7.5 microM, decreased virus production by 90%. In Mayaro virus-infected cells, PGA1 inhibited virus-specific protein synthesis. However, in mock-infected cells the presence of PGA1 stimulated the synthesis of several proteins with molecular masses of 70, 57 and 23 kDa, respectively. The data obtained from this study show that PGA1 plays a role in the metabolic regulation of Aedes albopictus cells, blocking the synthesis of Mayaro virus and inducing the synthesis of cellular polypeptides.

  16. Produtividade de criadouro de Aedes albopictus em ambiente urbano Productivity of container-breeding Aedes albopictus in an urban environment

    Directory of Open Access Journals (Sweden)

    Oswaldo Paulo Forattini

    1997-12-01

    Full Text Available INTRODUÇÃO: O encontro de Aedes albopictus na cidade de Cananéia, região Sudeste do Estado de São Paulo, Brasil, ensejou a ocasião de realizar observações que visassem avaliar a produtividade de criadouro grande e permanente. Como objetivo, após selecionar o habitat a ser estudado, tentou-se avaliar-lhe a contribuição para a densidade local do mosquito. MATERIAL E MÉTODO: Em área predeterminada procedeu-se a levantamento de criadouros potenciais. Constatada a presença da espécie, foi selecionado um dos recipientes que preenchia os requisitos desejados. O acompanhamento foi feito de maneira ininterrupta, no período de novembro de 1996 a maio de 1997. As observações obdeceram a ritmo quinzenal retirando, cada vez, amostra da água correspondente a 0,14, ou seja, um sétimo do volume total de 70 litros. Procurou-se coletar, identificar e numerar, por sexo, as pupas existentes. Concomitantemente, procedeu-se à captura de formas adultas. Foi utilizada a isca humana das 15:00 às 18:00h, instalada a cerca de 6 metros do mencionado criadouro. Finda essa coleta, foi feita aspiração com 30 min. de duração em locais de abrigo representados pela abundante vegetação circunjacente. RESULTADOS: Nas coletas de formas imaturas do criadouro, o Ae. albopictus compareceu com 44,9%. Ao longo de 15 amostras regularmente realizadas obteve-se a média de 31,13 pupas pertencentes a essa espécie. O índice de emergência(E foi de 2,1. A multiplicação desse valor por sete forneceu a média diária de 14,7 fêmeas. Nas coletas de adultos desse sexo, a média de Williams para a isca humana foi de 30,7, enquanto a densidade média horária da aspiração dos locais de abrigo foi de 9,2. O cálculo do acúmulo diário concluiu pela presença de 22,8 fêmeas, por dia, capazes de freqüentar a isca humana, nessa situação e condições. DISCUSSÃO: A contagem de pupas possibilitou estimar a produtividade de criadouro de Ae. albopictus, tipo grande

  17. Risk factors for the presence of Aedes aegypti and Aedes albopictus in domestic water-holding containers in areas impacted by the Nam Theun 2 hydroelectric project, Laos

    NARCIS (Netherlands)

    Hiscox, A.F.; Kaye, A.; Vongphayloth, K.; Banks, I.; Piffer, M.; Khammanithong, P.; Sananikhom, P.; Kaul, S.; Hill, N.; Lindsay, S.W.; Brey, P.T.

    2013-01-01

    We assessed risk factors for vectors of dengue and chikungunya viruses near a new hydroelectric project, Nam Theun 2, in Laos. Immature stages of Aedes aegypti were found only in sites within 40 km of the urban provincial capital, but Aedes albopictus was found throughout. Aedes aegypti pupae were m

  18. Risk factors for the presence of Aedes aegypti and Aedes albopictus in domestic water-holding containers in areas impacted by the Nam Theun 2 hydroelectric project, Laos

    NARCIS (Netherlands)

    Hiscox, A.F.; Kaye, A.; Vongphayloth, K.; Banks, I.; Piffer, M.; Khammanithong, P.; Sananikhom, P.; Kaul, S.; Hill, N.; Lindsay, S.W.; Brey, P.T.

    2013-01-01

    We assessed risk factors for vectors of dengue and chikungunya viruses near a new hydroelectric project, Nam Theun 2, in Laos. Immature stages of Aedes aegypti were found only in sites within 40 km of the urban provincial capital, but Aedes albopictus was found throughout. Aedes aegypti pupae were

  19. Risk factors for the presence of Aedes aegypti and Aedes albopictus in domestic water-holding containers in areas impacted by the Nam Theun 2 hydroelectric project, Laos

    NARCIS (Netherlands)

    Hiscox, A.F.; Kaye, A.; Vongphayloth, K.; Banks, I.; Piffer, M.; Khammanithong, P.; Sananikhom, P.; Kaul, S.; Hill, N.; Lindsay, S.W.; Brey, P.T.

    2013-01-01

    We assessed risk factors for vectors of dengue and chikungunya viruses near a new hydroelectric project, Nam Theun 2, in Laos. Immature stages of Aedes aegypti were found only in sites within 40 km of the urban provincial capital, but Aedes albopictus was found throughout. Aedes aegypti pupae were m

  20. How dengue vector Aedes albopictus (Diptera: Culicidae survive during the dry season in Dhaka City, Bangladesh?

    Directory of Open Access Journals (Sweden)

    Rajib Chowdhury

    2014-08-01

    Full Text Available Background & objectives: In 2000, a dengue outbreak occurred in Bangladesh that included Dhaka City. Both dengue vectors, Aedes aegypti and Ae. albopictus are present in Bangladesh. Aedes aegypti mosquitoes mainly breed in and around houses and Ae. albopictus is an outside breeder. There are many old trees throughout Dhaka City in different parks, streets and the university campus which may have holes that can contribute as potential breeding habitat for the dengue vector. Therefore, a survey was conducted to investigate the presence of eggs of the dengue vector mosquitoes in treeholes during the dry season in February 2001 to know their contribution on dengue outbreaks. Methods: All treeholes in 10 different localities (parks, streets and university campus of Dhaka City were surveyed. All trees were examined for treeholes up to the height of approximately 3 m and sampled. Debris were collected and packed in poly bags and brought to the laboratory for detailed studies. These were then soaked with tap water to observe egg hatching. The soaked materials were kept up to 20 days covered by a fine mosquito net. After 2-3 days, the eggs started hatching and larvae were separated from the sample for rearing up to IV instar. Results: A total of 245 treeholes were surveyed in 49 identified tree species and 18 unidentified trees. Altogether, 1365 Aedes larvae were found, of which 1096 were Aedes albopictus and 269 were other Aedes species. The largest number of larvae was observed in Delonix regia of Leguminosae family. The number of Aedes albopictus found in the treeholes have perfect positive correlation with the number of other Aedes species. Not a single egg of Aedes aegypti was found in this survey. Interpretation & conclusion: This information will inform public health workers as well as the national control programme to help to solve mosquito borne diseases specially that of dengue. This is critical in planning for vector control operations due to

  1. Biogeography of the two major arbovirus mosquito vectors, Aedes aegypti and Aedes albopictus (Diptera, Culicidae), in Madagascar

    Science.gov (United States)

    2012-01-01

    Background In the past ten years, the Indian Ocean region has been the theatre of severe epidemics of chikungunya and dengue. These outbreaks coincided with a high increase in populations of Aedes albopictus that outcompete its sister taxon Aedes aegypti in most islands sampled. The objective of this work was to update the entomological survey of the two Aedes species in the island of Madagascar which has to face these arboviroses. Methods The sampling of Aedes mosquitoes was conducted during two years, from October 2007 to October 2009, in fifteen localities from eight regions of contrasting climates. Captured adults were identified immediately whereas immature stages were bred until adult stage for determination. Phylogenetic analysis was performed using two mtDNA genes, COI and ND5 and trees were constructed by the maximum likelihood (ML) method with the gene time reversible (GTR) model. Experimental infections with the chikungunya virus strain 06.21 at a titer of 107.5 pfu/mL were performed to evaluate the vector competence of field-collected mosquitoes. Disseminated infection rates were measured fourteen days after infection by immunofluorescence assay performed on head squashes. Results The species Aedes aegypti was detected in only six sites in native forests and natural reserves. In contrast, the species Aedes albopictus was found in 13 out of the 15 sites sampled. Breeding sites were mostly found in man-made environments such as discarded containers, used tires, abandoned buckets, coconuts, and bamboo cuts. Linear regression models showed that the abundance of Ae. albopictus was significantly influenced by the sampling region (F = 62.00, p Madagascar, but the markers used were not discriminant enough to discern Malagasy populations. The experimental oral infection method showed that six Ae. albopictus populations exhibited high dissemination infection rates for chikungunya virus ranging from 98 to 100%. Conclusion In Madagascar, Ae. albopictus has extended

  2. Implications of saline concentrations for the performance and competitive interactions of the mosquitoes Aedes aegypti (Stegomyia aegypti) and Aedes albopictus (Stegomyia albopictus).

    Science.gov (United States)

    Yee, D A; Himel, E; Reiskind, M H; Vamosi, S M

    2014-03-01

    Aedes albopictus (Stegomyia albopictus) (Diptera: Culicidae) has probably supplanted Aedes aegypti (Stegomyia aegypti) throughout most of its historical range in the U.S.A., although Ae. aegypti still exists in large coastal cities in southern Florida. We measured salt concentrations in field containers along an axis perpendicular to the coast and examined intraspecific outcomes in these species under different salt concentrations in a factorial study using varying intra- and interspecific densities in different conditions of salinity to order to determine if salt could mitigate the documented competitive superiority of Ae. albopictus. Salt in field containers declined away from the coast, with maximal values similar to our lower salt concentrations. Egg hatching and short-term survival of pupae and late instars were not affected by salt concentrations; survival of early instars of both species decreased at higher concentrations. In high salt conditions, Ae. aegypti achieved higher survival. In the longterm experiment, both species displayed longer development times. Salt did not affect interactions for either species; Ae. aegypti survived in the highest salt conditions, regardless of density. The tolerance of Ae. aegypti to high salt concentrations may allow it to use coastal containers, although because salt did not mediate interspecific interactions between Ae. aegypti and Ae. albopictus, the ultimate effects of salt on the coexistence of these species or exclusion of either species remain unknown.

  3. Effects of density dependent larval competition on the life history traits of Aedes aegypti and Aedes albopictus (Diptera: Culicidae

    Directory of Open Access Journals (Sweden)

    Sampa Banerjee

    2017-06-01

    Full Text Available Consequences of larval competition at the population level provide explanation for the differences in relative abundance of Aedes aegypti and Aedes albopictus in different geographical regions. The outcome of competition is assessed through the estimates of the life history traits as a response to varying density and resource available for larval development. In the present study, variations in the life history traits due to density-dependent intra- and inter- specific competition involving A. aegypti and A. albopictus were assessed following the minimalist model. The instar-I larvae (0-day old F2 generation of both Aedes species were reared to the adult stages using the initial rearing density of 1, 2, 4 and 6 (individuals/10ml in multiple replicates. The age at pupation, pupal weight, adult weight and adult wing length of the individuals were considered as the response variables and surrogates of estimating the competitive interactions. Density dependent variations in the competitive interactions were evident for both the mosquitoes with reference to the selected life history traits. In A. aegypti, the life history traits varied with the levels of competition, which was not observed for A. albopictus. Although the density levels considered in the present instance were lower than in earlier studies, the observations were similar, with A. albopictus being competitively superior. It appears that irrespective of the density levels, interspecific competition affects A. aegypti and thus may bear population level consequences and overall abundance in the areas where both species are present.

  4. High Resolution Spatial Analysis of Habitat Preference of Aedes Albopictus (Diptera: Culicidae) in an Urban Environment

    NARCIS (Netherlands)

    Cianci, D.; Hartemink, N.; Zeimes, C.B.; Vanwambeke, S.O.; Ienco, A.; Caputo, B.

    2015-01-01

    Over the past decades, the Asian tiger mosquito (Aedes albopictus (Skuse, 1895)) has emerged in many countries, and it has colonized new environments, including urban areas. The species is a nuisance and a potential vector of several human pathogens, and a better understanding of the habitat prefere

  5. High Resolution Spatial Analysis of Habitat Preference of Aedes Albopictus (Diptera Culicidae) in an Urban Environment

    NARCIS (Netherlands)

    Cianci, Daniela; Hartemink, Nienke; Zeimes, Caroline B; Vanwambeke, Sophie O; Ienco, Annamaria; Caputo, Beniamino

    2015-01-01

    Over the past decades, the Asian tiger mosquito (Aedes albopictus (Skuse, 1895)) has emerged in many countries, and it has colonized new environments, including urban areas. The species is a nuisance and a potential vector of several human pathogens, and a better understanding of the habitat prefere

  6. High Resolution Spatial Analysis of Habitat Preference of Aedes Albopictus (Diptera: Culicidae) in an Urban Environment

    NARCIS (Netherlands)

    Cianci, D.; Hartemink, N.; Zeimes, C.B.; Vanwambeke, S.O.; Ienco, A.; Caputo, B.

    2015-01-01

    Over the past decades, the Asian tiger mosquito (Aedes albopictus (Skuse, 1895)) has emerged in many countries, and it has colonized new environments, including urban areas. The species is a nuisance and a potential vector of several human pathogens, and a better understanding of the habitat

  7. Vertical Transmission of Zika Virus by Aedes aegypti and Ae. albopictus Mosquitoes.

    Science.gov (United States)

    Ciota, Alexander T; Bialosuknia, Sean M; Ehrbar, Dylan J; Kramer, Laura D

    2017-05-01

    To determine the potential role of vertical transmission in Zika virus expansion, we evaluated larval pools of perorally infected Aedes aegypti and Ae. albopictus adult female mosquitoes; ≈1/84 larvae tested were Zika virus-positive; and rates varied among mosquito populations. Thus, vertical transmission may play a role in Zika virus spread and maintenance.

  8. High Resolution Spatial Analysis of Habitat Preference of Aedes Albopictus (Diptera Culicidae) in an Urban Environment

    NARCIS (Netherlands)

    Cianci, Daniela; Hartemink, Nienke; Zeimes, Caroline B; Vanwambeke, Sophie O; Ienco, Annamaria; Caputo, Beniamino

    2015-01-01

    Over the past decades, the Asian tiger mosquito (Aedes albopictus (Skuse, 1895)) has emerged in many countries, and it has colonized new environments, including urban areas. The species is a nuisance and a potential vector of several human pathogens, and a better understanding of the habitat prefere

  9. Primeiro registro de Aedes albopictus no Estado de Santa Catarina, Brasil

    Directory of Open Access Journals (Sweden)

    Peter Löwenberg-Neto

    2002-04-01

    Full Text Available Três fêmeas adultas de Aedes (Stegomyia albopictus (Skuse foram capturadas por meio de isca humana em área peridomiciliar de remanescente de Mata Atlântica na Praia de Itaguaçu, Ilha de São Francisco do Sul, litoral Norte de Santa Catarina.

  10. Occurrence and distribution of Aedes albopictus (Skuse) in the Netherlands; survey 2006-2007 : report

    NARCIS (Netherlands)

    Scholte, E.J.; Takken, W.

    2007-01-01

    In the summer of 2005, the Asian tigermosquito (Aedes albopictus) was found for the first time in the Netherlands. It was intercepted in several horticultural companies that import the ornamental plant Lucky bamboo from southern China, an endemic area for this mosquito species. The current report de

  11. REPELLENCY OF ESSENTIAL OIL OF PIPER ADUNCUM AGAINST AEDES ALBOPICTUS IN THE LABORATORY

    NARCIS (Netherlands)

    Misni, Norashiqin; Sulaiman, Sallehudin; Othman, Hidayatulfathi; Omar, Baharudin

    2009-01-01

    The repellent activity of Piper aduncum essential oil against Aedes albopictus was investigated under laboratory conditions with human volunteers. The lowest median effective dose (ED(50)) value was 1.5 mu g/cm(2) at 60 sec of exposure when compared to 90 see (2.1 mu g/cm(2)) and 120 see (1.8 mu g/c

  12. High Resolution Spatial Analysis of Habitat Preference of Aedes Albopictus (Diptera: Culicidae) in an Urban Environment

    NARCIS (Netherlands)

    Cianci, D.; Hartemink, N.; Zeimes, C.B.; Vanwambeke, S.O.; Ienco, A.; Caputo, B.

    2015-01-01

    Over the past decades, the Asian tiger mosquito (Aedes albopictus (Skuse, 1895)) has emerged in many countries, and it has colonized new environments, including urban areas. The species is a nuisance and a potential vector of several human pathogens, and a better understanding of the habitat prefere

  13. Infection of adult Aedes aegypti and Ae. albopictus mosquitoes with the entomopathogenic fungus Metarhizium anisopliae

    NARCIS (Netherlands)

    Scholte, E.J.; Takken, W.; Knols, B.G.J.

    2007-01-01

    This study describes a laboratory investigation on the use of the insect-pathogenic fungus Metarhizium anisopliae against adult Aedes aegypti and Ae. albopictus mosquitoes. At a dosage of 1.6 × 1010 conidia/m2, applied on material that served as a mosquito resting site, an average of 87.1 ± 2.65% of

  14. REPELLENCY OF ESSENTIAL OIL OF PIPER ADUNCUM AGAINST AEDES ALBOPICTUS IN THE LABORATORY

    NARCIS (Netherlands)

    Misni, Norashiqin; Sulaiman, Sallehudin; Othman, Hidayatulfathi; Omar, Baharudin

    2009-01-01

    The repellent activity of Piper aduncum essential oil against Aedes albopictus was investigated under laboratory conditions with human volunteers. The lowest median effective dose (ED(50)) value was 1.5 mu g/cm(2) at 60 sec of exposure when compared to 90 see (2.1 mu g/cm(2)) and 120 see (1.8 mu

  15. Infection of adult Aedes aegypti and Ae. albopictus mosquitoes with the entomopathogenic fungus Metarhizium anisopliae

    NARCIS (Netherlands)

    Scholte, E.J.; Takken, W.; Knols, B.G.J.

    2007-01-01

    This study describes a laboratory investigation on the use of the insect-pathogenic fungus Metarhizium anisopliae against adult Aedes aegypti and Ae. albopictus mosquitoes. At a dosage of 1.6 × 1010 conidia/m2, applied on material that served as a mosquito resting site, an average of 87.1 ± 2.65% of

  16. Occurrence and distribution of Aedes albopictus (Skuse) in the Netherlands; survey 2006-2007 : report

    NARCIS (Netherlands)

    Scholte, E.J.; Takken, W.

    2007-01-01

    In the summer of 2005, the Asian tigermosquito (Aedes albopictus) was found for the first time in the Netherlands. It was intercepted in several horticultural companies that import the ornamental plant Lucky bamboo from southern China, an endemic area for this mosquito species. The current report de

  17. Aedes albopictus (Diptera: Culicidae) Oviposition Response to Organic Infusions from Common Flora of Suburban Florida

    Science.gov (United States)

    We evaluated the oviposition response of Aedes albopictus to six organic infusions. Laboratory and field placed ovitraps baited with water oak (Quercus nigra L.), longleaf pine (Pinus palustris P. Mill) and St. Augustine grass (Stenotaphrum secundatum (Walt.) Kuntze), as well as two-species mixture...

  18. High Resolution Spatial Analysis of Habitat Preference of Aedes Albopictus (Diptera Culicidae) in an Urban Environment

    NARCIS (Netherlands)

    Cianci, Daniela; Hartemink, Nienke; Zeimes, Caroline B; Vanwambeke, Sophie O; Ienco, Annamaria; Caputo, Beniamino

    2015-01-01

    Over the past decades, the Asian tiger mosquito (Aedes albopictus (Skuse, 1895)) has emerged in many countries, and it has colonized new environments, including urban areas. The species is a nuisance and a potential vector of several human pathogens, and a better understanding of the habitat

  19. Updated Reported Distribution of Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus (Diptera: Culicidae) in the United States, 1995-2016.

    Science.gov (United States)

    Hahn, Micah B; Eisen, Lars; McAllister, Janet; Savage, Harry M; Mutebi, John-Paul; Eisen, Rebecca J

    2017-09-01

    Aedes (Stegomyia) aegypti (L.) and Aedes (Stegomyia) albopictus (Skuse) are potential vectors of Zika, dengue, and chikungunya viruses in the United States. A Zika virus outbreak in Florida in the summer of 2016, driven by Ae. aegypti and resulting in > 200 locally acquired cases of human illness, underscored the need for up-to-date information on the geographic distribution of Ae. aegypti and Ae. albopictus in the United States. In early 2016, we conducted a survey and literature review to compile county records for presence of Ae. aegypti and Ae. albopictus in the United States from 1995 to 2016. Surveillance for these vectors was intensified across the United States during the summer and fall of 2016. At the end of 2016, we therefore conducted a follow-up survey of mosquito control agencies, university researchers, and state and local health departments to document new collection records for Ae. aegypti and Ae. albopictus. The repeated survey at the end of the year added Ae. aegypti collection records from 38 new counties and Ae. albopictus collection records from 127 new counties, representing a 21 and 10 percent increase, respectively, in the number of counties with reported presence of these mosquitoes compared with the previous report. Moreover, through our updated survey, 40 and 183 counties, respectively, added additional years of collection records for Ae. aegypti and Ae. albopictus from 1995 to 2016. Our findings underscore the continued need for systematic surveillance of Ae. aegypti and Ae. albopictus. Published by Oxford University Press on behalf of Entomological Society of America 2017. This work is written by US Government employees and is in the public domain in the US.

  20. Utilization of larval and pupal detritus by Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Bara, J J; Clark, T M; Remold, S K

    2014-06-01

    The utilization of detritus sources by mosquito larvae during development may significantly affect adult life history traits and mosquito population growth. Many studies have shown invertebrate carcasses to be an important detritus source in larval habitats, but little is known regarding how invertebrate carcasses are utilized by mosquito larvae. We conducted two studies to investigate the rate of detritus consumption and its effect on larval development and life history traits. Overall, we found that Aedes aegypti and Aedes albopictus larvae rapidly consumed larval detritus, while pupal detritus was consumed at a significantly slower rate. We also found that the consumption of larval detritus significantly increased larval survivorship and decreased male development time but did not significantly influence female development time or pupal cephalothorax length for either sex. Our results suggest that the direct consumption of larval detritus can support the production of adults in larval habitats that lack allochthonous detritus inputs or where such organic inputs are insufficient. These studies indicate that different forms of invertebrate detritus are utilized in distinct ways by mosquito larvae, and therefore different forms of invertebrate detritus may have distinct effects on larval development and adult life history traits. © 2014 The Society for Vector Ecology.

  1. The effect of photoperiod on life history and blood-feeding activity in Aedes albopictus and Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Costanzo, K S; Schelble, S; Jerz, K; Keenan, M

    2015-06-01

    Several studies have examined how climatic variables such as temperature and precipitation may affect life history traits in mosquitoes that are important to disease transmission. Despite its importance as a seasonal cue in nature, studies investigating the influence of photoperiod on such traits are relatively few. This study aims to investigate how photoperiod alters life history traits, survival, and blood-feeding activity in Aedes albopictus (Skuse) and Aedes aegypti (Linnaeus). We performed three experiments that tested the effects of day length on female survival, development time, adult size, fecundity, adult life span, and propensity to blood feed in Ae. albopictus and Ae. aegypti. Each experiment had three photoperiod treatments: 1) short-day (10L:14D), 2) control (12L:12D), and 3) long-day (14L:10D). Aedes albopictus adult females were consistently larger in size when reared in short-day conditions. Aedes aegypti adult females from short-day treatments lived longer and were more likely to take a blood meal compared to other treatments. We discuss how species-specific responses may reflect alternative strategies evolved to increase survival during unfavorable conditions. We review the potential impacts of these responses on seasonal transmission patterns, such as potentially increasing vectorial capacity of Ae. aegypti during periods of shorter day lengths.

  2. Aedes (Stegomyia) albopictus' dynamics influenced by spatiotemporal characteristics in a Brazilian dengue-endemic risk city.

    Science.gov (United States)

    Bezerra, Juliana M T; Araújo, Raphaela G P; Melo, Fabrício F; Gonçalves, Caroline M; Chaves, Bárbara A; Silva, Breno M; Silva, Luciana D; Brandão, Silvana T; Secundino, Nágila F C; Norris, Douglas E; Pimenta, Paulo F P

    2016-12-01

    Brazil reported the majority of the dengue cases in Americas during the last two decades, where the occurrence of human dengue cases is exclusively attributed to the Aedes (Stegomyia) aegypti (Linnaeus). Nowadays, other recognized Dengue virus (DENV) vector in Asian countries, Aedes (Stegomyia) albopictus (Skuse), has been detected in more than half of the 5565 Brazilian municipalities. Therefore, the aim of the present study was to investigate the presence of, and determine the Ae. albopictus' dynamics influenced by spatiotemporal characteristics in a dengue-endemic risk city of Belo Horizonte, Minas Gerais State's capital. Aedes albopictus were collected across four consecutive DENV transmission seasons from 2010 to 2014. These mosquitoes were caught in three selected districts, which had been reported in the previous ten years as having high mosquito densities and an elevated concentration of human dengue cases during epidemic seasons. All field-caught Ae. albopictus was individually processed by real-time RT-PCR, to research the DENV presence. The third season (pdengue cases. Our study demonstrated that the number of field-caught DENV-infected Ae. albopictus was inversed correlated with the number of human dengue cases. Our study raises the possibility that the DENV circulating in mosquitoes Ae. albopictus is happening in non-epidemic periods, showing that this species may be keeping only the presence of the virus in nature. Further long-term studies are necessary to better understand the role of Ae. albopictus in DENV transmission and or its vectorial competence in Belo Horizonte and in other endemic cities in Brazil and in the New World countries. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Comparative Susceptibility of Aedes albopictus and Aedes aegypti to Dengue Virus Infection After Feeding on Blood of Viremic Humans: Implications for Public Health.

    Science.gov (United States)

    Whitehorn, James; Kien, Duong Thi Hue; Nguyen, Nguyet Minh; Nguyen, Hoa L; Kyrylos, Peter P; Carrington, Lauren B; Tran, Chau Nguyen Bich; Quyen, Nguyen Thanh Ha; Thi, Long Vo; Le Thi, Dui; Truong, Nguyen Thanh; Luong, Tai Thi Hue; Nguyen, Chau Van Vinh; Wills, Bridget; Wolbers, Marcel; Simmons, Cameron P

    2015-10-15

    Aedes albopictus is secondary to Aedes aegypti as a vector of dengue viruses (DENVs) in settings of endemicity, but it plays an important role in areas of dengue emergence. This study compared the susceptibility of these 2 species to DENV infection by performing 232 direct blood-feeding experiments on 118 viremic patients with dengue in Vietnam. Field-derived A. albopictus acquired DENV infections as readily as A. aegypti after blood feeding. Once infected, A. albopictus permitted higher concentrations of DENV RNA to accumulate in abdominal tissues, compared with A. aegypti. However, the odds of A. albopictus having infectious saliva were lower than the odds observed for A. aegypti (odds ratio, 0.70; 95% confidence interval, .52-.93). These results quantitate the susceptibility of A. albopictus to DENV infection and will assist parameterization of models for predicting disease risk in settings where A. albopictus is present.

  4. Competence of Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus Mosquitoes as Zika Virus Vectors, China

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    Liu, Zhuanzhuan; Zhou, Tengfei; Lai, Zetian; Zhang, Zhenhong; Jia, Zhirong; Zhou, Guofa; Williams, Tricia; Xu, Jiabao; Gu, Jinbao; Zhou, Xiaohong; Lin, Lifeng; Yan, Guiyun

    2017-01-01

    In China, the prevention and control of Zika virus disease has been a public health threat since the first imported case was reported in February 2016. To determine the vector competence of potential vector mosquito species, we experimentally infected Aedes aegypti, Ae. albopictus, and Culex quinquefasciatus mosquitoes and determined infection rates, dissemination rates, and transmission rates. We found the highest vector competence for the imported Zika virus in Ae. aegypti mosquitoes, some susceptibility of Ae. albopictus mosquitoes, but no transmission ability for Cx. quinquefasciatus mosquitoes. Considering that, in China, Ae. albopictus mosquitoes are widely distributed but Ae. aegypti mosquito distribution is limited, Ae. albopictus mosquitoes are a potential primary vector for Zika virus and should be targeted in vector control strategies. PMID:28430562

  5. Zika virus in Gabon (Central Africa--2007: a new threat from Aedes albopictus?

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    Gilda Grard

    2014-02-01

    Full Text Available Chikungunya and dengue viruses emerged in Gabon in 2007, with large outbreaks primarily affecting the capital Libreville and several northern towns. Both viruses subsequently spread to the south-east of the country, with new outbreaks occurring in 2010. The mosquito species Aedes albopictus, that was known as a secondary vector for both viruses, recently invaded the country and was the primary vector involved in the Gabonese outbreaks. We conducted a retrospective study of human sera and mosquitoes collected in Gabon from 2007 to 2010, in order to identify other circulating arboviruses.Sample collections, including 4312 sera from patients presenting with painful febrile disease, and 4665 mosquitoes belonging to 9 species, split into 247 pools (including 137 pools of Aedes albopictus, were screened with molecular biology methods. Five human sera and two Aedes albopictus pools, all sampled in an urban setting during the 2007 outbreak, were positive for the flavivirus Zika (ZIKV. The ratio of Aedes albopictus pools positive for ZIKV was similar to that positive for dengue virus during the concomitant dengue outbreak suggesting similar mosquito infection rates and, presumably, underlying a human ZIKV outbreak. ZIKV sequences from the envelope and NS3 genes were amplified from a human serum sample. Phylogenetic analysis placed the Gabonese ZIKV at a basal position in the African lineage, pointing to ancestral genetic diversification and spread.We provide the first direct evidence of human ZIKV infections in Gabon, and its first occurrence in the Asian tiger mosquito, Aedes albopictus. These data reveal an unusual natural life cycle for this virus, occurring in an urban environment, and potentially representing a new emerging threat due to this novel association with a highly invasive vector whose geographic range is still expanding across the globe.

  6. Vector competence of Malaysian Aedes albopictus with and without Wolbachia to four dengue virus serotypes.

    Science.gov (United States)

    Joanne, Sylvia; Vythilingam, Indra; Teoh, Boon-Teong; Leong, Cherng-Shii; Tan, Kim-Kee; Wong, Meng-Li; Yugavathy, Nava; AbuBakar, Sazaly

    2017-09-01

    To determine the susceptibility status of Aedes albopictus with and without Wolbachia to the four dengue virus serotypes. Two newly colonised colonies of Ae. albopictus from the wild were used for the study. One colony was naturally infected with Wolbachia while in the other Wolbachia was removed by tetracycline treatment. Both colonies were orally infected with dengue virus-infected fresh blood meal. Dengue virus load was measured using quantitative RT-PCR at four-time intervals in the salivary glands, midguts and ovaries. Wolbachia did not significantly affect Malaysian Ae. albopictus dengue infection or the dissemination rate for all four dengue virus serotypes. Malaysian Ae. albopictus had the highest replication kinetics for DENV-1 and the highest salivary gland and midgut infection rate for DENV-4. Wolbachia, which naturally exists in Malaysian Ae. albopictus, does not significantly affect dengue virus replication. Malaysian Ae. albopictus is susceptible to dengue virus infections and capable of transmitting dengue virus, especially DENV-1 and DENV-4. Removal of Wolbachia from Malaysian Ae. albopictus would not reduce their susceptibility status. © 2017 John Wiley & Sons Ltd.

  7. Reported Distribution of Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus in the United States, 1995-2016 (Diptera: Culicidae).

    Science.gov (United States)

    Hahn, Micah B; Eisen, Rebecca J; Eisen, Lars; Boegler, Karen A; Moore, Chester G; McAllister, Janet; Savage, Harry M; Mutebi, John-Paul

    2016-06-09

    Aedes (Stegomyia) aegypti (L.) and Aedes (Stegomyia) albopictus (Skuse) transmit arboviruses that are increasing threats to human health in the Americas, particularly dengue, chikungunya, and Zika viruses. Epidemics of the associated arboviral diseases have been limited to South and Central America, Mexico, and the Caribbean in the Western Hemisphere, with only minor localized outbreaks in the United States. Nevertheless, accurate and up-to-date information for the geographical ranges of Ae. aegypti and Ae. albopictus in the United States is urgently needed to guide surveillance and enhance control capacity for these mosquitoes. We compiled county records for presence of Ae. aegypti and Ae. albopictus in the United States from 1995-2016, presented here in map format. Records were derived from the Centers for Disease Control and Prevention ArboNET database, VectorMap, the published literature, and a survey of mosquito control agencies, university researchers, and state and local health departments. Between January 1995 and March 2016, 183 counties from 26 states and the District of Columbia reported occurrence of Ae. aegypti, and 1,241 counties from 40 states and the District of Columbia reported occurrence of Ae. albopictus During the same time period, Ae. aegypti was collected in 3 or more years from 94 counties from 14 states and the District of Columbia, and Ae. albopictus was collected during 3 or more years from 514 counties in 34 states and the District of Columbia. Our findings underscore the need for systematic surveillance of Ae. aegypti and Ae. albopictus in the United States and delineate areas with risk for the transmission of these introduced arboviruses.

  8. Established Population of the Invasive Mosquito Species Aedes albopictus in Romania, 2012-14.

    Science.gov (United States)

    Prioteasa, Liviu F; Dinu, Sorin; Fălcuţă, Elena; Ceianu, Cornelia S

    2015-06-01

    During an entomological investigation carried out in Bucharest and surroundings in fall of 2012, 45 adult mosquitoes (38 females and 7 males) of Aedes albopictus were collected in a neighborhood from the southern area of the city. The morphological identification of the species was further confirmed by sequencing 2 mitochondrial DNA markers: the cytochrome c oxidase subunit I and NADH dehydrogenase subunit 5 genes. Aedes albopictus was collected again in 2013 in the same area from July until October. During late summer the species was found also in another location in the city, downtown Bucharest. Larvae were found in water barrels and other types of household containers, as well as in rain catch basins. In 2014, following a nuisance complaint of a Bucharest inhabitant, the entomological investigation found aggressive Ae. albopictus adults on his property that harbored many mosquito larvae in container-type breeding habitats. These findings are the 1st records of this invasive species and of its breeding population in Romania, and show maintenance of the species over 2 winter seasons. Surveillance of the species outside the area of the capital city was not performed, therefore it is not known whether Ae. albopictus has been introduced in other regions of the country. The presence of Ae. albopictus has been reported every year (2012-14) to competent public health authorities, stressing on the importance of surveillance and of implementation of control measures.

  9. Global temperature constraints on Aedes aegypti and Ae. albopictus persistence and competence for dengue virus transmission

    Science.gov (United States)

    2014-01-01

    Background Dengue is a disease that has undergone significant expansion over the past hundred years. Understanding what factors limit the distribution of transmission can be used to predict current and future limits to further dengue expansion. While not the only factor, temperature plays an important role in defining these limits. Previous attempts to analyse the effect of temperature on the geographic distribution of dengue have not considered its dynamic intra-annual and diurnal change and its cumulative effects on mosquito and virus populations. Methods Here we expand an existing modelling framework with new temperature-based relationships to model an index proportional to the basic reproductive number of the dengue virus. This model framework is combined with high spatial and temporal resolution global temperature data to model the effects of temperature on Aedes aegypti and Ae. albopictus persistence and competence for dengue virus transmission. Results Our model predicted areas where temperature is not expected to permit transmission and/or Aedes persistence throughout the year. By reanalysing existing experimental data our analysis indicates that Ae. albopictus, often considered a minor vector of dengue, has comparable rates of virus dissemination to its primary vector, Ae. aegypti, and when the longer lifespan of Ae. albopictus is considered its competence for dengue virus transmission far exceeds that of Ae. aegypti. Conclusions These results can be used to analyse the effects of temperature and other contributing factors on the expansion of dengue or its Aedes vectors. Our finding that Ae. albopictus has a greater capacity for dengue transmission than Ae. aegypti is contrary to current explanations for the comparative rarity of dengue transmission in established Ae. albopictus populations. This suggests that the limited capacity of Ae. albopictus to transmit DENV is more dependent on its ecology than vector competence. The recommendations, which we

  10. Aedes albopictus (Diptera: Culicidae) and Mosquito-Borne Viruses in the United States.

    Science.gov (United States)

    Vanlandingham, Dana L; Higgs, Stephen; Huang, Yan-Jang S

    2016-09-01

    The Asian tiger mosquito Aedes albopictus (Skuse), is a highly invasive species that continues to expand its geographic distribution both in the United States and in countries on other continents. Studies have demonstrated its susceptibility to infection with at least 32 viruses, including 13 that are present in the United States. Despite this susceptibility, its role as a significant competent vector in natural transmission cycles of arboviruses, has been limited. However, with the recent introductions of chikungunya and Zika viruses into the Americas, for which Ae. albopictus is a recognized vector, it is possible that the species may contribute to the transmission of these viruses to humans and perhaps other susceptible vertebrates.

  11. First report of Aedes (Stegomyia) albopictus (Diptera: Culicidae) in Oran, West of Algeria.

    Science.gov (United States)

    Benallal, K E; Allal-Ikhlef, A; Benhamouda, K; Schaffner, F; Harrat, Z

    2016-12-01

    The increasing globalisation of trades, human movements and environmental changes facilitate the introduction and the establishment of the invasive Asian tiger mosquito Aedes albopictus outside its native geographical area. Alerted by the complaints about mosquito biting which occurred daytime for the inhabitants of the seaside town Ain Turk (West of Algeria), an entomological survey was conducted in December 2015 to determine the origin of this nuisance. Among the collected mosquitoes, specimens of Ae. albopictus (2 males, 3 females and 3 pupae) were collected. This is the first observation of that invasive mosquito in the west of Algeria which confirms its presence and establishment in Mediterranean Africa.

  12. Effect of brefeldin A on Mayaro virus replication in Aedes albopictus and Vero cells.

    Science.gov (United States)

    Da Costa, L J; Rebello, M A

    1999-12-01

    Brefeldin A (BFA), a fungal metabolite that blocks transport of newly synthesized proteins from the endoplasmic reticulum, was found to inhibit Mayaro virus replication. At the concentration of 0.05 microgram/ml, the yield of the virus was inhibited by 94% in Aedes albopictus cells and by 99.5% in Vero cells. Treatment of A. albopictus cells with BFA did not inhibit the virus protein synthesis. However, this compound drastically reduced viral protein synthesis in Vero cells. The inhibitory effect progressively declined when BFA was added at late times post infection (p.i.). The effect of BFA on protein glycosylation is discussed.

  13. Crouching tiger, hidden trouble: urban sources of Aedes albopictus (Diptera: Culicidae refractory to source-reduction.

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    Isik Unlu

    Full Text Available Our ultimate objective is to design cost-effective control strategies for Aedes albopictus, the Asian tiger mosquito, an important urban nuisance and disease vector that expanded worldwide during the last 40 years. We conducted mosquito larval surveys from May through October 2009 in the City of Trenton, New Jersey, USA, while performing intensive monthly source-reduction campaigns that involved removing, emptying, or treating all accessible containers with larvicides and pupicides. We examined patterns of occurrence of Ae. albopictus and Culex pipiens, another urban mosquito, among different container types by comparing observed and expected number of positive containers of each type. Expected use was based on the relative frequency of each container type in the environment. Aedes albopictus larvae and pupae were found significantly more often than expected in medium volumes of water in buckets and plant saucers but were rarely collected in small volumes of water found in trash items such as discarded cups and cans. They were also absent from large volumes of water such as in abandoned swimming pools and catch basins, although we consistently collected Cx. pipiens from those habitats. The frequency of Ae. albopictus in tires indicated rapid and extensive use of these ubiquitous urban containers. Standard larval-based indices did not correlate with adult catches in BG-Sentinel traps, but when based only on Ae. albopictus key containers (buckets, plant saucers, equipment with pockets of water, and tires they did. Although we found that only 1.2% of the 20,039 water-holding containers examined contained immature Ae. albopictus (5.3% if only key containers were counted, adult populations were still above nuisance action thresholds six times during the 2009 mosquito season. We conclude that in urban New Jersey, effective source reduction for Ae. albopictus control will require scrupulous and repeated cleaning or treatment of everyday use containers

  14. Crouching tiger, hidden trouble: urban sources of Aedes albopictus (Diptera: Culicidae) refractory to source-reduction.

    Science.gov (United States)

    Unlu, Isik; Farajollahi, Ary; Strickman, Daniel; Fonseca, Dina M

    2013-01-01

    Our ultimate objective is to design cost-effective control strategies for Aedes albopictus, the Asian tiger mosquito, an important urban nuisance and disease vector that expanded worldwide during the last 40 years. We conducted mosquito larval surveys from May through October 2009 in the City of Trenton, New Jersey, USA, while performing intensive monthly source-reduction campaigns that involved removing, emptying, or treating all accessible containers with larvicides and pupicides. We examined patterns of occurrence of Ae. albopictus and Culex pipiens, another urban mosquito, among different container types by comparing observed and expected number of positive containers of each type. Expected use was based on the relative frequency of each container type in the environment. Aedes albopictus larvae and pupae were found significantly more often than expected in medium volumes of water in buckets and plant saucers but were rarely collected in small volumes of water found in trash items such as discarded cups and cans. They were also absent from large volumes of water such as in abandoned swimming pools and catch basins, although we consistently collected Cx. pipiens from those habitats. The frequency of Ae. albopictus in tires indicated rapid and extensive use of these ubiquitous urban containers. Standard larval-based indices did not correlate with adult catches in BG-Sentinel traps, but when based only on Ae. albopictus key containers (buckets, plant saucers, equipment with pockets of water, and tires) they did. Although we found that only 1.2% of the 20,039 water-holding containers examined contained immature Ae. albopictus (5.3% if only key containers were counted), adult populations were still above nuisance action thresholds six times during the 2009 mosquito season. We conclude that in urban New Jersey, effective source reduction for Ae. albopictus control will require scrupulous and repeated cleaning or treatment of everyday use containers and extensive

  15. Crouching Tiger, Hidden Trouble: Urban Sources of Aedes albopictus (Diptera: Culicidae) Refractory to Source-Reduction

    Science.gov (United States)

    Unlu, Isik; Farajollahi, Ary; Strickman, Daniel; Fonseca, Dina M.

    2013-01-01

    Our ultimate objective is to design cost-effective control strategies for Aedes albopictus, the Asian tiger mosquito, an important urban nuisance and disease vector that expanded worldwide during the last 40 years.  We conducted mosquito larval surveys from May through October 2009 in the City of Trenton, New Jersey, USA, while performing intensive monthly source-reduction campaigns that involved removing, emptying, or treating all accessible containers with larvicides and pupicides. We examined patterns of occurrence of Ae. albopictus and Culex pipiens, another urban mosquito, among different container types by comparing observed and expected number of positive containers of each type. Expected use was based on the relative frequency of each container type in the environment. Aedes albopictus larvae and pupae were found significantly more often than expected in medium volumes of water in buckets and plant saucers but were rarely collected in small volumes of water found in trash items such as discarded cups and cans. They were also absent from large volumes of water such as in abandoned swimming pools and catch basins, although we consistently collected Cx. pipiens from those habitats. The frequency of Ae. albopictus in tires indicated rapid and extensive use of these ubiquitous urban containers. Standard larval-based indices did not correlate with adult catches in BG-Sentinel traps, but when based only on Ae. albopictus key containers (buckets, plant saucers, equipment with pockets of water, and tires) they did. Although we found that only 1.2% of the 20,039 water-holding containers examined contained immature Ae. albopictus (5.3% if only key containers were counted), adult populations were still above nuisance action thresholds six times during the 2009 mosquito season. We conclude that in urban New Jersey, effective source reduction for Ae. albopictus control will require scrupulous and repeated cleaning or treatment of everyday use containers and extensive

  16. Female-specific flightless (fsRIDL phenotype for control of Aedes albopictus.

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    Geneviève M C Labbé

    Full Text Available BACKGROUND: Aedes albopictus, the Asian tiger mosquito, is a vector of several arboviruses including dengue and chikungunya, and is also a significant nuisance mosquito. It is one of the most invasive of mosquitoes with a relentlessly increasing geographic distribution. Conventional control methods have so far failed to control Ae. albopictus adequately. Novel genetics-based strategies offer a promising alternative or aid towards efficient control of this mosquito. METHODOLOGY/PRINCIPAL FINDINGS: We describe here the isolation, characterisation and use of the Ae. albopictus Actin-4 gene to drive a dominant lethal gene in the indirect flight muscles of Ae. albopictus, thus inducing a conditional female-specific late-acting flightless phenotype. We also show that in this context, the Actin-4 regulatory regions from both Ae. albopictus and Ae. aegypti can be used to provide conditional female-specific flightlessness in either species. CONCLUSION/SIGNIFICANCE: With the disease-transmitting females incapacitated, the female flightless phenotype encompasses a genetic sexing mechanism and would be suitable for controlling Ae. albopictus using a male-only release approach as part of an integrated pest management strategy.

  17. Aedes aegypti and Aedes albopictus (Diptera: Culicidae: coexistence and susceptibility to temephos, in municipalities with occurrence of dengue and differentiated characteristics of urbanization

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    Josiane Somariva Prophiro

    2011-06-01

    Full Text Available INTRODUCTION: The aim of the present study was to verify the coexistence between Aedes aegypti and Aedes albopictus populations in municipalities of the States of Paraná and Santa Catarina with different urbanization profiles where dengue occurs and evaluate their susceptibility to the organophosphate temephos. METHODS: The number of eggs per ovitrap were counted and incubated for hatching to identify the species. Data analysis of the populations was conducted to determine randomness and aggregation, using the variance-to-mean ratio (index of dispersion. Susceptibility to temephos was evaluated by estimation of the resistance ratios RR50 and RR95. Aedes aegypti samples were compared with the population Rockefeller and Aedes albopictus samples were compared with a population from the State of Santa Catarina and with the Rockefeller population. RESULTS: Coexistence between Aedes aegypti and Aedes albopictus and the aggregation of their eggs were observed at all the sites analyzed in the State of Paraná. CONCLUSIONS: All the Aedes aegypti populations from the State of Parana showed alteration in susceptibility status to the organophosphate temephos, revealing incipient resistance. Similarly, all the Aedes albopictus populations (States of Paraná and Santa Catarina presented survival when exposed to the organophosphate temephos.

  18. Consequences of the expanding global distribution of Aedes albopictus for dengue virus transmission.

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    Louis Lambrechts

    Full Text Available The dramatic global expansion of Aedes albopictus in the last three decades has increased public health concern because it is a potential vector of numerous arthropod-borne viruses (arboviruses, including the most prevalent arboviral pathogen of humans, dengue virus (DENV. Ae. aegypti is considered the primary DENV vector and has repeatedly been incriminated as a driving force in dengue's worldwide emergence. What remains unresolved is the extent to which Ae. albopictus contributes to DENV transmission and whether an improved understanding of its vector status would enhance dengue surveillance and prevention. To assess the relative public health importance of Ae. albopictus for dengue, we carried out two complementary analyses. We reviewed its role in past dengue epidemics and compared its DENV vector competence with that of Ae. aegypti. Observations from "natural experiments" indicate that, despite seemingly favorable conditions, places where Ae. albopictus predominates over Ae. aegypti have never experienced a typical explosive dengue epidemic with severe cases of the disease. Results from a meta-analysis of experimental laboratory studies reveal that although Ae. albopictus is overall more susceptible to DENV midgut infection, rates of virus dissemination from the midgut to other tissues are significantly lower in Ae. albopictus than in Ae. aegypti. For both indices of vector competence, a few generations of mosquito colonization appear to result in a relative increase of Ae. albopictus susceptibility, which may have been a confounding factor in the literature. Our results lead to the conclusion that Ae. albopictus plays a relatively minor role compared to Ae. aegypti in DENV transmission, at least in part due to differences in host preferences and reduced vector competence. Recent examples of rapid arboviral adaptation to alternative mosquito vectors, however, call for cautious extrapolation of our conclusion. Vector status is a dynamic

  19. Screening for larvicidal activity of ethanolic and aqueous extracts of selected plants against Aedes aegypti and Aedes albopictus larvae

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    Michael Russelle Alvarez

    2016-02-01

    Full Text Available Objective: To screen for larvicidal activity of aqueous and ethanolic extracts (95% ethanol from Selaginella elmeri, Christella dentata, Elatostema sinnatum, Curculigo capitulata, Euphorbia hirta, Murraya koenigii (M. koenigii, Alpinia speciosa, Cymbopogon citratus, Eucalyptus globulus (E. globulus, Jatropha curcas (J. curcas, Psidium guajava, Gliricidia sepium, Ixora coccinea and Capsicum frutescens (C. frutescens against Aedes aegypti (A. aegypti and Aedes albopictus (A. albopictus 3rd instar larvae. Methods: Ethanolic and aqueous extracts were screened for larvicidal activity by exposing the A. aegypti and A. albopictus 3rd instar larvae (15 larvae per trial, triplicates for 48 h, counting the mortalities every 24 h. Additionally, phytochemical screening for flavonoids, tannins, alkaloids, anthraquinones, anthrones, coumarins, indoles and steroids were performed on active extracts using spray tests. Results: Against A. aegypti, the three most active extracts were C. frutescens ethanolic (100% after 24 and 48 h, J. curcas ethanolic (84.44% after 24 h and 88.89% after 48 h and M. koenigii ethanolic (53.33% after 24 h and 71.11% after 48 h. On the other hand, against A. albopictus, the three most active extracts were C. frutescens ethanolic (93.33% after 24 h and 100% after 48 h, J. curcas ethanolic (77.78% after 24 h and 82.22% after 48 h and E. globulus ethanolic (64.44% after 24 h and 73.33% after 48 h. Phytochemical screening was also performed on the active extracts, revealing alkaloids, tannins, indoles and steroids. Conclusios: The results demonstrate the larvicidal activities of ethanolic extracts of Cymbopogon citratus, Euphorbia hirta, Ixora coccinea, Gliricidia sepium, M. koenigii, E. globulus, J. curcas and C. frutescens against A. aegypti and A. albopictus 3rd instar larvae. These could be used as potential larvicidal agents for the control of these mosquitoes.

  20. Screening for larvicidal activity of ethanolic and aqueous extracts of selected plants against Aedes aegypti and Aedes albopictus larvae

    Institute of Scientific and Technical Information of China (English)

    Michael RusselleAlvarez; Francisco Heralde III; Noel Quiming

    2016-01-01

    Objective: To screen for larvicidal activity of aqueous and ethanolic extracts (95% ethanol) from Selaginella elmeri, Christella dentata, Elatostema sinnatum, Curculigo capitulata, Euphorbia hirta, Murraya koenigii (M. koenigii), Alpinia speciosa, Cymbopogon citratus, Eucalyptus globulus (E. globulus), Jatropha curcas (J. curcas), Psidium guajava, Gliricidia sepium, Ixora coccinea and Capsicum frutescens (C. frutescens) against Aedes aegypti (A. aegypti) and Aedes albopictus (A. albopictus) 3rd instar larvae. Methods: Ethanolic and aqueous extracts were screened for larvicidal activity by exposing the A. aegypti and A. albopictus 3rd instar larvae (15 larvae per trial, triplicates) for 48 h, counting the mortalities every 24 h. Additionally, phytochemical screening for flavonoids, tannins, alkaloids, anthraquinones, anthrones, coumarins, indoles and steroids were performed on active extracts using spray tests. Results: Against A. aegypti, the three most active extracts were C. frutescens ethanolic (100%after 24 and 48 h), J. curcas ethanolic (84.44% after 24 h and 88.89% after 48 h) and M. koenigii ethanolic (53.33% after 24 h and 71.11% after 48 h). On the other hand, against A. albopictus, the three most active extracts were C. frutescens ethanolic (93.33% after 24 h and 100% after 48 h), J. curcas ethanolic (77.78% after 24 h and 82.22% after 48 h) and E. globulus ethanolic (64.44% after 24 h and 73.33% after 48 h). Phytochemical screening was also performed on the active extracts, revealing alkaloids, tannins, indoles and steroids. Conclusios: The results demonstrate the larvicidal activities of ethanolic extracts of Cymbopogon citratus, Euphorbia hirta, Ixora coccinea, Gliricidia sepium, M. koenigii, E. globulus, J. curcas and C. frutescens against A. aegypti and A. albopictus 3rd instar larvae. These could be used as potential larvicidal agents for the control of these mosquitoes.

  1. Viral contamination of a mosquito cell line, Aedes albopictus, associated with syncytium formation.

    Science.gov (United States)

    Hirumi, H; Hirumi, K; Speyer, G; Yunker, C E; Thomas, L A; Cory, J; Sweet, B H

    1976-02-01

    Viral contamination associated with syncytium formation in two sbulines of Singh's Aedes albopictus cell cultures was investigated. Electron microscopy of the syncytia revealed the presence of five different types of virus-like particles, which morphologically resembled the parvo-, picorna-, toga-, and orbi-, and bacterial viruses. When a virus-free subline of the A. albopictus cells (SL3) was inoculated with extracts of the syncytium-forming A. albopictus cells, the parvo-, toga-, and orbi-type viral agents were consistently observed. Among these three agents, the togavirus-type agent is most likely responsible for the syncytium induction. Serological examination of the infected cell extract indicated that at least one of three virus-like agents, presumably the togavirus-type agent, was related to Chikungunya. O'nyong-nyong, and Western equine encephalomyelitis viruses (alphaviruses of the Togaviridae), but separable from these.

  2. Vector competence of three North American strains of Aedes albopictus for West Nile virus.

    Science.gov (United States)

    Sardelis, Michael R; Turell, Michael J; O'Guinn, Monica L; Andre, Richard G; Roberts, Donald R

    2002-12-01

    To evaluate the potential for North American (NA) Aedes albopictus to transmit West Nile virus (WN), mosquito strains derived from 3 NA sources (Frederick County, Maryland, FRED strain; Cheverly, MD, CHEV strain; Chambers and Liberty counties, Texas, TAMU strain) were tested. These strains were tested along with a previously tested strain from a Hawaiian source (OAHU strain). Mosquitoes were fed on 2- to 3-day-old chickens previously inoculated with a New York strain (Crow 397-99) of WN. All of the NA strains were competent laboratory vectors of WN, with transmission rates of 36, 50, 83, and 92% for the FRED, CHEV, OAHU, and TAMU strains, respectively. The extrinsic incubation period for WN in Ae. albopictus held at 26 degrees C was estimated to be 10 days. Based on efficiency of viral transmission, evidence of natural infection, bionomics, and distribution, Ae. albopictus could be an important bridge vector of WN in the southeastern USA.

  3. Aedes albopictus may not be vector of dengue virus in human epidemics in Brazil

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    Degallier Nicolas

    2003-01-01

    Full Text Available Over 60,500 dengue cases were reported in the state of Espírito Santo (ES, Brazil, between 1995 and 1998. The study's purpose was to identify whether Aedes albopictus was transmitting the dengue virus during an epidemic in the locality of Vila Bethânia (Viana County,Vitória, ES. From April 3 to 9, 1998, blood and serum samples were collected daily for virus isolation and serological testing. Four autochthonous cases were confirmed through DEN 1 virus isolation and two autochthonous cases through MAC ELISA testing. Of 37 Ae. aegypti and 200 Ae. albopictus adult mosquitoes collected and inoculated, DEN1 virus was isolated only from a pool of two Ae. aegypti female mosquitoes. The study results suggest that Ae. albopictus still cannot be considered an inter-human vector in dengue epidemics in Brazil.

  4. A chikungunya outbreak associated with the vector Aedes albopictus in remote villages of Gabon.

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    Paupy, Christophe; Kassa Kassa, Fabrice; Caron, Mélanie; Nkoghé, Dieudonné; Leroy, Eric M

    2012-02-01

    Chikungunya virus (CHIKV) recently caused major urban outbreaks in central African countries such as the Democratic Republic of Congo (DRC), Cameroon, and Gabon. In Gabon, the tiger mosquito Aedes albopictus was shown to be the main CHIKV vector during the 2007 outbreak. This invasive Asian species was first identified in Gabon in early 2007, and was thought to be restricted mainly to coastal provinces where urban epidemic CHIKV foci were recorded. Here we report a CHIKV outbreak in a small cluster of villages isolated in the deep forest of southern Gabon, in which A. albopictus was the main vector. This observation indicates concomitant geographic and ecological spread of CHIKV activity and A. albopictus in remote environments in central Africa, as well as an enhanced risk of propagation of epidemic arboviruses.

  5. Detection of Wolbachia in Aedes albopictus and Their Effects on Chikungunya Virus

    Science.gov (United States)

    Ahmad, Noor Afizah; Vythilingam, Indra; Lim, Yvonne A. L.; Zabari, Nur Zatil Aqmar M.; Lee, Han Lim

    2017-01-01

    Wolbachia-based vector control strategies have been proposed as a means to augment the currently existing measures for controlling dengue and chikungunya vectors. Prior to utilizing Wolbachia as a novel vector control strategy, it is crucial to understand the Wolbachia–mosquito interactions. In this study, field surveys were conducted to screen for the infection status of Wolbachia in field-collected Aedes albopictus. The effects of Wolbachia in its native host toward the replication and dissemination of chikungunya virus (CHIKV) was also studied. The prevalence of Wolbachia-infected field-collected Ae. albopictus was estimated to be 98.6% (N = 142) for females and 95.1% (N = 102) for males in the population studied. The Ae. albopictus were naturally infected with both wAlbA and wAlbB strains. We also found that the native Wolbachia has no impact on CHIKV infection and minimal effect on CHIKV dissemination to secondary organs. PMID:27920393

  6. Encontro de Aedes albopictus no Estado do Pará, Brasil

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    Maria de Nazaré de Oliveira Segura

    2003-06-01

    Full Text Available Pela primeira vez é registrada a presença do Aedes (Stg albopictus no Estado do Pará, Brasil, em área urbana no município de Medicilândia distante cerca de 90 km de Altamira, onde foram capturados por meio de isca humana 42 exemplares de mosquitos adultos. Estes foram inoculados em C6/36 e em camundongos recém-nascidos na tentativa de isolamento viral, não tendo sido isolado nenhum vírus. A presença de Aedes albopictus em áreas da Amazônia onde circulam os vírus de dengue e de febre amarela é preocupante e representa um risco potencial desta espécie de mosquito se tornar infectada com tais vírus.

  7. Encontro de Aedes albopictus no Estado do Pará, Brasil

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    Segura Maria de Nazaré de Oliveira

    2003-01-01

    Full Text Available Pela primeira vez é registrada a presença do Aedes (Stg albopictus no Estado do Pará, Brasil, em área urbana no município de Medicilândia distante cerca de 90 km de Altamira, onde foram capturados por meio de isca humana 42 exemplares de mosquitos adultos. Estes foram inoculados em C6/36 e em camundongos recém-nascidos na tentativa de isolamento viral, não tendo sido isolado nenhum vírus. A presença de Aedes albopictus em áreas da Amazônia onde circulam os vírus de dengue e de febre amarela é preocupante e representa um risco potencial desta espécie de mosquito se tornar infectada com tais vírus.

  8. Identification and characterization of seminal fluid proteins in the Asian tiger mosquito, Aedes albopictus.

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    Kathryn E Boes

    2014-06-01

    Full Text Available The Asian tiger mosquito (Aedes albopictus is an important vector for pathogens that affect human health, including the viruses that cause dengue and Chikungunya fevers. It is also one of the world's fastest-spreading invasive species. For these reasons, it is crucial to identify strategies for controlling the reproduction and spread of this mosquito. During mating, seminal fluid proteins (Sfps are transferred from male mosquitoes to females, and these Sfps modulate female behavior and physiology in ways that influence reproduction. Despite the importance of Sfps on female reproductive behavior in mosquitoes and other insects, the identity of Sfps in Ae. albopictus has not previously been reported. We used transcriptomics and proteomics to identify 198 Sfps in Ae. albopictus. We discuss possible functions of these Sfps in relation to Ae. albopictus reproduction-related biology. We additionally compare the sequences of these Sfps with proteins (including reported Sfps in several other species, including Ae. aegypti. While only 72 (36.4% of Ae. albopictus Sfps have putative orthologs in Ae. aegypti, suggesting low conservation of the complement of Sfps in these species, we find no evidence for an elevated rate of evolution or positive selection in the Sfps that are shared between the two Aedes species, suggesting high sequence conservation of those shared Sfps. Our results provide a foundation for future studies to investigate the roles of individual Sfps on feeding and reproduction in this mosquito. Functional analysis of these Sfps could inform strategies for managing the rate of pathogen transmission by Ae. albopictus.

  9. A study on container breeding mosquitoes with special reference to Aedes (Stegomyia aegypti and Aedes albopictus in Thiruvananthapuram district, India

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    K. Vijayakumar

    2014-01-01

    Full Text Available Background & objectives: The district of Thiruvananthapuram reports the maximum number of cases of dengue in the state of Kerala. To determine the larval diversity, density and breeding site preferences of Aedes mosquitoes, during pre-monsoon and monsoon periods in urban and rural areas of Thiruvananthapuram district. Methods: Based on the daily reports of dengue cases, 70 clusters were identified in Thiruvananthapuram district. A cross-sectional larval survey was done in the domestic and peri-domestic areas of 1750 houses, using the WHO standard techniques. The larval indices were calculated, and the larvae were identified by using taxonomic keys. Urban and rural differences and the variations during pre-monsoon and monsoon seasons were also studied. Results: In the surveyed houses, 15% had mosquito breeding, with 88% having Aedes larvae. The house index, container index and the breteau index were 13.08, 13.28 and 16.57%, respectively. About 86% of the clusters were found positive for Aedes albopictus and 11% for Ae. aegypti. Aedes albopictus was distributed almost equally in rural and urban clusters, whereas the distribution of Ae. aegypti was significantly higher in urban areas (p = 0.03. The most common water holding containers found (outdoor were of plastic, followed by coconut shells. The breeding preference ratio was highest for tyres. Significantly lesser positivity was found for containers during monsoon period when compared to pre-monsoon period. Conclusion: The geographical distribution of Ae. albopictus is significantly high in peri-domestic areas and, therefore, its epidemiological role in the widespread disease occurrence needs to be studied. The discarded tyres being the most preferred breeding sites, where IEC activities will help in source reduction.

  10. Assessing the potential risk of Zika virus epidemics in temperate areas with established Aedes albopictus populations.

    Science.gov (United States)

    Guzzetta, Giorgio; Poletti, Piero; Montarsi, Fabrizio; Baldacchino, Frederic; Capelli, Gioia; Rizzoli, Annapaola; Rosà, Roberto; Merler, Stefano

    2016-04-14

    Based on 2015 abundance of Aedes albopictus in nine northern Italian municipalities with temperate continental/oceanic climate, we estimated the basic reproductive number R0 for Zika virus (ZIKV) to be systematically below the epidemic threshold in most scenarios. Results were sensitive to the value of the probability of mosquito infection after biting a viraemic host. Therefore, further studies are required to improve models and predictions, namely evaluating vector competence and potential non-vector transmissions.

  11. Crouching Tiger, Hidden Trouble: Urban Sources of Aedes albopictus (Diptera: Culicidae) Refractory to Source-Reduction

    OpenAIRE

    Isik Unlu; Ary Farajollahi; Daniel Strickman; Fonseca, Dina M.

    2013-01-01

    Our ultimate objective is to design cost-effective control strategies for Aedes albopictus, the Asian tiger mosquito, an important urban nuisance and disease vector that expanded worldwide during the last 40 years. ?We conducted mosquito larval surveys from May through October 2009 in the City of Trenton, New Jersey, USA, while performing intensive monthly source-reduction campaigns that involved removing, emptying, or treating all accessible containers with larvicides and pupicides. We exami...

  12. Preliminary Analysis of Several Attractants and Spatial Repellents for the Mosquito, Aedes albopictus using an Olfactometer

    OpenAIRE

    Hao, Huiling; Sun, Jingcheng; Dai, Jianqing

    2012-01-01

    Mosquito attractants and spatial repellents hold great promise in controlling mosquito pests. In assessing the effectiveness of mosquito attractants and repellents, a good olfactometer system, and optimized testing conditions, are essential. In this research, we demonstrated the usefulness of an olfactometer system, and optimized testing conditions for Aedes albopictus (Diptera: Culicidae). We found no significant difference in the biting activity of the insect between 8:00 and 22:00. Further...

  13. Dose-Dependent Behavioral Response of the Mosquito Aedes albopictus to Floral Odorous Compounds

    OpenAIRE

    Hao, Huiling; Sun, Jingcheng; Dai, Jianqing

    2013-01-01

    The value of using plant volatiles as attractants for trapping and spatial repellents to protect hosts against mosquitoes has been widely recognized. The current study characterized behavioral responses of Aedes albopictus (Skuse) (Diptera: Culicidae) to different concentrations, ranging from 6 to 96%, of several common floral odorous compounds, including linalool, geraniol, citronellal, eugenol, anisaldehyde, and citral, using a wind tunnel olfactometer system. The results indicated that fem...

  14. Enhancement of Aedes albopictus collections by ovitrap and sticky adult trap

    OpenAIRE

    Velo, Enkelejda; Kadriaj, Perparim; Mersini, Kujtim; Shukullari, Ada; Manxhari, Blerta; Simaku, Artan; Hoxha, Adrian; Caputo, Beniamino; Bolzoni, Luca; Rosà, Roberto; Bino, Silvia; Reiter, Paul; della Torre, Alessandra

    2016-01-01

    Background In the last decades, Aedes albopictus has become an increasing public health threat in tropical as well as in more recently invaded temperate areas due to its capacity to transmit several human arboviruses, among which Dengue, Chikungunya and Zika. Enhancing the efficiency of currently used collection approaches, such as ovitraps and sticky traps, is desirable for optimal monitoring of the species abundance, for assessment of the risk of arbovirus transmission and for the optimisat...

  15. Primer hallazgo de Aedes albopictus Skuse en el Gran Área Metropolitana de Costa Rica

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    Rodrigo Marín Rodríguez

    2014-06-01

    Full Text Available Objetivo: Informar sobre el primer hallazgo de Aedes albopictus en el Gran Área Metropolitana de Costa Rica. Métodos: Formas inmaduras de mosquitos colectadas en la Ciudadela La Carpio, Distrito Uruca, San José, como parte de una barrida epidemiológica fueron diagnosticadas preliminarmente como Ae. albopictus. Dicho material se fijó en alcohol al 70 %, se aclaró en lactofenol y se evaluó taxonómicamente mediante claves dicotómicas especializadas. Resultados: Las formas inmaduras evaluadas procedieron de dos criaderos, un tarro y un balde. Las características de las larvas y pupas permitieron identificarlas taxonómicamente como Ae. albopictus. Este es el primer reporte sobre la presencia de dicho vector en Costa Rica. Discusión: La presencia de Ae. albopictus en la Gran Área Metropolitana ocurre como parte del proceso de expansión que está teniendo dicho vector por el territorio nacional. Su presencia debe ser motivo de estudio para determinar su eventual papel en la transmisión del dengue. Por otro lado la presencia de este vector complica la gestión de la vigilancia entomológica de dengue que ha estado dirigida fundamentalmente a la identificación y control del Aedes aegypti.

  16. Mosquitocidal and Oviposition Repellent Activities of the Extracts of Seaweed Bryopsis pennata on Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Yu, Ke-Xin; Wong, Ching-Lee; Ahmad, Rohani; Jantan, Ibrahim

    2015-01-01

    The ever-increasing threat from infectious diseases and the development of insecticide resistance in mosquito populations drive the global search for new natural insecticides. The aims of this study were to evaluate the mosquitocidal activity of the extracts of seaweed Bryopsis pennata against dengue vectors Aedes aegypti and Aedes albopictus, and determine the seaweed's toxic effect on brine shrimp nauplii (as a non-target organism). In addition, the chemical compositions of the active larvicidal extract and fraction were analyzed by using liquid chromatography-mass spectrometry (LC-MS). Chloroform extract exhibited strong ovicidal activity (with LC50 values of 229.3 and 250.5 µg/mL) and larvicidal activity against Ae. aegypti and Ae. albopictus. The larvicidal potential of chloroform extract was further ascertained when its A7 fraction exhibited strong toxic effect against Ae. aegypti (LC50 = 4.7 µg/mL) and Ae. albopictus (LC50 = 5.3 µg/mL). LC-MS analysis of the chloroform extract gave a tentative identification of 13 compounds; Bis-(3-oxoundecyl) tetrasulfide was identified as the major compound in A7 fraction. Methanol extract showed strong repellent effect against female oviposition, along with weak adulticidal activity against mosquito and weak toxicity against brine shrimp nauplii. The mosquitocidal results of B. pennata suggest further investigation for the development of effective insecticide.

  17. Mosquitocidal and Oviposition Repellent Activities of the Extracts of Seaweed Bryopsis pennata on Aedes aegypti and Aedes albopictus

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    Ke-Xin Yu

    2015-08-01

    Full Text Available The ever-increasing threat from infectious diseases and the development of insecticide resistance in mosquito populations drive the global search for new natural insecticides. The aims of this study were to evaluate the mosquitocidal activity of the extracts of seaweed Bryopsis pennata against dengue vectors Aedes aegypti and Aedes albopictus, and determine the seaweed’s toxic effect on brine shrimp nauplii (as a non-target organism. In addition, the chemical compositions of the active larvicidal extract and fraction were analyzed by using liquid chromatography-mass spectrometry (LC-MS. Chloroform extract exhibited strong ovicidal activity (with LC50 values of 229.3 and 250.5 µg/mL and larvicidal activity against Ae. aegypti and Ae. albopictus. The larvicidal potential of chloroform extract was further ascertained when its A7 fraction exhibited strong toxic effect against Ae. aegypti (LC50 = 4.7 µg/mL and Ae. albopictus (LC50 = 5.3 µg/mL. LC-MS analysis of the chloroform extract gave a tentative identification of 13 compounds; Bis-(3-oxoundecyl tetrasulfide was identified as the major compound in A7 fraction. Methanol extract showed strong repellent effect against female oviposition, along with weak adulticidal activity against mosquito and weak toxicity against brine shrimp nauplii. The mosquitocidal results of B. pennata suggest further investigation for the development of effective insecticide.

  18. Comportamento de Aedes albopictus e de Ae. scapularis adultos (Diptera: Culicidae no Sudeste do Brasil Adults Aedes albopictus and Ae. scapularis behavior (Diptera: Culidae in Southeastern Brazil

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    Oswaldo Paulo Forattini

    2000-10-01

    Full Text Available OBJETIVO: Observar e comparar o comportamento das espécies de Aedes albopictus e de Ae. scapularis, na localidade de Pedrinhas, litoral sul do Estado de São Paulo, Brasil. MÉTODOS: As observações foram feitas de outubro de 1996 a janeiro de 2000. Foram realizadas coletas sistemáticas de formas adultas mediante a utilização de isca humana, aspirações ambientais e armadilha tipo Shannon. A domiciliação foi estimada pelo índice de Nuorteva e pela razão de sinantropia. RESULTADOS: Foram feitas 87 coletas diurnas, com a obtenção de 872 adultos fêmeas. As médias de Williams', multiplicadas por 100, foram de 118 e 21 para Ae. albopictus nos horários de 7h às 18h e de 18h às 20h, respectivamente. Quanto a Ae. scapularis, foram de 100 e 106 nos mesmos períodos. Esse último revelou pico de atividade crepuscular vespertina. Na aspiração de abrigos, obteve-se o total de 1.124 espécimens, dos quais 226 Ae. albopictus e 898 Ae. scapularis. O período de janeiro a maio correspondeu ao de maior rendimento para ambos os mosquitos. Quanto à armadilha de Shannon, as coletas realizadas na mata revelaram a ausência de Ae. albopictus. No que concerne à domiciliação, esse último mostrou os maiores valores de índices, enquanto Ae. scapularis revelou comportamento de tipo ubiquista. CONCLUSÕES: Os resultados confirmam outras observações, permitindo levantar hipóteses. Em relação a Ae. scapularis, sugere-se que possa existir fenômeno de diapausa das fêmeas no período verão-outono, a qual cessaria no inverno-primavera quando então a atividade seria retomada. Quanto a Ae. albopictus, os dados sugerem que se trata de população em processo adaptativo ao novo ambiente.OBJECTIVE: Aedes albopictus and Ae. scapularis were found living together in the Pedrinhas Village, Southeastern of São Paulo State, Brazil. This finding was a good opportunity to make observations about the mosquitoes' behavior. METHODS: From October 1996 to

  19. Fipronil as a larvicide against the container-inhabiting mosquito, Aedes albopictus.

    Science.gov (United States)

    Xue, Rui-De; Pridgeon, Julia W; Becnel, James J; Ali, Arshad

    2009-06-01

    In the laboratory, fipronil was tested against laboratory-reared and field-collected early 4th-instars of Aedes albopictus. The insecticide was also bioassayed for activity against natural field populations of Ae. albopictus inhabiting 1-liter-capacity stone-made containers in a cemetery in St. Augustine, FL. The cemetery containers also were utilized to study initial efficacy and activity persistence of fipronil against natural populations of Ae. albopictus. The laboratory-reared larvae were 2-fold more susceptible than field-collected larvae as indicated by the 50% lethal concentration (LC50) values of 2.6 and 6 parts per billion (ppb) for laboratory-reared and field-collected larvae, respectively. In the field bioassay, in stone-made containers, the LC50 value of Ae. albopictus larvae amounted to 57.5 ppb. In the cemetery containers, fipronil applied at 3.2 and 32 ppb gave 100% control of Ae. albopictus larvae with either rate of application for at least up to 8 wk posttreatment.

  20. Population genetics and ecological niche of invasive Aedes albopictus in Mexico.

    Science.gov (United States)

    Pech-May, Angélica; Moo-Llanes, David A; Puerto-Avila, María Belem; Casas, Mauricio; Danis-Lozano, Rogelio; Ponce, Gustavo; Tun-Ku, Ezequiel; Pinto-Castillo, José Francisco; Villegas, Alejandro; Ibáñez-Piñon, Clemente R; González, Cassandra; Ramsey, Janine M

    2016-05-01

    The Asian tiger mosquito Aedes albopictus (Skuse), is one of the most invasive mosquito species worldwide. In Mexico it is now recorded in 12 states and represents a serious public health problem, given the recent introduction of Chikungunya on the southern border. The aim of this study was to analyze the population genetics of A. albopictus from all major recorded foci, and model its ecological niche. Niche similarity with that from its autochthonous distribution in Asia and other invaded countries were analyzed and its potential future expansion and potential human exposure in climate change scenarios measured. We analyzed 125 sequences of a 317 bp fragment of the cyt b gene from seven A. albopictus populations across Mexico. The samples belong to 25 haplotypes with moderate population structuring (Fst=0.081, pMexico. Both Neotropical and Nearctic regions are included in the Mexican niche model. Currently in Mexico, 38.6 million inhabitants are exposed to A. albopictus, which is expected to increase to 45.6 million by 2070. Genetic evidence supports collection information that A. albopictus was introduced to Mexico principally by land from the USA and Central and South America. Prevalent haplotypes from Mexico are shared with most invasive regions across the world, just as there was high niche similarity with both natural and invaded regions. The important overlap with the Asian niche model suggests a high potential for the species to disperse to sylvatic regions in Mexico.

  1. The invasive Asian tiger mosquito Aedes albopictus (Diptera: Culicidae) in Germany: Local reproduction and overwintering.

    Science.gov (United States)

    Walther, D; Scheuch, D E; Kampen, H

    2017-02-01

    Within the framework of a German mosquito monitoring programme, the 'Mueckenatlas' (mosquito atlas) has been established as an instrument of citizen participation in mosquito mapping. In 2015, a strikingly large number of Aedes albopictus, which had not been considered established in Germany, was submitted. Three of six collection sites showed local reproduction, with demonstration of developmental stages over three months at two sites. The third populated site was checked only once in October. Developmental stages of Ae. albopictus were found again at these three sites in spring 2016, including one site in southeastern Germany where reproduction had already been documented in 2014. Although population genetic analyses performed on specimens collected at the latter locality in 2014 and 2015 did not provide proof for hibernation, the finding of developmental stages at this and two other very same sites as in the year before and at very early times in the season strongly suggest accomplished overwintering of Ae. albopictus in Germany. Obviously, the second extremely mild winter in Germany in a row and ongoing adaptation of Ae. albopictus to the temperate European climate allow the species to push northwards from endemic regions in the south. Due to the vector competence of Ae. albopictus for numerous pathogens, including dengue, chikungunya and Zika viruses, action should be taken immediately after the detection of local reproduction to eliminate the populations. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Notes on the blood-feeding behavior of Aedes albopictus (Diptera: Culicidae in Cameroon

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    Kamgang Basile

    2012-03-01

    Full Text Available Abstract Background The invasive mosquito Aedes albopictus is often considered a poor vector of human pathogens, owing to its catholic feeding behavior. However, it was recently incriminated as a major vector in several Chikungunya epidemics, outside of its native range. Here we assessed two key elements of feeding behavior by Ae. albopictus females in Yaoundé, Cameroon, Central Africa. Host preference was explored and the human-biting activity of females was monitored over 24 h to determine periods of maximum bite exposure. Findings Analysis of ingested blood in outdoor-resting females showed that Ae. albopictus preferentially fed on humans rather than on available domestic animals (95% of the blood meals contained human blood. Our results further showed that Ae. albopictus is a day-biting species in Yaoundé, with a main peak of activity in the late afternoon. Conclusion This is the first report on the feeding behavior of Ae. albopictus in Central Africa. The species is highly aggressive to humans and might therefore be involved in human-human virus transmission in this setting.

  3. Holding back the tiger: Successful control program protects Australia from Aedes albopictus expansion

    Science.gov (United States)

    Devine, Gregor; Davis, Joseph; Crunkhorn, Bruce; van den Hurk, Andrew; Whelan, Peter; Russell, Richard; Walker, James; Horne, Peter; Ehlers, Gerhard; Ritchie, Scott

    2017-01-01

    Background The Asian tiger mosquito, Aedes albopictus, is an important vector of dengue, chikungunya and Zika viruses and is a highly invasive and aggressive biter. Established populations of this species were first recognised in Australia in 2005 when they were discovered on islands in the Torres Strait, between mainland Australia and Papua New Guinea. A control program was implemented with the original goal of eliminating Ae. albopictus from the Torres Strait. We describe the evolution of management strategies that provide a template for Ae. albopictus control that can be adopted elsewhere. Methodology / Principal findings The control strategy implemented between 2005 and 2008 targeted larval habitats using source reduction, insect-growth regulator and pyrethroid insecticide to control larvae and adults in the containers. However, the infrequency of insecticide reapplication, the continual accumulation and replacement of containers, and imminent re-introduction of mosquitoes through people’s movement from elsewhere compromised the program. Consequently, in 2009 the objective of the program changed from elimination to quarantine, with the goal of preventing Ae albopictus from infesting Thursday and Horn islands, which are the transport hubs connecting the Torres Strait to mainland Australia. However, larval control strategies did not prevent the species establishing on these islands in 2010. Thereafter, an additional strategy adopted by the quarantine program in early 2011 was harborage spraying, whereby the vegetated, well shaded resting sites of adult Ae. albopictus were treated with a residual pyrethroid insecticide. Inclusion of this additional measure led to a 97% decline in Ae. albopictus numbers within two years. In addition, the frequency of container treatment was increased to five weeks between treatments, compared to an average of 8 weeks that occurred in the earlier iterations of the program. By 2015 and 2016, Ae. albopictus populations on the two

  4. Biochemical studies of insecticide resistance in Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus (Diptera: Culicidae) in Thailand.

    Science.gov (United States)

    Pethuan, S; Jirakanjanakit, N; Saengtharatip, S; Chareonviriyaphap, T; Kaewpa, D; Rongnoparut, P

    2007-06-01

    Biochemical analysis was performed on field caught Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus (Diptera: Culicidae) mosquitoes to determine activities of enzymes including mixed function oxidases (MFO), nonspecific esterases (alpha- and beta-), glutathione-S-transferases (GST), and insensitive acetylcholinesterase (AChE). Biochemical tests were performed on F1 generation of Ae. aegypti field caught mosquitoes, while in Ae. albopictus F2 progenies were used. Twenty-six samples of Ae. aegypti mosquito were collected from areas across different parts of Thailand including Bangkok (central), and the provinces of Chiang Rai (north), Nakhon Sawan (north-central), Nakhon Ratchasrima (northeast), Chonburi (east), Chanthaburi (east), and Songkhla (south). Eight wild caught samples of Ae. albopictus were from Songkhla, Nakhon Sawan, Nakhon Ratchasrima and Kanchanaburi (west) provinces. The susceptibility to pyrethroids (deltamethrin, permethrin), organophosphate (fenitrothion) and carbamate (propoxur) insecticides were revealed in these samples. The biochemical test results were compared with those of the susceptible Bora (French Polynesia) strain. There was significant enhancement of MFO in pyrethroid resistant Ae. aegypti samples, except those from Songkhla and Hauykwang district in Bangkok. Biochemical assay results suggested that nonspecific esterases conferred fenitrothion resistance in Ae. aegypti in Nakhon Sawan, while insensitive AChE and/or nonspecific esterases could play role in fenitrothion resistance in Nakhon Ratchasrima. There was no consistent association of GST with pyrethroid resistance in Ae. aegypti. Low enzyme activities found in Ae. aegypti in Songkhla and in Ae. albopictus corresponded to their insecticide susceptibility status. The increased enzyme activity in field samples reflecting local history of insecticide employment was discussed.

  5. Repellent and Larvicidal Activity of the Essential Oil From Eucalyptus nitens Against Aedes aegypti and Aedes albopictus (Diptera: Culicidae).

    Science.gov (United States)

    Alvarez Costa, Agustín; Naspi, Cecilia V; Lucia, Alejandro; Masuh, Héctor M

    2017-05-01

    Dengue, chikungunya, and yellow fever are important vector-borne diseases transmitted by female mosquitoes when they feed on humans. The use of repellents based on natural products is an alternative for personal protection against these diseases. Application of chemicals with larvicidal activity is another strategy for controlling the mosquito population. The repellent and larvicidal activities of the essential oil from Eucalyptus nitens were tested against Aedes aegypti and Aedes albopictus, the main vectors of these arboviruses. The essential oil was extracted by hydrodistillation and then analyzed by gas chromatography-mass spectrometry. The main components of Eucalyptus nitens essential oil were found to be terpenes such as 1,8-cineole and p-cymene, followed by β-triketones and alkyl esters. The repellent activity of the essential oil against both species was significantly higher when compared with the main component, 1,8-cineole, alone. These results indicate that the repellent effect of E. nitens is not due only to the main component, 1,8-cineole, but also that other compounds may be responsible. Aedes aegypti was found to be more tolerant to the essential oil larvicidal effects than Ae. albopictus (Ae. aegypti LC50 = 52.83 ppm, Ae. albopictus LC 50 = 28.19 ppm). The repellent and larvicidal activity could be associated to the presence of cyclic β-triketones such as flavesone, leptospermone, and isoleptospermone. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Coexistence of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) in Peninsular Florida Two Decades After Competitive Displacements.

    Science.gov (United States)

    Lounibos, L Philip; Bargielowski, Irka; Carrasquilla, María Cristina; Nishimura, Naoya

    2016-11-01

    The spread of Aedes albopictus (Skuse) eastward in the mid-1980s from its initial establishment in Houston, TX, was associated with rapid declines and local disappearances of Aedes aegypti (L.) in Gulf Coast states and Florida where annual larval surveillance during the early 1990s described temporal and spatial patterns of competitive displacements in cemeteries and tire shops. Approximately 20 yr later in 2013-2014, we re-visited former collection sites and sampled aquatic immatures of these two species from tire shops in 10 cities on State Route 441 and from 9 cemeteries from Lakeland to Miami in southwest Florida. In the recent samples Ae. aegypti was recovered from three central Florida cities where it had not been detected in 1994, but its northern limit on Rte. 441, Apopka, did not change. Other evidence, such as trends at a few cemeteries, suggested a moderate resurgence of this species since 1994. Cage experiments that exposed female progeny of Ae. aegypti from recent Florida collection sites to interspecific mating by Ae. albopictus males showed that females from coexistence sites had evolved resistance to cross-mating, but Ae. aegypti from sites with no Ae. albopictus were relatively susceptible to satyrization. Habitat classifications of collection sites were reduced by principal component (PC) analysis to four variables that accounted for > 99% of variances; PCs with strong positive loadings for tree cover and ground vegetation were associated with collection sites yielding only Ae. albopictus Within the coexistence range of the two species, the numbers of Ae. aegypti among total Aedes collected were strongly correlated in stepwise logistic regression models with two habitat-derived PCs, distance from the coast, and annual rainfall and mean maximum temperatures at the nearest weather station. Subtle increases in the range of Ae. aegypti since its previous displacements are interpreted in the context of the evolution of resistance to mating

  7. COEXISTENCE, EXCLUSION, OR NEUTRALITY? A META-ANALYSIS OF COMPETITION BETWEEN AEDES ALBOPICTUS AND RESIDENT MOSQUITOES.

    Science.gov (United States)

    Juliano, Steven A

    2010-06-01

    Competition experiments estimating the relative effects of inter- and intraspecific competition can help to resolve whether interspecific competition results in coexistence or exclusion. For mosquitoes, most such experiments have focused on invasive Aedes albopictus and its interactions with resident Aedes. A meta-analysis of such experiments tested whether the effect of interspecific competition is greater than, less than, or equal to that of intraspecific competition, and whether competitive outcomes are dependent on food quality. For A. albopictus and A. aegypti, there was significant context dependence, with interspecific competitive advantage for A. albopictus with low food quality, and competitive equivalence with high food quality. Meta-analysis of survivorship yielded more significant effects than did estimated rate of increase. Competitive effects and competitive responses of each species yielded similar results. This meta-analysis suggests competitive exclusion of A. aegypti by A. albopictus, and is thus consistent with field sampling, qualitative reviews, and interpretations from individual publications. For A. albopictus and A. triseriatus, most results indicated competitive equivalence and no context dependence, and are thus contrary to previous qualitative reviews and to interpretations from individual publications. For both pairs of species, published results suitable for meta-analysis remain scarce, and better experimental designs and improved analysis and reporting of statistical results are needed. Greater emphasis needs to be placed on estimating species' inter- and intra-specific competitive effects, rather than the more common, but theoretically less interesting, competitive responses. Experiments without low-density controls (i.e., replacement series) are inadequate for comparing competitive effects and responses.

  8. Distribution of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) in small towns and villages of Penang Island, Malaysia--an ovitrap survey.

    Science.gov (United States)

    Yap, H H

    1975-12-01

    An ovitrap survey was carried out in April and May of 1975 at twenty-one locations scattered throughout Penang Island excluding the City of Georgetown. The results showed the ubiquitous presence of Ae. albopictus. Ae. aegypti was recorded only in Tanjung Tokong Lama, an area adjacent to the City of Georgetown. In the survey, Ae. albopictus females were found to prefer the outdoor ovitraps than indoor ones. The effectiveness of ovitrap in Aedes survey was discussed.

  9. miRNA genes of an invasive vector mosquito, Aedes albopictus.

    Directory of Open Access Journals (Sweden)

    Jinbao Gu

    Full Text Available Aedes albopictus, a vector of Dengue and Chikungunya viruses, is a robust invasive species in both tropical and temperate environments. MicroRNAs (miRNAs regulate gene expression and biological processes including embryonic development, innate immunity and infection. While a number of miRNAs have been discovered in some mosquitoes, no comprehensive effort has been made to characterize them from different developmental stages from a single species. Systematic analysis of miRNAs in Ae. albopictus will improve our understanding of its basic biology and inform novel strategies to prevent virus transmission. Between 10-14 million Illumina sequencing reads per sample were obtained from embryos, larvae, pupae, adult males, sugar-fed and blood-fed adult females. A total of 119 miRNA genes represented by 215 miRNA or miRNA star (miRNA* sequences were identified, 15 of which are novel. Eleven, two, and two of the newly-discovered miRNA genes appear specific to Aedes, Culicinae, and Culicidae, respectively. A number of miRNAs accumulate predominantly in one or two developmental stages and the large number that showed differences in abundance following a blood meal likely are important in blood-induced mosquito biology. Gene Ontology (GO analysis of the targets of all Ae. albopictus miRNAs provides a useful starting point for the study of their functions in mosquitoes. This study is the first systematic analysis of miRNAs based on deep-sequencing of small RNA samples of all developmental stages of a mosquito species. A number of miRNAs are related to specific physiological states, most notably, pre- and post-blood feeding. The distribution of lineage-specific miRNAs is consistent with mosquito phylogeny and the presence of a number of Aedes-specific miRNAs likely reflects the divergence between the Aedes and Culex genera.

  10. miRNA genes of an invasive vector mosquito, Aedes albopictus.

    Science.gov (United States)

    Gu, Jinbao; Hu, Wanqi; Wu, Jinya; Zheng, Peiming; Chen, Maoshan; James, Anthony A; Chen, Xiaoguang; Tu, Zhijian

    2013-01-01

    Aedes albopictus, a vector of Dengue and Chikungunya viruses, is a robust invasive species in both tropical and temperate environments. MicroRNAs (miRNAs) regulate gene expression and biological processes including embryonic development, innate immunity and infection. While a number of miRNAs have been discovered in some mosquitoes, no comprehensive effort has been made to characterize them from different developmental stages from a single species. Systematic analysis of miRNAs in Ae. albopictus will improve our understanding of its basic biology and inform novel strategies to prevent virus transmission. Between 10-14 million Illumina sequencing reads per sample were obtained from embryos, larvae, pupae, adult males, sugar-fed and blood-fed adult females. A total of 119 miRNA genes represented by 215 miRNA or miRNA star (miRNA*) sequences were identified, 15 of which are novel. Eleven, two, and two of the newly-discovered miRNA genes appear specific to Aedes, Culicinae, and Culicidae, respectively. A number of miRNAs accumulate predominantly in one or two developmental stages and the large number that showed differences in abundance following a blood meal likely are important in blood-induced mosquito biology. Gene Ontology (GO) analysis of the targets of all Ae. albopictus miRNAs provides a useful starting point for the study of their functions in mosquitoes. This study is the first systematic analysis of miRNAs based on deep-sequencing of small RNA samples of all developmental stages of a mosquito species. A number of miRNAs are related to specific physiological states, most notably, pre- and post-blood feeding. The distribution of lineage-specific miRNAs is consistent with mosquito phylogeny and the presence of a number of Aedes-specific miRNAs likely reflects the divergence between the Aedes and Culex genera.

  11. Vector competence of Aedes albopictus from Houston, Texas, for dengue serotypes 1 to 4, yellow fever and Ross River viruses.

    Science.gov (United States)

    Mitchell, C J; Miller, B R; Gubler, D J

    1987-09-01

    A combination of virus infection and transmission experiments showed that a Houston, Texas strain of Aedes albopictus is a competent vector for dengue (DEN), yellow fever (YF) and Ross River (RR) viruses. However, at 14 days incubation, DEN virus infection rates in a Puerto Rican strain of Aedes aegypti were significantly higher for each of the four DEN serotypes, except DEN-1, than in Houston Ae. albopictus fed simultaneously on the same virus suspensions. The degree of correlation between disseminated DEN infection rates in Houston Ae. albopictus and transmission to an in vitro system ranged from 42 to 88% for the four DEN serotypes. No significant difference was noted in YF virus infection rates or transmission rates in the two mosquito species fed on the same virus suspensions and incubated for the same time period. Also, RR virus infection and transmission rates in Houston and Hawaiian strains of Ae. albopictus were generally comparable.

  12. Variação sazonal de Aedes aegypti e Aedes albopictus no município de Potim, São Paulo Seasonal variation of Aedes aegypti and Aedes albopictus in a city of Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Lígia Leandro Nunes Serpa

    2006-12-01

    Full Text Available OBJETIVO: Verificar a variação sazonal de Aedes aegypti e Aedes albopictus e testar a associação da abundância das espécies com fatores abióticos. MÉTODOS: De novembro de 2002 a outubro de 2003 foram realizadas coletas mensais de imaturos de culicídeos em pneus-armadilha expostos por 15 dias em área urbana de Potim, Vale do Paraíba, SP, Brasil. Os imaturos foram criados em laboratório por 29 dias e identificados segundo espécie. A associação com temperatura, pluviosidade e umidade relativa do ar foram testadas utilizando-se correlações de Spearman (r s. As estatísticas descritivas foram apresentadas pela média e erro-padrão (EP e nos testes foi utilizado alfa=0,05. RESULTADOS: Do total de 20.727 imaturos coletados, 95,3% eram Ae. aegypti e 4,7% Ae. albopictus. A espécie Ae. aegypti esteve presente em todas as estações/meses do ano e Ae. albopictus somente de novembro a julho. As associações das espécies coletadas com fatores abióticos foram significantes em relação à temperatura máxima para Ae. aegypti (p=0,04 e Ae. albopictus (p=0,01, e pluviosidade (p=0,02 para esta última espécie. CONCLUSÕES: Ambas espécies apresentaram variação sazonal. Porém, Ae. aegypti esteve presente durante todo ano, com maiores quedas de densidade entre abril e maio e entre junho e julho. Ae. albopictus menos abundante, foi encontrado apenas de novembro a julho, com o pico em abril. A maior abundância de Ae. aegypti em relação à Ae. albopictus em área urbana mostrou maior capacidade de Ae. aegypti em colonizar pneus. A existência de tal criadouro no ambiente pode ser importante na manutenção e abundância de Ae. aegypti.OBJECTIVE: To assess the seasonal variation of Aedes aegypti and Aedes albopictus and to estimate the association between the species abundance and abiotic factors. METHODS: Tire-traps were kept for a period of 15 days monthly in an urban area of the city of Potim in the state of São Paulo, Southeastern

  13. Effects of Cohabitation on the Population Performance and Survivorship of the Invasive Mosquito Aedes albopictus and the Resident Mosquito Aedes notoscriptus (Diptera: Culicidae) in Australia.

    Science.gov (United States)

    Nicholson, J; Ritchie, S A; Russell, R C; Webb, C E; Cook, A; Zalucki, M P; Williams, C R; Ward, P; van den Hurk, A F

    2015-05-01

    The presence of Aedes albopictus (Skuse) in the Torres Strait of northern Australia increases the potential for colonization and establishment on the mainland. However, there is a possibility that native species that occupy the same habitats may influence the population performance of Ae. albopictus, potentially affecting the establishment of this species in Australia. Cohabitation experiments were performed with the endemic Aedes notoscriptus (Skuse), which has been found occupying the same larval habitats as Ae. albopictus in the Torres Strait and is the most widespread container-inhabiting Aedes species in Australia. The influence of environmental factors and cohabitation between the two species was examined using different climates, food resource levels, food resource types, and species densities. Survivorship proportions and a population performance index (λ') were calculated and compared. The consequences of increased Ae. notoscriptus densities were reduced survivorship and λ' for Ae. albopictus. Despite this, the mean λ' of Ae. albopictus and Ae. notoscriptus was consistently ≥ 1.06, indicating both species could increase under all conditions, potentially due to increasing conspecific densities negatively affecting Ae. notoscriptus. The outcomes from this study suggest that the preexisting presence of Ae. notoscriptus may not prevent the establishment of Ae. albopictus in Australia.

  14. Control of Aedes albopictus larvae using time-release larvicide formulations in Louisiana.

    Science.gov (United States)

    Nasci, R S; Wright, G B; Willis, F S

    1994-03-01

    The ability of time-release formulations of larvicides and insect growth regulators (IGRs) to provide long-term control of Aedes albopictus was investigated in the field. Larvicides used in the study were Bactimos pellets (Bacillus thuringiensis var. israelensis, active ingredient) and Abate pellets (temephos, active ingredient). The IGR Altosid (methoprene, active ingredient) was used in pellet and sand formulations. Application rates were higher than label recommendations. In a preliminary test, clay flower bowls were treated with 2 g of material. Bactimos pellets failed to provide control after 60 days. Abate pellets and the Altosid formulations provided essentially 100% control for 150 days. After 360 days in the field, the Abate pellets produced 100% larval mortality, and significant levels of control were provided by the Altosid formulations and the Bactimos pellets. In a small-scale operational trial of this technique, 1 g of Altosid pellets was applied to every container that could be located in 2 urban residential neighborhoods in Lake Charles, LA. Aedes albopictus biting populations were monitored weekly in the treated areas and in an untreated control area. Biting population densities declined significantly in treated areas compared with the control area. Results suggested that long-term control of Ae. albopictus populations can be achieved economically with one application of Altosid pellets or Abate pellets in containers.

  15. Toxicity and sub-lethal effect of endemic plants from family Anacardiaceae on oviposition behavior of Aedes albopictus

    OpenAIRE

    Wan Fatma Zuharah; Chan Jia Ling; Nurfazlina Zulkifly; Nik Fadzly

    2015-01-01

    Objective: To evaluate the lethal concentration, oviposition deterrence and ovicidal activity of acetone extracts of Melanochyla fasciculiflora (M. fasciculiflora) leaf and Gluta renghas (G. renghas) leaf against Aedes albopictus (Ae. albopictus). Methods: To determine the lethal concentration of Anacardiaceae, ten test concentrations of the extracts ranging from 200 to 650 mg/L were selected for larvicidal bioassays and 25 early fourth instar larvae were exposed to the extracts for 24 h. ...

  16. Evaluation of the Human IgG Antibody Response to Aedes albopictus Saliva as a New Specific Biomarker of Exposure to Vector Bites

    Science.gov (United States)

    Doucoure, Souleymane; Mouchet, François; Cornelie, Sylvie; DeHecq, Jean Sébastien; Rutee, Abdul Hamid; Roca, Yelin; Walter, Annie; Hervé, Jean Pierre; Misse, Dorothée; Favier, François; Gasque, Philippe; Remoue, Franck

    2012-01-01

    Background The spread of Aedes albopictus, a vector for re-emergent arbovirus diseases like chikungunya and dengue, points up the need for better control strategies and new tools to evaluate transmission risk. Human antibody (Ab) responses to mosquito salivary proteins could represent a reliable biomarker for evaluating human-vector contact and the efficacy of control programs. Methodology/Principal Findings We used ELISA tests to evaluate specific immunoglobulin G (IgG) responses to salivary gland extracts (SGE) in adults exposed to Aedes albopictus in Reunion Island. The percentage of immune responders (88%) and levels of anti-SGE IgG Abs were high in exposed individuals. At an individual level, our results indicate heterogeneity of the exposure to Aedes albopictus bites. In addition, low-level immune cross-reactivity between Aedes albopictus and Aedes aegypti SGEs was observed, mainly in the highest responders. Conclusion/Significance Ab responses to saliva could be used as an immuno-epidemiological tool for evaluating exposure to Aedes albopictus bites. Combined with entomological and epidemiological methods, a “salivary” biomarker of exposure to Aedes albopictus could enhance surveillance of its spread and the risk of arbovirus transmission, and could be used as a direct tool for the evaluation of Aedes albopictus control strategies. PMID:22363823

  17. Evaluation of the human IgG antibody response to Aedes albopictus saliva as a new specific biomarker of exposure to vector bites.

    Directory of Open Access Journals (Sweden)

    Souleymane Doucoure

    Full Text Available BACKGROUND: The spread of Aedes albopictus, a vector for re-emergent arbovirus diseases like chikungunya and dengue, points up the need for better control strategies and new tools to evaluate transmission risk. Human antibody (Ab responses to mosquito salivary proteins could represent a reliable biomarker for evaluating human-vector contact and the efficacy of control programs. METHODOLOGY/PRINCIPAL FINDINGS: We used ELISA tests to evaluate specific immunoglobulin G (IgG responses to salivary gland extracts (SGE in adults exposed to Aedes albopictus in Reunion Island. The percentage of immune responders (88% and levels of anti-SGE IgG Abs were high in exposed individuals. At an individual level, our results indicate heterogeneity of the exposure to Aedes albopictus bites. In addition, low-level immune cross-reactivity between Aedes albopictus and Aedes aegypti SGEs was observed, mainly in the highest responders. CONCLUSION/SIGNIFICANCE: Ab responses to saliva could be used as an immuno-epidemiological tool for evaluating exposure to Aedes albopictus bites. Combined with entomological and epidemiological methods, a "salivary" biomarker of exposure to Aedes albopictus could enhance surveillance of its spread and the risk of arbovirus transmission, and could be used as a direct tool for the evaluation of Aedes albopictus control strategies.

  18. Aedes albopictus (Diptera: Culicidae) Oviposition Preference as Influenced by Container Size and Buddleja davidii Plants.

    Science.gov (United States)

    Davis, Timothy J; Kline, Daniel L; Kaufman, Phillip E

    2016-03-01

    Aedes albopictus (Skuse) is a container-breeding mosquito commonly found in residential areas of its range in the United States. Mosquitoes are known to utilize flowering plants for sugar acquisition. Limited information is known about the influences on oviposition site selection, outside of container size. Residential areas are often landscaped with a variety of flowering plants and are known to provide numerous sizes of potential larval developmental sites for container-breeding mosqutioes. Through screened enclosure and field studies, the oviposition preference of Ae. albopictus for containers of three selected sizes (473, 946 and 1,892 ml) and the influence of flowering butterfly bush (Buddleja davidii Franchett cultivar 'Guinevere') plants were examined. Our results document that significantly more eggs were oviposited in the largest containers. Additionally, significantly more eggs were oviposited in containers adjacent to flowering butterfly bushes than in those without a flowering butterfly bush. Finally, our results document that flowering butterfly bushes exerted greater influence over Ae. albopictus oviposition decisions than did container size. Our findings can be applied to several aspects of Ae. albopictus surveillance and control.

  19. Survivorship of adult Aedes albopictus (Diptera: Culicidae) feeding on indoor ornamental plants with no inflorescence.

    Science.gov (United States)

    Qualls, Whitney A; Xue, Rui De; Beier, John C; Müller, Günter C

    2013-06-01

    The international trade of lucky bamboo (Dracaena sanderiana [Asparagaceae]) is responsible for certain introductions of the exotic species Aedes albopictus (Skuse) in California and the Netherlands. Understanding the association of this species with lucky bamboo and other ornamental plants is important from a public health standpoint. The aim of this study was to investigate the importance of indoor ornamental plants as sugar sources for adult A. albopictus. If exposed to D. sanderiana, bromeliad (Guzmania spp. hybrid [Bromeliaceae]), Moses-in-the-cradle (Rhoeo spathacea [Commelinaceae]), 10 % sucrose solution, and a negative water control as the only nutrient source, adult female A. albopictus mean survival time was 12, 7, 6, 15, and 4 days, respectively. Mean survival times for adult males were not significantly different (P > 0.05) from the females and were 10, 7, 6, 14, and 3 days, respectively. Combined male and female survival times were not significantly different on lucky bamboo compared to survival times on a 10 % sucrose control. Based on our findings, A. albopictus can readily survive long enough to complete a gonotrophic cycle and potentially complete the extrinsic incubation period for many arboviruses when only provided access to lucky bamboo plants or possibly other common ornamentals. Vector control professionals should be aware of potential in-home infestations and public health concerns associated with mosquito breeding and plant tissue feeding on ornamental plants.

  20. Primeira Ocorrência de Aedes (Stegomyia albopictus (Skuse no Estado de Sergipe

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    Antônio César Santana

    2014-12-01

    Abstract. The mosquito Aedes (Stegomyia albopictus (Skuse, a vector for several arboviral diseases, was recorded for the first time in the state of Sergipe, Brazil, in the municipality of Areia Branca, located in the central-eastern part of the state at the coordinates 10°45'29"S and 37°18'45"W and 36 km from the state capital, Aracaju. The first larva of Ae. albopictus was collected in the 32nd epidemiological week of 2011, in the settlement of Terra Preta de Cima and was identified systematically in the Central Public Health Laboratory (LACEN-SE during quality control activities within the yellow fever and dengue control program (PCFAD. In the 50th epidemiological week of 2012, another larva of Ae. albopictus was found, this time in the settlement of Manilha de Baixo. In the neighboring municipality of Campo do Brito, three larvae and two pupae of Ae. Albopictus were found in the settlement of Garangau (10º44'55"S and 37º29'40"W, 28 km from the main center of the municipality. As in the abovementioned records, systematic identification was only made at a late stage, given that the samples from the 47th epidemiological week of 2012 arrived at LACEN/SE in January, 2013. This technical note serves alert public health managers to the importance of quality control for endemic disease control programs, with the aim of effecting rapid and efficient control and prevention measures for mosquito-borne diseases.

  1. Evaluation of boric acid sugar baits against Aedes albopictus (Diptera: Culicidae) in tropical environments.

    Science.gov (United States)

    Naranjo, Diana P; Qualls, Whitney A; Müller, Gunter C; Samson, Dayana M; Roque, Deborah; Alimi, Temitope; Arheart, Kristopher; Beier, John C; Xue, Rui-De

    2013-04-01

    Attractive toxic sugar bait (active ingredient, 1% boric acid) was evaluated against Aedes albopictus Skuse populations in the laboratory, semi-field trials, and field trials in residential communities in St. Augustine, Florida. Laboratory evaluations of boric acid sugar baits applied to the plant Pentas lanceolata (Rubiaceae) demonstrated 100 and 92% mortality of A. albopictus at day 7 and 14, respectively. A semi-field study evaluating the bait application to the upperside or topside of leaves resulted in no significant difference on mortality (P>0.05). Overall combined top and bottom boric acid sugar bait application mortality at day 7 was 95% based on leaf bioassays. Field application of the boric acid sugar baits significantly (P<0.05) decreased adult A. albopictus populations up to day 21 post-treatment compared to the pre-treatment population numbers. A significant reduction in oviposition was demonstrated both at day 7 and 14 post-application (P=0.001) as monitored by ovitraps. Attractive toxic sugar bait application in tropical environments demonstrated efficacy, persistence, and feasibility in controlling A. albopictus populations.

  2. Larvicidal activities of hydro-ethanolic extracts of three Cameroonian medicinal plants against Aedes albopictus

    Institute of Scientific and Technical Information of China (English)

    Tankeu Nzufo Francine; Biapa Nya Prosper Cabral; Pieme Constant Anatole; Moukette Moukette Bruno; Nanfack Pauline; Ngogang Yonkeu Jeanne

    2016-01-01

    Objective: To investigate the larvicidal activity of Syzygium guineense (Myrtaceae) (S. guineense), Monodora myristica and Zanthoxylum heitzii (Rutaceae) (Z. heitzii) ex-tracts against Aedes albopictus (Ae. albopictus). Methods: The larvicidal activity of the hydro-ethanolic extracts from these plant species was assessed at three different concentrations (50, 100 and 200 mg/L) on first-instar of Ae. albopictus larvae in comparison with untreated controls. Mortality rate was recorded daily for a period of 12 days. The values of LC50 and lethal time killing 50%of the tested individuals (LT50) were calculated using the log-probit analysis. Results: The root extract of S. guineense exhibited the best activity with 100%mortality after 8 days of treatment at 200 mg/L, followed by the fruit extract of Z. heitzii with 83.33%mortality at the same concentration. Nonetheless, larvae were most susceptible to the fruit extract of Z. heitzii both in terms of LC50 (39.89 mg/L) and LT50 (145.68 h). A statistically significant difference between the control and the group treated at 200 mg/L was noticed in all the extracts. Conclusions: The present study shows that the hydro-ethanolic extracts of S. guineense, Monodora myristica and Z. heitzii tested have significant larvicidal activity. These pre-liminary results are of great interest and some of these plant species can be proposed for the formulation of new bioinsecticides to control Ae. albopictus populations.

  3. Repellency of essential oil of Piper aduncum against Aedes albopictus in the laboratory.

    Science.gov (United States)

    Misni, Norashiqin; Sulaiman, Sallehudin; Othman, Hidayatulfathi; Omar, Baharudin

    2009-12-01

    The repellent activity of Piper aduncum essential oil against Aedes albopictus was investigated under laboratory conditions with human volunteers. The lowest median effective dose (ED50) value was 1.5 microg/cm2 at 60 sec of exposure when compared to 90 sec (2.1 microg/cm2) and 120 sec (1.8 microg/cm2) of exposure. At 0.4 g, the essential oil gave a high protection (95.2%) against Ae. albopictus bites or landing at 2 h postapplication. The percentage of protection was reduced to 83.3% after 4 h, 64.5% after 6 h, and 51.6% after 8 h postapplication. As a comparison, treatment with 10% deet gave 100% protection against mosquito biting/landing for 4 h postapplication. There was no significant difference in percentage protection reduction between the plant extract and the commercial product deet, respectively (P = 0.739). The essential oil, which was not as good as deet, still gave moderate protection against Ae. albopictus biting even until 4 h postapplication. In conclusion, the P. aduncum essential oil has the potential to be used as a repellent against the dengue/dengue hemorrhagic fever vector, Ae. albopictus.

  4. An experimental field study of delayed density dependence in natural populations of Aedes albopictus.

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    Rachael K Walsh

    Full Text Available Aedes albopictus, a species known to transmit dengue and chikungunya viruses, is primarily a container-inhabiting mosquito. The potential for pathogen transmission by Ae. albopictus has increased our need to understand its ecology and population dynamics. Two parameters that we know little about are the impact of direct density-dependence and delayed density-dependence in the larval stage. The present study uses a manipulative experimental design, under field conditions, to understand the impact of delayed density dependence in a natural population of Ae. albopictus in Raleigh, North Carolina. Twenty liter buckets, divided in half prior to experimentation, placed in the field accumulated rainwater and detritus, providing oviposition and larval production sites for natural populations of Ae. albopictus. Two treatments, a larvae present and larvae absent treatment, were produced in each bucket. After five weeks all larvae were removed from both treatments and the buckets were covered with fine mesh cloth. Equal numbers of first instars were added to both treatments in every bucket. Pupae were collected daily and adults were frozen as they emerged. We found a significant impact of delayed density-dependence on larval survival, development time and adult body size in containers with high larval densities. Our results indicate that delayed density-dependence will have negative impacts on the mosquito population when larval densities are high enough to deplete accessible nutrients faster than the rate of natural food accumulation.

  5. Costs and benefits of Wolbachia infection in immature Aedes albopictus depend upon sex and competition level.

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    Gavotte, Laurent; Mercer, David R; Stoeckle, John J; Dobson, Stephen L

    2010-11-01

    Bacterial endosymbionts induce various effects on hosts and can dramatically impact host fitness and development. An example is provided by obligate, maternally-inherited Wolbachia, which infect a broad range of invertebrates. Wolbachia are capable of altering host reproduction, thereby promoting infection spread. Wolbachia also pose direct physiological costs and benefits to hosts, complicating their categorization as parasites or mutualists. This study examines for an effect of Wolbachia infection in intra-specific larval competition by Aedes albopictus mosquitoes, with the goal of examining for an impact of Wolbachia infection in mixed populations. Similar to prior work examining for an influence of Wolbachia infection on the fitness of A. albopictus in adults, the results presented here support the hypothesized impact of Wolbachia across all life stages, including immatures. The differential competitiveness of infected larvae detected in our experiments indicates that Wolbachia infected A. albopictus females are less competitive relative to uninfected females when competing under highly competitive conditions. In contrast, under low competitive pressures, infected females experience higher survivorship. Thus, Wolbachia infection shifts from parasitism to mutualism as a function of developmental conditions. Results are discussed in relation to the invasion and persistence of Wolbachia in A. albopictus populations. The results are important to the evolution of stable Wolbachia symbioses, including Wolbachia invasion of an uninfected population. The resulting infection dynamics that occur in an infected population are discussed.

  6. The biology and demographic parameters of Aedes albopictus in northern peninsular Malaysia

    Institute of Scientific and Technical Information of China (English)

    H Nur Aida; Hamady Dieng; AT Nurita; MR Che Salmah; Fumio Miake; B Norasmah

    2011-01-01

    To generate life table characteristics for the dengue vector Aedes albopictus (A.albopictus ) under uncontrolled conditions, incorporating both the aquatic and the adult stages. Methods: Ten females derived from wild pupae were allowed to fully blood-feed on restrained mice. 774 eggs were hatched in seasoned water. F1 larvae were followed for development until their F2 counterparts emerged as adults. Some population parameters were monitored (F1) or estimated (F2). Results: A. albopictus exhibited increased fecundity and egg hatch success. Immature development was quick. Immature survival was high, with lowest rate in the pupal stage. Adult emergence was about 81% and sex ratio was close to 1:1. Generational mortality (K) was about 28%. A high proportion of females completed a reproductive cycle and the obtained parity rate was predicted to lead to higher fecundity in the next generation. Conclusions: It can be concluded that natural A. albopictus populations in Penang seem largely determined by quick development in combination with low immature loss and increased oviposition.

  7. Population genetics of the Asian tiger mosquito Aedes albopictus, an invasive vector of human diseases.

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    Goubert, C; Minard, G; Vieira, C; Boulesteix, M

    2016-09-01

    The Asian tiger mosquito Aedes albopictus is currently one of the most threatening invasive species in the world. Native to Southeast Asia, the species has spread throughout the world in the past 30 years and is now present in every continent but Antarctica. Because it was the main vector of recent Dengue and Chikungunya outbreaks, and because of its competency for numerous other viruses and pathogens such as the Zika virus, A. albopictus stands out as a model species for invasive diseases vector studies. A synthesis of the current knowledge about the genetic diversity of A. albopictus is needed, knowing the interplays between the vector, the pathogens, the environment and their epidemiological consequences. Such resources are also valuable for assessing the role of genetic diversity in the invasive success. We review here the large but sometimes dispersed literature about the population genetics of A. albopictus. We first debate about the experimental design of these studies and present an up-to-date assessment of the available molecular markers. We then summarize the main genetic characteristics of natural populations and synthesize the available data regarding the worldwide structuring of the vector. Finally, we pinpoint the gaps that remain to be addressed and suggest possible research directions.

  8. Potential of Aedes aegypti and Aedes albopictus populations in the Central African Republic to transmit enzootic chikungunya virus strains.

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    Ngoagouni, Carine; Kamgang, Basile; Kazanji, Mirdad; Paupy, Christophe; Nakouné, Emmanuel

    2017-03-27

    Major chikungunya outbreaks have affected several Central African countries during the past decade. The chikungunya virus (CHIKV) was isolated from humans and sylvan mosquitoes in the Central African Republic (CAR) during the 1970 and 1980s but has not been found recently, despite the presence of Aedes albopictus since 2010. The risk of a massive chikungunya epidemic is therefore potentially high, as the human populations are immunologically naïve and because of the presence of the mosquito vector. In order to estimate the risk of a large outbreak, we assessed the vector competence of local Ae. aegypti and Ae. albopictus populations for ancient local strains of CHIKV in CAR. Mosquitoes were orally infected with the virus, and its presence in mosquito saliva was analysed 7 and 14 days post-infection (dpi) by quantitative reverse transcriptase polymerase chain reaction. The two species had similar infection rates at 7 and 14 days, and the dissemination rate of both vectors was ≥ 80% at 14 dpi. Only females followed up to 14 dpi had CHKV in their saliva. These results confirm the risk of transmission of enzootic CHIKV by anthropophilic vectors such as Ae. aegypti and Ae. albopictus.

  9. Retrospective search for dengue vector mosquito Aedes albopictus in areas visited by a German traveler who contracted dengue in Japan

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    Mutsuo Kobayashi

    2014-09-01

    Full Text Available A German traveler developed dengue fever in late August 2013, following a direct flight from Germany. Autochthonous dengue virus (DENV infection has not been reported in Japan. To evaluate the risk of autochthonous DENV transmission in Japan, the authors performed a retrospective search of the five areas visited by the German patient to determine the population density of dengue vector mosquito, Aedes albopictus. The annual mean temperature of each area was higher than 12 °C, which is considered suitable for the establishment of A. albopictus populations. Our retrospective search revealed the population density of A. albopictus to be high in the urban areas of Japan.

  10. Behavioral responses of Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and Anopheles minimus against various synthetic and natural repellent compounds.

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    Sathantriphop, Sunaiyana; White, Sabrina A; Achee, Nicole L; Sanguanpong, Unchalee; Chareonviriyaphap, Theeraphap

    2014-12-01

    The behavioral responses of colony populations of Aedes aegypti, Aedes albopictus, Culex quinquefasciatus, and Anopheles minimus to four essential oils (citronella, hairy basil, catnip, and vetiver), two standard repellents (DEET and picaridin), and two synthetic pyrethroids (deltamethrin and permethrin) were conducted in the laboratory using an excito-repellency test system. Results revealed that Cx. quinquefasciatus and An. minimus exhibited much stronger behavioral responses to all test compounds (65-98% escape for contact, 21.4-94.4% escape for non-contact) compared to Ae. aegypti (3.7-72.2% escape (contact), 0-31.7% (non-contact)) and Ae. albopictus (3.5-94.4% escape (contact), 11.2-63.7% (non-contact)). In brief, essential oil from vetiver elicited the greatest irritant responses in Cx. quinquefasciatus (96.6%) and An. minimus (96.5%) compared to the other compounds tested. The synthetic pyrethroids caused a stronger contact irritant response (65-97.8% escape) than non-contact repellents (0-50.8% escape for non-contact) across all four mosquito species. Picaridin had the least effect on all mosquito species. Findings from the current study continue to support the screening of essential oils from various plant sources for protective properties against field mosquitoes. © 2014 The Society for Vector Ecology.

  11. Detection and Establishment of Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Mosquitoes in California, 2011-2015.

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    Metzger, Marco E; Hardstone Yoshimizu, Melissa; Padgett, Kerry A; Hu, Renjie; Kramer, Vicki L

    2017-05-01

    In 2011, a thriving population of Aedes albopictus (Skuse), the Asian tiger mosquito, was discovered within three cities in Los Angeles County over an estimated 52-km2 urban area. Two years later in 2013, Aedes aegypti (L.), the yellow fever mosquito, was detected within several urban areas of Madera, Fresno, and San Mateo counties. State and local vector control agencies responded with an aggressive effort to eradicate or interrupt the spread of these two invasive mosquitoes; however, known populations continued to expand outward and new infestations were identified at an accelerated pace in central and southern California. By the end of 2015, one or both species had been detected within the jurisdictional boundaries of 85 cities and census-designated places in 12 counties. Herein we report on the discovery and widespread establishment of Ae. aegypti and Ae. albopictus in urban areas of coastal, central, and southern California between 2011 and 2015 and discuss the subsequent rapid changes to the activities and priorities of vector control agencies in response to this unprecedented invasion. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Wolbachia age-sex-specific density in Aedes albopictus: a host evolutionary response to cytoplasmic incompatibility?

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    Pablo Tortosa

    Full Text Available BACKGROUND: Wolbachia bacteria have invaded many arthropod species by inducing Cytoplasmic Incompatibility (CI. These symbionts represent fascinating objects of study for evolutionary biologists, but also powerful potential biocontrol agents. Here, we assess the density dynamics of Wolbachia infections in males and females of the mosquito Aedes albopitcus, an important vector of human pathogens, and interpret the results within an evolutionary framework. METHODOLOGY/PRINCIPAL FINDINGS: Wolbachia densities were measured in natural populations and in age controlled mosquitoes using quantitative PCR. We show that the density dynamics of the wAlbA Wolbachia strain infecting Aedes albopictus drastically differ between males and females, with a very rapid decay of infection in males only. CONCLUSIONS/SIGNIFICANCE: Theory predicts that Wolbachia and its hosts should cooperate to improve the transmission of infection to offspring, because only infected eggs are protected from the effects of CI. However, incompatible matings effectively lower the fertility of infected males, so that selection acting on the host genome should tend to reduce the expression of CI in males, for example, by reducing infection density in males before sexual maturation. The rapid decay of one Wolbachia infection in Aedes albopictus males, but not in females, is consistent with this prediction. We suggest that the commonly observed reduction in CI intensity with male age reflects a similar evolutionary process. Our results also highlight the importance of monitoring infection density dynamics in both males and females to assess the efficiency of Wolbachia-based control strategies.

  13. Growth characteristics of ChimeriVax-DEN2 vaccine virus in Aedes aegypti and Aedes albopictus mosquitoes.

    Science.gov (United States)

    Johnson, Barbara W; Chambers, Trudy V; Crabtree, Mary B; Bhatt, Tejal R; Guirakhoo, Farshad; Monath, Thomas P; Miller, Barry R

    2002-09-01

    The chimeric yellow fever (YF) 17D-dengue type 2 (ChimeriVax-DEN2) vaccine virus developed by Acambis, Inc. (Cambridge, MA) contains the prM and E genes of wild-type (wt) dengue 2 (DEN-2) (strain PUO-218) virus in the YF vaccine virus (strain 17D) backbone. The potential of ChimeriVax-DEN2 virus to infect and be transmitted by Aedes aegypti, the principal DEN and YF virus mosquito vector, and Aedes albopictus, a species that occurs in areas of active transmission of YF and DEN viruses, was evaluated. Mosquitoes were intrathoracically (IT) inoculated with virus or were fed a virus-laden blood meal, and the replication kinetics of ChimeriVax-DEN2 were compared with the wt DEN-2 and YF 17D vaccine viruses. Replication of YF 17D virus is attenuated in cultured Ae. albopictus C6/36 mosquito cells and in Ae. aegypti and Ae. albopictus mosquitoes. Growth of ChimeriVax-DEN2 virus similarly was restricted in C6/36 cells and in mosquitoes. ChimeriVax-DEN2 replicated in 56% of IT inoculated Ae. aegypti, and virus disseminated to head tissue in 36%, with a mean viral titer of 1.8 log10 PFU/mosquito. Of mosquitoes, 16% of Ae. aegypti and 24% of Ae. albopictus were infected 14 days after a blood meal containing ChimeriVax-DEN2, but virus did not disseminate to head tissue. In contrast, DEN-2 replicated in all IT inoculated and orally infected Ae. aegypti (mean titer 5.5 log10 PFU/mosquito), and virus disseminated to head tissue in 95%. Of Ae. albopictus, 84% were infected after a blood meal containing DEN-2 virus; dissemination occurred in 36%. Replication of ChimeriVax-DEN2 virus in mosquitoes corresponded to that of YF 17D vaccine virus, which is restricted in its ability to infect and replicate in mosquitoes. Therefore, transmission of ChimeriVax-DEN2 virus by vector mosquitoes is unlikely.

  14. Aedes albopictus em área rural do Brasil e implicações na transmissão de febre amarela silvestre Aedes albopictus in rural zone of Brazil and its implication in the sylvatic yellow fever transmission

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    Almério de Castro Gomes

    1999-02-01

    Full Text Available Durante estudos ecológicos sobre mosquitos anofelíneos no município de Bataguassu, Estado de Mato Grosso do Sul, foram encontradas larvas e adultos de Aedes albopictus. Pela primeira vez sua introdução ocorre numa área enzoótica do vírus selvático da febre amarela no Brasil. Isto sugere risco potencial para transferência desse vírus para área urbana infestada com Aedes aegypti.Larvae and adult forms of Aedes albopictus were found during ecological study of anopheline mosquitos in the rural zone of the state of Mato Grosso do Sul in Brazil. This occurrence was registered, for the first time in Brazil, in an enzoootic area if sylvatic yellow fever virus. This implies a potential risk of the transfer of this virus to an urban area infested with Aedes aegypti.

  15. Aedes albopictus control with spray application of Bacillus thuringiensis israelensis, strain AM 65-52.

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    Lam, Patrick H Y; Boon, Chia S; Yng, Ng Y; Benjamin, Seleena

    2010-09-01

    A Bacillus thuringiensis israelensis (Bti) formulation, VectoBac WG (strain AM 65-52), was evaluated for mosquito control in a training area with dense vegetation. Bti was spray applied to target Aedes albopictus larval habitats of 130 ha once every 2 weeks using a motorized back pack mist blower, Stihl SR420, and a vehicle mounted ultra low volume generator (ULV), IGEBA U40. Ovitrap index (OI) and larval density (LD) were used to measure the efficacy of larviciding. In the Bti treated area the OI and LD significantly decreased with time (p ovitrap by 3 months from the start of treatment. During the same period of time there was no significant reduction in OI and LD at the untreated site which was under a conventional mosquito control program. This large scale study indicates larvicidal spraying with Bti of natural breeding sites, was able to reduce Ae. albopictus adult density. This significant reduction was not achieved with conventional manual application methods.

  16. Inhibition of Mayaro virus replication by cerulenin in Aedes albopictus cells.

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    Pereira, H S; Rebello, M A

    1998-12-01

    The antibiotic cerulenin, an inhibitor of lipid synthesis, was shown to suppress Mayaro virus replication in Aedes albopictus cells at non-cytotoxic doses. Cerulenin blocked the incorporation of [3H]glycerol into lipids when present at any time post infection (p.i.). Cerulenin added at the beginning of infection inhibited the synthesis of virus proteins. However, when this antibiotic was added at later stages of infection, it had only a mild effect on the virus protein synthesis. The possibility that cerulenin acts by blocking an initial step in the Mayaro virus replication after virus entry and before late viral translation is discussed.

  17. Aedes albopictus (Diptera: Culicidae) as a potential vector of endemic and exotic arboviruses in Australia.

    Science.gov (United States)

    Nicholson, J; Ritchie, S A; van den Hurk, A F

    2014-05-01

    In 2005, established populations of Aedes albopictus (Skuse) were discovered in the Torres Strait, the region that separates Papua New Guinea from northern Australia. This increased the potential for this species to be introduced to mainland Australia. Because it is an arbovirus vector elsewhere, we undertook laboratory-based infection and transmission experiments to determine the potential for Ae. albopictus from the Torres Strait to become infected with and transmit the four major Australian endemic arboviruses--Murray Valley encephalitis virus, West Nile virus Kunjin strain (WNV(KUN)), Ross River virus (RRV), and Barmah Forest virus--as well as the exotic Japanese encephalitis virus. Ae. albopictus is susceptible to infection with all viruses, with infection rates ranging between 8% for WNV(KUN) and 71% for RRV. Transmission rates of approximately 25% were observed for RRV and Barmah Forest virus, but these were < 17% for Murray Valley encephalitis virus, WNV(KUN), and Japanese encephalitis virus. Given its relative vector competence for alphaviruses, we also examined the replication kinetics and extrinsic incubation periods required for transmission of RRV and chikungunya virus. Despite lower body titers, more mosquitoes reared and maintained at 28 degrees C became infected with and transmitted the virus than those reared and maintained at 22 degrees C. The minimum time between Ae. albopictus consuming an infected bloodmeal and transmitting chikungunya virus was 2 d at 28 degrees C and 4 d at 22 degrees C, and for RRV, it was 4 d, irrespective of the temperature. Given its opportunistic feeding habits and aggressive biting behavior, the establishment of Ae. albopictus on the Australian mainland could have a considerable impact on alphavirus transmission.

  18. Aedes (Stegomyia albopictus (Skuse: a potential vector of Zika virus in Singapore.

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    Pei-Sze Jeslyn Wong

    Full Text Available Zika virus (ZIKV is a little known arbovirus until it caused a major outbreak in the Pacific Island of Yap in 2007. Although the virus has a wide geographic distribution, most of the known vectors are sylvatic Aedes mosquitoes from Africa where the virus was first isolated. Presently, Ae. aegypti is the only known vector to transmit the virus outside the African continent, though Ae. albopictus has long been a suspected vector. Currently, Ae. albopictus has been shown capable of transmitting more than 20 arboviruses and its notoriety as an important vector came to light during the recent chikungunya pandemic. The vulnerability of Singapore to emerging infectious arboviruses has stimulated our interest to determine the competence of local Ae. albopictus to transmit ZIKV.To determine the competence of Ae. albopictus to ZIKV, we orally infected local mosquito strains to a Ugandan strain virus. Fully engorged mosquitoes were maintained in an environmental chamber set at 29°C and 80-85%RH. Twelve mosquitoes were then sampled daily from day one to seven and on day 10 and 14 post infection (pi. Zika virus titre in the midgut and salivary glands of each mosquito were determined using tissue culture infectious dose50 assay, while transmissibility of the virus was determined by detecting viral antigen in the mosquito saliva by qRT-PCR. High dissemination and transmission rate of ZIKV were observed. By day 7-pi, all mosquitoes have disseminated infection and 73% of these mosquitoes have ZIKV in their saliva. By day 10-pi, all mosquitoes were potentially infectious.The study highlighted the potential of Ae. albopictus to transmit ZIKV and the possibility that the virus could be established locally. Nonetheless, the threat of ZIKV can be mitigated by existing dengue and chikungunya control program being implemented in Singapore.

  19. European Aedes albopictus and Culex pipiens Are Competent Vectors for Japanese Encephalitis Virus

    Science.gov (United States)

    Desprès, Philippe

    2017-01-01

    Background Japanese encephalitis virus (JEV) is the causative agent of Japanese encephalitis, the leading cause of viral encephalitis in Asia. JEV transmission cycle involves mosquitoes and vertebrate hosts. The detection of JEV RNA in a pool of Culex pipiens caught in 2010 in Italy raised the concern of a putative emergence of the virus in Europe. We aimed to study the vector competence of European mosquito populations, such as Cx. pipiens and Aedes albopictus for JEV genotypes 3 and 5. Findings After oral feeding on an infectious blood meal, mosquitoes were dissected at various times post-virus exposure. We found that the peak for JEV infection and transmission was between 11 and 13 days post-virus exposure. We observed a faster dissemination of both JEV genotypes in Ae. albopictus mosquitoes, when compared with Cx. pipiens mosquitoes. We also dissected salivary glands and collected saliva from infected mosquitoes and showed that Ae. albopictus mosquitoes transmitted JEV earlier than Cx. pipiens. The virus collected from Ae. albopictus and Cx. pipiens saliva was competent at causing pathogenesis in a mouse model for JEV infection. Using this model, we found that mosquito saliva or salivary glands did not enhance the severity of the disease. Conclusions In this study, we demonstrated that European populations of Ae. albopictus and Cx. pipiens were efficient vectors for JEV transmission. Susceptible vertebrate species that develop high viremia are an obligatory part of the JEV transmission cycle. This study highlights the need to investigate the susceptibility of potential JEV reservoir hosts in Europe, notably amongst swine populations and local water birds. PMID:28085881

  20. European Aedes albopictus and Culex pipiens Are Competent Vectors for Japanese Encephalitis Virus.

    Science.gov (United States)

    de Wispelaere, Mélissanne; Desprès, Philippe; Choumet, Valérie

    2017-01-01

    Japanese encephalitis virus (JEV) is the causative agent of Japanese encephalitis, the leading cause of viral encephalitis in Asia. JEV transmission cycle involves mosquitoes and vertebrate hosts. The detection of JEV RNA in a pool of Culex pipiens caught in 2010 in Italy raised the concern of a putative emergence of the virus in Europe. We aimed to study the vector competence of European mosquito populations, such as Cx. pipiens and Aedes albopictus for JEV genotypes 3 and 5. After oral feeding on an infectious blood meal, mosquitoes were dissected at various times post-virus exposure. We found that the peak for JEV infection and transmission was between 11 and 13 days post-virus exposure. We observed a faster dissemination of both JEV genotypes in Ae. albopictus mosquitoes, when compared with Cx. pipiens mosquitoes. We also dissected salivary glands and collected saliva from infected mosquitoes and showed that Ae. albopictus mosquitoes transmitted JEV earlier than Cx. pipiens. The virus collected from Ae. albopictus and Cx. pipiens saliva was competent at causing pathogenesis in a mouse model for JEV infection. Using this model, we found that mosquito saliva or salivary glands did not enhance the severity of the disease. In this study, we demonstrated that European populations of Ae. albopictus and Cx. pipiens were efficient vectors for JEV transmission. Susceptible vertebrate species that develop high viremia are an obligatory part of the JEV transmission cycle. This study highlights the need to investigate the susceptibility of potential JEV reservoir hosts in Europe, notably amongst swine populations and local water birds.

  1. Native Wolbachia from Aedes albopictus Blocks Chikungunya Virus Infection In Cellulo

    Science.gov (United States)

    Raquin, Vincent; Valiente Moro, Claire; Saucereau, Yoann; Tran, Florence-Hélène; Potier, Patrick; Mavingui, Patrick

    2015-01-01

    Wolbachia, a widespread endosymbiont of terrestrial arthropods, can protect its host against viral and parasitic infections, a phenotype called "pathogen blocking". However, in some cases Wolbachia may have no effect or even enhance pathogen infection, depending on the host-Wolbachia-pathogen combination. The tiger mosquito Aedes albopictus is naturally infected by two strains of Wolbachia, wAlbA and wAlbB, and is a competent vector for different arboviruses such as dengue virus (DENV) and Chikungunya virus (CHIKV). Interestingly, it was shown in some cases that Ae. albopictus native Wolbachia strains are able to inhibit DENV transmission by limiting viral replication in salivary glands, but no such impact was measured on CHIKV replication in vivo. To better understand the Wolbachia/CHIKV/Ae. albopictus interaction, we generated a cellular model using Ae. albopictus derived C6/36 cells that we infected with the wAlbB strain. Our results indicate that CHIKV infection is negatively impacted at both RNA replication and virus assembly/secretion steps in presence of wAlbB. Using FISH, we observed CHIKV and wAlbB in the same mosquito cells, indicating that the virus is still able to enter the cell in the presence of the bacterium. Further work is needed to decipher molecular pathways involved in Wolbachia-CHIKV interaction at the cellular level, but this cellular model can be a useful tool to study the mechanism behind virus blocking phenotype induced by Wolbachia. More broadly, this underlines that despite Wolbachia antiviral potential other complex interactions occur in vivo to determine mosquito vector competence in Ae. albopictus. PMID:25923352

  2. Native Wolbachia from Aedes albopictus Blocks Chikungunya Virus Infection In Cellulo.

    Science.gov (United States)

    Raquin, Vincent; Valiente Moro, Claire; Saucereau, Yoann; Tran, Florence-Hélène; Potier, Patrick; Mavingui, Patrick

    2015-01-01

    Wolbachia, a widespread endosymbiont of terrestrial arthropods, can protect its host against viral and parasitic infections, a phenotype called "pathogen blocking". However, in some cases Wolbachia may have no effect or even enhance pathogen infection, depending on the host-Wolbachia-pathogen combination. The tiger mosquito Aedes albopictus is naturally infected by two strains of Wolbachia, wAlbA and wAlbB, and is a competent vector for different arboviruses such as dengue virus (DENV) and chikungunya virus (CHIKV). Interestingly, it was shown in some cases that Ae. albopictus native Wolbachia strains are able to inhibit DENV transmission by limiting viral replication in salivary glands, but no such impact was measured on CHIKV replication in vivo. To better understand the Wolbachia/CHIKV/Ae. albopictus interaction, we generated a cellular model using Ae. albopictus derived C6/36 cells that we infected with the wAlbB strain. Our results indicate that CHIKV infection is negatively impacted at both RNA replication and virus assembly/secretion steps in presence of wAlbB. Using FISH, we observed CHIKV and wAlbB in the same mosquito cells, indicating that the virus is still able to enter the cell in the presence of the bacterium. Further work is needed to decipher molecular pathways involved in Wolbachia-CHIKV interaction at the cellular level, but this cellular model can be a useful tool to study the mechanism behind virus blocking phenotype induced by Wolbachia. More broadly, this put into question the ecological role of Wolbachia symbiont in Ae. albopictus, but also the ability of the CHIKV to counteract Wolbachia's antiviral potential in vivo.

  3. Status of insecticide resistance and detoxifying enzyme activity of Aedes albopictus population in Sonitpur district of Assam, India

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    Momi Das

    2014-12-01

    Full Text Available Sonitpur district, Assam (India is well known for malaria incidence since many years. The extensive use of insecticides for the control of malaria and other vector species is being carried out for vector management. The insecticide resistance status of Aedes albopictus (Diptera: Culicidae to DDT (dichloro-diphenyl-trichloroethane and deltamethrin was studied in the Sonitpur district of Assam. Even today DDT is the most widely used insecticides for public health programs in India. Recent information on the level of resistance to DDT and deltamethrin in an Aedes mosquito population of North East India is scarce. Continued monitoring of insecticide resistance status and identification of the underlying mechanism of resistance in the Aedes mosquito population is of prime importance. Insecticide susceptibility assays were performed on wild-caught adult female Aedes albopictus mosquitoes to the discriminating doses of DDT (4% and deltamethrin (0. 05% recommended by the World health organization (WHO. In all study sites, mortality as a result of DDT varied from 40.2 to 80.2% as compared to 94.2% in the susceptible laboratory strain (S-lab, indicating that Ae. albopictus is resistant to DDT in all study sites except Gohpur. The species was found to be 100% susceptible to deltamethrin in all study sites. Results from biochemical assays demonstrated increased alpha esterase, beta esterase and glutathione - S-transferase activity of Aedes albopictus at all study sites. Therefore, alpha esterase, beta esterase and glutathione - S-transferase activity seems to be associated with mechanisms responsible for insecticide resistance in Ae. albopictus. The results presented here provide the first report and baseline information about the insecticide resistance status of Ae. albopictus in North East India, and associated information about biochemical mechanisms that are essential for monitoring the development of insecticide resistance in the area.

  4. Spatial and Temporal Variation in Aedes aegypti and Aedes albopictus (Diptera: Culicidae) Numbers in the Yogyakarta Area of Java, Indonesia, With Implications for Wolbachia Releases.

    Science.gov (United States)

    Tantowijoyo, W; Arguni, E; Johnson, P; Budiwati, N; Nurhayati, P I; Fitriana, I; Wardana, S; Ardiansyah, H; Turley, A P; Ryan, P; O'Neill, S L; Hoffmann, A A

    2016-01-01

    of mosquito vector populations, particularly through Wolbachia endosymbionts. The success of these strategies depends on understanding the dynamics of vector populations. In preparation for Wolbachia releases around Yogyakarta, we have studied Aedes populations in five hamlets. Adult monitoring with BioGent- Sentinel (BG-S) traps indicated that hamlet populations had different dynamics across the year; while there was an increase in Aedes aegypti (L.) and Aedes albopictus (Skuse) numbers in the wet season, species abundance remained relatively stable in some hamlets but changed markedly (>2 fold) in others. Local rainfall a month prior to monitoring partly predicted numbers of Ae. aegypti but not Ae. albopictus. Site differences in population size indicated by BG-S traps were also evident in ovitrap data. Egg or larval collections with ovitraps repeated at the same location suggested spatial autocorrelation (aegypti numbers were high. Overall, there was a weak negative association (raegypti and Ae. albopictus numbers in ovitraps when averaged across collections. Ae. albopictus numbers in ovitraps and BG-S traps were positively correlated with vegetation around areas where traps were placed, while Ae. aegypti were negatively correlated with this feature. These data inform intervention strategies by defining periods when mosquito densities are high, highlighting the importance of local site characteristics on populations, and suggesting relatively weak interactions between Ae. aegypti and Ae. albopictus. They also indicate local areas within hamlets where consistently high mosquito densities may influence Wolbachia invasions and other interventions.

  5. Potential Risk Areas of Aedes albopictus in South-Eastern Iran: A Vector of Dengue Fever, Zika, and Chikungunya

    Directory of Open Access Journals (Sweden)

    Jalil Nejati

    2017-09-01

    Full Text Available The possibility of the rapid and global spread of Zika, chikungunya, yellow fever, and dengue fever by Aedes albopictus is well documented and may be facilitated by changes in climate. To avert and manage health risks, climatic and topographic information can be used to model and forecast which areas may be most prone to the establishment of Ae. albopictus. We aimed to weigh and prioritize the predictive value of various meteorological and climatic variables on distributions of Ae. albopictus in south-eastern Iran using the Analytical Hierarchy Process. Out of eight factors used to predict the presence of Ae. albopictus, the highest weighted were land use, followed by temperature, altitude, and precipitation. The inconsistency of this analysis was 0.03 with no missing judgments. The areas predicted to be most at risk of Ae. albopictus-borne diseases were mapped using Geographic Information Systems and remote sensing data. Five-year (2011–2015 meteorological data was collected from 11 meteorological stations and other data was acquired from Landsat and Terra satellite images. Southernmost regions were at greatest risk of Ae. albopictus colonization as well as more urban sites connected by provincial roads. This is the first study in Iran to determine the regional probability of Ae. albopictus establishment. Monitoring and collection of Ae. albopictus from the environment confirmed our projections, though on-going field work is necessary to track the spread of this vector of life-threatening disease.

  6. Potential Risk Areas of Aedes albopictus in South-Eastern Iran: A Vector of Dengue Fever, Zika, and Chikungunya.

    Science.gov (United States)

    Nejati, Jalil; Bueno-Marí, Rubén; Collantes, Francisco; Hanafi-Bojd, Ahmad A; Vatandoost, Hassan; Charrahy, Zabihollah; Tabatabaei, Seyed M; Yaghoobi-Ershadi, Mohammad R; Hasanzehi, Abdolghafar; Shirzadi, Mohammad R; Moosa-Kazemi, Seyed H; Sedaghat, Mohammad M

    2017-01-01

    The possibility of the rapid and global spread of Zika, chikungunya, yellow fever, and dengue fever by Aedes albopictus is well documented and may be facilitated by changes in climate. To avert and manage health risks, climatic and topographic information can be used to model and forecast which areas may be most prone to the establishment of Ae. albopictus. We aimed to weigh and prioritize the predictive value of various meteorological and climatic variables on distributions of Ae. albopictus in south-eastern Iran using the Analytical Hierarchy Process. Out of eight factors used to predict the presence of Ae. albopictus, the highest weighted were land use, followed by temperature, altitude, and precipitation. The inconsistency of this analysis was 0.03 with no missing judgments. The areas predicted to be most at risk of Ae. albopictus-borne diseases were mapped using Geographic Information Systems and remote sensing data. Five-year (2011-2015) meteorological data was collected from 11 meteorological stations and other data was acquired from Landsat and Terra satellite images. Southernmost regions were at greatest risk of Ae. albopictus colonization as well as more urban sites connected by provincial roads. This is the first study in Iran to determine the regional probability of Ae. albopictus establishment. Monitoring and collection of Ae. albopictus from the environment confirmed our projections, though on-going field work is necessary to track the spread of this vector of life-threatening disease.

  7. Sublethal effects of atrazine and glyphosate on life history traits of Aedes aegypti and Aedes albopictus (Diptera: Culicidae).

    Science.gov (United States)

    Bara, Jeffrey J; Montgomery, Allison; Muturi, Ephantus J

    2014-08-01

    Although exposure of mosquito larvae to agricultural chemicals such as herbicides is common and widespread, our understanding of how these chemicals affect mosquito ecology and behavior is limited. This study investigated how an environmentally relevant concentration of two herbicides, atrazine and glyphosate, affects mosquito life history traits. One hundred and fifty (150) first instar Aedes (Stegomyia) aegypti (L.) or Aedes (Stegomyia) albopictus (Skuse) larvae were reared in 1.6 L of live oak leaf (Quercus virginiana) infusion in the presence (5 mg/L) or absence (0 mg/L) of atrazine or glyphosate. The containers were monitored daily to determine the emergence rates, sex ratio, male and female emergence times, and female body size. Emergence rates of A. aegypti from atrazine treatment were significantly higher relative to either glyphosate or control treatments (A. aegypti: atrazine = 93 ± 6% (±95% CI), glyphosate = 82 ± 5%, control = 78 ± 5%), while emergence rates of A. albopictus in atrazine treatments were significantly higher than in glyphosate treatments but not in controls (A. albopictus: atrazine = 84 ± 5 %, glyphosate = 76 ± 4%, control = 78 ± 4%). For both mosquito species, a sex ratio distortion with male bias was observed in control and glyphosate treatments, but not in atrazine treatments (A. aegypti: atrazine = 0.90 ± 0.17 (±SE), glyphosate = 1.63 ± 0.21, control = 1.69 ± 0.26; A. albopictus: atrazine = 1.09 ± 0.08, glyphosate = 1.88 ± 0.12, control = 1.37 ± 0.11). Emergence times for both sexes of the two mosquito species were significantly longer in atrazine treatments compared to glyphosate or control treatments (A. aegypti: females: atrazine = 11.20 ± 0.50 (days ± 95 % CI), glyphosate = 9.71 ± 0.23, control = 9.87 ± 0.21; males: atrazine = 9.46 ± 0.27, glyphosate = 8.80 ± 0.25, control

  8. Comparison of BG-Sentinel® Trap and Oviposition Cups for Aedes aegypti and Aedes albopictus Surveillance in Jacksonville, Florida, USA.

    Science.gov (United States)

    Wright, Jennifer A; Larson, Ryan T; Richardson, Alec G; Cote, Noel M; Stoops, Craig A; Clark, Marah; Obenauer, Peter J

    2015-03-01

    The BG-Sentinel® (BGS) trap and oviposition cups (OCs) have both proven effective in the surveillance of Aedes species. This study aimed to determine which of the 2 traps could best characterize the relative population sizes of Aedes albopictus and Aedes aegypti in an urban section of Jacksonville, FL. Until 1986, Ae. aegypti was considered the dominant container-breeding species in urban northeastern Florida. Since the introduction of Ae. albopictus, Ae. aegypti has become almost completely extirpated. In 2011, a resurgence of Ae. aegypti was detected in the urban areas of Jacksonville; thus this study initially set out to determine the extent of Ae. aegypti reintroduction to the area. We determined that the BGS captured a greater number of adult Ae. aegypti than Ae. albopictus, while OCs did not monitor significantly different numbers of either species, even in areas where the BGS traps suggested a predominance of one species over the other. Both traps were effective at detecting Aedes spp.; however, the BGS proved more diverse by detecting over 20 other species as well. Our results show that in order to accurately determine vectorborne disease threats and the impact of control operations on these 2 species, multiple trapping techniques should be utilized when studying Ae. aegypti and Ae. albopictus population dynamics.

  9. Field evaluation of the Off! Clip-on Mosquito Repellent (metofluthrin) against Aedes albopictus and Aedes taeniorhynchus (Diptera: Culicidae) in northeastern Florida.

    Science.gov (United States)

    Xue, Rui-De; Qualls, Whitney A; Smith, Michael L; Gaines, Marcia K; Weaver, James H; Debboun, Mustapha

    2012-05-01

    Repellent efficacy of the Off! Clip-on Mosquito Repellent device (S. C. Johnson and Son, Inc., Racine, WI) containing Metofluthrin was evaluated on six human volunteers against the container-breeding mosquito Aedes albopictus (Skuse) and the salt marsh mosquito Aedes taeniorhynchus (Wiedemann) at two field locations in northeastern Florida. The device repelled mosquitoes by releasing a vaporized form of the pyrethroid insecticide metofluthrin ([AI] 31.2%) and provided 70% protection from Ae. albopictus bites for > 3 h. For the second field trial, a repellent device that was used in the first trial was tested after being open for >1 wk. This device provided 79% protection from Ae. taeniorhynchus bites for 3 h. Our field results showed that the repellent device was 70 and 79% effective at repelling Ae. albopictus and Ae. taeniorhynchus from human test subjects in both field locations in northeastern Florida.

  10. Real-time PCR Tests in Dutch Exotic Mosquito Surveys; Implementation of Aedes aegypti and Aedes albopictus Identification Tests, and the Development of Tests for the Identification of Aedes atropalpus and Aedes japonicus japonicus (Diptera: Culicidae).

    Science.gov (United States)

    van de Vossenberg, B T L H; Ibáñez-Justicia, A; Metz-Verschure, E; van Veen, E J; Bruil-Dieters, M L; Scholte, E J

    2015-05-01

    Since 2009, The Netherlands Food and Consumer Product Safety Authority carries out surveys focusing on, amongst others, the presence of invasive mosquito species (IMS). Special attention is given to exotic container-breeding Aedes species Aedes aegypti (L.), Aedes albopictus (Skuse), Aedes atropalpus (Coquillett), and Aedes japonicus japonicus (Theobald). This study describes the implementation of real-time PCR tests described by Hill et al. (2008) for the identification of Ae. aegypti and Ae. albopictus, and the development of two novel real-time PCR tests for the identification of Ae. atropalpus and Ae. j. japonicus. Initial test showed that optimization of elements of the Ae. aegypti and Ae. albopictus tests was needed. Method validation tests were performed to determine if the implemented and newly developed tests are fit for routine diagnostics. Performance criteria of analytical sensitivity, analytical specificity, selectivity, repeatability, and reproducibility were determined. In addition, experiments were performed to determine the influence of environmental conditions on the usability of DNA extracted from mosquito specimens trapped in BG-Sentinel traps. The real-time PCR tests were demonstrated to be sensitive, specific, repeatable, reproducible, and are less prone to false negative results compared to partial cytochrome c oxidase I gene sequencing owing to the DNA fragmentation caused by environmental influences. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. A new challenge for hospitals in southeast France: monitoring local populations of Aedes albopictus to prevent nosocomial transmission of dengue or chikungunya.

    Science.gov (United States)

    Cotteaux-Lautard, Christelle; Berenger, Jean-Michel; Fusca, François; Chardon, Hubert; Simon, Fabrice; Pagès, Frederic

    2013-03-01

    Aedes albopictus was first identified in southern France in 2004, inducing an emerging risk for autochthonous transmission around imported cases of dengue or chikungunya, and also for mosquito-borne nosocomial transmission in hospitals. Aedes albopictus has been present in Marseille since September 2009 and in Aix-en-Provence since August 2010. Because of the possible admission of viremic patients with dengue or chikungunya in the hospitals of these cities, a mosquito survey was conducted in 2011 in 2 of the hospitals, with the use of mosquito traps. Aedes albopictus was detected with Eisenhans II traps and egg traps in both hospitals during the warm season.

  12. The hidden passenger of Lucky bamboo: Do imported Aedes albopictus mosquitoes cause Dengue virus transmission in the Netherlands?

    NARCIS (Netherlands)

    Hofhuis, A.; Reimerink, J.; Reusken, C.; Scholte, E.J.; Boer, de A.; Takken, W.; Koopmans, M.P.G.

    2009-01-01

    Since 2005, Aedes albopictus mosquitoes have been detected in companies in the Netherlands that import ornamental plants from China. To assess the risks of dengue transmission, a study was carried out in 48 persons who are professionally exposed to these mosquitoes. No evidence for

  13. The hidden passenger of Lucky bamboo: Do imported Aedes albopictus mosquitoes cause Dengue virus transmission in the Netherlands?

    NARCIS (Netherlands)

    Hofhuis, A.; Reimerink, J.; Reusken, C.; Scholte, E.J.; Boer, de A.; Takken, W.; Koopmans, M.P.G.

    2009-01-01

    Since 2005, Aedes albopictus mosquitoes have been detected in companies in the Netherlands that import ornamental plants from China. To assess the risks of dengue transmission, a study was carried out in 48 persons who are professionally exposed to these mosquitoes. No evidence for non-travel-relate

  14. The USDA-ARS area-wide project for management of the asian tiger mosquito, Aedes albopictus

    Science.gov (United States)

    The Asian tiger mosquito, Aedes albopictus, is among the most invasive species in the world. Established in the U.S. since 1985, this species now infests 30 states and continues to spread internationally. Concerned public health officials recognize this species as an important vector of chikunguny...

  15. Outcomes from the USDA/ARS area-wide project for management of the Asian tiger mosquito, Aedes albopictus

    Science.gov (United States)

    The Asian tiger mosquito, Aedes albopictus, became established in the continental US in 1985 and now infests 30 states. In 2007 the USDA Agricultural Research Service funded an “area-wide” project focused on the management of this species. The project was a unique federal, state, local collaborati...

  16. Effect of application rate and persistence of boric acid sugar baits applied to plants control of Aedes albopictus

    Science.gov (United States)

    The use of toxic baits to kill adult Aedes albopictus (Skuse) mosquitoes is a safe and potentially effective alternative to the use of synthetic chemical insecticides. This study was made to identify effective application rates for boric acid-sugar solution baits sprayed onto plant surfaces and to ...

  17. A comparative analysis of resistance testing methods in Aedes albopictus (Diptera: Culicidae) from St. Johns County, Florida

    Science.gov (United States)

    Aedes albopictus Skuse (Diptera: Culicidae) was tested for resistance to permethrin, bifenthrin, and malathion using Centers for Disease Control and Prevention (CDC) bottle bioassays and topical toxicology assays on adults and larval bioassays. Eggs were collected from 3 locations across St. Johns C...

  18. The hidden passenger of Lucky bamboo: Do imported Aedes albopictus mosquitoes cause Dengue virus transmission in the Netherlands?

    NARCIS (Netherlands)

    Hofhuis, A.; Reimerink, J.; Reusken, C.; Scholte, E.J.; Boer, de A.; Takken, W.; Koopmans, M.P.G.

    2009-01-01

    Since 2005, Aedes albopictus mosquitoes have been detected in companies in the Netherlands that import ornamental plants from China. To assess the risks of dengue transmission, a study was carried out in 48 persons who are professionally exposed to these mosquitoes. No evidence for non-travel-relate

  19. Efficacy of Ovitrap Colors and Patterns for Attracting Aedes albopictus (Diptera: Culicidae) at Suburban Field Sites in North Central Florida

    Science.gov (United States)

    We sought to visually enhance the attractiveness of a standard black ovitrap routinely used in surveillance of the Asian Tiger Mosquito, Aedes albopictus (Skuse), and now being used as lethal ovitraps in Ae. aegypti (L.) dengue control programs. Black plastic drinking cups (ovitraps) were visually ...

  20. Ovitrap Efficacy Using Plant Infusions to Monitor Vertical Distribution of Aedes albopictus Skuse (Diptera: Culicidae) in North-Central Florida

    Science.gov (United States)

    The response of Aedes albopictus to ovitraps containing water, oak or oak-pine was evaluated in four suburban and four sylvatic habitats in North-Central Florida to ascertain potential egg-laying heights. A total of 48 ovitraps were suspended at 1 and 6 meters and monitored weekly for five months....

  1. Genome sequence of the Asian Tiger mosquito, Aedes albopictus, reveals insights into its biology, genetics, and evolution

    NARCIS (Netherlands)

    Chena, X.G.; Jiang, X.; Gu, J.; Xu, M.; Wu, Y.; Deng, Y.; Zhang, C.; Bonizzoni, M.; Dermauw, W.; Vontas, J.; Armbruster, P.; Huang, X.; Yang, Y.; Zhang, H.; He, W.; Peng, H.; Liu, Y.; Wu, K.; Chen, J.; Lirakis, M.; Topalis, P.; Van Leeuwen, T.; Hall, B.A.; Thorpe, C.; Mueller, R.L.; Sun, C.; Waterhouse, R.M.; Yan, G.; Tu, Z.J.; Fang, X.; James, A.A.

    2015-01-01

    The Asian tiger mosquito, Aedes albopictus, is a highly successful invasive species that transmits a number of human viral diseases, including dengue and Chikungunya fevers. This species has a large genome with significant population-based size variation. The complete genome sequence was determined

  2. Encontro de Aedes (Stegomyia albopictus (Skuse em Bromeliaceae na periferia de São Paulo, SP, Brasil

    Directory of Open Access Journals (Sweden)

    Natal Delsio

    1997-01-01

    Full Text Available Foram coletadas larvas de Aedes albopictus em uma planta da família Bromeliaceae, na periferia da cidade de São Paulo, SP, Brasil. Esse encontro abre perspectivas de estudo para avaliação do potencial desse vegetal como criadouro desse mosquito no País.

  3. Cloning and sequence analysis of β-actin gene from Aedes albopictus (Diptera: Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Weijie Wang; Xiaobang Hu; Donghui Zhang; Jianhua Jiao; Yan Sun; Lei Ma; Changliang Zhu

    2007-01-01

    Objective: To obtain the complete β-actin gene from Aedes albopictus. Methods: Total RNA was extracted from C6/36 cells. Degenerate primers were designed based on the β-actin sequences of An. gambiae, Ae. aegypti, Cx. pipiens pallens and D.melanogaster. By RT-PCR, the product was amplified, purified, cloned into the pGT vector and sequenced. The β-actin sequence was aligned and phylogenetically analyzed by the BLAST program and the CLUSTAL W program. Results: A sequence of 1132 bp including an open reading frame of 1131 bp was obtained (GenBank DQ657949). The deduced protein had 376 amino acids.Aligned to SWISS-PROT, it exhibited a high level of identity with β-actins from Anopheles, Drosophila and Culex at the amino acid sequence level. Phylogenetic analysis indicated that Ae. albopictus β-actin was much more homologous with invertebrate β-actin than with vertebrate β-actin. Conclusion: The gene may be used as the internal control in the experiments of Ae. albopictus.

  4. Chemical composition, larvicidal action, and adult repellency of Thymus magnus against Aedes albopictus.

    Science.gov (United States)

    Park, Young-Uk; Koo, Hyun-Na; Kim, Gil-Hah

    2012-09-01

    Thymus magnus, an endemic species, is found in the Republic of Korea. The volatile compounds extracted by SPME from T. magnus were investigated for their chemical composition and electrophysiological response against the Asian tiger mosquito, Aedes albopictus. The volatile compounds of T. magnus as determined by gas chromatography mass spectrometry were gamma-terpinene (33.0%), thymol (29.9%), beta-bisabolene (8.9%), p-cymene (8.3%), alpha-terpinene (5.0%), myrcene (4.7%), beta-caryophyllene (4.0%), alpha-thujene (2.7%), camphene (1.3%), carvacrol (1.2%), and alpha-pinene (1.1%). Among these candidates, thymol exhibited complete (100%) repellent activity against female Ae. albopictus, an effect that was confirmed through evaluating the electrophysiological response on the antenna of Ae. albopictus. The effectiveness of a binary 1:2 mixture of thymol and vanillin (0.05:0.1 microl per cm2) was found to be significantly more effective than thymol alone for a period of 120 min. In addition, thymol, alpha-terpinene, and carvacrol showed high larvicidal activity against on the third-stage larvae with LC50 values of 0.9 microl per 100 ml.

  5. Female Adult Aedes albopictus Suppression by Wolbachia-Infected Male Mosquitoes

    Science.gov (United States)

    Mains, James W.; Brelsfoard, Corey L.; Rose, Robert I.; Dobson, Stephen L.

    2016-01-01

    Dengue, chikungunya and zika viruses are pathogens with an increasing global impact. In the absence of an approved vaccine or therapy, their management relies on controlling the mosquito vectors. But traditional controls are inadequate, and the range of invasive species such as Aedes albopictus (Asian Tiger Mosquito) is expanding. Genetically modified mosquitoes are being tested, but their use has encountered regulatory barriers and public opposition in some countries. Wolbachia bacteria can cause a form of conditional sterility, which can provide an alternative to genetic modification or irradiation. It is unknown however, whether openly released, artificially infected male Ae. albopictus can competitively mate and sterilize females at a level adequate to suppress a field population. Also, the unintended establishment of Wolbachia at the introduction site could result from horizontal transmission or inadvertent female release. In 2014, an Experimental Use Permit from the United States Environmental Protection Agency approved a pilot field trial in Lexington, Kentucky, USA. Here, we present data showing localized reduction of both egg hatch and adult female numbers. The artificial Wolbachia type was not observed to establish in the field. The results are discussed in relation to the applied use of Wolbachia-infected males as a biopesticide to suppress field populations of Ae. albopictus. PMID:27659038

  6. Detection of novel insect flavivirus sequences integrated in Aedes albopictus (Diptera: Culicidae in Northern Italy

    Directory of Open Access Journals (Sweden)

    Tenorio Antonio

    2009-07-01

    Full Text Available Abstract The presence of DNA sequences integrated from a new flavivirus related to Cell Fusing Agent and Kamiti River Virus was identified in wild Aedes albopictus mosquito populations from the provinces of Trentino and Padova, Northern Italy. Field work was developed during August–October 2007 with BG-traps, and mosquitoes were screened for flavivirus and alphavirus. No alphavirus was detected, indicating that Chikungunya virus is not present in these mosquitoes in Trentino and Padova area. However, 21% of the pools were positive for flavivirus, further recognised with BLAST as similar to Kamiti River Virus. Phylogenetical analysis with 708 nucleotides from the NS5 gene identified this virus as a new member of the insect flavivirus clade, together with others like Kamiti River Virus, Cell Fusing Agent or Culex flavivirus, and in the group of those transmitted by Aedes. Furthermore, the treatment with RNAse, indicated that this flavivirus should be integrated in the genome of Ae. albopictus. These results propose that these sequences are transmitted by both sexes, and with different prevalence in the studied populations, and support the idea of a widespread distribution of integrated genomes in several mosquitoes from different areas, as first demonstrated with Cell Silent Agent. Evolutionary implications of this discovery and application in flavivirus phylogeny are discussed.

  7. Incidência das Formas Imaturas de Aedes albopictus (Skuse e Aedes aegypti (Linnaeus no Município de Miguel Pereira, RJ, Brasil

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    Paulo Roberto Barbosa

    2010-07-01

    Abstract. The presence of Aedes albopictus (Skuse in urban areas represents a potential risk of inter-relationship of this species of mosquito with the population. This study aimed to evaluate the presence of the Ae. albopictus immature forms in deposits and building at Miguel Pereira city, Rio de Janeiro State. The study was carried in the last 12 months, 2007, in 27 locations in Miguel Pereira city. The larvae were identified in laboratory and data analysis was calculated by indicators of building infestation index and the Breteau index. The positive buildings were: residential (79.44% of total; waste land (2.56%, shopping (2.56% and other types of buildings (15.04% to Ae. albopictus, and homes (72.72% of total, shopping (6.06%; waste land (3.03% and other types of buildings (18.18% to Ae. aegypti (L.. The larvae (3731 collected, 3562 (95.5% were Ae. albopictus and 169 (4.5% were Ae. aegypti. The Ae. albopictus are more present in breeding that Ae. aegypti. The average rate of building infestation index (IFP and Breteau index (IB for Ae. albopictus was 1.0 and 1.9 and for Ae. aegypti was 0.1 and 0.1, respectively. The Ae. albopictus immature larvae forms were more abundantly found in the Miguel Pereira city in 2007; in future it may become a public health problem.

  8. The effect of Piper aduncum Linn. (Family: Piperaceae) essential oil as aerosol spray against Aedes aegypti (L.) and Aedes albopictus Skuse.

    Science.gov (United States)

    Misni, Norashiqin; Othman, Hidayatulfathi; Sulaiman, Sallehudin

    2011-08-01

    The bioefficacy of Piper aduncum L. essential oil formulated in aerosol cans was evaluated against Aedes aegypti and Aedes albopictus in a simulated room. The aerosol spray test was based on the Malaysian test standard for aerosol (MS 1221:1991UDC 632.982.2 modified from WHO 2009 methodology) and examined the knockdown effect within 20 minutes of exposure. Mortality rate after 24 hour of holding period was also determined. A commercial aerosol spray (0.09% prallethrin 0.05% d-phenothrin) was also tested as a comparison. Our results showed that the knockdown effect of the commercial aerosol spray and P. aduncum essential oil spray (8% and 10% concentrations) was significantly higher in Ae. albopictus adult females, when compared with that of Ae. aegypti adult females (Paduncum essential oil has the potential to be used as an aerosol spray against Aedes spp.

  9. Ovitrap surveillance of the dengue vectors, Aedes (Stegomyia) aegypti (L.) and Aedes (Stegomyia) albopictus Skuse in selected areas in Bentong, Pahang, Malaysia.

    Science.gov (United States)

    Norzahira, R; Hidayatulfathi, O; Wong, H M; Cheryl, A; Firdaus, R; Chew, H S; Lim, K W; Sing, K W; Mahathavan, M; Nazni, W A; Lee, H L; Vasan, S S; McKemey, A; Lacroix, R

    2011-04-01

    Ovitrap surveillance was conducted in methodically selected areas in Bentong, Pahang, Malaysia from June 2008 till December 2009 in order to identify insular sites with stable Aedes aegypti population. Eleven sites were surveyed in Bentong district, Pahang, and one of these locations (N3º33' E101º54') was found to have an ovitrap index of Ae. aegypti and Aedes albopictus ranging from 8%-47% and 37%-78% respectively, indicating that this site could be a high-risk area for dengue outbreak. Ae. aegypti larvae were found in both indoor and outdoor ovitraps (p>0.05) while significant difference between the populations of Ae. albopictus larvae from indoors and outdoors was observed (p<0.01). Data collected in this study could provide important entomological information for designing an effective integrated vector control programme to combat Aedes mosquitoes in this area.

  10. Genetic evidence for a worldwide chaotic dispersion pattern of the arbovirus vector, Aedes albopictus

    Science.gov (United States)

    Manni, Mosè; Guglielmino, Carmela R.; Scolari, Francesca; Vega-Rúa, Anubis; Failloux, Anna-Bella; Somboon, Pradya; Lisa, Antonella; Savini, Grazia; Bonizzoni, Mariangela; Gomulski, Ludvik M.; Malacrida, Anna R.

    2017-01-01

    Background Invasive species represent a global concern for their rapid spread and the possibility of infectious disease transmission. This is the case of the global invader Aedes albopictus, the Asian tiger mosquito. This species is a vector of medically important arboviruses, notably chikungunya (CHIKV), dengue (DENV) and Zika (ZIKV). The reconstruction of the complex colonization pattern of this mosquito has great potential for mitigating its spread and, consequently, disease risks. Methodology/Principal findings Classical population genetics analyses and Approximate Bayesian Computation (ABC) approaches were combined to disentangle the demographic history of Aedes albopictus populations from representative countries in the Southeast Asian native range and in the recent and more recently colonized areas. In Southeast Asia, the low differentiation and the high co-ancestry values identified among China, Thailand and Japan indicate that, in the native range, these populations maintain high genetic connectivity, revealing their ancestral common origin. China appears to be the oldest population. Outside Southeast Asia, the invasion process in La Réunion, America and the Mediterranean Basin is primarily supported by a chaotic propagule distribution, which cooperates in maintaining a relatively high genetic diversity within the adventive populations. Conclusions/Significance From our data, it appears that independent and also trans-continental introductions of Ae. albopictus may have facilitated the rapid establishment of adventive populations through admixture of unrelated genomes. As a consequence, a great amount of intra-population variability has been detected, and it is likely that this variability may extend to the genetic mechanisms controlling vector competence. Thus, in the context of the invasion process of this mosquito, it is possible that both population ancestry and admixture contribute to create the conditions for the efficient transmission of

  11. Evaluation of different formulations of IGRs against Aedes albopictus and Culex quinquefasciatus(Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Gul Zamin Khan; Inamullah Khan; Imtiaz Ali Khan; Alamzeb; Muhammad Salman; Kalim Ullah

    2016-01-01

    Objective: To test the relative efficacy of pyriproxyfen and methoprene on mortality,deformity, inhibition and emergence to adult stages of Culex quinquefasciatus and Aedes albopictus.Methods: Serial dilutions(0.01–0.05 mg/L) of methoprene, pyriproxyfen 0.5 water dispersible granules(WDG) and pyriproxyfen 1.0 WDG were used to assess mortality and inhibition of 3rd instar larvae of Aedes albopictus and Culex quinquefasciatus. Each concentration and control was replicated four times in completely randomized design.Data on larval mortality, growth inhibition, deformities and adult’s emergence was recorded weekly. On the basis of best comparative performance, the efficacy of pyriproxyfen 1.0 WDG at 0.1 g/m3 was also tested in the field by collecting treated water samples monthly for 1–6 months after field application. Twenty five 3rd instar larvae of Aedes and Culex spp. of the same cohorts were used for bioassays and compared with larvae in control cups containing 1 L of untreated tap water.Results: Results revealed variations in fatality of different insect growth regulators(IGRs) to the 3rd instar larvae of Culex and Aedes mosquitoes. Among the IGRs, pyriproxyfen 1.0 WDG was found best that exhibited significantly high emergence inhibition against Culex and Aedes spp. Based on the results, the IGRs were classified in terms of the tested parameters in order of pyriproxyfen 1.0 WDG > pyriproxyfen 0.5WDG > methoprene. In case of field studies, pyriproxyfen 1.0 WDG, pool data of the entire target treated sites showed minimum adult emergence from water sampled of habitats treated with 0.1 g/m3 of pyriproxyfen 1.0 WDG.Conclusions: It is thus concluded that IGRs can be utilized as environment friendly control measures for Culex and Aedes spp. of mosquitoes on small and large scale. This will reduce the use of conventional insecticides by the public health authorities and help in reducing selection pressure of insecticides.

  12. Evaluation of different formulations of IGRs against Aedes albopictus and Culex quinquefasciatus (Diptera:Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Gul Zamin Khan; Inamullah Khan; Imtiaz Ali Khan; Alamzeb; Muhammad Salman; Kalim Ullah

    2016-01-01

    Objective: To test the relative efficacy of pyriproxyfen and methoprene on mortality, deformity, inhibition and emergence to adult stages of Culex quinquefasciatus and Aedes albopictus. Methods: Serial dilutions (0.01–0.05 mg/L) of methoprene, pyriproxyfen 0.5 water dispersible granules (WDG) and pyriproxyfen 1.0 WDG were used to assess mortality and inhibition of 3rd instar larvae of Aedes albopictus and Culex quinquefasciatus. Each concentration and control was replicated four times in completely randomized design. Data on larval mortality, growth inhibition, deformities and adult's emergence was recorded weekly. On the basis of best comparative performance, the efficacy of pyr-iproxyfen 1.0 WDG at 0.1 g/m3 was also tested in the field by collecting treated water samples monthly for 1–6 months after field application. Twenty five 3rd instar larvae of Aedes and Culex spp. of the same cohorts were used for bioassays and compared with larvae in control cups containing 1 L of untreated tap water. Results: Results revealed variations in fatality of different insect growth regulators (IGRs) to the 3rd instar larvae of Culex and Aedes mosquitoes. Among the IGRs, pyr-iproxyfen 1.0 WDG was found best that exhibited significantly high emergence inhibition against Culex and Aedes spp. Based on the results, the IGRs were classified in terms of the tested parameters in order of pyriproxyfen 1.0 WDG > pyriproxyfen 0.5 WDG > methoprene. In case of field studies, pyriproxyfen 1.0 WDG, pool data of the entire target treated sites showed minimum adult emergence from water sampled of habitats treated with 0.1 g/m3 of pyriproxyfen 1.0 WDG. Conclusions: It is thus concluded that IGRs can be utilized as environment friendly control measures for Culex and Aedes spp. of mosquitoes on small and large scale. This will reduce the use of conventional insecticides by the public health authorities and help in reducing selection pressure of insecticides.

  13. An Unmanned Aerial Vehicle-Mounted Cold Mist Spray of Permethrin and Tetramethylfluthrin Targeting Aedes albopictus in China.

    Science.gov (United States)

    Li, Chun-Xiao; Zhang, Ying-Mei; Dong, Yan-De; Zhou, Ming-Hao; Zhang, Heng-Duan; Chen, Hong-Na; Tian, Ye; Yang, Wei-Fang; Wu, Xiao-Qun; Chu, Hong-Liang; Zhao, Tong-Yan

    2016-03-01

    Aedes albopictus is the primary vector of dengue fever and dengue hemorrhagic fever in China. Although there are previous studies on the application of adulticides to control this species, the application methods have either been back-pack or vehicle-mounted systems. However, many sites are too large to be effectively treated with back-pack sprayers, and the lack of roads restricts the use of vehicle-mounted sprayers. This paper provides the first study of using unmanned aerial vehicles to conduct cold mist sprays on Ae. albopictus habitats. A spray containing 4% permethrin and 1% tetramethylfluthrin was applied at an effective application rate of 9.0 mg/m(2). This method reduced Ae. albopictus populations by more than 90%. The results indicate this novel spray system is a powerful method to achieve a rapid decline of mosquito population in Ae. albopictus habitats in China.

  14. Rapid Surveillance for Vector Presence (RSVP): Development of a novel system for detecting Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Montgomery, Brian L; Shivas, Martin A; Hall-Mendelin, Sonja; Edwards, Jim; Hamilton, Nicholas A; Jansen, Cassie C; McMahon, Jamie L; Warrilow, David; van den Hurk, Andrew F

    2017-03-01

    The globally important Zika, dengue and chikungunya viruses are primarily transmitted by the invasive mosquitoes, Aedes aegypti and Aedes albopictus. In Australia, there is an increasing risk that these species may invade highly urbanized regions and trigger outbreaks. We describe the development of a Rapid Surveillance for Vector Presence (RSVP) system to expedite presence- absence surveys for both species. We developed a methodology that uses molecular assays to efficiently screen pooled ovitrap (egg trap) samples for traces of target species ribosomal RNA. Firstly, specific real-time reverse transcription-polymerase chain reaction (RT-PCR) assays were developed which detect a single Ae. aegypti or Ae. albopictus first instar larva in samples containing 4,999 and 999 non-target mosquitoes, respectively. ImageJ software was evaluated as an automated egg counting tool using ovitrap collections obtained from Brisbane, Australia. Qualitative assessment of ovistrips was required prior to automation because ImageJ did not differentiate between Aedes eggs and other objects or contaminants on 44.5% of ovistrips assessed, thus compromising the accuracy of egg counts. As a proof of concept, the RSVP was evaluated in Brisbane, Rockhampton and Goomeri, locations where Ae. aegypti is considered absent, present, and at the margin of its range, respectively. In Brisbane, Ae. aegypti was not detected in 25 pools formed from 477 ovitraps, comprising ≈ 54,300 eggs. In Rockhampton, Ae. aegypti was detected in 4/6 pools derived from 45 ovitraps, comprising ≈ 1,700 eggs. In Goomeri, Ae. aegypti was detected in 5/8 pools derived from 62 ovitraps, comprising ≈ 4,200 eggs. RSVP can rapidly detect nucleic acids from low numbers of target species within large samples of endemic species aggregated from multiple ovitraps. This screening capability facilitates deployment of ovitrap configurations of varying spatial scales, from a single residential block to entire suburbs or towns

  15. Rapid Surveillance for Vector Presence (RSVP: Development of a novel system for detecting Aedes aegypti and Aedes albopictus.

    Directory of Open Access Journals (Sweden)

    Brian L Montgomery

    2017-03-01

    Full Text Available The globally important Zika, dengue and chikungunya viruses are primarily transmitted by the invasive mosquitoes, Aedes aegypti and Aedes albopictus. In Australia, there is an increasing risk that these species may invade highly urbanized regions and trigger outbreaks. We describe the development of a Rapid Surveillance for Vector Presence (RSVP system to expedite presence- absence surveys for both species.We developed a methodology that uses molecular assays to efficiently screen pooled ovitrap (egg trap samples for traces of target species ribosomal RNA. Firstly, specific real-time reverse transcription-polymerase chain reaction (RT-PCR assays were developed which detect a single Ae. aegypti or Ae. albopictus first instar larva in samples containing 4,999 and 999 non-target mosquitoes, respectively. ImageJ software was evaluated as an automated egg counting tool using ovitrap collections obtained from Brisbane, Australia. Qualitative assessment of ovistrips was required prior to automation because ImageJ did not differentiate between Aedes eggs and other objects or contaminants on 44.5% of ovistrips assessed, thus compromising the accuracy of egg counts. As a proof of concept, the RSVP was evaluated in Brisbane, Rockhampton and Goomeri, locations where Ae. aegypti is considered absent, present, and at the margin of its range, respectively. In Brisbane, Ae. aegypti was not detected in 25 pools formed from 477 ovitraps, comprising ≈ 54,300 eggs. In Rockhampton, Ae. aegypti was detected in 4/6 pools derived from 45 ovitraps, comprising ≈ 1,700 eggs. In Goomeri, Ae. aegypti was detected in 5/8 pools derived from 62 ovitraps, comprising ≈ 4,200 eggs.RSVP can rapidly detect nucleic acids from low numbers of target species within large samples of endemic species aggregated from multiple ovitraps. This screening capability facilitates deployment of ovitrap configurations of varying spatial scales, from a single residential block to entire

  16. Large-Scale Modelling of the Environmentally-Driven Population Dynamics of Temperate Aedes albopictus (Skuse.

    Directory of Open Access Journals (Sweden)

    Kamil Erguler

    Full Text Available The Asian tiger mosquito, Aedes albopictus, is a highly invasive vector species. It is a proven vector of dengue and chikungunya viruses, with the potential to host a further 24 arboviruses. It has recently expanded its geographical range, threatening many countries in the Middle East, Mediterranean, Europe and North America. Here, we investigate the theoretical limitations of its range expansion by developing an environmentally-driven mathematical model of its population dynamics. We focus on the temperate strain of Ae. albopictus and compile a comprehensive literature-based database of physiological parameters. As a novel approach, we link its population dynamics to globally-available environmental datasets by performing inference on all parameters. We adopt a Bayesian approach using experimental data as prior knowledge and the surveillance dataset of Emilia-Romagna, Italy, as evidence. The model accounts for temperature, precipitation, human population density and photoperiod as the main environmental drivers, and, in addition, incorporates the mechanism of diapause and a simple breeding site model. The model demonstrates high predictive skill over the reference region and beyond, confirming most of the current reports of vector presence in Europe. One of the main hypotheses derived from the model is the survival of Ae. albopictus populations through harsh winter conditions. The model, constrained by the environmental datasets, requires that either diapausing eggs or adult vectors have increased cold resistance. The model also suggests that temperature and photoperiod control diapause initiation and termination differentially. We demonstrate that it is possible to account for unobserved properties and constraints, such as differences between laboratory and field conditions, to derive reliable inferences on the environmental dependence of Ae. albopictus populations.

  17. Variations in the male genitalia of Aedes (Stegomyia Albopictus (Skuse from Chandigarh and its surrounding areas (Diptera: Culicidae

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    Sagandeep Kaur

    2014-09-01

    Full Text Available The Asian tiger mosquito Aedes albopictus is the most dominant species of subgenus Stegomyia and is medically important from the standpoint of transmitting wide range of human pathogens of deadly diseases like dengue, yellow fever and chikungunya. During present investigations, it has been observed that IX tergum in the male genitalia of Aedes albopictus varies greatly. It shows variations with respect to the presence or absence of lateral projections on the IX tergum, as well as in the shape and size of median and lateral projections. The shape of IX tergum in the male genitalia of Aedes species is of great taxonomic importance as it is a diagnostic character of the species. These variations have been observed both in natural populations collected from various breeding sites as well as in the adults reared in laboratory. The observed differences have not been noticed by any of the previous workers.

  18. Susceptibility of Aedes albopictus from dengue outbreak areas to temephos and Bacillus thuringiensis subsp.israelensis

    Institute of Scientific and Technical Information of China (English)

    Ahmad Mohiddin; Asmalia Md Lasim; Wan Fatma Zuharah

    2016-01-01

    Objective:To monitor the current duration of the application rates in vector programme and the level of Aedes albopictus larvae susceptibility from three selected areas in northeast district of Penang on two selected larvicides,temephos and Bacillus thuringiensis subsp.israelensis(Bti) which are commonly used by Penang Health Department for vector control.Methods:The mosquito larvae were tested against two types of larvicides:(1) temephos(Abate?) with diagnostic dosage(0.012 mg/L) and operational dosage(1 mg/L) and(2)Bacillus thuringiensis subsp.israelensis(Vecto Bac?WG) with operational dosage ranging from 6 000 international toxic units per L to 24 000 international toxic unit per L.A total of 20 late third and early forth instar larvae were selected and transferred into paper cup sized 300 m L using wide-mouthed pipette.The larvae were distributed into each 300 m L paper cup containing 50 m L of aged tap water.The experiment was replicated five times for each concentration tested.Each test was repeated three times.The mortality was recorded after 24 h of exposure and recorded lethal time was based on 2 h for temephos and 6 h for Bti.The control consisted of ethanol for temephos and only seasoned water for Bti.Results:The result showed that Aedes albopictus from Flat Hamna,Kampung Sungai Gelugor and Kampung Tanjung Tokong were still susceptible to Bti and temephos.However,higher lethal time and resistance ratio were detected in strain from Flat Hamna which was a known dengue hot spot area in northeast of Penang.Conclusions:The application of temephos and Bti in vector control activity in these selected localities is still relevant in the control of Aedes larvae populations.

  19. Geospatial analysis of invasion of the Asian tiger mosquito Aedes albopictus: competition with Aedes japonicus japonicus in its northern limit area in Japan

    Directory of Open Access Journals (Sweden)

    Naoko Nihei

    2014-05-01

    Full Text Available The mosquito Aedes albopictus, indigenous to Southeast Asia and nearby islands, has spread almost worldwide during recent decades. We confirm the invasion of this mosquito, first reported in Yamagata city in northeast Honshu, Japan in 2000. Previously, only Ae. japonicus japonicus had been collected in this place, but 2 years later, the population of Ae. albopictus had increased, so more than 80% of the total number of larval colonies there consisted of this species. In contrast to Yamagata’s new residential area, now infested by Ae. albopictus, the original mosquito remains in the city but its habitats are generally closer to the surrounding mountains, where the normalized difference vegetation index is higher. The factors affecting the distribution of both species in Yamagata city were studied using geographical information systems (GIS based on data derived from field surveys, aerial photographs, satellite images and digital maps. The range of Aedes mosquito habitats was estimated and visualised on polygon maps and no significant differences were noted when the polygon area was calculated by GIS software in comparison with the satellite images. Although Ae. j. japonicus was expected to be rapidly overrun by Ae. albopictus, this did not happen. Currently, both species coexist; not only in separate sites, but also simultaneously in various water bodies, where larvae from both species have frequently been seen. However, the competitive relationship between these two Aedes species within a warming environment is an issue that should be closely monitored.

  20. The key breeding sites by pupal survey for dengue mosquito vectors, Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse), in Guba, Cebu City, Philippines.

    Science.gov (United States)

    Edillo, Frances E; Roble, Noel D; Otero, Nenito D

    2012-11-01

    We conducted this study to assess how well a pupal survey of dengue mosquito vectors, Aedes aegypti and Aedes albopictus, is able to target the most productive breeding sites. The study was carried out monthly during the rainy season (8 months) in 2008 in Cuba, Cebu City, Philippines. The hypotheses tested were: 1) most pupae of Ae. aegypti or Ae. albopictus were produced in a few types of breeding sites and 2) the most productive types of breeding sites for each species were the most abundant. Approximately 2,500 pupae were collected from 554 breeding sites in 279 houses. Thirty-eight point four percent of ten types of breeding sites were positive for Ae. aegypti, and 11.9% of nine types of sites were positive for Ae. albopictus. Plastic drums (40.2%), metal drums (29.6%), and plastic containers (10.5%) were the key sites for Ae. aegypti pupae, whereas bamboo stumps (28.5%), plastic drums (21.1%), and rubber tires (19.1%) were the key sites for Ae. albopictus. The most productive breeding sites for Ae. aegypti were common but not the most common for Ae. albopictus. These results are relevant for dengue vector control programs.

  1. Taming a Tiger in the City: Comparison of Motorized Backpack Applications and Source Reduction Against the Asian Tiger Mosquito, Aedes albopictus

    Science.gov (United States)

    2014-06-01

    Med Vet Entomol 18:215–227. Gubler DJ, Clark GG. 1996. Community involvement in the control of Aedes aegypti . Acta Trop 61:169– 179. Hawley WA. 1988...albopictus a top priority for control efforts (Farajollahi and Nelder 2009, Farajollahi et al. 2012, Rochlin et al. 2013). Aedes albopictus suppression...penetrating hidden containers. Previous studies have shown that Bti is well suited for control of Ae. aegypti (L.) in container habitats (Lacey 2009

  2. Control of Aedes albopictus with attractive toxic sugar baits (ATSB) and potential impact on non-target organisms in St. Augustine, Florida

    OpenAIRE

    Revay, Edita E.; Müller, Gunter C; Qualls, Whitney A.; Kline, Daniel; Naranjo, Diana P.; Arheart, Kristopher L; Kravchenko, Vasiliy D; Yfremova, Zoya; Hausmann,Axel; Beier, John C.; Schlein, Yosef; Xue, Rui-De

    2014-01-01

    The purpose of this study was to test the efficacy of bait stations and foliar applications containing attractive toxic sugar baits (ATSB) and eugenol to control Aedes albopictus. At the same time the potential impact of these control methods was evaluated on non-target organisms. The study was conducted at five tire sites in St. Augustine, Florida. Aedes albopictus populations were significantly reduced with ATSB-eugenol applications applied directly to non-flowering vegetation and as bait s...

  3. Seasonal Differences in Density But Similar Competitive Impact of Aedes albopictus (Skuse) on Aedes aegypti (L.) in Rio de Janeiro, Brazil.

    Science.gov (United States)

    Camara, Daniel Cardoso Portela; Codeço, Claudia Torres; Juliano, Steven A; Lounibos, L Philip; Riback, Thais Irene Souza; Pereira, Glaucio Rocha; Honorio, Nildimar Alves

    2016-01-01

    Previous studies have shown that the negative effects of density of Ae. albopictus on Ae. aegypti exceed those of Ae. aegypti on Ae. albopictus for population growth, adult size, survivorship, and developmental rate. This competitive superiority has been invoked to explain the displacement of Ae. aegypti by Ae. albopictus in the southeastern USA. In Brazil, these species coexist in many vegetated suburban and rural areas. We investigated a related, but less-well-studied question: do effects of Ae. albopictus on Ae. aegypti larval development and survival occur under field conditions at realistic densities across multiple seasons in Brazil? We conducted additive competition experiments in a vegetated area of Rio de Janeiro where these species coexist. We tested the hypothesis that Ae. aegypti (the focal species, at a fixed density) suffers negative effects on development and survivorship across a gradient of increasing densities of Ae. albopictus (the associate species) in three seasons. The results showed statistically significant effects of both season and larval density on Ae. aegypti survivorship, and significant effects of season on development rate, with no significant season-density interactions. Densities of Aedes larvae in these habitats differed among seasons by a factor of up to 7x. Overall, Spring was the most favorable season for Ae. aegypti survivorship and development. Results showed that under natural conditions the negative competitive effects of Ae. albopictus on Ae. aegypti were expressed primarily as lower survivorship. Coexistence between Ae. aegypti and Ae. albopictus in vegetated areas is likely affected by seasonal environmental differences, such as detrital resource levels or egg desiccation, which can influence competition between these species. Interactions between these Aedes are important in Brazil, where both species are well established and widely distributed and vector dengue, Zika and chikungunya viruses.

  4. Seasonal Differences in Density But Similar Competitive Impact of Aedes albopictus (Skuse on Aedes aegypti (L. in Rio de Janeiro, Brazil.

    Directory of Open Access Journals (Sweden)

    Daniel Cardoso Portela Camara

    Full Text Available Previous studies have shown that the negative effects of density of Ae. albopictus on Ae. aegypti exceed those of Ae. aegypti on Ae. albopictus for population growth, adult size, survivorship, and developmental rate. This competitive superiority has been invoked to explain the displacement of Ae. aegypti by Ae. albopictus in the southeastern USA. In Brazil, these species coexist in many vegetated suburban and rural areas. We investigated a related, but less-well-studied question: do effects of Ae. albopictus on Ae. aegypti larval development and survival occur under field conditions at realistic densities across multiple seasons in Brazil? We conducted additive competition experiments in a vegetated area of Rio de Janeiro where these species coexist. We tested the hypothesis that Ae. aegypti (the focal species, at a fixed density suffers negative effects on development and survivorship across a gradient of increasing densities of Ae. albopictus (the associate species in three seasons. The results showed statistically significant effects of both season and larval density on Ae. aegypti survivorship, and significant effects of season on development rate, with no significant season-density interactions. Densities of Aedes larvae in these habitats differed among seasons by a factor of up to 7x. Overall, Spring was the most favorable season for Ae. aegypti survivorship and development. Results showed that under natural conditions the negative competitive effects of Ae. albopictus on Ae. aegypti were expressed primarily as lower survivorship. Coexistence between Ae. aegypti and Ae. albopictus in vegetated areas is likely affected by seasonal environmental differences, such as detrital resource levels or egg desiccation, which can influence competition between these species. Interactions between these Aedes are important in Brazil, where both species are well established and widely distributed and vector dengue, Zika and chikungunya viruses.

  5. The global distribution of the arbovirus vectors Aedes aegypti and Ae. albopictus

    Science.gov (United States)

    Kraemer, Moritz UG; Sinka, Marianne E; Duda, Kirsten A; Mylne, Adrian QN; Shearer, Freya M; Barker, Christopher M; Moore, Chester G; Carvalho, Roberta G; Coelho, Giovanini E; Van Bortel, Wim; Hendrickx, Guy; Schaffner, Francis; Elyazar, Iqbal RF; Teng, Hwa-Jen; Brady, Oliver J; Messina, Jane P; Pigott, David M; Scott, Thomas W; Smith, David L; Wint, GR William; Golding, Nick; Hay, Simon I

    2015-01-01

    Dengue and chikungunya are increasing global public health concerns due to their rapid geographical spread and increasing disease burden. Knowledge of the contemporary distribution of their shared vectors, Aedes aegypti and Aedes albopictus remains incomplete and is complicated by an ongoing range expansion fuelled by increased global trade and travel. Mapping the global distribution of these vectors and the geographical determinants of their ranges is essential for public health planning. Here we compile the largest contemporary database for both species and pair it with relevant environmental variables predicting their global distribution. We show Aedes distributions to be the widest ever recorded; now extensive in all continents, including North America and Europe. These maps will help define the spatial limits of current autochthonous transmission of dengue and chikungunya viruses. It is only with this kind of rigorous entomological baseline that we can hope to project future health impacts of these viruses. DOI: http://dx.doi.org/10.7554/eLife.08347.001 PMID:26126267

  6. Protein expression in the midgut of sugar-fed Aedes albopictus females

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    Saboia-Vahia Leonardo

    2012-12-01

    Full Text Available Abstract Background Aedes albopictus is a vector for several fatal arboviruses in tropical and sub-tropical regions of the world. The midgut of the mosquito is the first barrier that pathogens must overcome to establish infection and represents one of the main immunologically active sites of the insect. Nevertheless, little is known about the proteins involved in the defense against pathogens, and even in the processing of food, and the detoxification of metabolites. The identification of proteins exclusively expressed in the midgut is the first step in understanding the complex physiology of this tissue and can provide insight into the mechanisms of pathogen-vector interaction. However, identification of the locally expressed proteins presents a challenge because the Ae. albopictus genome has not been sequenced. Methods In this study, two-dimensional electrophoresis (2DE was combined with liquid chromatography in line with tandem mass spectrometry (LC-MS/MS and data mining to identify the major proteins in the midgut of sugar-fed Ae. albopictus females. Results Fifty-six proteins were identified by sequence similarity to entries from the Ae. aegypti genome. In addition, two hypothetical proteins were experimentally confirmed. According to the gene ontology analysis, the identified proteins were classified into 16 clusters of biological processes. Use of the STRING database to investigate protein functional associations revealed five functional networks among the identified proteins, including a network for carbohydrate and amino acid metabolism, a group associated with ATP production and a network of proteins that interact during detoxification of toxic free radicals, among others. This analysis allowed the assignment of a potential role for proteins with unknown function based on their functional association with other characterized proteins. Conclusion Our findings represent the first proteome map of the Ae. albopictus midgut and denotes the

  7. Aedes aegypti and Aedes albopictus (Diptera: Culicidae: coexistence and susceptibility to temephos, in municipalities with occurrence of dengue and differentiated characteristics of urbanization Aedes aegypti e Aedes albopictus (Diptera: Culicidae: coexistência e susceptibilidade ao temephos, em municípios com ocorrência de casos de dengue e diferentes características de urbanização

    Directory of Open Access Journals (Sweden)

    Josiane Somariva Prophiro

    2011-06-01

    Full Text Available INTRODUCTION: The aim of the present study was to verify the coexistence between Aedes aegypti and Aedes albopictus populations in municipalities of the States of Paraná and Santa Catarina with different urbanization profiles where dengue occurs and evaluate their susceptibility to the organophosphate temephos. METHODS: The number of eggs per ovitrap were counted and incubated for hatching to identify the species. Data analysis of the populations was conducted to determine randomness and aggregation, using the variance-to-mean ratio (index of dispersion. Susceptibility to temephos was evaluated by estimation of the resistance ratios RR50 and RR95. Aedes aegypti samples were compared with the population Rockefeller and Aedes albopictus samples were compared with a population from the State of Santa Catarina and with the Rockefeller population. RESULTS: Coexistence between Aedes aegypti and Aedes albopictus and the aggregation of their eggs were observed at all the sites analyzed in the State of Paraná. CONCLUSIONS: All the Aedes aegypti populations from the State of Parana showed alteration in susceptibility status to the organophosphate temephos, revealing incipient resistance. Similarly, all the Aedes albopictus populations (States of Paraná and Santa Catarina presented survival when exposed to the organophosphate temephos.INTRODUÇÃO: O presente estudo teve como objetivo verificar a coexistência de populações de Aedes aegypti e de Aedes albopictus em municípios do Estado do Paraná e Santa Catarina com diferentes formas de urbanização, onde ocorrem casos de dengue, e avaliar a susceptibilidade ao organofosforado temephos. MÉTODOS: O número de ovos por ovitrampa foram contados (sem distinguir a espécie e colocados para eclosão e posterior identificação das espécies. A análise das populacões foi conduzida para determinar aleatoriedade e agregação usando a razão variância/média (índice de dispersão. A susceptibilidade ao

  8. Basic surface properties of Aedes albopictus cells: effect of Mayaro virus infection on electrostatic charge and surface tension.

    Science.gov (United States)

    Mezêncio, J M; Costa e Silva Filho, F; Rebello, M A

    1997-01-01

    Aedes albopictus cells possess a negative cell surface charge of -12.7 mV with an isoelectrophoretic point (IEP) located between pH 3.0 and 4.0. Infection with Mayaro virus rendered the surface of A. albopictus cells less negative reaching a zeta-potential value of -9.7 mV after 100 h of infection. Concomitantly, the IEP of the infected cells were also altered from 3.0-4.0 to 4.0-5.0. Furthermore, the contact angle measurements clearly showed qualitative alterations in the cell surface of infected cells.

  9. Comportamento de Aedes albopictus e de Ae. scapularis adultos (Diptera: Culicidae no Sudeste do Brasil

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    Oswaldo Paulo Forattini

    2000-10-01

    Full Text Available OBJETIVO: Observar e comparar o comportamento das espécies de Aedes albopictus e de Ae. scapularis, na localidade de Pedrinhas, litoral sul do Estado de São Paulo, Brasil. MÉTODOS: As observações foram feitas de outubro de 1996 a janeiro de 2000. Foram realizadas coletas sistemáticas de formas adultas mediante a utilização de isca humana, aspirações ambientais e armadilha tipo Shannon. A domiciliação foi estimada pelo índice de Nuorteva e pela razão de sinantropia. RESULTADOS: Foram feitas 87 coletas diurnas, com a obtenção de 872 adultos fêmeas. As médias de Williams', multiplicadas por 100, foram de 118 e 21 para Ae. albopictus nos horários de 7h às 18h e de 18h às 20h, respectivamente. Quanto a Ae. scapularis, foram de 100 e 106 nos mesmos períodos. Esse último revelou pico de atividade crepuscular vespertina. Na aspiração de abrigos, obteve-se o total de 1.124 espécimens, dos quais 226 Ae. albopictus e 898 Ae. scapularis. O período de janeiro a maio correspondeu ao de maior rendimento para ambos os mosquitos. Quanto à armadilha de Shannon, as coletas realizadas na mata revelaram a ausência de Ae. albopictus. No que concerne à domiciliação, esse último mostrou os maiores valores de índices, enquanto Ae. scapularis revelou comportamento de tipo ubiquista. CONCLUSÕES: Os resultados confirmam outras observações, permitindo levantar hipóteses. Em relação a Ae. scapularis, sugere-se que possa existir fenômeno de diapausa das fêmeas no período verão-outono, a qual cessaria no inverno-primavera quando então a atividade seria retomada. Quanto a Ae. albopictus, os dados sugerem que se trata de população em processo adaptativo ao novo ambiente.

  10. Avaliação da influência da temperatura sobre o desenvolvimento de Aedes albopictus Evaluation of the temperature influence on the development of Aedes albopictus

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    Daniéla Cristina Calado

    2002-04-01

    Full Text Available OBJETIVO: Verificar a influência da temperatura sobre os estágios de desenvolvimento de Aedes albopictus sob condições de laboratório. MÉTODOS: Foi avaliado o período de desenvolvimento dos estágios de ovo, larva e pupa em quatro temperaturas constantes de 15ºC, 20ºC, 25ºC e 30ºC em câmaras climatizadas com umidade relativa do ar oscilando entre 70% e 85% e fotoperíodo de CE 12:12 horas. Pela análise de variância, foram testados os efeitos das quatro temperaturas constantes. RESULTADOS: O período de incubação dos ovos compreendeu 38,38; 19,09; 13,10; e 10,44 dias; o período larval dos indivíduos machos atingiu 30,13; 13,83; 7,36; e 5,57 dias; o período larval para fêmeas apresentou duração de 33,22; 15,00; 8,06; e 6,16 dias; o período pupal em machos compreendeu 8,01; 4,92; 2,40; e 1,76 dias, enquanto nas fêmeas foi de 8,15; 5,11; 2,60; e 1,88 dias sob as temperaturas de 15ºC, 20ºC, 25ºC e 30ºC, respectivamente. Em todos os estágios de desenvolvimento, foram encontradas diferenças significativas, entre as temperaturas avaliadas, em torno de 5% no tempo de desenvolvimento. O período de desenvolvimento foi inversamente relacionado à temperatura, com o período larval mais breve em machos que em fêmeas. Nas temperaturas de 20ºC a 30ºC, o desenvolvimento foi mais breve e com maior viabilidade que a 15ºC. CONCLUSÕES: Nas condições em que foram realizados os experimentos, a temperatura afetou de forma significativa e inversamente proporcional os estágios imaturos de Aedes albopictus. Esses resultados mostram que os estágios imaturos são mais suscetíveis durante os períodos de baixas temperaturas devido ao maior tempo necessário para completar o desenvolvimento, informação que pode ser utilizada em estratégias de controle.OBJECTIVE: To verify the temperature's influence on the Aedes albopictus development stages under laboratory conditions. METHODS: The development period of eggs, larvae and pupas were

  11. Aedes albopictus in northeast Mexico: An update on adult distribution and first report of parasitism by Ascogregarina taiwanensis

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    Filiberto Reyes-Villanueva

    2013-08-01

    Full Text Available Background & objectives: Aedes albopictus has been known as efficient vector of dengue in Asian countries and its wide displacement of Ae. aegypti has been documented in many parts of the world. The present survey was carried out to update the distribution of Ae. albopictus in northeast Mexico and to report the first record of parasitism of mosquitoes by Ascogregarina taiwanensis in Mexico. Methods: Human landing collections were conducted in the month of May every year between 2007 and 2009 across the three states, Nuevo Leon (NL, Tamaulipas and Coahuila in northeast Mexico. Six human bait collections were also organized at the cemetery of Gomez Farias (GF, a village in southern Tamaulipas during the rainy and dry seasons in 2010. Aedes albopictus caught in 2010 were dissected for parasitic protozoan gregarines. Results: The results of human landing collections carried out during 2007-10 across the three states of northeast zone of Mexico revealed that Ae. albopictus is invading along the route between Monterrey City in NL and Tampico, Tamaulipas, but not into the arid state of Coahuila. Aedes albopictus was recorded in nine new municipalities in addition to the 15 municipalities reported before 2005. Furthermore, six human-bait collections performed during the dry and rainy seasons in 2010 at the cemetery of GF suggest the exclusion of Ae. aegypti on that site. Dominance was shared by Ae. quadrivittatus, another container-inhabitant but indigenous species, and Ae. albopictus during the dry and rainy seasons, respectively. The results of dissection of the mosquitoes for gregarines revealed the parasitism of Ae. albopictus by A. taiwanensis. Interpretation & conclusion: The results of this study showed that Ae. albopictus has spread to all the municipalities in the northeastern Mexico except the arid area and reported the first record of parasitic protozoan A. taiwanensis in Mexico. We recommend further studies on larval and adult populations of

  12. Simple Indices Provide Insight to Climate Attributes Delineating the Geographic Range of Aedes albopictus (Diptera: Culicidae) Prior to Worldwide Invasion.

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    Mogi, Motoyoshi; Armbruster, Peter; Tuno, Nobuko; Campos, Raúl; Eritja, Roger

    2015-07-01

    Aedes albopictus (Skuse) has expanded its distribution worldwide during the past decades. Despite attempts to explain and predict its geographic occurrence, analyses of the distribution of Ae. albopictus in the context of broad climatic regions (biomes) has not been performed. We analyzed climate conditions at its distribution sites in the range before the worldwide invasions (from the easternmost Hawaii through westernmost Madagascar) by using thermal and aridity-humidity indices descriptive of major biomes. A significant advantage of this approach is that it uses simple indices clearly related to the population dynamics of Ae. albopictus. Although Ae. albopictus has been regarded as a forest species preferring humid climate, in areas with significant human habitation, the distribution sites extended from the perhumid, rain forest zone to the semiarid, steppe zone. This pattern was common from the tropics through the temperate zone. Across the distribution range, there was no seasonal discordance between temperature and precipitation; at sites where winter prevents Ae. albopictus reproduction (monthly means10°C) under the Asian summer monsoon. Absence of the species in northern and eastern coastal Australia and eastern coastal Africa was not attributable solely to climate conditions. However, Asia west of the summer monsoon range was climatically unsuitable because of low precipitation throughout the year or in warm months favorable to reproduction (concentration of precipitation in winter). We hypothesized that Ae. albopictus originated in continental Asia under the monsoon climate with distinct dry seasons and hot, wet summer, enabling rapid population growth.

  13. Distribution of Aedes albopictus (Diptera, Culicidae in southwestern Pacific countries, with a first report from the Kingdom of Tonga

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    Guillaumot Laurent

    2012-11-01

    Full Text Available Abstract Background Aedes (Stegomyia albopictus is currently one of the most notorious globally invasive mosquito species. Its medical importance is well documented, and its fast expansion throughout most continents is being monitored with concern. It is generally assumed that its expansion through the Western Pacific island countries has not progressed since its establishment in Fiji in 1989. However, the current status of Ae. albopictus in the Pacific region is largely unknown. Findings According to data from the literature and our own observations, Ae. albopictus is currently present in the following countries of the southern Pacific region: Papua New Guinea, Solomon Islands, Fiji, and the Kingdom of Tonga, where it was first detected in July 2011. It is absent from New Caledonia and French Polynesia where routine entomological surveillance is carried out, and was not detected during entomological work in 2007, either on the Cook Islands or on the Wallis and Futuna Islands. The species was not reported from American Samoa in 2004, but it is mentioned as probably present in Vanuatu. This is the first report of Ae. albopictus in Tonga. Conclusions The introduction and establishment of Ae. albopictus in Tonga was expected due to the geographical proximity of this country to Fiji where the species is strongly established. The pathway of introduction is unknown. The expansion of Ae. albopictus in the Pacific region poses an increasing threat to public health given the role this mosquito plays as primary vector of emerging infectious diseases such as Chikungunya fever.

  14. Wolbachia Do Not Induce Reactive Oxygen Species-Dependent Immune Pathway Activation in Aedes albopictus

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    Jennifer C. Molloy

    2015-08-01

    Full Text Available Aedes albopictus is a major vector of dengue (DENV and chikungunya (CHIKV viruses, causing millions of infections annually. It naturally carries, at high frequency, the intracellular inherited bacterial endosymbiont Wolbachia strains wAlbA and wAlbB; transinfection with the higher-density Wolbachia strain wMel from Drosophila melanogaster led to transmission blocking of both arboviruses. The hypothesis that reactive oxygen species (ROS-induced immune activation plays a role in arbovirus inhibition in this species was examined. In contrast to previous observations in Ae. aegypti, elevation of ROS levels was not observed in either cell lines or mosquito lines carrying the wild-type Wolbachia or higher-density Drosophila Wolbachia strains. There was also no upregulation of genes controlling innate immune pathways or with antioxidant/ROS-producing functions. These data suggest that ROS-mediated immune activation is not an important component of the viral transmission-blocking phenotype in this species.

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

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    Gomes Almério de Castro

    1995-01-01

    Full Text Available 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 18degrees C to 22degrees 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.

  16. Proteomic analysis of an Aedes albopictus cell line infected with Dengue serotypes 1 and 3 viruses

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    Thomas Frédéric

    2011-07-01

    Full Text Available Abstract Background Proteomic analysis was performed to identify proteins regulated during infection by Dengue serotypes 1 and 3 in an Aedes albopictus cell line. The potential of these viruses to cause severe disease at primary infection is of interest although few studies have been performed with these two Dengue serotypes. Results The most relevant observation of our study is the significant overexpression of proteins involved in the cellular stress response and the glycolysis pathway after 48 hours of infection. Viral infection activates the translation of some host genes, which may result in stress due to responses involving unfolded proteins. Conclusions Therefore, the oxidation reduction and glycolytic mechanisms could participate in the antiviral response against Dengue virus. The results of our study should help to improve our knowledge of the virus-mosquito interaction at a cellular level with the aim of designing efficient strategies for the control of Dengue virus.

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

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    Almério de Castro Gomes

    1995-02-01

    Full Text Available 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° C to 22° 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.

  18. The Insect Growth Regulator Pyriproxyfen Terminates Egg Diapause in the Asian Tiger Mosquito, Aedes albopictus.

    Science.gov (United States)

    Suman, Devi S; Wang, Yi; Gaugler, Randy

    2015-01-01

    The Asian tiger mosquito, Aedes albopictus, is a highly invasive mosquito species that transmits chikungunya and dengue. This species overwinters as diapausing eggs in temperate climates. Early diapause termination may be a beneficial strategy for winter mosquito control; however, a mechanism to terminate the diapause process using chemicals is not known. We tested the hypothesis that a hormonal imbalance caused by the administration of juvenile hormone analog would terminate egg diapause in A. albopictus. We tested the insect growth regulator pyriproxyfen on all developmental stages to identify a susceptible stage for diapause termination. We found that pyriproxyfen treatment of mosquito eggs terminated embryonic diapause. The highest rates of diapause termination were recorded in newly deposited (78.9%) and fully embryonated (74.7%) eggs at 0.1 and 1 ppm, respectively. Hatching was completed earlier in newly deposited eggs (25-30 days) compared to fully embryonated eggs (71-80 days). The combined mortality from premature diapause termination and ovicidal activity was 98.2% in newly deposited and >98.9% in fully embryonated eggs at 1 ppm. The control diapause eggs did not hatch under diapausing conditions. Pyriproxyfen exposure to larvae, pupae and adults did not prevent the females from ovipositing diapausing eggs. There was no effect of pyriproxyfen on diapausing egg embryonic developmental time. We also observed mortality in diapausing eggs laid by females exposed to pyriproxyfen immediately after blood feeding. There was no mortality in eggs laid by females that survived larval and pupal exposures. In conclusion, diapausing eggs were the more susceptible to pyriproxyfen diapause termination compared to other life stages. This is the first report of diapause termination in A. albopictus with a juvenile hormone analog. We believe our findings will be useful in developing a new control strategy against overwintering mosquito populations.

  19. The Insect Growth Regulator Pyriproxyfen Terminates Egg Diapause in the Asian Tiger Mosquito, Aedes albopictus.

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    Devi S Suman

    Full Text Available The Asian tiger mosquito, Aedes albopictus, is a highly invasive mosquito species that transmits chikungunya and dengue. This species overwinters as diapausing eggs in temperate climates. Early diapause termination may be a beneficial strategy for winter mosquito control; however, a mechanism to terminate the diapause process using chemicals is not known. We tested the hypothesis that a hormonal imbalance caused by the administration of juvenile hormone analog would terminate egg diapause in A. albopictus. We tested the insect growth regulator pyriproxyfen on all developmental stages to identify a susceptible stage for diapause termination. We found that pyriproxyfen treatment of mosquito eggs terminated embryonic diapause. The highest rates of diapause termination were recorded in newly deposited (78.9% and fully embryonated (74.7% eggs at 0.1 and 1 ppm, respectively. Hatching was completed earlier in newly deposited eggs (25-30 days compared to fully embryonated eggs (71-80 days. The combined mortality from premature diapause termination and ovicidal activity was 98.2% in newly deposited and >98.9% in fully embryonated eggs at 1 ppm. The control diapause eggs did not hatch under diapausing conditions. Pyriproxyfen exposure to larvae, pupae and adults did not prevent the females from ovipositing diapausing eggs. There was no effect of pyriproxyfen on diapausing egg embryonic developmental time. We also observed mortality in diapausing eggs laid by females exposed to pyriproxyfen immediately after blood feeding. There was no mortality in eggs laid by females that survived larval and pupal exposures. In conclusion, diapausing eggs were the more susceptible to pyriproxyfen diapause termination compared to other life stages. This is the first report of diapause termination in A. albopictus with a juvenile hormone analog. We believe our findings will be useful in developing a new control strategy against overwintering mosquito populations.

  20. Discarded cigarette butts attract females and kill the progeny of Aedes albopictus.

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    Dieng, Hamady; Saifur, Rahman G M; Ahmad, Abu Hassan; Rawi, Che Salmah Md; Boots, Michael; Satho, Tomomitsu; Zuharah, Wan Fatma; Fadzly, Nik; Althbyani, Abdulaziz; Miake, Fumio; Jaal, Zairi; Abubakar, Sazaly

    2011-09-01

    Discarded cigarette butts (DCB) waste occurs worldwide, pollutes landscapes, is unsightly, and results in added debris removal costs. There is, therefore, a great deal of current interest in making use of DCBs in beneficial ways. Despite evidence that DCBs are harmful to water fleas (Daphnia magna), which breed in aquatic environments as do mosquito larvae, their impact on dengue vectors is unknown. We examined whether Aedes albopictus alters its ovipositional responses, larval eclosion, and development in response to presence of DCBs in its habitats. We found oviposition activity in DCB-treated water similar to that of control water and that ovipositional activity in DCB solutions steadily increased over time as those solutions aged to 10 days. Larval eclosion was initially suppressed on day 1 in DCB solution, but increased thereafter to levels similar to control larval eclosion rates. The DCB-water solutions produced significantly higher mortality in both 1st and 2nd instars over control larvae for several days after initial exposure. Mortality rates decreased sharply 3 to 5 days postexposure as DCBs continued to decompose. We found increased survival rates during late development, but daily input of fresh DCBs prevented most young larvae from completing development. Taken together, these observations suggest that decomposing did not deter gravid Ae. albopictus females from ovipositing in treated containers and that DCB solutions had larvicidal effects on early instars. Our results are discussed in the context of DCB use to control container-breeding Ae. albopictus, a competent dengue vector in Asia and other parts of the world.

  1. The Insect Growth Regulator Pyriproxyfen Terminates Egg Diapause in the Asian Tiger Mosquito, Aedes albopictus

    Science.gov (United States)

    2015-01-01

    The Asian tiger mosquito, Aedes albopictus, is a highly invasive mosquito species that transmits chikungunya and dengue. This species overwinters as diapausing eggs in temperate climates. Early diapause termination may be a beneficial strategy for winter mosquito control; however, a mechanism to terminate the diapause process using chemicals is not known. We tested the hypothesis that a hormonal imbalance caused by the administration of juvenile hormone analog would terminate egg diapause in A. albopictus. We tested the insect growth regulator pyriproxyfen on all developmental stages to identify a susceptible stage for diapause termination. We found that pyriproxyfen treatment of mosquito eggs terminated embryonic diapause. The highest rates of diapause termination were recorded in newly deposited (78.9%) and fully embryonated (74.7%) eggs at 0.1 and 1 ppm, respectively. Hatching was completed earlier in newly deposited eggs (25–30 days) compared to fully embryonated eggs (71–80 days). The combined mortality from premature diapause termination and ovicidal activity was 98.2% in newly deposited and >98.9% in fully embryonated eggs at 1 ppm. The control diapause eggs did not hatch under diapausing conditions. Pyriproxyfen exposure to larvae, pupae and adults did not prevent the females from ovipositing diapausing eggs. There was no effect of pyriproxyfen on diapausing egg embryonic developmental time. We also observed mortality in diapausing eggs laid by females exposed to pyriproxyfen immediately after blood feeding. There was no mortality in eggs laid by females that survived larval and pupal exposures. In conclusion, diapausing eggs were the more susceptible to pyriproxyfen diapause termination compared to other life stages. This is the first report of diapause termination in A. albopictus with a juvenile hormone analog. We believe our findings will be useful in developing a new control strategy against overwintering mosquito populations. PMID:26090954

  2. How does the dengue vector mosquito Aedes albopictus respond to global warming?

    Science.gov (United States)

    Jia, Pengfei; Chen, Xiang; Chen, Jin; Lu, Liang; Liu, Qiyong; Tan, Xiaoyue

    2017-03-11

    Global warming has a marked influence on the life cycle of epidemic vectors as well as their interactions with human beings. The Aedes albopictus mosquito as the vector of dengue fever surged exponentially in the last decade, raising ecological and epistemological concerns of how climate change altered its growth rate and population dynamics. As the global warming pattern is considerably uneven across four seasons, with a confirmed stronger effect in winter, an emerging need arises as to exploring how the seasonal warming effects influence the annual development of Ae. albopictus. The model consolidates a 35-year climate dataset and designs fifteen warming patterns that increase the temperature of selected seasons. Based on a recently developed mechanistic population model of Ae. albopictus, the model simulates the thermal reaction of blood-fed adults by systematically increasing the temperature from 0.5 to 5 °C at an interval of 0.5 °C in each warming pattern. The results show the warming effects are different across seasons. The warming effects in spring and winter facilitate the development of the species by shortening the diapause period. The warming effect in summer is primarily negative by inhibiting mosquito development. The warming effect in autumn is considerably mixed. However, these warming effects cannot carry over to the following year, possibly due to the fact that under the extreme weather in winter the mosquito fully ceases from development and survives in terms of diapause eggs. As the historical pattern of global warming manifests seasonal fluctuations, this study provides corroborating and previously ignored evidence of how such seasonality affects the mosquito development. Understanding this short-term temperature-driven mechanism as one chain of the transmission events is critical to refining the thermal reaction norms of the epidemic vector under global warming as well as developing effective mosquito prevention and control strategies.

  3. Enhancement of Aedes albopictus collections by ovitrap and sticky adult trap.

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    Velo, Enkelejda; Kadriaj, Perparim; Mersini, Kujtim; Shukullari, Ada; Manxhari, Blerta; Simaku, Artan; Hoxha, Adrian; Caputo, Beniamino; Bolzoni, Luca; Rosà, Roberto; Bino, Silvia; Reiter, Paul; della Torre, Alessandra

    2016-04-21

    In the last decades, Aedes albopictus has become an increasing public health threat in tropical as well as in more recently invaded temperate areas due to its capacity to transmit several human arboviruses, among which Dengue, Chikungunya and Zika. Enhancing the efficiency of currently used collection approaches, such as ovitraps and sticky traps, is desirable for optimal monitoring of the species abundance, for assessment of the risk of arbovirus transmission and for the optimisation of control activities. Two sets of 4 × 4 Latin-square experiments were carried out in Tirana (Albania) to test whether modifications in ovitrap shape and size and in oviposition substrate would increase collections of Ae. albopictus eggs and whether hay-infusion would increase adult catches by sticky trap. Generalized Linear Mixed Models with negative binomial error distribution were carried out to analyse the data. Cylindrical ovitraps lined with germination paper yielded significantly higher egg catches than those exploiting either the (commonly used) wooden paddles or floating polystyrene blocks as oviposition substrates. No difference was observed between cylindrical and conical shaped ovitraps. Ovitraps and sticky traps baited with hay infusion yielded significantly higher egg and adult catches than un-baited ones. A significant relationship between ovitrap and sticky trap catches was observed both in the absence and in the presence of attractants, with ovitrap catches increasing more than sticky trap catches at increasing adult female densities. This study provides grounds for optimisation of ovitraps and sticky traps as monitoring tools for Ae. albopictus by (i) supporting use of germination paper as most appropriate oviposition substrate; (ii) suggesting the possible use of stackable conical ovitraps for large scale monitoring; (iii) confirming the use of hay-infusion to increase egg catches in ovitraps, and showing that hay-infusion also significant increases adult

  4. A large-scale stochastic spatiotemporal model for Aedes albopictus-borne chikungunya epidemiology

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    Chandra, Nastassya L.; Proestos, Yiannis; Lelieveld, Jos; Christophides, George K.; Parham, Paul E.

    2017-01-01

    Chikungunya is a viral disease transmitted to humans primarily via the bites of infected Aedes mosquitoes. The virus caused a major epidemic in the Indian Ocean in 2004, affecting millions of inhabitants, while cases have also been observed in Europe since 2007. We developed a stochastic spatiotemporal model of Aedes albopictus-borne chikungunya transmission based on our recently developed environmentally-driven vector population dynamics model. We designed an integrated modelling framework incorporating large-scale gridded climate datasets to investigate disease outbreaks on Reunion Island and in Italy. We performed Bayesian parameter inference on the surveillance data, and investigated the validity and applicability of the underlying biological assumptions. The model successfully represents the outbreak and measures of containment in Italy, suggesting wider applicability in Europe. In its current configuration, the model implies two different viral strains, thus two different outbreaks, for the two-stage Reunion Island epidemic. Characterisation of the posterior distributions indicates a possible relationship between the second larger outbreak on Reunion Island and the Italian outbreak. The model suggests that vector control measures, with different modes of operation, are most effective when applied in combination: adult vector intervention has a high impact but is short-lived, larval intervention has a low impact but is long-lasting, and quarantining infected territories, if applied strictly, is effective in preventing large epidemics. We present a novel approach in analysing chikungunya outbreaks globally using a single environmentally-driven mathematical model. Our study represents a significant step towards developing a globally applicable Ae. albopictus-borne chikungunya transmission model, and introduces a guideline for extending such models to other vector-borne diseases. PMID:28362820

  5. IMPLICACIONES SANITARIAS DEL ESTABLECIMIENTOY EXPANSION EN ESPAÑA DEL MOSQUITO AEDES ALBOPICTUS

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    Rubén Bueno Marí

    2012-01-01

    Full Text Available La expansión de Aedes albopictus por el Levante español no ha cesado desde su primigenia detección en nuestro país en el año 2004, habiéndose constatado ya su presencia en las provincias de Girona, Barcelona, Tarragona, Castellón, Alicante y Murcia. La elevada sinantropía de la especie, unida al alto grado de antropofília y extensa capacidad vectorial para transmitir diversas arbovirosis, han propiciado el retorno al sur de Europa de ciclos de transmisión activa de enfermedades frecuentes en el pasado como el Dengue o la aparición de virosis tropicales inéditas hasta entonces como Chikungunya. El presente manuscrito analiza de forma pormenorizada las implicaciones para la salud pública de la previsible expansión de Ae. albopictus por gran parte del territorio peninsular, en el contexto climático y sociodemográfico actual. Adicionalmente, también se discuten diversas cuestiones relativas al control poblacional de la especie en ambientes urbanos y periurbanos, así como los datos preliminares existentes acerca de otros aedinos invasores de reciente hallazgo en el continente europeo.

  6. Carboxylesterase gene amplifications associated with insecticide resistance in Aedes albopictus: Geographical distribution and evolutionary origin.

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    Linda Grigoraki

    2017-04-01

    Full Text Available Aedes albopictus is one of the most invasive human disease vectors. Its control has been largely based on insecticides, such as the larvicide temephos. Temephos resistance has been associated with the up-regulation, through gene amplification, of two carboxylesterase (CCE genes closely linked on the genome, capable of sequestering and metabolizing temephos oxon, the activated form of temephos.Here, we investigated the occurrence, geographical distribution and origin of the CCE amplicon in Ae. albopictus populations from several geographical regions worldwide. The haplotypic diversity at the CCEae3a locus revealed high polymorphism, while phylogenetic analysis showed an absence of correlation between haplotype similarity and geographic origin. Two types of esterase amplifications were found, in two locations only (Athens and Florida: one, previously described, results in the amplification of both CCEae3a and CCEae6a; the second is being described for the first time and results in the amplification of CCEae3a only. The two amplification events are independent, as confirmed by sequence analysis. All individuals from Athens and Florida carrying the CCEae3a-CCEae6a co-amplicon share a common haplotype, indicating a single amplification event, which spread between the two countries.The importance of passive transportation of disease vectors, including individuals carrying resistance mechanisms, is discussed in the light of efficient and sustainable vector control strategies.

  7. Dose-dependent behavioral response of the mosquito Aedes albopictus to floral odorous compounds.

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    Hao, Huiling; Sun, Jingcheng; Dai, Jianqing

    2013-01-01

    The value of using plant volatiles as attractants for trapping and spatial repellents to protect hosts against mosquitoes has been widely recognized. The current study characterized behavioral responses of Aedes albopictus (Skuse) (Diptera: Culicidae) to different concentrations, ranging from 6 to 96%, of several common floral odorous compounds, including linalool, geraniol, citronellal, eugenol, anisaldehyde, and citral, using a wind tunnel olfactometer system. The results indicated that female mosquitoes reacted differently to different concentrations of the tested compounds, and the reactions also were different when those chemicals were tested alone or in the presence of human host odor. When tested alone, anisaldehyde was attractive at all tested concentrations, eugenol was attractive only at concentrations of 48-96%, while citronellal, linalool, citral, and geraniol were attractive at lower concentrations and repellent at higher concentrations. When tested in the presence of a human host, all compounds except for anisaldehyde at all tested concentrations showed host-seeking inhibition to certain degrees. Based on the results, it was concluded that anisaldehyde was effective in attracting Ae. albopictus when used alone but could also remarkably inhibit the host-seeking ability at a concentration of 96%, while citral, geraniol, linalool, citronellal, and eugenol are suitable as spatial repellents.

  8. Preliminary analysis of several attractants and spatial repellents for the mosquito, Aedes albopictus using an olfactometer.

    Science.gov (United States)

    Hao, Huiling; Sun, Jingcheng; Dai, Jianqing

    2012-01-01

    Mosquito attractants and spatial repellents hold great promise in controlling mosquito pests. In assessing the effectiveness of mosquito attractants and repellents, a good olfactometer system, and optimized testing conditions, are essential. In this research, we demonstrated the usefulness of an olfactometer system, and optimized testing conditions for Aedes albopictus (Diptera: Culicidae). We found no significant difference in the biting activity of the insect between 8:00 and 22:00. Furthermore, 5-10 day old mosquitoes were relatively strongly attracted, with bloodsucking rate 75.8%. The random capture rate (entered trap in absence of odor) was less than 20% for the 20-40 tested insects. Capture rates and systematic errors increased as the number of testing insects increased. Wind speed affected the capture rate significantly, whereas variations in temperature between 25-28°C did not result in significant difference. The wind speed of 0.2 m/s exhibited a higher capture rate, which was significantly different from those at either 0.1 m/s or 0.4 m/s (P eugenol, anisaldehyde, geraniol, citronellal, citral, and linalool all exhibited some inhibition effect on mosquitoes to successfully trace human odor or 1% of L-lactic acid in dichloromethane. The results of these two tests indicate that the L-lactic acid/dichloromethane mixture may be used as an effective attractant to evaluate the effect of possible spatial repellents on Ae. albopictus.

  9. Population structure of Aedes albopictus (Skuse): the mosquito which is colonizing Mediterranean countries.

    Science.gov (United States)

    Urbanelli, S; Bellini, R; Carrieri, M; Sallicandro, P; Celli, G

    2000-03-01

    Multilocus electrophoresis analysis has been used to study the genetic structure of 18 populations of Aedes albopictus newly introduced to Italy, in comparison with two populations in the United States, four in Japan, and four in Indonesia. Allozyme analysis revealed that 15 out of the 18 studied loci were polymorphic among the 28 populations. No significant deviations from Hardy-Weinberg equilibrium were found at polymorphic loci. High genetic affinity was observed between the Italian populations and those from the United States and Japan. The analysis of variance in allele frequencies showed that variance among subpopulations accounted for most of the total variance, suggesting that isolation of the Italian populations is not related to distance. Analysis of linkage disequilibrium using Ohta's method shows that the variance in the frequency of allele combinations could be explained by the action of the genetic drift which accompanies the establishment of new populations. The colonization process of Ae. albopictus in Italy is following a trend similar to that previously observed in the U.S. A., probably because both infestations derive from several successive introductions, each with large numbers of individuals.

  10. Modulation of La Crosse virus infection in Aedes albopictus mosquitoes following larval exposure to coffee extracts

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    Nicole E. Eastep

    2012-03-01

    Full Text Available The mosquito-borne La Crosse virus (LACV; Family Bunyaviridae may cause encephalitis, primarily in children, and is distributed throughout much of the eastern United States. No antivirals or vaccines are available for LACV, or most other mosquito-borne viruses, and prevention generally relies on mosquito control. We sought to determine whether coffee extracts could interfere with LACV replication and vector mosquito development. Both regular and decaffeinated coffee demonstrated significant reductions in LACV replication in direct antiviral assays. This activity was not due to the presence of caffeine, which did not inhibit the virus life cycle. Aedes albopictus (Skuse (Diptera: Culicidae mosquito larvae suffered near total mortality when reared in high concentrations of regular and decaffeinated coffee and in caffeine. Following larval exposure to sublethal coffee concentrations, adult Ae. albopictus mosquitoes had signficantly reduced whole-body LACV titers five days post-infection, compared to larvae reared in distilled water. These results suggest that it may be possible to both control mosquito populations and alter the vector competence of mosquitoes for arthropod-borne viruses by introducing antiviral compounds into the larval habitat.

  11. Eclosion rate, development and survivorship of Aedes albopictus (Skuse)(Diptera: Culicidae) under different water temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Monteiro, Laura C.C. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Programa de Pos-Graduacao em Biologia Animal (PPGBA). Curso de Ciencias Biologicas; Souza, Jose R.B. de; Albuquerque, Cleide M.R. de [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Programa de Pos-Graduacao em Biologia Animal (PPGBA). Dept. de Zoologia

    2007-11-15

    In tropical areas, where vector insects populations are particularly numerous, temperature usually range between 25 de C and 35 deg C. Considering the importance of such temperature variation in determining mosquitoes population dynamics, in this work the developmental, eclosion and survival rates of the immature stages of Aedes albopictus (Skuse) were compared under constant 25, 30 and 35 deg C (using acclimatized chambers) and environmental (25 deg C to 29 deg C) temperatures. The hatching rate was considered as total number of larvae recovered after 24h. The development period as well as larval and pupal survival rate were evaluated daily. Eclosion rate was significantly higher under environmental temperature than under the studied constant temperatures, suggesting that temperature variation may be an eclosion-stimulating factor. The mean eclosion time increased with the temperature, ranging from 2.8 h (25 deg C) to 5.2 h (35 deg C). The larval period was greatly variable inside each group, although it did not differ significantly amongst groups (11.0 +- 4.19 days), with individuals showing longer larval stages in water at 35 deg C (12.0 +- 4.95 days) and environmental temperature (13.6 +- 5.98 days). Oppositely, survival was strongly affected by the higher temperature, where only one individual lived through to adult phase. The results suggest that population of Ae. albopictus from Recife may be adapting to increasing of environmental temperatures and that the limiting temperature to larval development is around 35 deg C. (author)

  12. Biology and Role of Aedes albopictus (Skuse 1894 as Vector of Diseases

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    Hasan Boesri

    2011-12-01

    Full Text Available Behavior of the mosquito Aedes albopictus is generally res ting outside the home with the brood in a natural or artificial containers protected from sunlight. Human biting activity between the hours of9:00 to 11:00 and between the hours of 17:00 to 18:00 inside and outside the home. The period of rest after sucking the blood 4-5 days and is ready to lie. Habitat or the environment that most coveted of th is mosquito is a forest or gar­den with temperatures of 24-30 0 C. eggs hatch after 4-5 days with a temperature of 24-30 0 C, the eggs usually form elus ters of 49-60 eggs Larvae and pupae usually found in contain­ers, pieces of bambo containing water. The period of the larvae to adults between 20-25 days. The spread of Ae albopictus mosquitoes from Africa, India, Pakistan, Sri Lanka, Thai­land, Malaysia, Vietnam, Papua New Guinea, northern Australia, and Indonesia. Role in disease transmission is a secondary vector or as the primary vector of dengue hemorrhagic fever. On viral diseases that attack the nerves like encephalistis Japanese, Western or East­ern encephalistis, and Chikuguya has been demonstrated by laboratories, as well as on ani­mal diseases caused by Dirofilaria immitis agent, Plasmodium lophurae, P. gallinaceum, and P. fallax.

  13. Primeiras observações sobre o Aedes Albopictus no estado do Espírito Santo, Brasil First observations on Aedes albopictus in the State of Espirito Santo, Brasil

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    Joaquim A. Ferreira Neto

    1987-03-01

    Full Text Available Observações realizadas no Estado do Espírito Santo mostraram que o Aedes albopictus, ao ser introduzido no Brasil, não modificou, significativamente, o seu comportamento. Os criadouros são os mesmos utilizados na Ásia e situados, de preferência, em áreas abertas. Os mosquitos adultos se abrigam em vegetação baixa e freqüentam pouco o domicílio.Observations performed at the State of Espirito Santo showed that Aedes albopictus did not change its behaviour to a significant extent after being introduced in Brazil. The breeding places are the same as those described in Asia and can be found more frequently in open areas. The adult mosquitoes rest in short vegetation and only sporadically penetrate into the human habitations.

  14. Susceptibility of Aedes albopictus and Aedes aegypti to three imported Chikungunya virus strains, including the E1/226V variant in Taiwan.

    Science.gov (United States)

    Chen, Tien-Huang; Jian, Shu-Wan; Wang, Chih-Yuan; Lin, Cheo; Wang, Pei-Feng; Su, Chien-Ling; Teng, Hwa-Jen; Shu, Pei-Yun; Wu, Ho-Sheng

    2015-06-01

    An E1/226V variant Chikungunya virus (CHIKV) efficiently transmitted by Aedes albopictus to humans poses a significant threat to public health for those areas with the presence of Aedes albopictus, including Taiwan. We infected three imported CHIKV isolates including the E1/226V variant with Ae. albopictus and Aedes aegypti in the laboratory to understand the disease risk. Viral RNA was measured by real time reverse transcription polymerase chain reaction. The viral susceptibility varied by virus strain and mosquito species and strain. The Asian virus strain started to replicate at 5-6 days post infection (dpi) with the maximum virus yield, ranging from 10(3.63) to 10(3.87) at 5-10 dpi in both species. The variant CHIKV Central/East/South African (CESA) virus genotype replicated earlier at 1 dpi with the maximum virus yield ranging from 10(5.63) to 10(6.52) at 3-6 dpi in Ae. albopictus females while the nonvariant virus strain replicated at 1-2 dpi with the maximum virus yield ranging from 10(5.51) to 10(6.27) at 6-12 dpi. In Ae. aegypti, these viruses replicated at 1-2 dpi, with maximum yields at 4-5 dpi (range from 10(5.38) to 10(5.62)). We concluded that the risk of CHIKV in Taiwan is high in all distribution areas of Ae. aegypti and Ae. albopictus for the CESA genotype and that the E1/226V variant virus strain presents an even higher risk. Copyright © 2015. Published by Elsevier B.V.

  15. Evaluation of Simultaneous Transmission of Chikungunya Virus and Dengue Virus Type 2 in Infected Aedes aegypti and Aedes albopictus (Diptera: Culicidae).

    Science.gov (United States)

    Nuckols, J T; Huang, Y-J S; Higgs, S; Miller, A L; Pyles, R B; Spratt, H M; Horne, K M; Vanlandingham, D L

    2015-05-01

    The simultaneous transmission of chikungunya virus (CHIKV) and dengue viruses (DENV) has been a major public health concern because of their sympatric distribution and shared mosquito vectors. Groups of Aedes aegypti (L.) and Aedes albopictus (Skuse) were orally infected with 1.5 × 10(5) PFU/ml of CHIKV and 3.2 × 10(6) FFU/ml of DENV-2 simultaneously or separately in inverse orders and evaluated for dissemination and transmission by qRT-PCR. Simultaneous dissemination of both viruses was detected for all groups in Ae. aegypti and Ae. albopictus while cotransmission of CHIKV and DENV-2 only occurred at low rates after sequential but not simultaneous infection.

  16. Primeiro registro de Aedes albopictus em área da Mata Atlântica, Recife, PE, Brasil First report of Aedes albopictus in areas of rain forest in Brazil

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    Cleide MR de Albuquerque

    2000-06-01

    Full Text Available Pela primeira vez é registrada a presença do Aedes albopictus em remanescentes de Mata Atlântica, localizada em área urbana em Recife (Pernambuco, Brasil. As coletas foram realizadas em isca humana e em criadouros de formas jovens (ocos de árvores, bambus, bromélias e pneu. A presença de Ae. albopictus na região metropolitana do Recife representa um risco potencial do inter-relacionamento dessa espécie de mosquito com a população.This is the first report of the presence of Aedes albopictus in the native rain forest, near the urban area of Recife (State of Pernambuco, Brazil. Adult female mosquitoes were collected using human bait. Mosquitoes in aquatic stages were looked for in treeholes, bamboos, bromeliads and old tires. The existence of Ae. albopictus in the metropolitan area of Recife poses a potential risk for the interaction of this mosquito species with the urban human population.

  17. Retrospective search for dengue vector mosquito Aedes albopictus in areas visited by a German traveler who contracted dengue in Japan.

    Science.gov (United States)

    Kobayashi, Mutsuo; Komagata, Osamu; Yonejima, Mayuko; Maekawa, Yoshihide; Hirabayashi, Kimio; Hayashi, Toshihiko; Nihei, Naoko; Yoshida, Masahiro; Tsuda, Yoshio; Sawabe, Kyoko

    2014-09-01

    A German traveler developed dengue fever in late August 2013, following a direct flight from Germany. Autochthonous dengue virus (DENV) infection has not been reported in Japan. To evaluate the risk of autochthonous DENV transmission in Japan, the authors performed a retrospective search of the five areas visited by the German patient to determine the population density of dengue vector mosquito, Aedes albopictus. The annual mean temperature of each area was higher than 12°C, which is considered suitable for the establishment of A. albopictus populations. Our retrospective search revealed the population density of A. albopictus to be high in the urban areas of Japan. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. To catch a tiger in a concrete jungle: operational challenges for trapping Aedes albopictus in an urban environment.

    Science.gov (United States)

    Unlu, Isik; Farajollahi, Ary

    2012-12-01

    We have been using BG-Sentinel (BGS) traps to monitor populations of Aedes albopictus as part of an area-wide project for management of this species. Although BGS traps are very effective for collecting adult Ae. albopictus, the device is expensive and must be properly maintained to be effective. The trap also poses a challenge for mosquito control personnel because secure locations free from the risk of vandalism or pet damage during surveillance efforts are scarce. Additionally, acquiring access to private property or finding suitable shaded habitats to place traps can be difficult. Here we summarize a protocol for BGS trap surveillance of Ae. albopictus in a highly urbanized environment during an active mosquito season.

  19. piggybac- and PhiC31-mediated genetic transformation of the Asian tiger mosquito, Aedes albopictus (Skuse.

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    Geneviève M C Labbé

    Full Text Available BACKGROUND: The Asian tiger mosquito, Aedes albopictus (Skuse, is a vector of several arboviruses including dengue and chikungunya. This highly invasive species originating from Southeast Asia has travelled the world in the last 30 years and is now established in Europe, North and South America, Africa, the Middle East and the Caribbean. In the absence of vaccine or antiviral drugs, efficient mosquito control strategies are crucial. Conventional control methods have so far failed to control Ae. albopictus adequately. METHODOLOGY/PRINCIPAL FINDINGS: Germline transformation of Aedes albopictus was achieved by micro-injection of embryos with a piggyBac-based transgene carrying a 3xP3-ECFP marker and an attP site, combined with piggyBac transposase mRNA and piggyBac helper plasmid. Five independent transgenic lines were established, corresponding to an estimated transformation efficiency of 2-3%. Three lines were re-injected with a second-phase plasmid carrying an attB site and a 3xP3-DsRed2 marker, combined with PhiC31 integrase mRNA. Successful site-specific integration was observed in all three lines with an estimated transformation efficiency of 2-6%. CONCLUSIONS/SIGNIFICANCE: Both piggybac- and site-specific PhiC31-mediated germline transformation of Aedes albopictus were successfully achieved. This is the first report of Ae. albopictus germline transformation and engineering, a key step towards studying and controlling this species using novel molecular techniques and genetic control strategies.

  20. Aedes albopictus (Skuse en la Región Huetar Atlántica de Costa Rica

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    Olger Calderón Arguedas

    2012-12-01

    Full Text Available Objetivo: Determinar las características de los hábitats larvales de Ae. albopictus y su culicidofauna asociada en la comunidad “La Primavera”. Métodos: Se realizó una encuesta larval en 20 de 28 casas ubicadas en un área de 10 000 m², en la cual se evaluaron los entornos intra y peridomiciliares para la ubicación de posibles criaderos de mosquitos. El material entomológico se fijó en etanol al 70 % y se procesó para su análisis por microscopía de luz. Resultados: En 15 viviendas los criaderos de mosquitos resultaron positivos. En dichas viviendas se encontraron 48 criaderos, de los cuales 31,2 % estuvieron positivos por larvas o pupas de mosquitos. Se encontró Aedes albopictus en cinco criaderos en coexistencia con otras especies como Culex coronator, Haemagogus regalis y Limatus durhamii. También fueron observados Culex quinquefasciatus, Culex corniger, Culex interrogator, Trichoprosopon compressum y Aedes motoecopus. No se observó Aedes aegypti en la muestra. Discusión: Los resultados preliminares muestran que Ae. albopictus tiene gran afinidad por compartir el hábitat con otros culícidos en entornos rurales y semi-rurales, donde los criaderos se encuentran preferencialmente en el peridomicilio. La ausencia de Ae. aegypti podría reflejar algún grado de exclusión competitiva que genera Ae. albopictus sobre esta última. Queda pendiente determinar el papel que podría jugar Ae. albopictus en la transmisión local del dengue en la región.

  1. Dengue virus serotype 2 infection alters midgut and carcass gene expression in the Asian tiger mosquito, Aedes albopictus

    Science.gov (United States)

    Hanley, Kathryn A.; Sundararajan, Anitha; Devitt, Nicholas P.; Schilkey, Faye D.; Hansen, Immo A.

    2017-01-01

    Background The Asian tiger mosquito, Aedes albopictus is currently an important vector for dengue, chikungunya and Zika virus, and its role in transmission of arthropod-borne viruses (arboviruses) may increase in the future due to its ability to colonize temperate regions. In contrast to Aedes aegypti, the dominant vector of dengue, chikungunya and Zika virus, genetic responses of Ae. albopictus upon infection with an arbovirus are not well characterized. Here we present a study of the changes in transcript expression in Ae. albopictus exposed to dengue virus serotype 2 via feeding on an artificial bloodmeal. Methodology/Principal findings We isolated midguts and midgut-free carcasses of Ae. albopictus fed on bloodmeals containing dengue virus as well as controls fed on virus-free control meals at day 1 and day 5 post-feeding. We confirmed infection of midguts from mosquitoes sampled on day 5 post-feeding via RT-PCR. RNAseq analysis revealed dynamic modulation of the expression of several putative immunity and dengue virus-responsive genes, some of whose expression was verified by qRT-PCR. For example, a serine protease gene was up-regulated in the midgut at 1 day post infection, which may potentially enhance mosquito susceptibility to dengue infection, while 14 leucine-rich repeat genes, previously shown to be involved in mosquito antiviral defenses, were down-regulated in the carcass at 5 days post infection. The number of significantly modulated genes decreased over time in midguts and increased in carcasses. Conclusion/Significance Dengue virus exposure results in the modulation of genes in a time- and site-specific manner. Previous literature on the interaction between mosquitoes and mosquito-borne pathogens suggests that most of the changes that occurred in Ae. albopictus exposed to DENV would favor virus infection. Many genes identified in this study warrant further characterization to understand their role in viral manipulation of and antiviral response of

  2. Macrocyclops albidus (Copepoda: cyclopidae) for the Biocontrol of Aedes albopictus and Culex pipiens in Italy.

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    Veronesi, Rodolfo; Carrieri, Marco; Maccagnani, Bettina; Maini, Stefano; Bellini, Romeo

    2015-03-01

    The aim of our study was to assess the potential of Macrocyclops albidus as a biological control agent against the 1st and 2nd instars of Culex pipiens and Aedes albopictus. Under laboratory conditions of prey saturation (50 1st instars/copepod), an average of 58.98% of Cx. pipiens and 54.99% of Ae. albopictus larvae were killed by 1 copepod in 24 h. Trials run in big drums containing 200 liters of water showed that the M. albidus population, inoculated in April, efficiently controlled the mosquito population for the entire season. The predator was particularly effective against Ae. albopictus, as only 2 larvae of this species were found in the treated drums, compared to 814 larvae in untreated control drums throughout the study period. No difference was observed in the control efficacy between the 2 initial densities of copepods used. The reduction in Ae. albopictus density in the drums with 100 and 500 M. albidus with respect to the control drums was 99.90 ± 0.35% and 100.0 ± 0.0%, respectively. For Cx. pipiens, the reduction in density was 88.69 ± 13.51% and 84.65% in drums inoculated with 100 and 500 copepods, respectively. Macrocyclops albidus populations survived through the winter and continued to keep the mosquito population under control during the 2008 season. The M. albidus population developed very well both in drums placed in sunny and shaded areas and proved to be tolerant to both high (summer) and low (winter) temperatures. Trials performed on M. albidus survival in catch basins showed that after a few weeks, the copepod population dramatically decreased and subsequently disappeared. The main problem for copepod survival in catch basins seemed to be the low oxygen tension and accumulation of toxic substances, rather than copepods being flushed out in heavy rainfall episodes. During the period when copepods were present, they maintained the mosquito population under control; their partial disappearance from the catch basins, however, would

  3. Dispersion of Aedes aegypti (Linnaeus, 1762 and Aedes albopictus (Skuse, 1894 in the rural zone of north Paraná State

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    José Lopes

    2004-09-01

    Full Text Available Seventy-two tyres were placed in four transects (Northern, Southern, Eastern and Western, every 5 km, from the Londrina city limits to the rural areas, to verify the dispersion of Aedes aegypti and Ae. albopictus vectors. Mosquito larvae were collected fortnightly from August 1998 to August 1999. Data were organized according to the average number of larvae collected for each species in each collection site. A total of 62,517 mosquito larvae were collected and distributed into the following species: Aedes albopictus (21.71%; Ae. aegypti (5.54%; Ae. terrens (0.53%; Ae. fluviatilis (0.36%; Anopheles argyritarsi (0.01%; Culex quinquefasciatus (48.37%; Cx. mollis (8.88%; Cx. eduardoi (8.65%; Cx. corniger (0.61%; Cx. bigoti (0.24%; Cx. grupo coronator (0.12%; Limatus durhanii (4.61% e Toxorhynchites sp. (0.32%. There was a drastic decrease in the Ae. aegypti population from the city limits to the rural area (x1= 21.72 ± 4.71; x2=0.00 and an increase in the population of Ae. albopictus (x1 = 15.64 ± 2.73; x2 = 38.37 ± 8.87. Aedes aegypti was not present in the collection sites located 30 km away from the urban area; however, Ae. albopictus was found in all the sites. Although the frequency rate for the Aedes aegypti was low, both species were dispersed in the rural area studied. The redimensioning of these vectors’ control areas is recommended since rural areas can function as reservoirs for these species.Com o objetivo de avaliar a dispersão de Aedes aegypti e Ae. albopictus para a área rural, foram instalados pneus em quatro transectos (Norte, Sul, Leste e Oeste, a cada 5 Km, do limite da zona urbana de Londrina em direção a zona rural. Larvas de Culicidae foram coletadas quinzenalmente de agosto de 1998 a agosto de 1999. Um total de 62.517 larvas de Culicidae foram coletadas, distribuídas entre as seguintes espécies: Aedes albopictus (21.71%; Ae. aegypti (5.54%; Ae. terrens (0.53%; Ae. fluviatilis (0.36%; Anopheles argyritarsi (0

  4. Molecular and functional characterization of odorant-binding protein genes in an invasive vector mosquito, Aedes albopictus.

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    Yuhua Deng

    Full Text Available Aedes albopictus is a major vector of dengue and Chikungunya viruses. Olfaction plays a vital role in guiding mosquito behaviors and contributes to their ability to transmit pathogens. Odorant-binding proteins (OBPs are abundant in insect olfactory tissues and involved in the first step of odorant reception. While comprehensive descriptions are available of OBPs from Aedes aegypti, Culex quinquefasciatus and Anopheles gambiae, only a few genes from Ae. albopictus have been reported. In this study, twenty-one putative AalbOBP genes were cloned using their homologues in Ae. aegypti to query an Ae. albopictus partial genome sequence. Two antenna-specific OBPs, AalbOBP37 and AalbOBP39, display a remarkable similarity in their overall folding and binding pockets, according to molecular modeling. Binding affinity assays indicated that AalbOBP37 and AalbOBP39 had overlapping ligand affinities and are affected in different pH condition. Electroantennagrams (EAG and behavioral tests show that these two genes were involved in olfactory reception. An improved understanding of the Ae. albopictus OBPs is expected to contribute to the development of more efficient and environmentally-friendly mosquito control strategies.

  5. Differential Larval Toxicity and Oviposition Altering Activity of Some Indigenous Plant Extracts against Dengue and Chikungunya Vector Aedes albopictus.

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    Ruchi Yadav

    2014-12-01

    Full Text Available Mosquitoes are well known as vectors of several disease causing pathogens. The extensive use of synthetic insecticides in the mosquito control strategies resulted to the development of pesticide resistance and fostered environmental deterioration. Hence in recent years plants become alternative source of mosquito control agents. The present study assessed the larvicidal and oviposition altering activity of six different plants species-Alstonia scholaris, Callistemon viminalis, Hyptis suaveolens, Malvastrum coromandelianum, Prosopis juliflora, Vernonia cinerea against Aedes albopictus mosquito in laboratory.Leaf extracts of all the six plants species in five different solvents of various polarities were used in the range of 20-400ppm for larval bioassay and 50,100 and 200ppm for cage bioassay (for the study of oviposition behavior against Ae. albopictus. The larval mortality data were recorded after 24 h and subjected to Probit analysis to determine the lethal concentrations (LC50, while OAI (Oviposition activity index was calculated for oviposition altering activity of the plant extracts.Vernonia cinerea extract in acetone and C. viminalis extract in isopropanol were highly effective against Aedes albopictus larvae with LC50 value 64.57, 71.34ppm respectively. Acetone extract of P. juliflora found to be strong oviposition-deterrent which inhibited >2 fold egg laying (OAI-0.466 at 100ppm.Vernonia cinerea and C. viminallis leaf extracts have the potential to be used as larvicide and P. juliflora as an oviposition-deterrent for the control of Ae. albopictus mosquito.

  6. Bioassay and biochemical studies of the status of pirimiphos-methyl and cypermethrin resistance in Aedes (Stegomyia) aegypti and Aedes (Stegomyia) albopictus (Diptera: Culicidae) in Singapore.

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    Lee, R M L; Choong, C T H; Goh, B P L; Ng, L C; Lam-Phua, S G

    2014-12-01

    Aedes (Stegomyia) aegypti (Linnaeus) and Ae. (Stegomyia) albopictus (Skuse) were sampled from five regions of Singapore (Central, North East, North West, South East and South West) and tested with diagnostic concentrations of the technical grade insecticides, pirimiphos-methyl and cypermethrin. Biochemical assays were performed on the same populations of Ae. aegypti and Ae. albopictus to determine activities of detoxifying enzymes, including non-specific esterase (EST), monooxygenase (MFO) and acetylcholinesterase (AChE). The diagnostic test showed that all Ae. aegypti populations were susceptible to pirimiphos-methyl (mortality = 99 to 100%), but resistant to cypermethrin (mortality = 11 to 76%). Resistance to pirimiphos-methyl was observed in all Ae. albopictus populations (mortality = 49 to 74%) while cypermethrin resistance was detected in most Ae. albopictus populations (mortality = 40 to 75%), except those from Central (mortality = 86%) and South East (mortality = 94%) showing incipient resistance. The biochemical assays showed that there was significant enhancement (P aegypti populations. The biochemical assay results suggested that AChE could play a role in pirimiphos-methyl resistance of Ae. albopictus in South West, South East and North East regions. The small but significant increase in EST activities in Ae. aegypti from all regions suggest that it may play a role in the observed cypermethrin resistance.

  7. Larvicidal efficacy of different plant parts of railway creeper, Ipomoea cairica Extract Against Dengue Vector Mosquitoes, Aedes albopictus (Diptera: Culicidae) and Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    AhbiRami, Rattanam; Zuharah, Wan Fatma; Thiagaletchumi, Maniam; Subramaniam, Sreeramanan; Sundarasekar, Jeevandran

    2014-01-01

    Natural insecticides from plant origin against mosquito vectors have been the main concern for research due to their high level of eco-safety. Control of mosquitoes in their larval stages are an ideal method since Aedes larvae are aquatic, thus it is easier to deal with them in this habitat. The present study was specifically conducted to explore the larvicidal efficacy of different plant parts of Ipomoea cairica (L.) or railway creeper crude extract obtained using two different solvents; methanol and acetone against late third-stage larvae of Aedes albopictus (Skuse) and Aedes aegypti (L.) (Diptera: Culicidae). Plant materials of I. cairica leaf, flower, and stem were segregated, airdried, powdered, and extracted using Soxhlet apparatus. Larvicidal bioassays were performed by using World Health Organization standard larval susceptibility test method for each species which were conducted separately for different concentration ranging from 10 to 450 ppm. Both acetone and methanol extracts showed 100% mortality at highest concentration tested (450 ppm) after 24 h of exposure. Results from factorial ANOVA indicated that there were significant differences in larvicidal effects between mosquito species, solvent used and plant parts (F=5.71, df=2, Paegypti with LC50 of 101.94 ppm followed by Ae. albopictus with LC50 of 105.59 ppm compared with other fractions of I. cairica extract obtained from flower, stem, and when methanol are used as solvent. The larvae of Ae. aegypti appeared to be more susceptible to I. cairica extract with lower LC50 value compared with Ae. albopictus (F=8.83, df=1, Pinsecticide for the control of Aedes mosquitoes. This study quantified the larvicidal property of I. cairica extract, providing information on lethal concentration that may have potential for a more eco-friendly Aedes mosquito control program.

  8. Genetic analysis of invasive Aedes albopictus populations in Los Angeles County, California and its potential public health impact.

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    Daibin Zhong

    Full Text Available The Asian tiger mosquito, Aedes albopictus, is an anthropophilic aggressive daytime-biting nuisance and an efficient vector of certain arboviruses and filarial nematodes. Over the last 30 years, this species has spread rapidly through human travel and commerce from its native tropical forests of Asia to every continent except Antarctica. In 2011, a population of Asian tiger mosquito (Aedes albopictus was discovered in Los Angeles (LA County, California. To determine the probable origin of this invasive species, the genetic structure of the population was compared against 11 populations from the United States and abroad, as well as preserved specimens from a 2001 introduction into California using the mitochondrial cytochrome c oxidase 1 (CO1 gene. A total of 66 haplotypes were detected among samples and were divided into three main groups. Aedes albopictus collected in 2001 and 2011 from LA County were genetically related and similar to those from Asia but distinct from those collected in the eastern and southeastern United States. In view of the high genetic similarities between the 2001 and 2011 LA samples, it is possible that the 2011 population represents in part the descendants of the 2001 introduction. There remains an imperative need for improved surveillance and control strategies for this species.

  9. Genetic analysis of invasive Aedes albopictus populations in Los Angeles County, California and its potential public health impact.

    Science.gov (United States)

    Zhong, Daibin; Lo, Eugenia; Hu, Renjie; Metzger, Marco E; Cummings, Robert; Bonizzoni, Mariangela; Fujioka, Kenn K; Sorvillo, Teresa E; Kluh, Susanne; Healy, Sean P; Fredregill, Chris; Kramer, Vicki L; Chen, Xiaoguang; Yan, Guiyun

    2013-01-01

    The Asian tiger mosquito, Aedes albopictus, is an anthropophilic aggressive daytime-biting nuisance and an efficient vector of certain arboviruses and filarial nematodes. Over the last 30 years, this species has spread rapidly through human travel and commerce from its native tropical forests of Asia to every continent except Antarctica. In 2011, a population of Asian tiger mosquito (Aedes albopictus) was discovered in Los Angeles (LA) County, California. To determine the probable origin of this invasive species, the genetic structure of the population was compared against 11 populations from the United States and abroad, as well as preserved specimens from a 2001 introduction into California using the mitochondrial cytochrome c oxidase 1 (CO1) gene. A total of 66 haplotypes were detected among samples and were divided into three main groups. Aedes albopictus collected in 2001 and 2011 from LA County were genetically related and similar to those from Asia but distinct from those collected in the eastern and southeastern United States. In view of the high genetic similarities between the 2001 and 2011 LA samples, it is possible that the 2011 population represents in part the descendants of the 2001 introduction. There remains an imperative need for improved surveillance and control strategies for this species.

  10. Detection of and monitoring for Aedes albopictus (Diptera: Culicidae) in suburban and sylvatic habitats in north central Florida using four sampling techniques.

    Science.gov (United States)

    Obenauer, P J; Kaufman, P E; Kline, D L; Allan, S A

    2010-10-01

    A sampling study using a BG-Sentinel trap baited with CO(2), a gravid trap baited with an oak-pine infusion, a human subject, and a vegetative aspirator was conducted to compare their reliability at detecting Aedes albopictus Skuse in suburban and sylvatic habitats. We collected 73,849 mosquitoes, representing 29 species from 11 genera over a 20-wk period. The BG-Sentinel trap accounted for over 85% of all Ae. albopictus captured and was significantly more effective at detecting the presence of Ae. albopictus compared with the other three techniques. Landing counts provided the fewest mosquito species (n = 10), yet provided a quick and effective weekly assessment of the major biting species and were the most effective method for sampling Ae. albopictus within a 10-min period. Fewer Ae. albopictus were sampled from sylvatic habitats compared with suburban ones. Sampling criteria advantageous for surveying Ae. albopictus and other mosquito species are discussed.

  11. Updating the geographical distribution and frequency of Aedes albopictus in Brazil with remarks regarding its range in the Americas

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    Roberta Gomes Carvalho/

    2014-09-01

    Full Text Available The geographical distribution of Aedes albopictus in Brazil was updated according to the data recorded across the country over the last eight years. Countrywide house indexes (HI for Ae. albopictus in urban and suburban areas were described for the first time using a sample of Brazilian municipalities. This mosquito is currently present in at least 59% of the Brazilian municipalities and in 24 of the 27 federal units (i.e., 26 states and the Federal District. In 34 Brazilian municipalities, the HI values for Ae. albopictus were higher than those recorded for Ae. aegypti, reaching figures as high as HI = 7.72 in the Southeast Region. Remarks regarding the current range of this mosquito species in the Americas are also presented. Nineteen American countries are currently infested and few mainland American countries have not confirmed the occurrence of Ae. albopictus. The large distribution and high frequency of Ae. albopictus in the Americas may become a critical factor in the spread of arboviruses like chikungunya in the new world.

  12. Vector competence of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) for DEN2-43 and New Guinea C virus strains of dengue 2 virus.

    Science.gov (United States)

    Guo, Xiao-Xia; Zhu, Xiao-Juan; Li, Chun-Xiao; Dong, Yan-De; Zhang, Ying-Mei; Xing, Dan; Xue, Rui-De; Qin, Cheng-Feng; Zhao, Tong-Yan

    2013-12-01

    The vector competence of Aedes albopictus and Aedes aegypti with regard to DEN2-43 and New Guinea C (NGC) virus strains of Dengue 2 viruses was assessed and compared. The infection and dissemination rate and distribution of DEN2-43 antigens in orally infected Ae. albopictus was investigated using the reverse transcription polymerase chain reaction and an indirect immunofluorescence assay. To better understand the initial infection, dissemination and transmission of these viral strains in vector mosquitoes, Ae. albopoictus and Ae. aegypti were fed an artificial blood meal containing either the DEN2-43 or NGC strain. There was no significant difference in the infection and dissemination rates of DEN2-43 and NGC virus strains in Ae. albopictus, however, Ae. aegypti was more susceptible to infection by NGC than DEN2-43 vrius strain. Ae. albopictus mosquitoes infected with the NGC strain developed a higher percentage of midgut infections than those infected with the DEN2-43 strain (t=2.893, df=7, P=0.024). Approximately 26.7% of midgut samples were positive for the NGC antigen 5 days after infection, and 80% of mosquitoes had infected midgets after 15 days. The NGC antigen first became evident in mosquito salivary glands on Day 5, and 40% of mosquitoes had infected salivary by Day 9. In contrast, the DEN2-43 antigen first became evident in salivary glands on Day 7. The infection rate of NGC and DEN2-43 virus strains in salivary glands were similar. These results indicate that Ae. albopictus and Ae. aegypti are moderately competent vectors for the DEN2-43 virus, which could provide basic data for the epidemiology study of dengue fever in China.

  13. Relationship between leaf litter identity, expression of cytochrome P450 genes and life history traits of Aedes aegypti and Aedes albopictus.

    Science.gov (United States)

    Kim, Chang-Hyun; Muturi, Ephantus J

    2012-04-01

    The role of toxic component of leaf litter in mediating the outcome of mosquito species interactions is not well documented. To examine the effect of leaf litter toxins on mosquito performance and interspecific interactions, we reared monospecific and heterospecific cultures of Aedes aegypti L. and Aedes albopictus Skuse larvae in microcosms with one of five leaf species and measured the expression of five cytochrome P450 genes and life history traits of the two mosquito species. For both mosquito species, survival to adulthood was significantly higher in black alder, black walnut, and cypress infusion compared to sugar maple and eastern white pine infusion. In pine but not in other leaf treatments, the presence of A. albopictus had significant positive effects on A. aegypti wing length and development time to adulthood. A. albopictus from heterospecific cultures were larger than those from monospecific cultures and were smaller and took longer to develop in pine and sugar maple infusions than in the other infusions. Up regulation of CYP6Z6 and CYP9M9 in A. aegypti and A. albopictus respectively appeared to be closely associated with the deleterious effects of sugar maple infusion on mosquito performance as was the down regulation of CYP6N12 (in A. aegypti) and lack of induction of CYP6Z6 and CYP9M9 (in A. aegypti and A. albopictus respectively) in pine infusion. Results suggest that metabolic capabilities that enable the two species to tolerate natural xenobiotics are associated with a fitness cost. Published by Elsevier B.V.

  14. 白纹伊蚊对登革热病毒易感性研究%Research progress on Dengue virus susceptibility in Aedes albopictus

    Institute of Scientific and Technical Information of China (English)

    朱碧青; 郑学礼

    2012-01-01

    白纹伊蚊(Aedes albopictus)是登革热的主要传播媒介之一,分布于世界各地.白纹伊蚊的易感性主要涉及白纹伊蚊和登革病毒之间的相互作用.该文主要从遗传效应和环境因子方面对白纹伊蚊种群遗传、生理遗传、环境因素对虫媒病毒传播的影响及控制易感性的基因等研究进行综述.%Aedes albopictus is one of primary vectors of dengue fever worldwide.Current research is discussing how genetic and environmental factors jointly affect susceptibility ofAedes albopictus to dengue virus.In this paper it is reviewed as follows:population genetics and physiological genetics of Aedes albopictus,environmental factors affecting transmission of arboviruses,gene for dengue virus vector competence in Aedes albopictus.

  15. Reproductive strategies of Aedes albopictus (Diptera: Culicidae) and implications for the sterile insect technique.

    Science.gov (United States)

    Oliva, Clelia F; Damiens, David; Vreysen, Marc J B; Lemperière, Guy; Gilles, Jérémie

    2013-01-01

    Male insects are expected to optimize their reproductive strategy according to the availability of sperm or other ejaculatory materials, and to the availability and reproductive status of females. Here, we investigated the reproductive strategy and sperm management of male and virgin female Aedes albopictus, a mosquito vector of chikungunya and dengue viruses. The dynamics of semen transfer to the female bursa inseminalis and spermathecae were observed. Double-mating experiments were conducted to study the effect of time lapsed or an oviposition event between two copulations on the likelihood of a female double-insemination and the use of sperm for egg fertilization; untreated fertile males and radio-sterilised males were used for this purpose. Multiple inseminations and therefore the possibility of sperm competition were limited to matings closely spaced in time. When two males consecutively mated the same female within a 40 min interval, in ca. 15% of the cases did both males sire progeny. When the intervals between the copulations were longer, all progeny over several gonotrophic cycles were offspring of the first male. The mating behavior of males was examined during a rapid sequence of copulations. Male Ae. albopictus were parceling sperm allocation over several matings; however they would also attempt to copulate with females irrespective of the available sperm supply or accessory gland secretion material. During each mating, they transferred large quantities of sperm that was not stored for egg fertilization, and they attempted to copulate with mated females with a low probability of transferring their genes to the next generation. The outcomes of this study provided in addition some essential insights with respect to the sterile insect technique (SIT) as a vector control method.

  16. Aedes albopictus (Skuse) males in laboratory and semi-field cages: release ratios and mating competitiveness.

    Science.gov (United States)

    Madakacherry, Odessa; Lees, Rosemary Susan; Gilles, Jeremie Roger Lionel

    2014-04-01

    To control the container-breeding mosquito and major vector of dengue and chikungunya Aedes albopictus, the sterile insect technique (SIT) is proposed as a component of integrated vector management programs in endemic areas. For the technique to be successful, released males, sterilized with 35 Gy of ionizing radiation during the pupal stage, must be able to compete for mating opportunities with wild counterparts and successfully copulate with wild females to induce sterility in the population. Any reduction in competitiveness can be compensated for by increasing the ratio of released sterile to wild males, a ratio which must be optimized for effectiveness and efficiency. Fruit fly SIT programs use field enclosures to test the competitiveness of sterile males to monitor the quality of the colony and adjust release ratios. This is laborious and time consuming, and for mosquito programs it would be advantageous if similarly useful results could be obtained by smaller scale laboratory tests, conducted on a more regular basis. In the present study we compared the competitiveness, as measured by hatching rate of resulting egg batches, of irradiated males measured in small and large laboratory cages and semi-field enclosures in a greenhouse setting, when competing in a 1:1, 3:1, and 5:1 ratio with fertile males. The sterile males were found to be equally competitive when compared to unirradiated counterparts, and a 5:1 ratio was sufficient to reduce, but not eliminate, the fertility of the female populations, irrespective of cage size. Variability in hatch rate in eggs laid by individual females and so-called indeterminate matings, when we could not be certain whether a female had mated a fertile or a sterile male, could be investigated by closer investigation of mating status and the frequency of multiple matings in Ae. albopictus. The laboratory results are encouraging for the effectiveness of the SIT using irradiated males of this species, and we support further

  17. Association between fertilizer-mediated changes in microbial communities and Aedes albopictus growth and survival.

    Science.gov (United States)

    Muturi, Ephantus J; Ramirez, Jose L; Rooney, Alejandro P; Dunlap, Chris

    2016-12-01

    Contamination of aquatic habitats with anthropogenic nutrients has been associated with an increase in mosquito larval populations but the underlying mechanisms remain poorly understood. We examined the individual and combined effects of two synthetic fertilizers (ammonium sulfate and potassium chloride) on Aedes albopictus survival, development time, and sex ratio. The bacterial and fungal communities of water samples from different fertilizer treatments were also characterized by MiSeq sequencing of the 16S rRNA gene (bacteria) and internal transcribed spacer 1 (fungi) and their relationship with mosquito survival and development determined. Mosquitoes from ammonium sulfate treatment had significantly lower survival rates and longer development times compared to those from control, potassium chloride or a mixture of the two fertilizers. Fertilizer treatment had no significant effects on Ae. albopictus sex ratio although ammonium sulfate treatment tended to be more biased towards males relative to the other treatments. There were no significant effects of fertilizer treatment on fungal communities. However, potassium chloride treatments had lower bacterial diversity compared to the other treatments and the bacterial community structure of control and potassium chloride treatments differed significantly from that of ammonium sulfate and a mixture of the two fertilizers. Microbial composition but not diversity was significantly associated with mosquito survival and development. These findings suggest that anthropogenic nutrients can have a profound impact on mosquito survival and development. In addition to any potential direct effects on mosquito physiology, our results suggest that fertilizers can act indirectly by disrupting the microbial communities that provide a critical food resource for mosquito larvae.

  18. Comparison of Irradiation and Wolbachia Based Approaches for Sterile-Male Strategies Targeting Aedes albopictus.

    Science.gov (United States)

    Atyame, Célestine M; Labbé, Pierrick; Lebon, Cyrille; Weill, Mylène; Moretti, Riccardo; Marini, Francesca; Gouagna, Louis Clément; Calvitti, Maurizio; Tortosa, Pablo

    2016-01-01

    The global expansion of Aedes albopictus together with the absence of vaccines for most of the arboviruses transmitted by this mosquito has stimulated the development of sterile-male strategies aiming at controlling disease transmission through the suppression of natural vector populations. In this context, two environmentally friendly control strategies, namely the Sterile Insect Technique (SIT) and the Wolbachia-based Incompatible Insect Technique (IIT) are currently being developed in several laboratories worldwide. So far however, there is a lack of comparative assessment of these strategies under the same controlled conditions. Here, we compared the mating capacities, i.e. insemination capacity, sterilization capacity and mating competitiveness of irradiated (35 Gy) and incompatible Ae. albopictus males at different ages and ratios under laboratory controlled conditions. Our data show that there was no significant difference in insemination capacity of irradiated and incompatible males, both male types showing lower capacities than untreated males at 1 day but recovering full capacity within 5 days following emergence. Regarding mating competitiveness trials, a global observed trend is that incompatible males tend to induce a lower hatching rate than irradiated males in cage controlled confrontations. More specifically, incompatible males were found more competitive than irradiated males in 5:1 ratio regardless of age, while irradiated males were only found more competitive than incompatible males in the 1:1 ratio at 10 days old. Overall, under the tested conditions, IIT seemed to be slightly more effective than SIT. However, considering that a single strategy will likely not be adapted to all environments, our data stimulates the need for comparative assessments of distinct strategies in up-scaled conditions in order to identify the most suitable and safe sterilizing technology to be implemented in a specific environmental setting and to identify the

  19. High Resolution Spatial Analysis of Habitat Preference of Aedes Albopictus (Diptera: Culicidae) in an Urban Environment.

    Science.gov (United States)

    Cianci, Daniela; Hartemink, Nienke; Zeimes, Caroline B; Vanwambeke, Sophie O; Ienco, Annamaria; Caputo, Beniamino

    2015-05-01

    Over the past decades, the Asian tiger mosquito (Aedes albopictus (Skuse, 1895)) has emerged in many countries, and it has colonized new environments, including urban areas. The species is a nuisance and a potential vector of several human pathogens, and a better understanding of the habitat preferences of the species is needed for help in successful prevention and control. So far, the habitat preference in urban environments has not been studied in Southern European cities. In this paper, spatial statistical models were used to evaluate the relationship between egg abundances and land cover types on the campus of Sapienza University in Rome, which is taken as an example of a European urban habitat. Predictor variables included land cover types, classified in detail on a high resolution image, as well as solar radiation and month of capture. The models account for repeated measures in the same trap and are adjusted for meteorological circumstances. Vegetation and solar radiation were found to be positively related to the number of eggs. More specifically, trees were positively related to the number of eggs and the relationship with grass was negative. These findings are consistent with the species' known preference for shaded areas. The unexpected positive relationship with solar radiation is amply discussed in the paper. This study represents a first step toward a better understanding of the spatial distribution of Ae. albopictus in urban environments. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Differential attraction of Aedes albopictus in the field to flowers, fruits and honeydew.

    Science.gov (United States)

    Müller, Günter C; Xue, Rui-De; Schlein, Yosef

    2011-04-01

    Sugar is the main source of energy for the activities of mosquitoes; however, information on the vital sugar feeding of Aedes albopictus in the field is scanty and often anecdotal. Using glue traps and baits, we evaluated the attraction of Ae. albopictus to 28 different, potential sugar sources. Control traps were baited with either sugar-water solution or water alone, and since there was no significant difference between these controls, the water control was used as the standard for comparison. The total catch amounted to 1347 females and 1127 males. An attraction index (mean number of mosquitoes attracted to the baits/mean number of mosquitoes attracted to the control) was used to compare the relative attraction of the baits. The attraction index of significantly attractive baits ranged from 2.5 to 50.0 and the index of others ranged from 0.50 to 2.75. None of the baits were repellent. Significantly high attraction was observed for four of six ornamental flowers (Tamarix chinensis, Vitex agnus-castus, Polygonum baldchuanicum, Buddleja davidii), four of eleven wild flowers (Prosopis farcta, Ziziphus spina-christi, Polygonum equisetiforme, Ceratonia siliqua), the only tested seed pod when damaged and fermenting (C. siliqua), and all five of the tested fruits: Opuntia ficus indica (sabra), Ficus carica (fig), Punica granatum (pomegranate, damaged), Eriobotyra japonica (loquat), and Rubus sanctus (raspberry). Unlike damaged, fermenting carob seed pods and pomegranates, the fresh fruits were not attractive. Attraction to foliage soiled with honeydew excretion of three different aphid species was also not significant. The potential to use attractive sugar sources for mosquito control is discussed.

  1. High efficiency of temperate Aedes albopictus to transmit chikungunya and dengue viruses in the Southeast of France.

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    Anubis Vega-Rua

    Full Text Available BACKGROUND: Since 2005, cases of chikungunya (CHIK were caused by an unusual vector, Aedes albopictus. This mosquito, present in Europe since 1979, has gained importance since its involvement in the first CHIK outbreak in Italy in 2007. The species is capable of transmitting experimentally 26 arboviruses. However, the vectorial status of its temperate populations has remained little investigated. In 2010, autochthonous cases of CHIK and dengue (DEN were reported in southeastern France. We evaluated the potential of a French population of Ae. albopictus in the transmission of both viruses. METHODOLOGY AND PRINCIPAL FINDINGS: We used two strains of each virus, CHIK AND DEN: one strain was isolated from an imported case, and one from an autochthonous case. We used as controls Aedes aegypti from India and Martinique, the source of the imported cases of CHIK and DEN, respectively. We showed that Ae. albopictus from Cagnes-sur-Mer (AL-CSM was as efficient as the typical tropical vector Ae. aegypti from India to experimentally transmit both CHIK strains isolated from patients in Fréjus, with around 35-67% of mosquitoes delivering up to 14 viral particles at day 3 post-infection (pi. The unexpected finding came from the high efficiency of AL-CSM to transmit both strains of DENV-1 isolated from patients in Nice. Almost 67% of Ae. albopictus AL-CSM which have ensured viral dissemination were able to transmit at day 9 pi when less than 21% of the typical DEN vector Ae. aegypti from Martinique could achieve transmission. CONCLUSIONS/SIGNIFICANCE: Temperate Ae. albopictus behaves differently compared to its counterpart from tropical regions, where recurrent epidemic outbreaks occur. Its potential responsibility for outbreaks in Europe should not be minimized.

  2. Pyrosequencing 16S rRNA genes of bacteria associated with wild tiger mosquito Aedes albopictus: a pilot study

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    Guillaume eMinard

    2014-05-01

    Full Text Available The Asian tiger mosquito Aedes (Stegomya albopictus is an invasive species that has spread across the world in the last two decades, showing a great capacity to adapt to contrasting climates and environments. While demonstrated in many insects, the contribution of bacterial symbionts in Aedes ecology is a challenging aspect that needs to be investigated however. Some bacterial species have already been identified in Ae. albopictus using classical methods, but a more accurate survey of mosquito-associated bacterial diversity is needed to decipher the potential biological functions of bacterial symbionts in mediating or constraining insect adaptation. We surveyed the bacteria associated with field populations of Ae. albopictus from Madagascar by pyrosequencing 16S rRNA gene amplicons. Different aspects of amplicon preparation and sequencing depth were tested to optimise the breadth of bacterial diversity identified. The results revealed that all mosquitoes collected from different sites have a bacterial microbiota dominated by a single taxon, Wolbachia pipientis, which accounted for about 99% of all 98,520 sequences obtained. Ae. albopictus is known to harbour two Wolbachia strains, wAlbA and wAlbB, and quantitative PCR was used to estimate the relative densities, i.e. the bacteria-to-host gene ratios, of the strains in individual mosquitoes. Relative densities were between 6.25 × 100.01 and 5.47 × 100.1 for wAlbA and between 2.03 × 100.1 and 1.4 × 101 for wAlbB. Apart from Wolbachia, a total of 32 bacterial taxa were identified at the genus level using the different in method variations. Diversity index values were low and probably underestimated the true diversity due to the high abundance of Wolbachia sequences vastly outnumbering sequences from other taxa. Further studies should implement alternative strategies to specifically discard from analysis any sequences from Wolbachia, the dominant endosymbiotic bacterium in Ae. albopictus from

  3. From eggs to bites: do ovitrap data provide reliable estimates of Aedes albopictus biting females?

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    Mattia Manica

    2017-03-01

    Full Text Available Background Aedes albopictus is an aggressive invasive mosquito species that represents a serious health concern not only in tropical areas, but also in temperate regions due to its role as vector of arboviruses. Estimates of mosquito biting rates are essential to account for vector-human contact in models aimed to predict the risk of arbovirus autochthonous transmission and outbreaks, as well as nuisance thresholds useful for correct planning of mosquito control interventions. Methods targeting daytime and outdoor biting Ae. albopictus females (e.g., Human Landing Collection, HLC are expensive and difficult to implement in large scale schemes. Instead, egg-collections by ovitraps are the most widely used routine approach for large-scale monitoring of the species. The aim of this work was to assess whether ovitrap data can be exploited to estimate numbers of adult biting Ae. albopictus females and whether the resulting relationship could be used to build risk models helpful for decision-makers in charge of planning of mosquito-control activities in infested areas. Method Ovitrap collections and HLCs were carried out in hot-spots of Ae. albopictus abundance in Rome (Italy along a whole reproductive season. The relationship between the two sets of data was assessed by generalized least square analysis, taking into account meteorological parameters. Result The mean number of mosquito females/person collected by HLC in 15′ (i.e., females/HLC and the mean number of eggs/day were 18.9 ± 0.7 and 39.0 ± 2.0, respectively. The regression models found a significant positive relationship between the two sets of data and estimated an increase of one biting female/person every five additional eggs found in ovitraps. Both observed and fitted values indicated presence of adults in the absence of eggs in ovitraps. Notably, wide confidence intervals of estimates of biting females based on eggs were observed. The patterns of exotic arbovirus outbreak

  4. From eggs to bites: do ovitrap data provide reliable estimates of Aedes albopictus biting females?

    Science.gov (United States)

    Manica, Mattia; Rosà, Roberto; Della Torre, Alessandra; Caputo, Beniamino

    2017-01-01

    Aedes albopictus is an aggressive invasive mosquito species that represents a serious health concern not only in tropical areas, but also in temperate regions due to its role as vector of arboviruses. Estimates of mosquito biting rates are essential to account for vector-human contact in models aimed to predict the risk of arbovirus autochthonous transmission and outbreaks, as well as nuisance thresholds useful for correct planning of mosquito control interventions. Methods targeting daytime and outdoor biting Ae. albopictus females (e.g., Human Landing Collection, HLC) are expensive and difficult to implement in large scale schemes. Instead, egg-collections by ovitraps are the most widely used routine approach for large-scale monitoring of the species. The aim of this work was to assess whether ovitrap data can be exploited to estimate numbers of adult biting Ae. albopictus females and whether the resulting relationship could be used to build risk models helpful for decision-makers in charge of planning of mosquito-control activities in infested areas. Ovitrap collections and HLCs were carried out in hot-spots of Ae. albopictus abundance in Rome (Italy) along a whole reproductive season. The relationship between the two sets of data was assessed by generalized least square analysis, taking into account meteorological parameters. The mean number of mosquito females/person collected by HLC in 15' (i.e., females/HLC) and the mean number of eggs/day were 18.9 ± 0.7 and 39.0 ± 2.0, respectively. The regression models found a significant positive relationship between the two sets of data and estimated an increase of one biting female/person every five additional eggs found in ovitraps. Both observed and fitted values indicated presence of adults in the absence of eggs in ovitraps. Notably, wide confidence intervals of estimates of biting females based on eggs were observed. The patterns of exotic arbovirus outbreak probability obtained by introducing these estimates

  5. From eggs to bites: do ovitrap data provide reliable estimates of Aedes albopictus biting females?

    Science.gov (United States)

    Manica, Mattia; Rosà, Roberto; della Torre, Alessandra

    2017-01-01

    Background Aedes albopictus is an aggressive invasive mosquito species that represents a serious health concern not only in tropical areas, but also in temperate regions due to its role as vector of arboviruses. Estimates of mosquito biting rates are essential to account for vector-human contact in models aimed to predict the risk of arbovirus autochthonous transmission and outbreaks, as well as nuisance thresholds useful for correct planning of mosquito control interventions. Methods targeting daytime and outdoor biting Ae. albopictus females (e.g., Human Landing Collection, HLC) are expensive and difficult to implement in large scale schemes. Instead, egg-collections by ovitraps are the most widely used routine approach for large-scale monitoring of the species. The aim of this work was to assess whether ovitrap data can be exploited to estimate numbers of adult biting Ae. albopictus females and whether the resulting relationship could be used to build risk models helpful for decision-makers in charge of planning of mosquito-control activities in infested areas. Method Ovitrap collections and HLCs were carried out in hot-spots of Ae. albopictus abundance in Rome (Italy) along a whole reproductive season. The relationship between the two sets of data was assessed by generalized least square analysis, taking into account meteorological parameters. Result The mean number of mosquito females/person collected by HLC in 15′ (i.e., females/HLC) and the mean number of eggs/day were 18.9 ± 0.7 and 39.0 ± 2.0, respectively. The regression models found a significant positive relationship between the two sets of data and estimated an increase of one biting female/person every five additional eggs found in ovitraps. Both observed and fitted values indicated presence of adults in the absence of eggs in ovitraps. Notably, wide confidence intervals of estimates of biting females based on eggs were observed. The patterns of exotic arbovirus outbreak probability obtained by

  6. Coffee and its waste repel gravid Aedes albopictus females and inhibit the development of their embryos.

    Science.gov (United States)

    Satho, Tomomitsu; Dieng, Hamady; Ahmad, Muhammad Hishamuddin Itam; Ellias, Salbiah Binti; Hassan, Ahmad Abu; Abang, Fatimah; Ghani, Idris Abd; Miake, Fumio; Ahmad, Hamdan; Fukumitsu, Yuki; Zuharah, Wan Fatma; Majid, Abdul Hafiz Ab; Kassim, Nur Faeza Abu; Hashim, Nur Aida; Ajibola, Olaide Olawunmi; Al-Khayyat, Fatima Abdulla; Nolasco-Hipolito, Cirilo

    2015-05-14

    Dengue is a prevalent arboviral disease and the development of insecticide resistance among its vectors impedes endeavors to control it. Coffee is drunk by millions of people daily worldwide, which is associated with the discarding of large amounts of waste. Coffee and its waste contain large amounts of chemicals many of which are highly toxic and none of which have a history of resistance in mosquitoes. Once in solution, coffee is brownish in colour, resembling leaf infusion, which is highly attractive to gravid mosquitoes. To anticipate the environmental issues related to the increasing popularity of coffee as a drink, and also to combat insecticide resistance, we explored the deterrence potentials of coffee leachates against the ovipositing and embryonic stages of the dengue vector, Aedes albopictus. In a series of choice, no-choice, and embryo toxicity bioassays, we examined changes in the ovipositional behaviours and larval eclosion of Ae. albopictus in response to coffee extracts at different concentrations. Oviposition responses were extremely low when ovicups holding highly concentrated extract (HCE) of coffee were the only oviposition sites. Gravid females retained increased numbers of mature eggs until 5 days post-blood feeding. When provided an opportunity to oviposit in cups containing coffee extracts and with water, egg deposition occurred at lower rates in those containing coffee, and HCE cups were far less attractive to females than those containing water only. Females that successfully developed in a coffee environment preferentially oviposited in such cups when in competition with preferred oviposition sites (water cups), but this trait did not continue into the fourth generation. Larval eclosion occurred at lower rates among eggs that matured in a coffee environment, especially among those that were maintained on HCE-moistened substrates. The observations of the present study indicate a pronounced vulnerability of Ae. albopictus to the presence

  7. Diversity of culturable bacteria including Pantoea in wild mosquito Aedes albopictus

    Science.gov (United States)

    2013-01-01

    Background The microbiota has been shown to play an important role in the biology of insects. In recent decades, significant efforts have been made to better understand the diversity of symbiotic bacteria associated with mosquitoes and assess their influence on pathogen transmission. Here, we report the bacterial composition found in field-caught Aedes albopictus populations by using culture-dependent methods. Results A total of 104 mosquito imagos (56 males and 48 females) were caught from four contrasting biotopes of Madagascar and their bacterial contents were screened by plating whole body homogenates on three different culture media. From 281 bacterial colony types obtained, amplified ribosomal DNA restriction analysis (ARDRA) showed they had 40 distinct ribotypes. Sequencing and BLAST analysis of the 16S rDNA genes responsible for each representative profile made it possible to identify 27 genera distributed in three major phyla. In female mosquitoes, bacterial isolates were mostly Proteobacteria (51.3%) followed by Firmicutes (30.3%) and Actinobacteria (18.4%). Conversely, Actinobacteria was the most abundant phylum in male mosquitoes (48%) followed by Proteobacteria (30.6%) and Firmicutes (20.4%). The relative abundance and composition of isolates also varied between sampling sites, ranging from 3 distinct families in Ankazobe to 8 in Tsimbazaza Park, and Toamasina and Ambohidratrimo. Pantoea was the most common genus in both females and males from all sampling sites, except for Ambohidratrimo. No differences in genome size were found between Pantoea isolates from mosquitoes and reference strains in pulse field gel electrophoresis. However, according to the numbers and sizes of plasmids, mosquito isolates clustered into three different groups with other strains isolated from insects but distinct from isolates from the environment. Conclusions The recent upsurge in research into the functional role of the insect microbiota prompts the interest to better

  8. Evaluations of dual attractant toxic sugar baits for surveillance and control of Aedes aegypti and Aedes albopictus in Florida.

    Science.gov (United States)

    Scott-Fiorenzano, Jodi M; Fulcher, Alice P; Seeger, Kelly E; Allan, Sandra A; Kline, Daniel L; Koehler, Philip G; Müller, Günter C; Xue, Rui-De

    2017-01-05

    Dual attractant toxic sugar baits (D-ATSB) containing two host kairomones, L-lactic (LA) and 1-octen-3-ol (O), and fruit-based attractants were evaluated through olfactory, consumption and mortality, and semi-field experiments to determine if host kairomones could first, enhance attraction of a fruit-based (attractant) toxic sugar bait (ATSB), and second, increase the efficacy of a fruit based attractive toxic sugar bait (ATSB). Four combinations of LA and O were incorporated into the ATSB and evaluated in an olfactometer to determine if these combinations could enhance attraction of Aedes aegypti (L.) to the bait. Ae. albopictus (Skuse) and Ae. aegypti were used to determine bait consumption through excrement droplet counts and percent mortality, of the most attractive D-ATSB (1% LA and 1% O) from the olfactory study. Semi-field evaluations were conducted in screened portable field cages to determine if the D-ATSB applied to non-flowering plants controlled more mosquitoes than the fruit-based ATSB, and ASB. Mosquitoes were exposed to D-ATSB and the two controls for 48 h and collected with BGS traps. The catch rates of the BGS traps were compared to determine efficacy of the D-ATSB. During olfactometer evaluations of D-ATSB, Ae. aegypti mosquitoes were more attracted to 1% LA and 1% O compared to the fruit-based toxic sugar bait alone. Both species of mosquito consumed more fruit-based non-toxic bait (ASB) and ATSB than the D-ATSB. For both species, percent mortality bioassays indicated D-ATSB controlled mosquitoes, as compared to non-toxic control, but not more than the fruit based ATSB. Semi-field evaluations, BioGents sentinel traps at 48 h confirmed that ATSB (positive control) controlled Ae. albopictus, but there was no statistical difference between ASB (negative control) and the D-ATSB. No differences were observed between the mosquitoes caught in any of the experimental formulations for Ae. aegypti. L-lactic (1%) and 1-octen-3-ol (1%) added to a fruit

  9. INHIBITION OF MAYARO VIRUS REPLICATION BY PROSTAGLANDIN A1 IN Aedes albopictus CELLS

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    Joel Antonio Barbosa

    1998-09-01

    Full Text Available Prostaglandin A1 (PGA1 inhibits Mayaro virus replication in Aedes albopictus cells at nontoxic doses to uninfected cells. At 10 µg/ml, PGA1 decreases virus production by 90%. The presence of PGA1 during virus adsorption, with no treatment after infection, reduces virus yield by 41%. Antiviral activity is observed even when treatment starts at one or two hours post-infection. However, in cells pre-treated with PGA1 during 24 hours, virus replication is not impaired. Thus, events ocurring during initial stages of infection and after virus adsorption and penetration must be the target of PGA1 action. SDS-PAGE analysis of 35S-methionine labelled proteins shows that PGA1 inhibits the synthesis of viral proteins and induces the synthesis of polypeptides with molecular weight of 70 kDa, 57 kDa and 23 kDa. In cells pre-treated with actinomycin D the induction of those proteins is suppressed. In addition, actinomycin D treatment prevents PGA1antiviral activity, indicating that PGA1-induced stress proteins are probably involved in this mechanism.Prostaglandin A1 (PGA1 inibe a replicação do vírus Mayaro em células de Aedes albopictus em doses não tóxicas para células não infectadas. A presença de PGA1 durante o período de adsorção, reduz a produção do vírus em 41%. A atividade antiviral é observada mesmo quando o tratamento é iniciado com 1 ou 2 horas após a infecção. Entretanto, em células pré-tratadas com PGA1 durante 24 h a replicação viral é inalterada. A análise das proteínas marcadas com 35S-metionina, por eletroforese em gel de poliacrilamida, mostra que a PGA1 inibe a síntese de proteínas virais e induz a síntese de polipeptídeos com peso molecular de 70 Kda, 57 Kda e 23 Kda. Em células pré-tratadas com actinomicina D observa-se um bloqueio da atividade antiviral, indicando que as proteínas de estresse induzidas pela PGA1 estão envolvidas neste mecanismo.

  10. Dispersal of Aedes aegypti and Aedes albopictus (Diptera: Culicidae in an urban endemic dengue area in the State of Rio de Janeiro, Brazil

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    Nildimar Alves Honório

    2003-03-01

    Full Text Available Experimental releases of female Aedes (Stegomyia aegypti and Aedes (Stegomyia albopictus were performed in August and September 1999, in an urban area of Nova Iguaçu, State of Rio de Janeiro, Brazil, to estimate their flight range in a circular area of 1,600 m where 1,472 ovitraps were set. Releases of 3,055 Ae. aegypti and 2,225 Ae. albopictus females, fed with rubidium (Rb-marked blood and surgically prevented from subsequent blood-feeding, were separated by 11 days. Rb was detected in ovitrap-collected eggs by atomic emission spectrophotometry. Rb-marked eggs of both species were detected up to 800 m from the release point. Eggs of Ae. albopictus were more numerous and more heterogeneously distributed in the area than those of Ae. aegypti. Eggs positively marked for Rb were found at all borders of the study area, suggesting that egg laying also occurred beyond these limits. Results from this study suggest that females can fly at least 800 m in 6 days and, if infected, potentially spread virus rapidly.

  11. Bromeliad-inhabiting mosquitoes in an urban botanical garden of dengue endemic Rio de Janeiro - Are bromeliads productive habitats for the invasive vectors Aedes aegypti and Aedes albopictus?

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    Márcio Goulart Mocellin

    2009-12-01

    Full Text Available Immatures of both Aedes aegypti and Aedes albopictus have been found in water-holding bromeliad axils in Brazil. Removal of these plants or their treatment with insecticides in public and private gardens have been undertaken during dengue outbreaks in Brazil despite uncertainty as to their importance as productive habitats for dengue vectors. From March 2005-February 2006, we sampled 120 randomly selected bromeliads belonging to 10 species in a public garden less than 200 m from houses in a dengue-endemic neighborhood in Rio de Janeiro. A total of 2,816 mosquito larvae and pupae was collected, with an average of 5.87 immatures per plant per collection. Culex (Microculex pleuristriatus and Culex spp of the Ocellatus Group were the most abundant culicid species, found in all species of bromeliads; next in relative abundance were species of the genus Wyeomyia. Only two individuals of Ae. aegypti (0.07% and five of Ae. albopictus(0.18% were collected from bromeliads. By contrast, immatures of Ae. aegypti were found in manmade containers in nearly 5% of nearby houses. These results demonstrate that bromeliads are not important producers of Ae. aegypti and Ae. albopictus and, hence, should not be a focus for dengue control. However, the results of this study of only one year in a single area may not represent outcomes in other urban localities where bromeliads, Ae. aegypti and dengue coincide in more disturbed habitats.

  12. Preliminary investigation on geographic distribution of Aedes albopictus in northwest China%西北地区白纹伊蚊地理分布初步调查

    Institute of Scientific and Technical Information of China (English)

    施耀勇; 张军民

    2012-01-01

    目的 调查了解白纹伊蚊在西北地区的分布.方法 帐诱、人诱法、畜诱法、网捕法和文献资料收集.结果 白纹伊蚊在陕西省除陕北黄土高原外遍布大部分地区;甘肃省仅在文县、康县、徽县、成县和两当县发现有白纹伊蚊;在宁夏和青海采集的大量标本中没有发现白纹伊蚊.结论 白纹伊蚊在西北地区分布的界限有向西扩大.%Objective To clarify the geographical distribution oi Aedes albopictus in northwest China. Methods Using bedent snars, person soars, animal snars and insert net to collect Aedes alhopictus from northwest China. Results Aedes albopictus distributed in most parts oi Shanxi Province, except the Shanbei plateau; but Aedes albopic-lus was only found in Wen County, Kang County,Cheng County and Liangdang County in Gansu Province;Aedes albopictus was not found in the large number of specimens collected in Ningxia Province and Qinghai Province. Conclusion Distribution boundaries of Aedes albopictus in the northwest China is expanding westward.

  13. Ovitrap surveys of dengue vector mosquitoes in Chiang Mai, northern Thailand: seasonal shifts in relative abundance of Aedes albopictus and Ae. aegypti.

    Science.gov (United States)

    Mogi, M; Khamboonruang, C; Choochote, W; Suwanpanit, P

    1988-10-01

    Aedes aegypti (L.) and Aedes albopictus (Skuse) were surveyed using ovitraps in residential areas in Chiang Mai, northern Thailand. Egg populations (both species inclusive) remained low in the dry season, but increased/decreased exponentially during the first/latter half of the rainy season, respectively. This seasonal pattern was similar to the seasonal distribution of dengue haemorrhagic fever cases in the area. During the dry season (November-March) Ae.aegypti was dominant in urban and indoor ovitraps. With onset of the rainy season in April, relative abundance of Ae.albopictus increased in rural and outdoor ovitraps. Ae.albopictus displaced Ae.aegypti in the latter half of the rainy season in the rural area. Possible mechanisms to account for this seasonal decline of Ae.aegypti and reciprocal fluctuations in relative abundance of Ae.albopictus are discussed in relation to food availability for larvae in container habitats.

  14. A rapid molecular detection protocol for Chikungunya virus directly performed on Aedes albopictus (tiger mosquito

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    Simone Barocci

    2010-03-01

    Full Text Available In the last few years tiger mosquitoes (Aedes albopictus, quickly and widely spread in Italy, represent ideal vectors for different Arboviruses, particularly Dengue virus (DenV and Chikungunya virus (ChikV, who are causing millions of patients in the world per year. For ChikV, appeared for the first time in Italy in 2007, a Surveillance Plan was defined in the Marche Region, a neighbour county of the Italian outbreak site. As a support for this surveillance, we decided to create a new multiplex RT-PCR protocol to detect ChikV directly in tiger mosquitoes. All the mosquitoes were collected with BG-Sentinel® traps (Biogents AG, Regensburg, Germany.Total RNA extraction was carried with Helix RNA plus kit (Diatech srl, Jesi, Italy. For retro-transcription and amplification a Mastercycler® ep gradient S thermal cycler (Eppendorf AG, Hamburg, Germany was used. From the whole RNA extracted from captured mosquitoes, we developed a new end-point multiplex retro transcriptase polymerase chain reaction (RT-PCR, for both the detection and identification of Aedes spp. and ChikV. This RT-PCR protocol is able to detect ChikV directly from adult insects, during alerts or emergencies.The entomological trapping associated with bio-molecular methods represents an effective strategy to detect ChikV directly from vectors. Moreover, after a specific evaluation, this RT-PCR protocol could be applied also for human blood samples in regions with the certain presence of this virus.

  15. A Survey of Insecticide Resistance in Aedes albopictus (Diptera: Culicidae) During a 2014 Dengue Fever Outbreak in Guangzhou, China.

    Science.gov (United States)

    Yiguan, Wang; Xin, Liu; Chengling, Li; Su, Tianyun; Jianchao, Jin; Yuhong, Guo; Dongsheng, Ren; Zhicong, Yang; Qiyong, Liu; Fengxia, Meng

    2016-12-23

    A dengue fever outbreak in Guangzhou, Guangdong Province, China, in 2014 resulted in ∼37,000 cases and five deaths. Insecticides were sprayed to control the vector of this outbreak, Aedes albopictus (Skuse), a species of mosquito. Aedes albopictus specimens collected from Huadu District (HD), Huangpu District (HP), Luogang District (LG), and Nansha District (NS) in Guangzhou were evaluated using WHO-recommended bioassays for both larvae and adult mosquitoes to determine population resistance to deltamethrin, beta-cypermethrin, cypermethrin, permethrin, dichlorvos, temephos, propoxur, and DDT. Compared with a susceptible laboratory strain of Ae. albopictus (S-lab), all populations showed decreased sensitivities to the eight insecticides, with resistance ratios (RRs) ranging from 2.2 to 275. The RRs were 6.8-275 for pyrethroids, 2.2-4.4 for organophosphates, 5.7-9.0 for carbamates, and 5.3-94.3 for organochlorines. For adult mosquitoes, all populations were sensitive to dichlorvos with 100% mortalities. Mosquitoes from HP, LG, and NS were also sensitive to propoxur. But for other tested insecticides, different degrees of resistance (mortality rate ranging from 11.7% to 94.7%) were observed. Among the four field populations, the resistance levels are presented as follows in descending order: HP > HD > NS > LG. The levels among insecticides classes were pyrethroids > organochlorines > carbamates > organophosphates.

  16. Cytoarchitecture of Zika virus infection in human neuroblastoma and Aedes albopictus cell lines.

    Science.gov (United States)

    Offerdahl, Danielle K; Dorward, David W; Hansen, Bryan T; Bloom, Marshall E

    2017-01-15

    The Zika virus (ZIKV) pandemic is a global concern due to its role in the development of congenital anomalies of the central nervous system. This mosquito-borne flavivirus alternates between mammalian and mosquito hosts, but information about the biogenesis of ZIKV is limited. Using a human neuroblastoma cell line (SK-N-SH) and an Aedes albopictus mosquito cell line (C6/36), we characterized ZIKV infection by immunofluorescence, transmission electron microscopy (TEM), and electron tomography (ET) to better understand infection in these disparate host cells. ZIKV replicated well in both cell lines, but infected SK-N-SH cells suffered a lytic crisis. Flaviviruses scavenge host cell membranes to serve as replication platforms and ZIKV showed the hallmarks of this process. Via TEM, we identified virus particles and 60-100nm spherular vesicles. ET revealed these vesicular replication compartments contain smaller 20-30nm spherular structures. Our studies indicate that SK-N-SH and C6/36 cells are relevant models for viral cytoarchitecture study. Published by Elsevier Inc.

  17. Bio-Pesticides: New Tool for the Control of Aedes (Stegomyia albopictus (Culicidae: Diptera in Pakistan

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    Hazrat Bilal

    2017-06-01

    Full Text Available Background: Application of plant extracts as mosquito control strategy was practiced from centuries. These are easily available, non-toxic, biodegradable and exhibit broad-spectrum target specific activities against larval stages of mosquitoes.Method: Different potential parts of locally grown plants, seeds of nutmeg (Myristica fragrans, peel of musambi (Citrus sinensis, leaves of babuna (Matricaria chamomilla, mint (Mentha spicata and ginger rhizome (Zingiber officinale selected and evaluated for their larvicidal properties against Aedes (Stegomyis albopictus. Oils were ex­tracted through steam distillation process and extracts were evaluated as per WHO 2005 guidelines for testing of insecticides against larvae of mosquitoes.Result: Among the five plant extracts, C. sinensis had the lowest LC50 (400.81ppm while M. fragrans had the high­est LC50 value (710.30ppm respectively after 24h of exposure. In terms of % age mortality, a series of con­centra­tions (300–800ppm gave high % mortality in case of C. sinensis while M. fragrans gave low % age mortality.Conclusion: All the five plant species have larvicidal effects to certain extant and C. sinensis had great potential. Further small-scale field trials with the extracts of the most promising one (C. sinensis shall be conducted to deter­mine operational feasibility.    

  18. Requirement of cell nucleus for Sindbis virus replication in cultured Aedes albopictus cells.

    Science.gov (United States)

    Erwin, C; Brown, D T

    1983-02-01

    The ability of Sindbis virus to grow in enucleated BHK-21 (vertebrate) and Aedes albopictus (invertebrate) cells was tested to determine the dependence of this virus upon nuclear function in these two phylogenetically unrelated hosts. Although both cell types could be demonstrated to produce viable cytoplasts (enucleated cells) which produced virus-specific antigen subsequent to infection. BHK cytoplasts produced a significant number of progeny virions, whereas mosquito cytoplasts did not. The production of vesicular stomatitis virus in mosquito cells was not significantly reduced by enucleation. That such a host function was not essential for vesicular stomatitis virus growth in insect cells is supported by the observation that the production of this virus by mosquito cells is not actinomycin D sensitive. This result agrees with a previously published report in which it was shown that Sindbis virus maturation in invertebrate cells is inhibited by actinomycin D, indicating a possible requirement for host cell nuclear function (Scheefers-Borchel et al., Virology, 110:292-301, 1981).

  19. Optimization of pyrethroid and repellent on fabrics against Stegomyia albopicta (=Aedes albopictus) using a microencapsulation technique.

    Science.gov (United States)

    Yao, T-T; Wang, L-K; Cheng, J-L; Hu, Y-Z; Zhao, J-H; Zhu, G-N

    2015-03-01

    A new approach employing a combination of pyrethroid and repellent is proposed to improve the protective efficacy of conventional pyrethroid-treated fabrics against mosquito vectors. In this context, the insecticidal and repellent efficacies of commonly used pyrethroids and repellents were evaluated by cone tests and arm-in-cage tests against Stegomyia albopicta (=Aedes albopictus) (Diptera: Culicidae). At concentrations of LD50 (estimated for pyrethroid) or ED50 (estimated for repellent), respectively, the knock-down effects of the pyrethroids or repellents were further compared. The results obtained indicated that deltamethrin and DEET were relatively more effective and thus these were selected for further study. Synergistic interaction was observed between deltamethrin and DEET at the ratios of 5 : 1, 2 : 1, 1 : 1 and 1 : 2 (but not 1 : 5). An optimal mixing ratio of 7 : 5 was then microencapsulated and adhered to fabrics using a fixing agent. Fabrics impregnated by microencapsulated mixtures gained extended washing durability compared with those treated with a conventional dipping method. Results indicated that this approach represents a promising method for the future impregnation of bednet, curtain and combat uniform materials.

  20. Mating competitiveness of Aedes albopictus radio-sterilized males in large enclosures exposed to natural conditions.

    Science.gov (United States)

    Bellini, R; Balestrino, F; Medici, A; Gentile, G; Veronesi, R; Carrieri, M

    2013-01-01

    Mating competitiveness trials have been conducted in large net-screened enclosures (8 by 5 by 2.8 m) built in a natural shaded environment, in the summers of 2006, 2007, 2008, and 2009 in northern Italy. Aedes albopictus (Skuse) males were radio-sterilized by applying gamma radiations at doses in the range 30-60 Gy. Gamma radiation was administered to aged pupae at the rate of 2.3 Gy/min. Reared radiated males (originally collected in Rimini, Forli, Bologna, Matera, Pinerolo) and hybrid radiated males were tested against wild fertile males (originated from eggs collected in Rimini and Cesena) and reared fertile males, in multiple comparisons for mating competitiveness with reared or wild females. The ratio was kept constant at 100-100_100 (fertile males-radiated males_virgin females). Mating competitiveness was estimated through the calculation of the hatching rate of the eggs laid in oviposition traps positioned inside enclosures. No clear effect of the strains tested (reared, wild, or hybrid) was found. Results demonstrated that reducing the radiation dose from 60 to 30 Gy increases males' competitiveness. Laboratory investigations conducted after controversial results in the 2006 preliminary trials, showed that radiation induces precociousness in adult male emergence.

  1. Identification of mayaro virus nucleocapsid protein in nucleus of Aedes albopictus cells.

    Science.gov (United States)

    Mitchell, C; de Andrade-Rozental, A F; Souto-Padrón, T; Carvalho, M G

    1997-01-01

    The modifications in the pattern of nuclear proteins of Aedes albopictus cells in response to Mayaro virus infection were analysed early and late after infection. The viral capsid (C) protein of 34 kDa (p34) could be detected in the nuclear compartment 4 h after infection, soon after its synthesis in the cytoplasm. In addition to p34, a group of high molecular weight proteins was also present in this compartment late after infection. The exposition of infected cells to supra optimal temperature of growth modifies significantly the pattern of nuclear proteins. However, the stress condition does not inhibit the transport of p34 to the nucleus. The transport of proteins into nuclei was also followed under "in vitro' conditions by incubating radiolabeled post-mitochondrial extract of infected cells with unlabeled nuclei. Under these conditions, as observed "in vivo', a specific transport of viral C protein and of a group of proteins of high molecular weight to the nuclei was also detected. These results indicate that Mayaro virus infection modifies the nuclear protein pattern in invertebrate cells.

  2. Assessing the susceptibility status of Aedes albopictus on Penang Island using two different assays.

    Science.gov (United States)

    Chan, H H; Mustafa, F F W; Zairi, J

    2011-08-01

    Routine surveillance on resistant status of field mosquito populations is important to implement suitable strategies in order to prevent pest outbreaks. WHO test kit bioassay is the most frequent bioassay used to investigate the susceptibility status of field-collected mosquitoes, as it is relatively convenient to be carried out in the field. In contrast, the topical application of active ingredient is less popular in investigating the susceptibility status of mosquitoes. In this study, we accessed the susceptibility status of Aedes albopictus Skuse collected from two dengue hotspots on Penang Island: Sungai Dua and Persiaran Mayang Pasir. Two active ingredients: permethrin and deltamethrin, were used. WHO test kit bioassay showed that both wild strains collected were susceptible to the two active ingredients; while topical application assay showed that they were resistant. This indicated that WHO test kit bioassay less sensitive to low level of resistance compared to topical application assay. Hence, topical application is expected to be more indicative when used in a resistance surveillance programme.

  3. Genetic Polymorphism of Aedes albopictus Population Inferred From ND5 Gene Variabilities In Subang Jaya, Malaysia.

    Science.gov (United States)

    Adilah-Amrannudin, Nurul; Hamsidi, Mayamin; Ismail, Nurul-Ain; Ismail, Rodziah; Dom, Nazri Che; Ahmad, Abu Hassan; Mastuki, Mohd Fahmi; Basri, Tengku Shahrul Anuar Tengku Ahmad; Khalid, Adira; Muslim, Mohammad; Daud, Nurul Amalina Ahmad; Camalxaman, Siti Nazrina

    2016-12-01

    This study was performed to establish the genetic variability of Aedes albopictus within Subang Jaya, Selangor, Malaysia, by using the nicotinamide adenine dinucleotide dehydrogenase 5 subunit (ND5) mitochondrial DNA (mtDNA) marker. A total of 90 samples were collected from 9 localities within an area of the Subang Jaya Municipality. Genetic variability was determined through the amplification and sequencing of a fragment of the ND5 gene. Eight distinct mtDNA haplotypes were identified. The evolutionary relationship of the local haplotypes alongside 28 reference strains was used to construct a phylogram, the analysis of which revealed low genetic differentiation in terms of both nucleotide and haplotype diversity. Bayesian method was used to infer the phylogenetic tree, revealing a unique relationship between local isolates. The study corroborates the reliability of ND5 to identify distinct lineages for polymorphism-based studies and supplements the existing body of knowledge regarding its genetic diversity. This in turn could potentially aid existing vector control strategies to help mitigate the risk and spread of the dengue virus.

  4. The use of andiroba Carapa guianensis as larvicide against Aedes albopictus.

    Science.gov (United States)

    Silva, Onilda S; Romão, Pedro R T; Blazius, Rene D; Prohiro, Josiane S

    2004-12-01

    Andiroba Carapa guianensis Aubl. Meliacea is known to possess repellent activity against many mosquito species. We evaluated the larvicidal effect of dry-scratched seed kernels of andiroba against a sylvatic F1 progeny and a laboratory-colonized population of Aedes albopictus (Skuse). The 3rd instar of F1 treated with 0.5 to 2% of C. guianensis for 24 and 48 hours, had mortality with LC50 of 0.74 (0.56-0.90%) and 0.68 (0.53-0.84%), respectively, and the 4th instar 0.66 (0.52-0.80%) and 0.55 (0.20-0.91%), respectively. For the 3rd instars of laboratory-colonized larvae, the treatment with 0.5 to 4% of C. guianensis induced mortality after 24 hours with LC50 of 1.81 (1.39-2.22%), and an LC50 of 1.82 (1.57-2.07%) to the 4th instar. This is the 1st report of the larvicidal effect of C. guianensis on mosquitoes.

  5. Toxic effects of neem cake extracts on Aedes albopictus (Skuse) larvae.

    Science.gov (United States)

    Nicoletti, Marcello; Serafini, Mauro; Aliboni, Andrea; D'Andrea, Armando; Mariani, Susanna

    2010-06-01

    In order to investigate its insecticide potential, the neem cake methanol extract was first analyzed and then separated by different solvents. The high-performance liquid chromatography analysis showed that the neem cake methanol extract still contained relevant quantities of nortriterpenes. Fractions of increasing polarity were obtained from the separation process: hexane fraction (Hp), EtOAc fraction (Ep), n-BuOH fraction (Bp), and aqueous fraction (Wp). The activity of the fractions on Aedes albopictus (Skuse) eggs and larvae was tested, and the Ep fraction exhibits the most relevant larvicide effect. The nuclear magnetic resonance fingerprint analysis of this phytocomplex isolated on EtOAc fraction was performed. The larvicidal effectiveness of the phytocomplex isolated on EtOAc, compared to that of pure and commercial azadirachtin solutions of different concentrations, was checked. The results showed that the activity of the phytocomplex, as a whole, was significantly higher than those of isolated compound solutions. As a consequence, the neem cake is a promising low-cost, easily available on the market, and natural resource to develop a new bioinsecticide, mainly in developing countries.

  6. Evaluation of vector competence for West Nile virus in Italian Stegomyia albopicta (=Aedes albopictus) mosquitoes.

    Science.gov (United States)

    Fortuna, C; Remoli, M E; Severini, F; Di Luca, M; Toma, L; Fois, F; Bucci, P; Boccolini, D; Romi, R; Ciufolini, M G

    2015-12-01

    West Nile virus (WNV) is a zoonotic arboviral pathogen transmitted by mosquitoes in a cycle that involves wild birds as reservoir hosts. The virus is responsible for outbreaks of viral encephalitis in humans and horses. In Europe, Culex pipiens (Diptera: Culicidae) is considered to be the main vector of WNV, but other species such as Stegomyia albopicta (=Aedes albopictus) (Diptera: Culicidae) may also act as competent vectors of this virus. Since 2008 human cases of WNV disease have been reported in northeast Italy. In 2011, new areas of southern Italy became involved and a first outbreak of WNV lineage 1 occurred on the island of Sardinia. On the assumption that a potential involvement of St. albopicta in WNV transmission cannot be excluded, and in order to evaluate the competence of this species for the virus, an experimental infection of an St. albopicta laboratory colony, established from mosquitoes collected in Sardinia, was carried out. The results were compared with those obtained in a colony of the main vector Cx. pipiens. The study showed St. albopicta collected on Sardinia to be susceptible to WNV infection, which suggests this Italian mosquito species is able to act as a possible secondary vector, particularly in urban areas where the species reaches high levels of seasonal abundance.

  7. Water surface area and depth determine oviposition choice in Aedes albopictus (Diptera: Culicidae).

    Science.gov (United States)

    Reiskind, Michael H; Zarrabi, Ali A

    2012-01-01

    Oviposition choice is a well-studied aspect of the mosquito life cycle, and offers a potential avenue for species-specific surveillance and control. In container inhabiting mosquitoes, there has been a focus on how the components of the aquatic media determine choice, with little work on the physical characteristics of the containers themselves. We performed five experiments examining the effect of physical container parameters on oviposition choice by Aedes albopictus. We examined containers of three different surface areas (small, 496 cm2; medium, 863 cm2; and large, 1,938 cm2) at the same water depth and the same or different heights in a series of binary choice assays. We also examined different depths with the same surface area in clear containers (where the depth may be perceived by the darkness of the water) and in opaque containers, which appear uniformly dark at different depths. We found a significant preference for medium containers over large containers, whether the containers were different or the same heights, and a trend toward a preference for small containers over medium containers. There was a preference for deeper water regardless of whether containers were clear or opaque. These behaviors suggest mosquitoes take into account physical aspects of their habitats and their oviposition choices are consistent with minimizing the risk of habitat drying.

  8. Polypeptide synthesis in alphavirus-infected Aedes albopictus cells during the establishment of persistent infection.

    Science.gov (United States)

    Richardson, M A; Boulton, R W; Raghow, R S; Dalgarno, L

    1980-01-01

    Polypeptide synthesis was examined in mosquito cells during the establishment of a persistent infection with two alphaviruses, Ross River virus (RRV) and Semliki Forest virus (SFV), and in vertebrate cells cytopathically-infected with the same viruses. In Aedes albopictus cell, RRV reached peak titres at 34--48 hours p.i. At 12 hours 85 per cent of cells assayed as infected by infective centre assay; by 48 hours when persistence was established, virus production was reduced and less than 5 per cent of cells assayed as infected. There was no shut-down of host polypeptide synthesis during infection. Viral polypeptide synthesis was maximal between 10 and 24 hours p.i. The major viral polypeptides labelled were nucleocapsid protein and envelope protein(s). The precursor polypeptide p95 which was prominent in infected BHK cells was not detected in mosquito cells. Similar results were obtained on SFV infection. During the establishment of persistence there was a coordinate decline in the synthesis of RRV polypeptides, reaching undetectable levels by 72 hours p.i. Subculturing persitently-infected cells led to a small increase in viral polypeptide synthesis and virus titre. In contrast, during RRV growth in BHK celos host protein synthesis was severly inhibited and by 9--11 hours p.i. virus-specific polypeptide synthesis represented more than 90 per cent of total protein synthetic activity.

  9. Larvicidal Effects of Four Citrus Peel Essential Oils Against the Arbovirus Vector Aedes albopictus (Diptera: Culicidae).

    Science.gov (United States)

    Campolo, Orlando; Romeo, Flora V; Algeri, Giuseppe M; Laudani, Francesca; Malacrinò, Antonino; Timpanaro, Nicolina; Palmeri, Vincenzo

    2016-02-01

    In this study, we evaluated the larvicidal activity of four citrus essential oils (EOs; sweet orange, mandarin, bergamot, and lemon) against the arbovirus vector Aedes albopictus (Skuse) (Diptera: Culicidae) under laboratory conditions. Through gas chromatography-mass spectrometry (GC-MS) analyses, we found that in sweet orange, mandarin, and lemon EOs, limonene was the most abundant compound, whereas linalyl acetate was the most abundant in the bergamot EO. All tested EOs showed a marked larvicidal activity, in particular sweet orange, lemon, and bergamot that killed all treated larvae. After 24 h of exposure, the LC50 values of the tested citrus EOs ranged from 145.27 (lemon EO) to 318.07 mg liter(-1) (mandarin EO), while LC(95) ranged from 295.13 to 832.44 mg liter(-1). After 48 h of exposure, the estimated LC(50) values decreased to values ranging from 117.29 to 209.38 mg liter(-1), while LC(95) ranged from 231.85 to 537.36 mg liter(-1). The results obtained from these evaluations, together with the large availability at reasonable costs of citrus EOs, are promising for the potential development of a new botanical mosquitocide. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Permethrin resistance in Aedes albopictus (Diptera: Culicidae) and associated fitness costs.

    Science.gov (United States)

    Chan, Hiang Hao; Zairi, Jaal

    2013-03-01

    Insecticide resistance has become a serious issue in vector management programs. Information on insecticidal resistance and its associated mechanisms is important for successful insecticide resistance management. The selection of a colony of permethrin-resistant Aedes albopictus (Skuse) (Diptera: Culicidae), originating from Penang Island, Malaysia, yielded high larval-specific resistance to permethrin and cross-resistance to deltamethrin. Synergism assays showed that the major mechanism underlying this resistance involves cytochrome P450 monooxygenase. The resistance is autosomal, polygenically inherited and incompletely dominant (D = 0.26). Resistant larvae were reared under different conditions to assess the fitness costs. Under high larval density, larval development time of the resistant SGI strain was significantly longer than the susceptible VCRU strain. In both high- and low-density conditions SGI showed a lower rate of emergence and survival compared with the VCRU strain. Resistant larvae were more susceptible to predation by Toxorhynchites splendens (Wiedemann) (Diptera: Culicidae) larvae. The body size of SGI females reared under high-density conditions was larger compared with females of the susceptible strain. SGI females survived longer when starved than did VCRU females. The energy reserve upon eclosion was positively correlated with the size of the adults.

  11. Evaluation of a New Thermal Fog Machine for Control of Adult Aedes albopictus in a Large Enclosed Space.

    Science.gov (United States)

    Gibson, Jennifer; Smith, Michael L; Xue, Rui-De; Ren, Dong-Sheng

    2016-06-01

    Testing of the PSO BASDKA-AC1200 multifunction ultrafine particle atomization machine, a thermal fog machine, with Aqualuer 20-20(®) (permethrin 20.6%, piperonyl butoxide 20.6%) was conducted against Aedes albopictus. The machine was set at a 40 sec maximum burst interval dispersing 36 ml of chemical with an average droplet volume of 50%. Female adult Ae. albopictus were placed into cylindrical paper cages and adhered to poles at 5, 8, 10, 15, and 25 m from the center point of the machine. Control cages consisted of 1 cage placed at 5, 10, and 25 m. Control and treatment groups were left in the experiment area for 15 min. Initial knockdown after 15 min and 24 h mortality were documented. At 15 min post-treatment, Ae. albopictus displayed less than 50% knockdown. After 24 h, all treatment cages displayed greater than 90% mortality. Further bottle bioassays were conducted to determine the lowest chemical dose possible to achieve a lethal dose of 90%. A 1% dilution (10 ml Aqualuer 20-20 to 1,000 ml of polyether) of Aqualuer showed high mortality in the laboratory. However, after running 3 repetitions of a 1% dilution, there was no significant difference between the mortality of the mosquitoes at any of the distances 24 h post-treatment. This study indicates that the test machine would be an applicable and suitable machine for control of Ae. albopictus in enclosed spaces.

  12. 白纹伊蚊实验种群感染沃尔巴体Wolbachia的研究%STUDY ON WOLBACHIA INFECTION IN EXPERIMENTAL POPULATION OF AEDES ALBOPICTUS

    Institute of Scientific and Technical Information of China (English)

    张东京; 杨潇; 吴贤生; 陈婧; 李卓雅; 吴瑜; 詹希美; 郑小英

    2012-01-01

    为了了解白纹伊蚊实验种群沃尔巴体Wolbachia感染率、感染品系、组织分布及系统发育,运用引物PCR方法检测实验种群白纹伊蚊Wolbachia 的感染情况.解剖白纹伊蚊,提取头部、卵巢/睾丸、脂肪体、唾液腺/胸部、马氏管、中肠组织的基因组DNA,PCR法扩增Wolbachia表面膜蛋白(wsp),扩增产物进行克隆及测序,并用BLAST软件对其进行系统发育分析.将随机抽取的白纹伊蚊雌雄各50只分别检测,均为阳性.卵巢/睾丸、脂肪体和唾液腺/胸部均存在着Wolbachia A、B组超感染;雌蚊头部、雄蚊马氏管和中肠为B组单感染;雄蚊头部则未检测到Wolbachia.将wsp基因克隆测序后进行系统发育分析显示白纹伊蚊体内Wolbachia与尖音库蚊、菜蛾、宽边黄粉蝶四者同源性较高达99%,这表明四者体内所感染的Wolbachia可能来源于同一个分支.%In order to investigate the infection profiles of Wolbachia in Aedes albopictus rearing in laboratory, we carried out a survey in Ae. Albopictus using polymerase chain reaction ( PCR ) assay to detect Wolbachia to analysis the infection rates, strains, tissue distribution and the phylogeny relationships. Briefly, template DNA was extracted from the head, ovary/ testis, fat body, salivary glands/ thorax, malpighian tubules and midgut respectively to amplify Wolbachia Surface Protein ( wsp ) gene. The amplification product was cloned and sequenced to analyze the phylogenesis with BLAST tools. Of fifty male and female mosquitoes randomly selected, all of them were positively infected with Wolbachia. The ovary/tesis, fat body and salivary glands/thorax of both sexes were superinfected by Wolbachia A and B strains. The malpighian tubules and midgut of male were only infected by B strain. As for the head, the female were found only infected by B strain, the male were not found infection. The identity of Wolbachia in Ae. Albopictus, is 99% as high as Culex pipents, Cotesia

  13. The Strica Homolog AaCASPS16 Is Involved in Apoptosis in the Yellow Fever Vector, Aedes albopictus

    Science.gov (United States)

    Meng, Kun; Li, Xiaomei; Wang, Shengya; Zhong, Chunyan; Yang, Zhouning; Feng, Lingyan; Liu, Qingzhen

    2016-01-01

    Caspases are a family of cysteine proteases playing essential roles during apoptosis. Seven caspases identified in Drosophila were Dronc, Dredd, Strica, Dcp-1, Decay, Drice and Damm. Among them, Strica is an insect-specific caspase containing a long serine- and threonine- rich prodomain, of which function is not yet well studied. Here we identified a homolog of strica from Aedes albopictus, named as Aacasps16. Aacasps16 encoded a protein containing a putative serine- and threonine-rich prodomain and a well conserved caspase catalytic domain. AaCASPS16 shared high identity with dipteran insects Strica homologs. Alignment showed that the closest relative of AaCASPS16 was Aedes aegypti AeCASPS16. The expression profiles of Aacasps16 during developmental and adult stages were analyzed. Purified recombinant AaCASPS16 exhibited the highest caspase activity to WEHD, which is the substrate preferred by human caspase-9. AaCASPS16 induced apoptosis when over-expressed in C6/36 cells. AaCASPS16 was processed during apoptosis induced by actinomycin D and ultraviolet irradiation treatment, whereas partial silencing of Aacasps16 reduced actinomycin D- and ultraviolet irradiation-triggered apoptosis in C6/36 cells. Taken together, our study identified AaCASPS16 as a novel apoptotic caspase in Aedes albopictus. PMID:27351972

  14. The Strica Homolog AaCASPS16 Is Involved in Apoptosis in the Yellow Fever Vector, Aedes albopictus.

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    Kun Meng

    Full Text Available Caspases are a family of cysteine proteases playing essential roles during apoptosis. Seven caspases identified in Drosophila were Dronc, Dredd, Strica, Dcp-1, Decay, Drice and Damm. Among them, Strica is an insect-specific caspase containing a long serine- and threonine- rich prodomain, of which function is not yet well studied. Here we identified a homolog of strica from Aedes albopictus, named as Aacasps16. Aacasps16 encoded a protein containing a putative serine- and threonine-rich prodomain and a well conserved caspase catalytic domain. AaCASPS16 shared high identity with dipteran insects Strica homologs. Alignment showed that the closest relative of AaCASPS16 was Aedes aegypti AeCASPS16. The expression profiles of Aacasps16 during developmental and adult stages were analyzed. Purified recombinant AaCASPS16 exhibited the highest caspase activity to WEHD, which is the substrate preferred by human caspase-9. AaCASPS16 induced apoptosis when over-expressed in C6/36 cells. AaCASPS16 was processed during apoptosis induced by actinomycin D and ultraviolet irradiation treatment, whereas partial silencing of Aacasps16 reduced actinomycin D- and ultraviolet irradiation-triggered apoptosis in C6/36 cells. Taken together, our study identified AaCASPS16 as a novel apoptotic caspase in Aedes albopictus.

  15. Effect of Common Species of Florida Landscaping Plants on the Efficacy of Attractive Toxic Sugar Baits Against Aedes albopictus.

    Science.gov (United States)

    Seeger, Kelly E; Scott, Jodi M; Muller, Gunter C; Qualls, Whitney A; Xue, Rui-De

    2017-06-01

    Attractive toxic sugar bait (ATSB) was applied to 5 different types of commonly found plants in landscaping of northeastern Florida. The ATSB applications were assessed for possible plant effects and preference against Aedes albopictus in semifield evaluations. Positive and negative controls consisted of plants sprayed with attractive sugar bait (no toxicant) and plants with nothing applied. Bioassays were conducted on stems with leaf clippings and on full plants to assess any difference in mosquito mortality on the different plants. Plants utilized in these evaluations were Indian hawthorne, Yaupon holly, Japanese privet, Loropetalum ruby, and podocarpus. In both assays, no significant difference was observed in the effect of ATSBs on adult female mosquitoes based on the type of plant. ATSB could be applied to common landscape plants for adult Ae. albopictus control.

  16. Aedes albopictus may not be vector of dengue virus in human epidemics in Brazil Aedes albopictus pode não ser vetor da dengue durante epidemias no Brasil

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    Nicolas Degallier

    2003-06-01

    Full Text Available Over 60,500 dengue cases were reported in the state of Espírito Santo (ES, Brazil, between 1995 and 1998. The study's purpose was to identify whether Aedes albopictus was transmitting the dengue virus during an epidemic in the locality of Vila Bethânia (Viana County,Vitória, ES. From April 3 to 9, 1998, blood and serum samples were collected daily for virus isolation and serological testing. Four autochthonous cases were confirmed through DEN 1 virus isolation and two autochthonous cases through MAC ELISA testing. Of 37 Ae. aegypti and 200 Ae. albopictus adult mosquitoes collected and inoculated, DEN1 virus was isolated only from a pool of two Ae. aegypti female mosquitoes. The study results suggest that Ae. albopictus still cannot be considered an inter-human vector in dengue epidemics in Brazil.Mais de 60.500 casos de dengue foram notificados no Espírito Santo, entre 1995 e 1998. Realizou-se estudo com o objetivo de averiguar se o mosquito Aedes albopictus estava transmitindo o vírus durante uma epidemia em Vila Bethânia (Viana, no sudeste de Vitória, capital capixaba. De 3 a 9 de abril de 1998, amostras de sangue e (ou soro de pacientes foram coletadas e os mosquitos foram capturados diariamente, tanto para isolamento viral como para testes sorológicos. Em onze casos autóctonos, quatro foram confirmados por isolamento do vírus DEN 1, e dois por reação MAC ELISA Dos 37 Ae. aegypti e 200 Ae. albopictus adultos capturados e inoculados, apenas uma amostra de vírus DEN 1 foi obtida de um lote de duas fêmeas de Ae. aegypti. Os resultados sugerem que a espécie Ae. albopictus ainda não pode ser considerada um vetor inter-humano durante epidemias de dengue no Brasil.

  17. Development and Evaluation of an Attractive Self-Marking Ovitrap to Measure Dispersal and Determine Skip Oviposition in Aedes albopictus (Diptera: Culicidae) Field Populations.

    Science.gov (United States)

    Davis, Timothy J; Kaufman, Phillip E; Tatem, Andrew J; Hogsette, Jerome A; Kline, Daniel L

    2016-01-01

    Aedes albopictus (Skuse) is a container-breeding species with considerable public health importance. To date, Ae. albopictus oviposition behavior has been assessed in outdoor conditions, but only with laboratory-reared specimens. In outdoor large-cage and field studies, we used an attractive self-marking ovipositional device to assess Ae. albopictus skip oviposition behavior. In field studies, 37 wild Ae. albopictus that visited an attractive self-marking ovisite were subsequently captured at a sticky ovitrap within a 4-d period. Because the average Ae. albopictus gonotrophic period is 4.5-6 d, the wild-caught Ae. albopictus visited at least two oviposition sites within a single gonotrophic period. This provided field-based indirect evidence of skip oviposition. The mean distance traveled (MDT) during the 20-d evaluations ranged from 58 to 78 m. The maximum observed distance traveled was 149 m, which was the outer edge of our trapping ability. As populations of Ae. albopictus increased, the MDT during the 4- and 20-d post-marking period increased significantly. Additional observations of wild-marked and captured Aedes triseriatus (Say) are discussed. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Transcriptome Profiling and Genetic Study Reveal Amplified Carboxylesterase Genes Implicated in Temephos Resistance, in the Asian Tiger Mosquito Aedes albopictus.

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    Linda Grigoraki

    2015-05-01

    Full Text Available The control of Aedes albopictus, a major vector for viral diseases, such as dengue fever and chikungunya, has been largely reliant on the use of the larvicide temephos for many decades. This insecticide remains a primary control tool for several countries and it is a potential reliable reserve, for emergency epidemics or new invasion cases, in regions such as Europe which have banned its use. Resistance to temephos has been detected in some regions, but the mechanism responsible for the trait has not been investigated.Temephos resistance was identified in an Aedes albopictus population isolated from Greece, and subsequently selected in the laboratory for a few generations. Biochemical assays suggested the association of elevated carboxylesterases (CCE, but not target site resistance (altered AChE, with this phenotype. Illumina transcriptomic analysis revealed the up-regulation of three transcripts encoding CCE genes in the temephos resistant strain. CCEae3a and CCEae6a showed the most striking up-regulation (27- and 12-folds respectively, compared to the reference susceptible strain; these genes have been previously shown to be involved in temephos resistance also in Ae. aegypti. Gene amplification was associated with elevated transcription levels of both CCEae6a and CCEae3a genes. Genetic crosses confirmed the genetic link between CCEae6a and CCEae3a amplification and temephos resistance, by demonstrating a strong association between survival to temephos exposure and gene copy numbers in the F2 generation. Other transcripts, encoding cytochrome P450s, UDP-glycosyltransferases (UGTs, cuticle and lipid biosynthesis proteins, were upregulated in resistant mosquitoes, indicating that the co-evolution of multiple mechanisms might contribute to resistance.The identification of specific genes associated with insecticide resistance in Ae. albopictus for the first time is an important pre-requirement for insecticide resistance management. The genomic

  19. Bioekologi vektor demam berdarah dengue (DBD serta deteksi virus dengue pada Aedes aegypti (Linnaeus dan Ae. albopictus (Skuse (Diptera: Culicidae di kelurahan endemik DBD Bantarjati, Kota Bogor

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    Zahara Fadilla

    2015-09-01

    Full Text Available Dengue hemorrhagic fever (DHF is a viral disease that threatened community health in Indonesia. As part of an eradication program, it is important to learn the behavioral aspect of the disease vector. The aims of this study were to detect the presence of dengue virus in Aedes spp., at Bantarjati Village, Bogor City and to learn to bioecology of. Aedes aegypti (Linnaeus. Detection of dengue virus in Aedes spp. were done by reverse transcription-polymerase chain reaction (RT-PCR technique that consist of two phase were synthesis phase and cDNA amplification and dengue virus serotipe characterization. The Ae. aegypti and Ae. albopictus (Skuse mosquitoes were collected using the landing and resting moquito collection technique booth indoors and outdoors. The highest density of Ae. aegypti and Ae. albopictus were found in April and the peak activity was occurred at 10:00-11:00 am. Dengue virus was not detected in female mosquitoes Aedes spp.

  20. Molecular cloning and xenobiotic induction of seven novel cytochrome P450 monooxygenases in Aedes albopictus.

    Science.gov (United States)

    Chan, Hiang Hao; Wajidi, Mustafa Fadzil Farid; Zairi, Jaal

    2014-01-01

    Cytochrome P450 monooxygenase (P450) is a superfamily of enzymes that is important in metabolism of endogenous and exogenous compounds. In insects, these enzymes confer resistance to insecticides through its metabolic activities. Members of P450 from family 6 in insects are known to play a role in such function. In this study, we have isolated seven novel family 6 P450 from Aedes albopictus (Skuse) (Diptera: Culicidae), a vector of dengue and chikungunya fever. Induction profile of these seven genes was studied using several insecticides and xenobiotics. It was found that deltamethrin and permethrin did not induce expression of any genes. Another insecticide, temephos, inhibited expression of CYP6P15 for fivefold and twofold for CYP6N29, CYP6Y7, and CYP6Z18. In addition, copper II sulfate induced expression of CYP6M17 and CYP6N28 for up to sixfold. Benzothiazole (BZT), a tire leachate induced the expression of CYP6M17 by fourfold, CYP6N28 by sevenfold, but inhibited the expression of CYP6P15 for threefold and CYP6Y7 for twofold. Meanwhile, piperonyl butoxide (PBO) induced the expression CYP6N28 (twofold), while it inhibited the expression of CYP6P15 (fivefold) and CYP6Y7 (twofold). Remarkably, all seven genes were induced two- to eightfold by acetone in larval stage, but not adult stage. Expression of CYP6N28 was twofold higher, while expression of CYP6P15 was 15-fold lower in adult than larva. The other five P450s were not differentially expressed between the larvae and adult. This finding showed that acetone can be a good inducer of P450 in Ae. albopictus. On the other hand, temephos can act as good suppressor of P450, which may affect its own bioefficacy because it needs to be bioactivated by P450. To the best of our knowledge, this is the first report on acetone-inducible P450 in insects. Further study is needed to characterize the mechanisms involved in acetone induction in P450.

  1. Updated distribution of Aedes albopictus (Diptera: Culicidae) in Spain: new findings in the mainland Spanish Levante, 2013

    Science.gov (United States)

    Alarcón-Elbal, Pedro María; Estrella, Sarah Delacour; Arrondo, Ignacio Ruiz; Collantes, Francisco; Iniesta, Juan Antonio Delgado; Morales-Bueno, José; Sánchez-López, Pedro Francisco; Amela, Carmen; Sierra-Moros, María José; Molina, Ricardo; Lucientes, Javier

    2014-01-01

    In 2004, Aedes (Stegomyia) albopictus (Skuse, 1894) was observed for the first time in Catalonia, northeastern Spain. A decade later, it has spread throughout the eastern Mediterranean region of the country and the Balearic Islands. Framed within a national surveillance project, we present the results of monitoring in 2013 in the autonomous communities of the mainland Levante. The current study reveals a remarkable increase in the spread of the invasive mosquito in relation to results from 2012; the species was present and well-established in 48 municipalities, most of which were along the Mediterranean coastline from the Valencian Community to the Region of Murcia. PMID:25317706

  2. Updated distribution of Aedes albopictus (Diptera: Culicidae in Spain: new findings in the mainland Spanish Levante, 2013

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    Pedro María Alarcón-Elbal

    2014-09-01

    Full Text Available In 2004, Aedes (Stegomyia albopictus (Skuse, 1894 was observed for the first time in Catalonia, northeastern Spain. A decade later, it has spread throughout the eastern Mediterranean region of the country and the Balearic Islands. Framed within a national surveillance project, we present the results of monitoring in 2013 in the autonomous communities of the mainland Levante. The current study reveals a remarkable increase in the spread of the invasive mosquito in relation to results from 2012; the species was present and well-established in 48 municipalities, most of which were along the Mediterranean coastline from the Valencian Community to the Region of Murcia.

  3. Larvicidal activities of Knema attenuata (Hook. f. & Thomson) Warb. (Myristicaceae) extracts against Aedes albopictus Skuse and Anopheles stephensi Liston.

    Science.gov (United States)

    Vinayachandra; Shwetha, R; Chandrashekar, K R

    2011-12-01

    In recent years, uses of environment friendly and biodegradable natural insecticides of plant origin have received renewed attention as agents for vector control. The present study was undertaken to investigate the effect of aril and kernel extracts of Knema attenuata (Hook. f. & Thomson) Warb. (Myristicaceae) on larvae of Aedes albopictus Skuse and Anopheles stephensi Liston under laboratory conditions. The aril was extracted with chloroform and ethanol; the kernel was extracted with ethanol and hexane. The extracts were tested against the 3rd-4th instar larvae collected from Bunder area, Mangalore, India, which is a well-known fishing harbour, where several mosquito-borne diseases were reported. All the graded concentrations (100, 200, 300, 400 and 500 ppm) showed significant larval mortality after 24 h of observation. Chloroform extracts of aril showed 100% mortality against both larval forms of A. albopictus and A. stephensi at the concentration of 500 ppm. Among the extracts tested, chloroform extracts of aril and ethanol extracts of kernel exhibited higher toxicity against both A. albopictus (LC(50), 141 ppm and 159 ppm; LC(90), 290 ppm and 342 ppm) and A. stephensi (LC(50), 160 ppm and 162 ppm; LC90, 445 ppm and 458 ppm). Hexane extracts of kernel exhibited least toxicity against A. albopictus (LC50, 239 ppm; LC(90), 484 ppm), whereas ethanol extracts of aril showed the least toxicity against A. stephensi (LC(50), 290; LC(90), 498). A preliminary phytochemical assay revealed the presence of phenolics, tannins, steroids, terpenes, resins, and glycolipids in all the extracts. Alkaloids, flavonoids and saponins were absent. The lower LC(50) value of the chloroform extracts of K. attenuata aril indicates its potentiality as a larvicide against A. albopictus and A. stephensi mosquito larvae.

  4. Modeling dengue vector dynamics under imperfect detection: three years of site-occupancy by Aedes aegypti and Aedes albopictus in urban Amazonia.

    Science.gov (United States)

    Padilla-Torres, Samael D; Ferraz, Gonçalo; Luz, Sergio L B; Zamora-Perea, Elvira; Abad-Franch, Fernando

    2013-01-01

    Aedes aegypti and Ae. albopictus are the vectors of dengue, the most important arboviral disease of humans. To date, Aedes ecology studies have assumed that the vectors are truly absent from sites where they are not detected; since no perfect detection method exists, this assumption is questionable. Imperfect detection may bias estimates of key vector surveillance/control parameters, including site-occupancy (infestation) rates and control intervention effects. We used a modeling approach that explicitly accounts for imperfect detection and a 38-month, 55-site detection/non-detection dataset to quantify the effects of municipality/state control interventions on Aedes site-occupancy dynamics, considering meteorological and dwelling-level covariates. Ae. aegypti site-occupancy estimates (mean 0.91; range 0.79-0.97) were much higher than reported by routine surveillance based on 'rapid larval surveys' (0.03; 0.02-0.11) and moderately higher than directly ascertained with oviposition traps (0.68; 0.50-0.91). Regular control campaigns based on breeding-site elimination had no measurable effects on the probabilities of dwelling infestation by dengue vectors. Site-occupancy fluctuated seasonally, mainly due to the negative effects of high maximum (Ae. aegypti) and minimum (Ae. albopictus) summer temperatures (June-September). Rainfall and dwelling-level covariates were poor predictors of occupancy. The marked contrast between our estimates of adult vector presence and the results from 'rapid larval surveys' suggests, together with the lack of effect of local control campaigns on infestation, that many Aedes breeding sites were overlooked by vector control agents in our study setting. Better sampling strategies are urgently needed, particularly for the reliable assessment of infestation rates in the context of control program management. The approach we present here, combining oviposition traps and site-occupancy models, could greatly contribute to that crucial aim.

  5. Modeling dengue vector dynamics under imperfect detection: three years of site-occupancy by Aedes aegypti and Aedes albopictus in urban Amazonia.

    Directory of Open Access Journals (Sweden)

    Samael D Padilla-Torres

    Full Text Available Aedes aegypti and Ae. albopictus are the vectors of dengue, the most important arboviral disease of humans. To date, Aedes ecology studies have assumed that the vectors are truly absent from sites where they are not detected; since no perfect detection method exists, this assumption is questionable. Imperfect detection may bias estimates of key vector surveillance/control parameters, including site-occupancy (infestation rates and control intervention effects. We used a modeling approach that explicitly accounts for imperfect detection and a 38-month, 55-site detection/non-detection dataset to quantify the effects of municipality/state control interventions on Aedes site-occupancy dynamics, considering meteorological and dwelling-level covariates. Ae. aegypti site-occupancy estimates (mean 0.91; range 0.79-0.97 were much higher than reported by routine surveillance based on 'rapid larval surveys' (0.03; 0.02-0.11 and moderately higher than directly ascertained with oviposition traps (0.68; 0.50-0.91. Regular control campaigns based on breeding-site elimination had no measurable effects on the probabilities of dwelling infestation by dengue vectors. Site-occupancy fluctuated seasonally, mainly due to the negative effects of high maximum (Ae. aegypti and minimum (Ae. albopictus summer temperatures (June-September. Rainfall and dwelling-level covariates were poor predictors of occupancy. The marked contrast between our estimates of adult vector presence and the results from 'rapid larval surveys' suggests, together with the lack of effect of local control campaigns on infestation, that many Aedes breeding sites were overlooked by vector control agents in our study setting. Better sampling strategies are urgently needed, particularly for the reliable assessment of infestation rates in the context of control program management. The approach we present here, combining oviposition traps and site-occupancy models, could greatly contribute to that

  6. Mathematical studies on the sterile insect technique for the Chikungunya disease and Aedes albopictus.

    Science.gov (United States)

    Dumont, Y; Tchuenche, J M

    2012-11-01

    Chikungunya is an arthropod-borne disease caused by the Asian tiger mosquito, Aedes albopictus. It can be an important burden to public health and a great cause of morbidity and, sometimes, mortality. Understanding if and when disease control measures should be taken is key to curtail its spread. Dumont and Chiroleu (Math Biosc Eng 7(2):315-348, 2010) showed that the use of chemical control tools such as adulticide and larvicide, and mechanical control, which consists of reducing the breeding sites, would have been useful to control the explosive 2006 epidemic in Réunion Island. Despite this, chemical control tools cannot be of long-time use, because they can induce mosquito resistance, and are detrimental to the biodiversity. It is therefore necessary to develop and test new control tools that are more sustainable, with the same efficacy (if possible). Mathematical models of sterile insect technique (SIT) to prevent, reduce, eliminate or stop an epidemic of Chikungunya are formulated and analysed. In particular, we propose a new model that considers pulsed periodic releases, which leads to a hybrid dynamical system. This pulsed SIT model is coupled with the human population at different epidemiological states in order to assess its efficacy. Numerical simulations for the pulsed SIT, using an appropriate numerical scheme are provided. Analytical and numerical results indicate that pulsed SIT with small and frequent releases can be an alternative to chemical control tools, but only if it is used or applied early after the beginning of the epidemic or as a preventive tool.

  7. Effects of larval habitat substrate on pyriproxyfen efficacy against Aedes albopictus (Diptera: Culicidae).

    Science.gov (United States)

    Suman, Devi Shankar; Wang, Yi; Dong, Limin; Gaugler, Randy

    2013-11-01

    Pyriproxyfen, a juvenile hormone analog insect growth regulator (IGR), is a recommended insecticide for the control of container-inhabiting mosquitoes. The effects of eight container substrates (three plastics, wood, tire rubber, clay pot, concrete, and glass) were studied on reduction of bio-efficacy of pyriproxyfen for Aedes albopictus (Skuse) in the laboratory. Insect growth regulator-bioassay of third instars showed significant increase of LC50 with some substrates compared with control probably because of pyriproxyfen adsorption to the substrate. The LC50 for the control substrate (glass mug) was 0.029 microg/liter. In comparison to the control, LC50 increased 150.1 times with tire rubber (4.354 microg/liter) and 8-10 times with wood and high-density polyethylene plastic containers. Slight increases of LC50 were detected for clay pots, polypropylene, and polystyrene plastics (1.9-2.7 times). Pyriproxyfen efficacy with concrete substrate was higher than with glass containers, which might be caused by high pH. The pH of water with wood (5.6) and concrete (9.8) substrates differed from the other substrates tested (6.3-7.1). There was no pupal mortality at pH 5-11 without pyriproxyfen; however, interaction of pH (5-11) with pyriproxyfen (0.05 microg/liter) showed additive effects at both low and high pH values. Different substrates have variable impacts on pyriproxyfen efficacy, which might be associated with the failure of larval control strategies for the container mosquitoes under certain field conditions.

  8. Impact of inter- and intra-specific competition among larvae on larval, adult, and life-table traits of Aedes aegypti and Aedes albopictus females.

    Science.gov (United States)

    Noden, Bruce H; O'Neal, Paul A; Fader, Joseph E; Juliano, Steven A

    2016-04-01

    Few studies have taken a comprehensive approach of measuring the impact of inter- and intra-specific larval competition on adult mosquito traits. In this study, the impact of competition Aedes aegypti and A. albopictus was quantified over the entire life of a cohort.Competitive treatments affected hatch-to-adult survivorship and development time to adulthood of females for both species, but affected median wing length of females only for A. albopictus. Competitive treatments had no significant effect on the median adult female longevity nor were there any effects on other individual traits related to bloodfeeding and reproductive success.Analysis of life table traits revealed no effect of competitive treatment on net reproductive rate (R0) but there were significant effects on cohort generation time (Tc) and cohort rate of increase (r) for both species.Inter-specific and intra-specific competition among Aedes larvae may produce individual and population-level effects that are manifest in adults; however, benign conditions may enable resulting adults to compensate for some impacts of competition, particularly those affecting blood feeding success, fecundity, and net reproductive rate, R0. The effect of competition, therefore, affects primarily larva - to - adult survivorship and larval development time, which in turn impact the cohort generation time, Tc and ultimately cohort rate of increase, r.The lack of effects of larval rearing environment on adult longevity suggests that effects on vectorial capacity due to longevity may be limited if adults have easy access to sugar and blood meals.

  9. Field Comparisons of the Gravid Aedes Trap (GAT) and BG-Sentinel Trap for Monitoring Aedes albopictus (Diptera: Culicidae) Populations and Notes on Indoor GAT Collections in Vietnam.

    Science.gov (United States)

    Johnson, Brian J; Hurst, Tim; Quoc, Hung Luu; Unlu, Isik; Freebairn, Christopher; Faraji, Ary; Ritchie, Scott A

    2016-10-05

    We report on the use of the Gravid Aedes Trap (GAT) as a surveillance device for Aedes albopictus (Skuse) relative to the BG-Sentinel (BGS) trap in field studies conducted in Trenton, NJ, and on Hammond Island, Queensland, Australia. A parallel study conducted in Nha Trang, Vietnam, assessed the use of the GAT as an indoor surveillance device as well as the use of canola oil as a noninsecticide killing agent. In Trenton and Hammond Island, the GAT collected fewer male (0.40 ± 0.12 and 0.43 ± 0.30, respectively) and female (3.05 ± 0.67 and 2.7 ± 2.3, respectively) Ae. albopictus than the BGS trap (males: 3.54 ± 1.26 and 3.75 ± 0.83; females: 4.66 ± 1.18 and 3.9 ± 0.23) over their respective sampling periods (i.e., 24 h for the BGS and 1 wk for the GAT). Despite differences in capture rates, the percentage of traps positive for female Ae. albopictus was similar between the BGS and GAT (Trenton: 60.1 ± 6.3% and 64.4 ± 4.1%; Hammond: 87.5 ± 6.9% and 80.0 ± 8.2%). In Nha Trang, the GAT was equally effective indoors and outdoors with (10 g hay or 3 g fish food) and without (water or empty) infusion. Additionally, no significant decrease in collections was observed between GATs set with canola oil or long-lasting insecticidal net. In summary, both traps were successful in monitoring female Ae. albopictus over their respective trapping intervals, but would be best used to complement each other to monitor both sexes and all physiological stages of female Ae. albopictus However, the versatility and low-cost of the GAT makes it an attractive alternative to the more expensive BGS trap.

  10. Vector competence of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) for the DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus in Fujian, China.

    Science.gov (United States)

    Guo, Xiao-Xia; Li, Chun-Xiao; Zhang, Ying-Mei; Xing, Dan; Dong, Yan-De; Zhang, Heng-Duan; Qin, Cheng-Feng; Zhao, Tong-Yan

    2016-09-01

    Dengue is an acute, emerging, infectious disease transmitted by Aedes mosquitoes that has become a serious global public health problem. The DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus were originally isolated from the serum of a patient with dengue fever in Fujian Province, China, in 1999. Our data provide the first assessment of the vector competence of Aedes mosquitoes with respect to the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus. There were significant differences in the replication rates of these two viral strains in Aedes albopictus and Aedes aegypti (Paegypti than in Ae. albopictus 5 days post infection whereas replication of the DEN2-FJ11 was greater in Ae. albopictus than in Ae. aegypti 7 days post infection. The replicative ability of the DEN2-FJ11 strain was greater than that of the DEN2-FJ10 strain in infected Ae. albopictus. In infected Ae. aegypti, rapid proliferation of the DEN2-FJ10 strain occurred earlier than in the DEN2-FJ11 strain. There were no significant differences in the midgut and salivary gland infection rates of Ae. albopictus and Ae. aegypti with respect to either viral strain. Although the DEN2-FJ10 and DEN2-FJ11 strains differ in their virulence to neonatal rats, there was no significant difference in the ability of either Ae. albopictus or Ae. aegypti to transmit the DEN2-FJ10 and DEN2-FJ10 strains of the dengue 2 virus (P>0.05). In summary, our results indicate that Ae. albopictus and Ae. aegypti mosquitoes are moderately competent vectors of the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus and provide the first evidence of the effect of these two viral strains on the vector competence of mosquitoes in China.

  11. Risk Factors for the Presence of Chikungunya and Dengue Vectors (Aedes aegypti and Aedes albopictus), Their Altitudinal Distribution and Climatic Determinants of Their Abundance in Central Nepal

    Science.gov (United States)

    Dhimal, Meghnath; Gautam, Ishan; Joshi, Hari Datt; O’Hara, Robert B.; Ahrens, Bodo; Kuch, Ulrich

    2015-01-01

    Background The presence of the recently introduced primary dengue virus vector mosquito Aedes aegypti in Nepal, in association with the likely indigenous secondary vector Aedes albopictus, raises public health concerns. Chikungunya fever cases have also been reported in Nepal, and the virus causing this disease is also transmitted by these mosquito species. Here we report the results of a study on the risk factors for the presence of chikungunya and dengue virus vectors, their elevational ceiling of distribution, and climatic determinants of their abundance in central Nepal. Methodology/Principal Findings We collected immature stages of mosquitoes during six monthly cross-sectional surveys covering six administrative districts along an altitudinal transect in central Nepal that extended from Birgunj (80 m above sea level [asl]) to Dhunche (highest altitude sampled: 2,100 m asl). The dengue vectors Ae. aegypti and Ae. albopictus were commonly found up to 1,350 m asl in Kathmandu valley and were present but rarely found from 1,750 to 2,100 m asl in Dhunche. The lymphatic filariasis vector Culex quinquefasciatus was commonly found throughout the study transect. Physiographic region, month of collection, collection station and container type were significant predictors of the occurrence and co-occurrence of Ae. aegypti and Ae. albopictus. The climatic variables rainfall, temperature, and relative humidity were significant predictors of chikungunya and dengue virus vectors abundance. Conclusions/Significance We conclude that chikungunya and dengue virus vectors have already established their populations up to the High Mountain region of Nepal and that this may be attributed to the environmental and climate change that has been observed over the decades in Nepal. The rapid expansion of the distribution of these important disease vectors in the High Mountain region, previously considered to be non-endemic for dengue and chikungunya fever, calls for urgent actions to

  12. Aedes albopictus em bromélias de solo em Ilhabela, litoral do Estado de São Paulo Aedes albopictus in soil bromeliads in Ilhabela, coastal area of Southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Gisela R A M Marques

    2005-08-01

    Full Text Available OBJETIVO: Analisar a presença de Aedes albopictus em bromélias de solo localizadas em ambientes ecologicamente distintos, em termos de positividade, densidade e volume de água. MÉTODOS: O estudo foi realizado no município de Ilhabela, litoral norte do Estado de São Paulo. Realizaram-se coletas quinzenais, de março de 1998 a julho de 1999, em tanques de bromélias localizadas nos ambientes urbano, periurbano e mata; o conteúdo aquático das plantas foi medido e registrado. O tratamento dos dados baseou-se na análise da freqüência de bromélias com presença de Ae. albopictus (ANOVA, abundância (Kruskal-Wallis e volume de água das bromélias positivas (Teste t de Student. RESULTADOS: A presença e a densidade de Ae. albopictus em bromélias de solo variou com o tipo de ambiente. Os maiores percentuais de positividade (85% e abundância (81% foram observados nas plantas localizadas em ambiente urbano. Constatou-se ainda preferência dos mosquitos pelas bromélias com maiores volumes de água (média de 300 ml. CONCLUSÕES: As diferentes freqüências com que Ae. albopictus foi registrado nos ambientes e suas respectivas densidades mostraram sua capacidade de invasão a novos habitats. Recomenda-se intensificar a vigilância entomológica nessas plantas, dada a sua capacidade em traduzir-se em criadouros permanentes. A presença desse mosquito de importância médica em bromélias em área preservada da Mata Atlântica poderá resultar em agravo à saúde.OBJECTIVE: To analyze the presence of Aedes albopictus in soil bromeliads in ecologically distinct environments in terms of positivity, density and volume of water. METHODS: The study was carried out in the municipality of Ilhabela, North coast of the state of São Paulo, Brazil. Collections were fortnightly performed between March 1998 and July 1999, in containers of bromeliads located in urban, peri-urban and forest environments. The water content in plants was measured and recorded

  13. Aedes albopictus: it's invasion, expansion of range, and the use of an area wide management project to control its population in the USA.

    Science.gov (United States)

    Aedes albopictus invaded the U.S.A. between 1983-85. It has become a widely distributed nuisance pest. A n ARS-sponsored 5 year Area Wide Pest Management cooperative program between USDA-ARS, Mosquito and Fly Research Unit (Florida), Rutgers University (New Jersey) and Brandeis University (Massach...

  14. Accidental importation of the mosquito Aedes albopictus into the Netherlands: a survey of mosquito distribution and the presence of dengue virus

    NARCIS (Netherlands)

    Scholte, E.J.; Dijkstra, E.; Blok, H.; Vries, de A.; Takken, W.; Hofhuis, A.; Koopmans, M.P.G.; Boer, de A.; Reusken, C.B.E.M.

    2008-01-01

    In the summer of 2005, the Asian tiger mosquito, Aedes albopictus (Skuse) (Diptera: Culicidae) was found for the first time in the Netherlands. It was collected on the premises of several horticultural companies that import the ornamental plant Dracaena sanderiana (Sparagalus: Dracaenaceae

  15. Field evaluation of a novel synthetic odour blend and of the synergistic role of carbon dioxide for sampling host-seeking Aedes albopictus adults in Rome, Italy

    NARCIS (Netherlands)

    Pombi, M.; Jacobs, F.H.H.; Verhulst, N.O.; Caputo, B.; Torre, della A.; Takken, W.

    2014-01-01

    Background Despite the expanding worldwide distribution of Aedes albopictus and its increasing relevance as arboviral vector, current methods to collect adult specimens are not optimal. Improved approaches are thus needed to monitor their density and pathogen infections, and to establish baseline da

  16. Accidental importation of the mosquito Aedes albopictus into the Netherlands: a survey of mosquito distribution and the presence of dengue virus

    NARCIS (Netherlands)

    Scholte, E.J.; Dijkstra, E.; Blok, H.; Vries, de A.; Takken, W.; Hofhuis, A.; Koopmans, M.P.G.; Boer, de A.; Reusken, C.B.E.M.

    2008-01-01

    In the summer of 2005, the Asian tiger mosquito, Aedes albopictus (Skuse) (Diptera: Culicidae) was found for the first time in the Netherlands. It was collected on the premises of several horticultural companies that import the ornamental plant Dracaena sanderiana (Sparagalus: Dracaenaceae [Agavacea

  17. TrapTech R-Octenol Lure Does Not Improve the Capture Rates of Aedes albopictus (Diptera: Culicidae) and Other Container-Inhabiting Species in Biogents Sentinel Traps.

    Science.gov (United States)

    Unlu, Isik; Faraji, Ary; Indelicato, Nicholas; Rochlin, Ilia

    2016-07-01

    Aedes albopictus (Skuse) and other container-inhabiting species have become important public health concerns due to the transmission of dengue, chikungunya, and Zika viruses. Effective surveillance is dependent on the ability to collect a sufficient number of mosquitoes for population monitoring and pathogen isolation. The Biogents Sentinel (BGS) trap supplied with a proprietary human skin lure has become the standard tool for container-inhabiting Aedes species collections worldwide. Recently, R-octenol, a single isomer of the well characterized mosquito attractant octenol, was shown to greatly improve the capture rate of some Aedes species when utilized with the Center for Disease Control and Prevention (CDC) light traps and Mosquito Magnet traps. This study evaluated the effectiveness of the TrapTech lure (TT lure), containing R-octenol, alone or in combination with the human skin lure in a BGS trap to capture Ae. albopictus and other species. BGS traps with human skin lures or a combination of the two lures collected approximately twice as many Ae. albopictus females compared to those with TT lures. Unlike previous studies, baiting BGS traps with TT lures did not result in increased diversity of mosquito species, or in higher numbers of other container-inhabiting Aedes species. Although human skin lures were clearly superior to TT R-octenol lures in BGS traps, R-octenol lures are more widely available and might still be used as an alternative lure, especially when Ae. albopictus populations are high.

  18. Efficacy of ovitrap colors and patterns for attracting Aedes albopictus at suburban field sites in north-central Florida.

    Science.gov (United States)

    Hoel, David F; Obenauer, Peter J; Clark, Marah; Smith, Richard; Hughes, Tony H; Larson, Ryan T; Diclaros, Joseph W; Allan, Sandra A

    2011-09-01

    We sought to visually enhance the attractiveness of a standard black ovitrap routinely used in surveillance of the Asian tiger mosquito, Aedes albopictus, and now being used as lethal ovitraps in Ae. aegypti dengue control programs. Black plastic drinking cups (ovitraps) were visually altered to offer field populations of gravid female Ae. albopictus 6 different oviposition site choices. Trials were conducted at 3 field locations in Gainesville, Orange Park, and Jacksonville, FL, during July-August 2009. A black glossy cup served as the control and was tested against 5 cup choices consisting of white, blue, orange, or black-and-white contrasting patterns (checkered or vertically striped). Means (SE) of eggs collected over 6 wk for each choice were: black 122.53 (9.63) > blue 116.74 (10.74) > checkered 101.84 (9.53) > orange 97.15 (7.95) > striped 84.62 (8.17) > white 81.84 (8.74). Black ovitraps outperformed competing colored and contrasting patterned ovicups with respect to choice from gravid Ae. albopictus seeking artificial oviposition sites.

  19. Effect of application rate and persistence of boric acid sugar baits applied to plants for control of Aedes albopictus.

    Science.gov (United States)

    Xue, Rui-De; Müller, Günter C; Kline, Daniel L; Barnard, Donald R

    2011-03-01

    The use of toxic bait to kill adult Aedes albopictus is a safe and potentially effective alternative to the use of synthetic chemical insecticides. This study was carried out to determine effective concentrations of boric acid needed in sugar bait solutions applied to plant surfaces, and to determine its residual effect in reducing adult mosquito densities. In outdoor tests in 1,100-m3 screened enclosures, landing rates of Ae. albopictus on a human subject and the number of female mosquitoes in mechanical traps were significantly reduced by a 1% boric acid bait compared with the other tested concentrations (0.25%, 0.50%, and 0.75%) and untreated control. Studies of the duration of boric acid activity on plant surfaces were made in 1.4-m3 cages in the laboratory and outdoors in 78-m3 screened enclosures. In the laboratory tests, 1% boric acid bait resulted in >96% mortality in male and female Ae. albopictus for 14 days, whereas in outdoor tests, mosquito landing rates in the treated enclosures were significantly lower than in the control enclosures for 7 days. Also, mosquito mortality responses to boric acid baits between plants with flowers and nonflowers (1.4-m3 cages in the laboratory) were not significantly different. The results of this study suggest that boric acid baits applied to plant surfaces may provide specific data related to the development of an effective point-source-based adjunct/alternative to the use of conventional adulticides for mosquito control.

  20. Attractive toxic sugar baits mixed with pyriproxyfen sprayed on plants against adult and larval Aedes albopictus (Diptera: Culicidae).

    Science.gov (United States)

    Fulcher, Ali; Scott, Jodi M; Qualls, Whitney A; Müller, Günter C; Xue, Rui-De

    2014-07-01

    The effect of spraying a mixture of the insect growth regulator (IGR) pyriproxyfen (1 mg/liter) and either 1% boric acid sugar bait or eugenol sugar bait on croton petra plants (Codiaeum variegatum L.) was evaluated against the container-inhabiting mosquito, Aedes albopictus (Skuse). Treatments were applied to plants and evaluated against adult and larval Ae. albopictus in the laboratory through contact and wash off experiments, respectively. The control treatment lacked an active ingredient and were treated with an attractive sugar bait. The plants treated with attractive toxic sugar baits plus the IGR resulted in 60-100% mortality of laboratory-reared adult Ae. albopictus. The pyriproxyfen solutions collected from the plant wash experiment resulted in 80-100% emergence inhibition to the exposed third- and fourth-instar larvae, compared with the untreated control. Attractive toxic sugar baits mixed with the IGR not only provide effective control of adult mosquitoes, but also provide additional control of larval mosquitoes after being washed off from the treated plants.

  1. Impact of climate change on the distribution of Aedes albopictus (Diptera: Culicidae) in northern Japan: retrospective analyses.

    Science.gov (United States)

    Mogi, Motoyoshi; Tuno, Nobuko

    2014-05-01

    The impact of climate change on the distribution of Aedes albopictus (Skuse) was analyzed in northern Japan, where chronological distribution records are incomplete. We analyzed local climate data using linear regression of the thermal suitability index (TSI) for the mosquito and mean annual temperature as functions of time. In northern Japan, thermal conditions since the early 20th century have become increasingly suitable for Ae. albopictus, more as a result of decreasing coldness in the overwintering season than increasing warmth in the reproductive season. Based on recent discovery records of Ae. albopictus in the northern border range, we determined thermal criteria for estimating when its persistent establishment became thermally possible. Retrospective analyses indicated that those criteria were reached in most coastal lowlands of northern Honshu before the accelerated temperature increase after the mid-1980s and the first records of this species after 1990; at some sites, temperature criteria were reached during or before the early 20th century. Expansion of the thermally suitable range after 1990 was supported only for inland areas and the northernmost Pacific coast. The estimated expansion rate was approximately 26 km per decade. Our analyses also demonstrated the importance of local climate heterogeneity (apart from north-south or altitudinal temperature gradients) in determining the expansion pattern.

  2. Effect of Larval Competition on Extrinsic Incubation Period and Vectorial Capacity of Aedes albopictus for Dengue Virus.

    Science.gov (United States)

    Bara, Jeffrey; Rapti, Zoi; Cáceres, Carla E; Muturi, Ephantus J

    2015-01-01

    Despite the growing awareness that larval competition can influence adult mosquito life history traits including susceptibility to pathogens, the net effect of larval competition on human risk of exposure to mosquito-borne pathogens remains poorly understood. We examined how intraspecific larval competition affects dengue-2 virus (DENV-2) extrinsic incubation period and vectorial capacity of its natural vector Aedes albopictus. Adult Ae. albopictus from low and high-larval density conditions were orally challenged with DENV-2 and then assayed for virus infection and dissemination rates following a 6, 9, or 12-day incubation period using real-time quantitative reverse transcription PCR. We then modeled the effect of larval competition on vectorial capacity using parameter estimates obtained from peer-reviewed field and laboratory studies. Larval competition resulted in significantly longer development times, lower emergence rates, and smaller adults, but did not significantly affect the extrinsic incubation period of DENV-2 in Ae. albopictus. Our vectorial capacity models suggest that the effect of larval competition on adult mosquito longevity likely has a greater influence on vectorial capacity relative to any competition-induced changes in vector competence. Furthermore, we found that large increases in the viral dissemination rate may be necessary to compensate for small competition-induced reductions in daily survivorship. Our results indicate that mosquito populations that experience stress from larval competition are likely to have a reduced vectorial capacity, even when susceptibility to pathogens is enhanced.

  3. Increased detection of Aedes albopictus in Belgium: no overwintering yet, but an intervention strategy is still lacking.

    Science.gov (United States)

    Deblauwe, Isra; Demeulemeester, Julie; De Witte, Jacobus; Hendy, Adam; Sohier, Charlotte; Madder, Maxime

    2015-09-01

    In 2013 and 2014, routine surveillance for invasive mosquito species was implemented in Belgium at 13 potential points of entry. Following the introduction of Aedes (Stegomyia) albopictus (Skuse 1895) to Belgium via a used tyre import company (Vrasene, Province of East Flanders) in July 2013, one female and 17 larvae were collected outdoors during a period of intensive surveillance in summer and autumn 2013, but no control measures were implemented. Although climatic conditions were suitable during the winter of 2013-2014, this reproducing population did not overwinter. Lack of genetic variation, incomplete diapause adaptation and egg desiccation due to long dry periods during diapause or competition with endemic species are possible reasons. More studies on the diapause/longevity of Ae. albopictus eggs in northern temperate climatic conditions and on the competition with endemic species in western and central Europe are warranted to assess the potential for this invasive mosquito to overwinter. Furthermore, following the detection of four Ae. albopictus larvae in a shipment of lucky bamboo at the port of Antwerp in August 2014, one female, one male, 11 pupae and six larvae were collected at the destined lucky bamboo company (Lochristi, Province of East Flanders) in autumn 2014. In this case, immediate control measures were successfully implemented at the nursery. Because of increasing threats and the absence of an invasive mosquito species control policy in Belgium, the need for a permanent vector surveillance and control plan has never been so high.

  4. First report of field evolved resistance to agrochemicals in dengue mosquito, Aedes albopictus (Diptera: Culicidae), from Pakistan

    Science.gov (United States)

    2011-01-01

    Background Agrochemicals have been widely used in Pakistan for several years. This exposes mosquito populations, particularly those present around agricultural settings, to an intense selection pressure for insecticide resistance. The aim of the present study was to investigate the toxicity of representative agrochemicals against various populations of Aedes albopictus (Skuse) collected from three different regions from 2008-2010. Results For organophosphates and pyrethroids, the resistance ratios compared with susceptible Lab-PK were in the range of 157-266 fold for chlorpyrifos, 24-52 fold for profenofos, 41-71 fold for triazofos, and 15-26 fold for cypermethrin, 15-53 fold for deltamethrin and 21-58 fold for lambdacyhalothrin. The resistance ratios for carbamates and new insecticides were in the range of 13-22 fold for methomyl, 24-30 fold for thiodicarb, and 41-101 fold for indoxacarb, 14-27 fold for emamectin benzoate and 23-50 fold for spinosad. Pair wise comparisons of the log LC50s of insecticides revealed correlation among several insecticides, suggesting a possible cross resistance mechanism. Moreover, resistance remained stable across 3 years, suggesting field selection for general fitness had also taken place for various populations of Ae. albopictus. Conclusion Moderate to high level of resistance to agrochemicals in Pakistani field populations of Ae. albopictus is reported here first time. The geographic extent of resistance is unknown but, if widespread, may lead to problems in future vector control. PMID:21781290

  5. First report of field evolved resistance to agrochemicals in dengue mosquito, Aedes albopictus (Diptera: Culicidae, from Pakistan

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    Shehzad Khurram

    2011-07-01

    Full Text Available Abstract Background Agrochemicals have been widely used in Pakistan for several years. This exposes mosquito populations, particularly those present around agricultural settings, to an intense selection pressure for insecticide resistance. The aim of the present study was to investigate the toxicity of representative agrochemicals against various populations of Aedes albopictus (Skuse collected from three different regions from 2008-2010. Results For organophosphates and pyrethroids, the resistance ratios compared with susceptible Lab-PK were in the range of 157-266 fold for chlorpyrifos, 24-52 fold for profenofos, 41-71 fold for triazofos, and 15-26 fold for cypermethrin, 15-53 fold for deltamethrin and 21-58 fold for lambdacyhalothrin. The resistance ratios for carbamates and new insecticides were in the range of 13-22 fold for methomyl, 24-30 fold for thiodicarb, and 41-101 fold for indoxacarb, 14-27 fold for emamectin benzoate and 23-50 fold for spinosad. Pair wise comparisons of the log LC50s of insecticides revealed correlation among several insecticides, suggesting a possible cross resistance mechanism. Moreover, resistance remained stable across 3 years, suggesting field selection for general fitness had also taken place for various populations of Ae. albopictus. Conclusion Moderate to high level of resistance to agrochemicals in Pakistani field populations of Ae. albopictus is reported here first time. The geographic extent of resistance is unknown but, if widespread, may lead to problems in future vector control.

  6. Wolbachia density and cytoplasmic incompatibility in Aedes albopictus: concerns with using artificial Wolbachia infection as a vector suppression tool.

    Science.gov (United States)

    Calvitti, Maurizio; Marini, Francesca; Desiderio, Angiola; Puggioli, Arianna; Moretti, Riccardo

    2015-01-01

    The mosquito Aedes albopictusi is a competent vector of harmful human pathogens, including viruses causing dengue and chikungunya. Cytoplasmic incompatibility (CI) induced by endosymbiotic Wolbachia can be used to produce functionally sterile males that can be released in the field as a suppression tool against this mosquito. Because the available sexing methods are not efficient enough to avoid unintentional release of a few transinfected females, we assessed the CI pattern in crosses between wPip Wolbachia-transinfected (ARwP) females and wild-type males of Ae. albopictus in this study. Quantitative polymerase chain reaction was used to monitor the titer of the Wolbachia strains that naturally infect Ae. albopictus, that is, wAlbA and wAlbB, in age-controlled males and females. Data were coupled with incompatibility level detected when the above-mentioned males were crossed with ARwP females. Wolbachia infection titer was also monitored in samples of wild caught males. Incompatibility level was positively correlated only with wAlbA density. Crosses between wild-type males having very low wAlbA density (Wolbachia as a tool to control Ae. albopictus.

  7. Potential Risk of Dengue and Chikungunya Outbreaks in Northern Italy Based on a Population Model of Aedes albopictus (Diptera: Culicidae.

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    Giorgio Guzzetta

    2016-06-01

    Full Text Available The rapid invasion and spread of Aedes albopictus (Skuse, 1894 within new continents and climatic ranges has created favorable conditions for the emergence of tropical arboviral diseases in the invaded areas. We used mosquito abundance data from 2014 collected across ten sites in northern Italy to calibrate a population model for Aedes albopictus and estimate the potential of imported human cases of chikungunya or dengue to generate the condition for their autochthonous transmission in the absence of control interventions. The model captured intra-year seasonality and heterogeneity across sites in mosquito abundance, based on local temperature patterns and the estimated site-specific mosquito habitat suitability. A robust negative correlation was found between the latter and local late spring precipitations, indicating a possible washout effect on larval breeding sites. The model predicts a significant risk of chikungunya outbreaks in most sites if a case is imported between the beginning of summer and up to mid-November, with an average outbreak probability between 4.9% and 25%, depending on the site. A lower risk is predicted for dengue, with an average probability between 4.2% and 10.8% for cases imported between mid-July and mid-September. This study shows the importance of an integrated entomological and medical surveillance for the evaluation of arboviral disease risk, which is a precondition for designing cost-effective vector control programs.

  8. Dengue virus detection by using reverse transcription-polymerase chain reaction in saliva and progeny of experimentally infected Aedes albopictus from Brazil

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    Márcia Gonçalves de Castro

    2004-12-01

    Full Text Available Oral susceptibility and vertical transmission of dengue virus type 2 (DENV-2 in an Aedes albopictus sample from Rio de Janeiro was estimated. The infection (36.7% and transmission (83.3% rates for Ae. albopictus were higher than those of an Ae. aegypti colony used as control, 32.8 and 60%, respectively. Fourth instar larvae and females descendants of 48.5 and 39.1% of experimentally infected Ae. albopictus showed to harbor the virus. The oral susceptibility and the high capacity to assure vertical transmission exhibited by Ae. albopictus from Brazil reinforce that this species may play a role in the maintenance of the virus in nature and be a threat for dengue control in the country.

  9. Tracing the tiger: population genetics provides valuable insights into the Aedes (Stegomyia albopictus invasion of the Australasian Region.

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    Nigel W Beebe

    Full Text Available BACKGROUND: The range of the Asian tiger mosquito Aedes albopictus is expanding globally, raising the threat of emerging and re-emerging arbovirus transmission risks including dengue and chikungunya. Its detection in Papua New Guinea's (PNG southern Fly River coastal region in 1988 and 1992 placed it 150 km from mainland Australia. However, it was not until 12 years later that it appeared on the Torres Strait Islands. We hypothesized that the extant PNG population expanded into the Torres Straits as an indirect effect of drought-proofing the southern Fly River coastal villages in response to El Nino-driven climate variability in the region (via the rollout of rainwater tanks and water storage containers. METHODOLOGY/PRINCIPAL FINDINGS: Examination of the mosquito's mitochondrial DNA cytochrome oxidase I (COI sequences and 13 novel nuclear microsatellites revealed evidence of substantial intermixing between PNG's southern Fly region and Torres Strait Island populations essentially compromising any island eradication attempts due to potential of reintroduction. However, two genetically distinct populations were identified in this region comprising the historically extant PNG populations and the exotic introduced population. Both COI sequence data and microsatellites showed the introduced population to have genetic affinities to populations from Timor Leste and Jakarta in the Indonesian region. CONCLUSIONS/SIGNIFICANCE: The Ae. albopictus invasion into the Australian region was not a range expansion out of PNG as suspected, but founded by other, genetically distinct population(s, with strong genetic affinities to populations sampled from the Indonesian region. We now suspect that the introduction of Ae. albopictus into the Australian region was driven by widespread illegal fishing activity originating from the Indonesian region during this period. Human sea traffic is apparently shuttling this mosquito between islands in the Torres Strait and the

  10. Global transcriptional dynamics of diapause induction in non-blood-fed and blood-fed Aedes albopictus.

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    Xin Huang

    2015-04-01

    Full Text Available Aedes albopictus is a vector of increasing public health concern due to its rapid global range expansion and ability to transmit Dengue virus, Chikungunya virus and a wide range of additional arboviruses. Traditional vector control strategies have been largely ineffective against Ae. albopictus and novel approaches are urgently needed. Photoperiodic diapause is a crucial ecological adaptation in a wide range of temperate insects. Therefore, targeting the molecular regulation of photoperiodic diapause or diapause-associated physiological processes could provide the basis of novel approaches to vector control.We investigated the global transcriptional profiles of diapause induction in Ae. albopictus by performing paired-end RNA-Seq of biologically replicated libraries. We sequenced RNA from whole bodies of adult females reared under diapause-inducing and non-diapause-inducing photoperiods either with or without a blood meal. We constructed a comprehensive transcriptome assembly that incorporated previous assemblies and represents over 14,000 annotated dipteran gene models. Mapping of sequence reads to the transcriptome identified differential expression of 2,251 genes in response to diapause-inducing short-day photoperiods. In non-blood-fed females, potential regulatory elements of diapause induction were transcriptionally up-regulated, including two of the canonical circadian clock genes, timeless and cryptochrome 1. In blood-fed females, genes in metabolic pathways related to energy production and offspring provisioning were differentially expressed under diapause-inducing conditions, including the oxidative phosphorylation pathway and lipid metabolism genes.This study is the first to utilize powerful RNA-Seq technologies to elucidate the transcriptional basis of diapause induction in any insect. We identified candidate genes and pathways regulating diapause induction, including a conserved set of genes that are differentially expressed as part

  11. Behavioral and electrophysiological responses of Aedes albopictus to certain acids and alcohols present in human skin emanations.

    Science.gov (United States)

    Guha, Lopamudra; Seenivasagan, T; Iqbal, S Thanvir; Agrawal, O P; Parashar, B D

    2014-10-01

    Human skin emanations attract hungry female mosquitoes toward their host for blood feeding. In this study, we report the flight orientation and electroantennogram response of Aedes albopictus females to certain unsaturated acids and alcohols found in human skin. In the Y-tube olfactometer, odors of lactic acid and 2-methyl-3-pentanol attracted 54-65% of Ae. albopictus females at all doses in a dose-dependent manner. However, at the highest dose (10(-2) g), the acids repelled 40-45% females. Attractancy (ca. 62-68%) at lower doses and repellency (ca. 30-45%) at higher doses were recorded for 3-methyl-3-pentanol and 1-octen-3-ol, while 5-hexen-1-ol, cis-2-hexen-1-ol, and trans 2-hexen-1-ol odor repelled ca. 55-65% of Ae. albopictus females at all doses. Antenna of female Ae. albopictus exhibited a dose-dependent EAG response up to 10(-3) g of L-lactic acid, trans-2-methyl-2-pentenoic acid, 2-octenoic acid, trans-2-hexen-1-ol and 1-octen-3-ol stimulations; however, the highest dose (10(-2) g) caused a little decline in the EAG response. EAG response of 9-10-fold was elicited by lactic acid, 2-octenoic acid, trans-2-hexenoic acid, and 3-methyl-3-pentanol, while cis-2-hexen-1-ol and trans-2-methyl pentenoic acid elicited 1-5-fold responses compared to solvent control. A blend of attractive compounds could be utilized in odor-baited trap for surveillance and repellent molecules with suitable formulation could be used to reduce the biting menace of mosquitoes.

  12. Field observation on the efficacy of Toxorhynchites splendens (Wiedemann) as a biocontrol agent against Aedes albopictus (Skuse) larvae in a cemetery.

    Science.gov (United States)

    Nyamah, M A; Sulaiman, S; Omar, B

    2011-08-01

    This study explored the efficacy of Toxorhynchites splendens, predator of Aedes albopictus as a biocontrol agent. There was a negative correlation between Ae. albopictus larval population and Tx. splendens larval population in ovitraps (r=-0.287, R²=0.0821). The correlation is higher between the mean number of Ae. albopictus larvae per ovitrap and the number of Tx. splendens larvae in an ovitrap (r=-0.987, R²=0.9737). Larvae of Tx. splendens were observed to co-exist with larvae of Ae. albopictus and Culex fuscocephala in the ovitraps placed in the study area. The existence of Tx. splendens larvae in the study area coincides with their habit, preferring to breed in bamboo stumps. A total of 480 ovitraps were inspected for 30-week study period and 281 ovitraps were positive with Ae. albopictus larvae respectively. There was a significant difference between numbers of ovitrap positive for Ae. albopictus larvae with number of Tx. splendens larvae in the ovitraps (ANOVA, F((4,475)) 2.655, povitraps positive with Ae. albopictus larvae, 255 ovitraps contained only one Tx. splendens larva each. Only one ovitrap contained four, the most number of Tx. splendens larvae (p< 0.05). Thus, Tx. splendens could be utilised as an alternative for dengue vector control programme.

  13. Ovitrampas para Avaliação da Presença de Aedes aegypti (Linnaeus e Aedes albopictus (Skuse no Município de Vassouras, Estado do Rio de Janeiro

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    Alexandre Oliveira

    2014-04-01

    Abstract. Aedes aegypti (Linnaeus and Aedes albopictus (Skuse are vectors of many arboviruses including urban yellow fever and dengue, the latter being one of the biggest problems in the world in cities that have hot and humid climate. Having the consecutive cases of dengue in Vassouras, RJ it was important to ascertain the presence and behavior of the vector in different seasons of year and their predominance in the city. In this study we observed the presence of 10.44% Ae. aegypti and 89.56% Ae. albopictus of the 364 viable eggs and being the Matadouro neighborhood (point 4, the local with the largest presence of these culicids. These data showed that Ae. albopictus is ever more present in urban areas.

  14. First isolation of Aedes flavivirus in the Western Hemisphere and evidence of vertical transmission in the mosquito Aedes (Stegomyia) albopictus (Diptera: Culicidae)

    Energy Technology Data Exchange (ETDEWEB)

    Haddow, Andrew D., E-mail: adhaddow@gmail.com [Institute for Human Infections and Immunity, Center for Emerging Infectious Diseases and Biodefense, Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-0609 (United States); Guzman, Hilda; Popov, Vsevolod L. [Institute for Human Infections and Immunity, Center for Emerging Infectious Diseases and Biodefense, Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-0609 (United States); Wood, Thomas G.; Widen, Steven G. [Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-0609 (United States); Haddow, Alastair D. [Mercy Clinic, 2115 S. Fremont, Springfield, MO 65804 (United States); Tesh, Robert B.; Weaver, Scott C. [Institute for Human Infections and Immunity, Center for Emerging Infectious Diseases and Biodefense, Department of Pathology, University of Texas Medical Branch, Galveston, TX 77555-0609 (United States)

    2013-06-05

    We report here the first evidence of vertical transmission of Aedes flavivirus (AEFV) and its first isolation in the Western Hemisphere. AEFV strain SPFLD-MO-2011-MP6 was isolated in C6/36 cells from a pool of male Aedes albopictus mosquitoes that were reared to adults from larvae collected in southwest Missouri, USA, in 2011. Electron micrographs of the virus showed virions of approximately 45 nm in diameter with morphological characteristics associated with flaviviruses. The genomic sequence demonstrated that AEFV-SPFLD-MO-2011-MP6 shares a high degree of nucleotide and amino acid sequence identity with the AEFV Narita-21 strain, isolated in Japan in 2003. Intracerebral inoculation of newborn mice with the virus failed to produce observable illness or death and the virus did not replicate in vertebrate cells, consistent with a lack of vertebrate host range. - Highlights: ► The first report of Aedes flavivirus (AEFV) in the Western Hemisphere. ► The first evidence of vertical transmission of AEFV in mosquitoes. ► The first electron micrograph of AEFV. ► The first attempt to infect animals with AEFV.

  15. Expression of heat shock proteins (HSPs) in Aedes aegypti (L) and Aedes albopictus (Skuse) (Diptera: Culicidae) larvae in response to thermal stress.

    Science.gov (United States)

    Sivan, Arun; Shriram, Ananganallur Nagarajan; Muruganandam, Nagarajan; Thamizhmani, Ramanathan

    2017-03-01

    Climatic changes are responsible, to a certain extent for the occurrence and spread of arboviral pathogens world over. Temperature is one of the important abiotic factors influencing the physiological processes of mosquitoes. Several genes of heat shock protein (HSP) families are known to be expressed in mosquitoes, which aid in overcoming stress induced by elevated temperature. In order to understand expression of HSP family genes in the Andaman population of Aedes aegypti and Aedes albopictus, we used quantitative real-time polymerase chain reaction (qPCR) to examine expression levels of HSPs in response to thermal stress under laboratory and in actual field conditions. HSP genes AeaHsp26, AeaHsp83 and AeaHsc70 were examined by comparing relative transcript expression levels at 31°C, 33°C, 34°C, 37°C and 39°C respectively. Enhanced up-regulation of HSPs was evident in third instar larvae of Ae. aegypti with rise in water temperatures (31°C, 33°C, 34°C) in the containers in the nature and thermally stressed (37°C and 39°C) in laboratory conditions. In Ae. albopictus up-regulation of HSPs was observed in field conditions at 34°C only and when thermally treated at 37°C, while down regulation was evident in larvae subjected to thermal stress in laboratory at 39°C. Data on expression levels revealed that larvae of Ae. aegypti was tolerant to thermal stress, while Ae. albopictus larvae was sensitive to heat shock treatment. Statistical analysis indicated that AeaHsp83 genes were significantly up-regulated in Ae. aegypti larvae after 360min exposure to high temperature (39°C). The difference in expression levels of AeaHsp26, AeaHsc70 and AeaHsp83 genes in Ae. albopictus larvae was statistically significant between different exposure temperatures. All of these genes were significantly up-regulated at 37°C. These results indicate that AeaHsp26, AeaHsc70 and AeaHsp83 are important markers of stress and perhaps function as proteins conferring protection and

  16. Sugar administration to newly emerged Aedes albopictus males increases their survival probability and mating performance.

    Science.gov (United States)

    Bellini, Romeo; Puggioli, Arianna; Balestrino, Fabrizio; Brunelli, Paolo; Medici, Anna; Urbanelli, Sandra; Carrieri, Marco

    2014-04-01

    Aedes albopictus male survival in laboratory cages is no more than 4-5 days when kept without any access to sugar indicating their need to feed on a sugar source soon after emergence. We therefore developed a device to administer energetic substances to newly emerged males when released as pupae as part of a sterile insect technique (SIT) programme, made with a polyurethane sponge 4 cm thick and perforated with holes 2 cm in diameter. The sponge was imbibed with the required sugar solution and due to its high retention capacity the sugar solution was available for males to feed for at least 48 h. When evaluated in lab cages, comparing adults emerged from the device with sugar solution vs the device with water only (as negative control), about half of the males tested positive for fructose using the Van Handel anthrone test, compared to none of males in the control cage. We then tested the tool in semi-field and in field conditions with different sugar concentrations (10%, 15%, and 20%) and compared results to the controls fed with water only. Males were recaptured by a battery operated manual aspirator at 24 and 48 h after pupae release. Rather high share 10-25% of captured males tested positive for fructose in recollections in the vicinity of the control stations, while in the vicinity of the sugar stations around 40-55% of males were positive, though variability between replicates was large. The sugar positive males in the control test may have been released males that had access to natural sugar sources found close to the release station and/or wild males present in the environment. Only a slight increase in the proportion of positive males was obtained by increasing the sugar concentration in the feeding device from 10% to 20%. Surprisingly, modification of the device to add a black plastic inverted funnel above the container reduced rather than increased the proportion of fructose positive males collected around the station. No evidence of difference in the

  17. A de novo transcriptome of the Asian tiger mosquito, Aedes albopictus, to identify candidate transcripts for diapause preparation

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    Poelchau Monica F

    2011-12-01

    Full Text Available Abstract Background Many temperate insects survive the harsh conditions of winter by undergoing photoperiodic diapause, a pre-programmed developmental arrest initiated by short day lengths. Despite the well-established ecological significance of photoperiodic diapause, the molecular basis of this crucial adaptation remains largely unresolved. The Asian tiger mosquito, Aedes albopictus (Skuse, represents an outstanding emerging model to investigate the molecular basis of photoperiodic diapause in a well-defined ecological and evolutionary context. Ae. albopictus is a medically significant vector and is currently considered the most invasive mosquito in the world. Traits related to diapause appear to be important factors contributing to the rapid spread of this mosquito. To generate novel sequence information for this species, as well as to discover transcripts involved in diapause preparation, we sequenced the transcriptome of Ae. albopictus oocytes destined to become diapausing or non-diapausing pharate larvae. Results 454 GS-FLX transcriptome sequencing yielded >1.1 million quality-filtered reads, which we assembled into 69,474 contigs (N50 = 1,009 bp. Our contig filtering approach, where we took advantage of strong sequence similarity to the fully sequenced genome of Aedes aegypti, as well as other reference organisms, resulted in 11,561 high-quality, conservative ESTs. Differential expression estimates based on normalized read counts revealed 57 genes with higher expression, and 257 with lower expression under diapause-inducing conditions. Analysis of expression by qPCR for 47 of these genes indicated a high correlation of expression levels between 454 sequence data and qPCR, but congruence of statistically significant differential expression was low. Seven genes identified as differentially expressed based on qPCR have putative functions that are consistent with the insect diapause syndrome; three genes have unknown function and represent

  18. Toxicity and sub-lethal effect of endemic plants from family Anacardiaceae on oviposition behavior of Aedes albopictus

    Institute of Scientific and Technical Information of China (English)

    Wan; Fatma; Zuharah; Chan; Jia; Ling; Nurfazlina; Zulkifly; Nik; Fadzly

    2015-01-01

    Objective: To evaluate the lethal concentration, oviposition deterrence and ovicidal activity of acetone extracts of Melanochyla fasciculiflora(M. fasciculiflora) leaf and Gluta renghas(G. renghas) leaf against Aedes albopictus(Ae. albopictus). Methods: To determine the lethal concentration of Anacardiaceae, ten test concentrations of the extracts ranging from 200 to 650 mg/L were selected for larvicidal bioassays and 25 early fourth instar larvae were exposed to the extracts for 24 h. The sub-lethal concentrations used for oviposition deterrence was the value of LC25, LC50 and LC75 from above study which is 235 mg/L, 470 mg/L and 705 mg/L for M. fasciculiflora extract and 187.5 mg/L, 375 mg/L and 562.5 mg/L for G. renghas extract, respectively. Twenty gravid Ae. albopictus were allowed to oviposit in different treated concentrations. For oviciding procedure, a total of 300 eggs of Ae. albopictus were soaked in solution with each treated concentration as mentioned above for 24 h. After 24 h, eggs were sieved and soaked in seasoned water, and hatching rates were calculated. For comparison, only seasoned water was used in control experiment.Results: G. renghas demonstrated lower LC50 value of 372.80 mg/L compared to M. fasciculiflora(467.90 mg/L). The activity index of negative oviposition revealed the deterrent effect and thus, caused a remarkable negative response resulting in oviposition of fewer eggs compared with control(without plant extract). The acetone extract of M. fasciculiflora was more effective than G. renghas extract in displaying oviposition deterrence potential since the latter did not possess the deterring effect within the concentration range tested. However, both plant extracts exhibited excellent oviciding effect as 92.33% of eggs failed to be hatched when treated with 705.0 mg/L of M. fasciculiflora and 86.67% with 562.5 mg/L of G. renghas. The oviposition deterrence and percentage of egg mortality were directly proportional to the

  19. Estudo de áreas e depósitos preferenciais de Aedes albopictus (Skuse, 1894 e Aedes aegypti (Linnaeus, 1762 no Município de Paracambi – Rio de Janeiro, Brasil

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    Vanessa Aparecida Ribeiro Canela Soares

    2008-12-01

    Full Text Available Resumo. A presença de Aedes albopictus e Aedes aegypti em área urbana representa um risco potencial do inter-relacionamento dessa espécie de mosquito com a população. Este estudo teve como objetivo avaliar a presença do Ae. albopictus (S. e de Ae. aegypti (L. no município de Paracambi, Estado do Rio de Janeiro, Brasil. As amostras foram obtidas através de coletas das formas imaturas em depósitos e/ou criadouros (caixas d’água, cisternas, tanques, ocos de árvores, lixo, pneus, etc em três áreas do município (urbana, rural e área de transição no período de 12 meses. Os resultados mostraram que Ae. albopictus distribuiu-se igualmente nas áreas urbanas e rurais. A área urbana e a área de transição apresentaram uma maior positividade para Ae. aegypti. Os produtos de descartes, caracterizados por depósito de letra I = outros (artificiais especiais, foram os preferenciais para ambas as espécies de mosquito. Study of the preferred areas and deposits of Aedes albopictus (Skuse, 1894 and Aedes aegypti (Linnaeus, 1762 in the Paracambi city, Rio de Janeiro, Brazil. Abstract. The presence of Aedes albopictus (S. and Aedes aegypti (L. in urban areas represents a potential risk of inter-relationship of this species of mosquito with the population. This study aimed to evaluate the presence of Ae. albopictus and Ae. aegypti in the Paracambi city, Rio de Janeiro State, Brazil. Samples were obtained from collections of immature forms in deposits (water tanks, cisterns, tanks, hollow trees, trash, tires, etc. in three areas of the city (urban, rural and the transition area in the last 12 months. The results showed that Ae. albopictus is also distributed in urban and rural areas. The urban area and the area of transition had a higher positive for Ae. aegypti. They refused material that is the distinguished mark of letter I = other (artificial special deposit has been preferred for both species of mosquito.

  20. Studies on insecticide susceptibility of Aedes aegypti (Linn) and Aedes albopictus (Skuse) vectors of dengue and chikungunya in Andaman and Nicobar Islands, India.

    Science.gov (United States)

    Sivan, Arun; Shriram, A N; Sunish, I P; Vidhya, P T

    2015-12-01

    Dengue and chikungunya are important arboviral infections in the Andaman Islands. Competent vectors viz. Aedes aegypti and Aedes albopictus are widely prevalent. The most effective proven method for interrupting the transmission of these arboviruses is vector control, mediated through insecticides. Currently, DDT and temephos are the insecticides used for vector control in these islands. Lack of information on susceptibility necessitated assessing the susceptibility profile of A. aegypti and A. albopictus. F1 generation of adult and larvae were assayed, and LT50 and LT90 values were interpreted following the World Health Organization (WHO) protocol. Adults were found resistant to DDT-4 % while susceptible to dieldrin-0.4 %. Against organophosphates, both showed resistance to fenitrothion but susceptible to malathion-5 %. Both species showed resistance to carbamate and bendiocarb-0.1 % while susceptible to propoxur-0.1 %. Of the four synthetic pyrethroids, both were susceptible to deltamethrin-0.05 %, while resistant to permethrin-0.75 %, lambdacyhalothrin-0.05 % and cyfluthrin-0.15 %. Larvae of both species showed resistance to temephos at 0.02 mg/L but susceptible to malathion at 1 mg/L and fenthion at 0.05 mg/L. Currently, there is no prescribed WHO dose for adult-insecticide susceptibility testing. The emergence of resistance to DDT and temephos in the vector population poses a challenge to the on-going vector control measures. The results highlight the need for monitoring resistance to insecticides in the vector population. Impetus for source reduction and alternative choices of control measures are discussed for tackling future threat of arboviral infections in these islands.

  1. Freqüência e distribuição espacial de Aedes aegypti e Aedes albopictus (Diptera, Culicidae no Rio de Janeiro, Brasil

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    Tamara Nunes de Lima-Camara

    Full Text Available No presente estudo, procuramos avaliar a freqüência de Aedes aegypti e Ae. albopictus dentro e fora das casas de bairros urbanos, suburbanos e rurais nos municípios de Nova Iguaçu e Rio de Janeiro, Brasil, no período de agosto de 2002 a julho de 2004. A maioria das fêmeas e dos machos de Ae. aegyptifoi capturada em ambientes urbanos (56% e no intradomicílio (78%, o que demonstra maior freqüência dessa espécie em se abrigar no interior de casas e em áreas de maior concentração populacional humana, caráter que aumentam as chances de seu contato com humanos. Já fêmeas e machos de Ae. albopictus foram mais presentes em áreas rurais (93% e no peridomicílio (90%, demonstrando maior freqüência em se abrigar em áreas com elevada cobertura vegetal e população humana mais rarefeita, atitude que diminui as suas chances de contato com humanos e, por conseguinte, de veiculação do vírus dengue nessa área.

  2. Mapping past, present, and future climatic suitability for invasive Aedes aegypti and Aedes albopictus in the United States: a process-based modeling approach using CMIP5 downscaled climate scenarios

    Science.gov (United States)

    Donnelly, M. A. P.; Marcantonio, M.; Melton, F. S.; Barker, C. M.

    2016-12-01

    The ongoing spread of the mosquitoes, Aedes aegypti and Aedes albopictus, in the continental United States leaves new areas at risk for local transmission of dengue, chikungunya, and Zika viruses. All three viruses have caused major disease outbreaks in the Americas with infected travelers returning regularly to the U.S. The expanding range of these mosquitoes raises questions about whether recent spread has been enabled by climate change or other anthropogenic influences. In this analysis, we used downscaled climate scenarios from the NASA Earth Exchange Global Daily Downscaled Projections (NEX GDDP) dataset to model Ae. aegypti and Ae. albopictus population growth rates across the United States. We used a stage-structured matrix population model to understand past and present climatic suitability for these vectors, and to project future suitability under CMIP5 climate change scenarios. Our results indicate that much of the southern U.S. is suitable for both Ae. aegypti and Ae. albopictus year-round. In addition, a large proportion of the U.S. is seasonally suitable for mosquito population growth, creating the potential for periodic incursions into new areas. Changes in climatic suitability in recent decades for Ae. aegypti and Ae. albopictus have occurred already in many regions of the U.S., and model projections of future climate suggest that climate change will continue to reshape the range of Ae. aegypti and Ae. albopictus in the U.S., and potentially the risk of the viruses they transmit.

  3. Study of the distribution and abundance of the eggs of Aedes aegypti and Aedes albopictus according to the habitat and meteorological variables, municipality of São Sebastião, São Paulo State, Brazil

    Science.gov (United States)

    2013-01-01

    Background This study focused on the distribution and abundance of the eggs of Aedes aegypti and Aedes albopictus. Methods Eighty ovitraps were exposed for four days of each month in peri- and intradomiciliary environments of 40 urban residences on 20 street blocks that were drawn monthly in Sebastião, SP, between February 2011 and February 2012. The monthly distribution of positive ovitrap indices (POI) and mean egg counts per trap (MET) of Ae. aegypti and Ae. albopictus were analyzed using the Kruskal-Wallis test, followed by the Dwass-Steel-Critchlow-Fligner (DSCF) test. Spearman's rank correlation coefficient and simple linear regression were used to determine the association between the meteorological variables of temperature and rainfall and the number of ovitraps with eggs and the egg count. Results The POI and MET of Ae. aegypti were higher in peridomiciliary premises. A positive correlation was found between the temperature and the number of ovitraps with eggs and the egg count of this species in domestic environments. There was no difference in the POI and MET of Ae. albopictus between the environments. A positive correlation was found between temperature and positive ovitraps of Ae. albopictus in peridomiciliary premises. The POI and MET of Ae. aegypti were higher than those of Ae. albopictus. Conclusions Peridomiciliary premises were the preferred environments for oviposition of Ae. aegypti. The use of ovitraps for surveillance and vector control is reiterated. PMID:24499530

  4. Mapping Past, Present, and Future Climatic Suitability for Invasive Aedes Aegypti and Aedes Albopictus in the United States: A Process-Based Modeling Approach Using CMIP5 Downscaled Climate Scenarios

    Science.gov (United States)

    Donnelly, Marisa Anne Pella; Marcantonio, Matteo; Melton, Forrest S.; Barker, Christopher M.

    2016-01-01

    The ongoing spread of the mosquitoes, Aedes aegypti and Aedes albopictus, in the continental United States leaves new areas at risk for local transmission of dengue, chikungunya, and Zika viruses. All three viruses have caused major disease outbreaks in the Americas with infected travelers returning regularly to the U.S. The expanding range of these mosquitoes raises questions about whether recent spread has been enabled by climate change or other anthropogenic influences. In this analysis, we used downscaled climate scenarios from the NASA Earth Exchange Global Daily Downscaled Projections (NEX GDDP) dataset to model Ae. aegypti and Ae. albopictus population growth rates across the United States. We used a stage-structured matrix population model to understand past and present climatic suitability for these vectors, and to project future suitability under CMIP5 climate change scenarios. Our results indicate that much of the southern U.S. is suitable for both Ae. aegypti and Ae. albopictus year-round. In addition, a large proportion of the U.S. is seasonally suitable for mosquito population growth, creating the potential for periodic incursions into new areas. Changes in climatic suitability in recent decades for Ae. aegypti and Ae. albopictus have occurred already in many regions of the U.S., and model projections of future climate suggest that climate change will continue to reshape the range of Ae. aegypti and Ae. albopictus in the U.S., and potentially the risk of the viruses they transmit.

  5. Targeting a Hidden Enemy: Pyriproxyfen Autodissemination Strategy for the Control of the Container Mosquito Aedes albopictus in Cryptic Habitats.

    Directory of Open Access Journals (Sweden)

    Kshitij Chandel

    2016-12-01

    Full Text Available The Asian tiger mosquito, Aedes albopictus, is a vector of dengue, Chikungunya, and Zika viruses. This mosquito inhabits a wide range of artificial water-holding containers in urban and suburban areas making it difficult to control. We tested the hypothesis that female-driven autodissemination of an insect growth regulator could penetrate cryptic oviposition habitats difficult to treat with conventional insecticidal sprays.Oviposition preferences of Ae. albopictus females for open and cryptic cups were tested in semi-field experiments. Two conventional larvicidal sprayers were tested to determine droplet penetration and larvicidal efficacy in open and cryptic habitats using Bacillus thuringiensis var. israelensis (Bti in the field. Finally, the efficacy of pyriproxyfen autodissemination stations was assessed in cryptic and open cups in residential areas during 2013 and 2014.Gravid females strongly preferred cryptic (53.1±12.9 eggs/cup over open (10.3±4.3 eggs/cup cups for oviposition. Cryptic cups showed limited droplet penetration and produced 0.1-0.3% larval mortality with a conventional backpack and low-volume sprays of Bti. The autodissemination stations effectively contaminated these cryptic cups (59.3-84.6% and produced 29.7-40.8% pupal mortality during 2013-2014. Significant pupal mortality was also observed in open cups.The autodissemination station effectively exploits the oviposition behavior of wild gravid females to deliver pyriproxyfen to targeted oviposition habitats. Although the pupal mortality in cryptic cups was relatively lower than expected for the effective vector control. Autodissemination approach may be a suitable supporting tool to manage Ae. albopictus immatures in the cryptic habitats those are less accessible to conventional larvicidal sprays.

  6. Targeting a Hidden Enemy: Pyriproxyfen Autodissemination Strategy for the Control of the Container Mosquito Aedes albopictus in Cryptic Habitats

    Science.gov (United States)

    Suman, Devi Shankar; Wang, Yi; Unlu, Isik; Williges, Eric; Williams, Gregory M.; Gaugler, Randy

    2016-01-01

    Background The Asian tiger mosquito, Aedes albopictus, is a vector of dengue, Chikungunya, and Zika viruses. This mosquito inhabits a wide range of artificial water-holding containers in urban and suburban areas making it difficult to control. We tested the hypothesis that female-driven autodissemination of an insect growth regulator could penetrate cryptic oviposition habitats difficult to treat with conventional insecticidal sprays. Methodology Oviposition preferences of Ae. albopictus females for open and cryptic cups were tested in semi-field experiments. Two conventional larvicidal sprayers were tested to determine droplet penetration and larvicidal efficacy in open and cryptic habitats using Bacillus thuringiensis var. israelensis (Bti) in the field. Finally, the efficacy of pyriproxyfen autodissemination stations was assessed in cryptic and open cups in residential areas during 2013 and 2014. Principal Findings Gravid females strongly preferred cryptic (53.1±12.9 eggs/cup) over open (10.3±4.3 eggs/cup) cups for oviposition. Cryptic cups showed limited droplet penetration and produced 0.1–0.3% larval mortality with a conventional backpack and low-volume sprays of Bti. The autodissemination stations effectively contaminated these cryptic cups (59.3–84.6%) and produced 29.7–40.8% pupal mortality during 2013–2014. Significant pupal mortality was also observed in open cups. Conclusions The autodissemination station effectively exploits the oviposition behavior of wild gravid females to deliver pyriproxyfen to targeted oviposition habitats. Although the pupal mortality in cryptic cups was relatively lower than expected for the effective vector control. Autodissemination approach may be a suitable supporting tool to manage Ae. albopictus immatures in the cryptic habitats those are less accessible to conventional larvicidal sprays. PMID:28033379

  7. Storm drains as larval development and adult resting sites for Aedes aegypti and Aedes albopictus in Salvador, Brazil

    OpenAIRE

    Paploski, Igor Adolfo Dexheimer; Moreno S Rodrigues; Mugabe, Vánio André; Kikuti,Mariana; Tavares, Aline S.; Reis, Mitermayer Galvão; Kitron, Uriel; Ribeiro, Guilherme Sousa

    2016-01-01

    Background Dengue (DENV), Chikungunya (CHIKV), Zika (ZIKV), as well as yellow fever (YFV) viruses are transmitted to humans by Aedes spp. females. In Salvador, the largest urban center in north-eastern Brazil, the four DENV types have been circulating, and more recently, CHIKV and ZIKV have also become common. We studied the role of storm drains as Aedes larval development and adult resting sites in four neighbourhoods of Salvador, representing different socioeconomic, infrastructure and topo...

  8. Insecticidal activity and expression of cytochrome P450 family 4 genes in Aedes albopictus after exposure to pyrethroid mosquito coils.

    Science.gov (United States)

    Avicor, Silas W; Wajidi, Mustafa F F; El-Garj, Fatma M A; Jaal, Zairi; Yahaya, Zary S

    2014-10-01

    Mosquito coils are insecticides commonly used for protection against mosquitoes due to their toxic effects on mosquito populations. These effects on mosquitoes could induce the expression of metabolic enzymes in exposed populations as a counteractive measure. Cytochrome P450 family 4 (CYP4) are metabolic enzymes associated with a wide range of biological activities including insecticide resistance. In this study, the efficacies of three commercial mosquito coils with different pyrethroid active ingredients were assessed and their potential to induce the expression of CYP4 genes in Aedes albopictus analyzed by real-time quantitative PCR. Coils containing 0.3 % D-allethrin and 0.005 % metofluthrin exacted profound toxic effects on Ae. albopictus, inducing high mortalities (≥90 %) compared to the 0.2 % D-allethrin reference coil. CYP4H42 and CYP4H43 expressions were significantly higher in 0.3 % D-allethrin treated mosquitoes compared to the other treated populations. Short-term (KT50) exposure to mosquito coils induced significantly higher expression of both genes in 0.005 % metofluthrin exposed mosquitoes. These results suggest the evaluated products provided better protection than the reference coil; however, they also induced the expression of metabolic genes which could impact negatively on personal protection against mosquito.

  9. Genome sequence of the Asian Tiger mosquito, Aedes albopictus, reveals insights into its biology, genetics, and evolution.

    Science.gov (United States)

    Chen, Xiao-Guang; Jiang, Xuanting; Gu, Jinbao; Xu, Meng; Wu, Yang; Deng, Yuhua; Zhang, Chi; Bonizzoni, Mariangela; Dermauw, Wannes; Vontas, John; Armbruster, Peter; Huang, Xin; Yang, Yulan; Zhang, Hao; He, Weiming; Peng, Hongjuan; Liu, Yongfeng; Wu, Kun; Chen, Jiahua; Lirakis, Manolis; Topalis, Pantelis; Van Leeuwen, Thomas; Hall, Andrew Brantley; Jiang, Xiaofang; Thorpe, Chevon; Mueller, Rachel Lockridge; Sun, Cheng; Waterhouse, Robert Michael; Yan, Guiyun; Tu, Zhijian Jake; Fang, Xiaodong; James, Anthony A

    2015-11-03

    The Asian tiger mosquito, Aedes albopictus, is a highly successful invasive species that transmits a number of human viral diseases, including dengue and Chikungunya fevers. This species has a large genome with significant population-based size variation. The complete genome sequence was determined for the Foshan strain, an established laboratory colony derived from wild mosquitoes from southeastern China, a region within the historical range of the origin of the species. The genome comprises 1,967 Mb, the largest mosquito genome sequenced to date, and its size results principally from an abundance of repetitive DNA classes. In addition, expansions of the numbers of members in gene families involved in insecticide-resistance mechanisms, diapause, sex determination, immunity, and olfaction also contribute to the larger size. Portions of integrated flavivirus-like genomes support a shared evolutionary history of association of these viruses with their vector. The large genome repertory may contribute to the adaptability and success of Ae. albopictus as an invasive species.

  10. Strain-specific differences in mating, oviposition, and host-seeking behavior between Wolbachia-infected and uninfected Aedes albopictus.

    Science.gov (United States)

    Wiwatanaratanabutr, Itsanun; Allan, Sandra; Linthicum, Kenneth; Kittayapong, Pattamaporn

    2010-09-01

    Wolbachia are maternally inherited bacteria that cause various reproductive alterations in their arthropod hosts, including cytoplasmic incompatibility. In this study, we compared mating, oviposition, and host-seeking behavior of Wolbachia-infected (Houston [HOU], Gainesville [GNV]) and Houston uninfected (HT1) Aedes albopictus. In mating assays with virgin mosquitoes, mating success of Wolbachia-infected males was significantly higher than uninfected strains. Mating success was highest with HOU males exposed to infected (95%) and uninfected females (100%), and lowest with HT1 males exposed to infected (20%) and uninfected (25%) females. Results suggested that Wolbachia infection may influence the reproductive behavior of this mosquito. There were no clear differences in oviposition responses between strains, with all strains ovipositing significantly more often on hay infusion and larval rearing water than on water controls and least frequently on 4-methylphenol. Strains of Ae. albopictus females were host-seeking a human when given a choice. Responses to a human arm, acetone, CO2, and dichloromethane were generally higher from the Houston strains than from the GNV strain. Responses of HOU and HT1 females differed from GNV with greater responses to the arm and CO2.

  11. Effectiveness of a multiple intervention strategy for the control of the tiger mosquito (Aedes albopictus) in Spain.

    Science.gov (United States)

    Abramides, Gisela Chebabi; Roiz, David; Guitart, Raimon; Quintana, Salvador; Guerrero, Irene; Giménez, Nuria

    2011-05-01

    This study was undertaken to evaluate the effectiveness of four complementary and combined strategies to minimize the presence of the invasive mosquito Aedes albopictus, firmly established in Sant Cugat del Vallès, Catalonia, Spain. A quasi-experimental design including six neighbourhoods was performed in 2008-2009. The abundance of mosquitoes was monitored through ovitraps. The multiple intervention strategy consisted of four actions: source reduction; larvicide treatments (Bacillus thuringiensis israelensis and diflubenzuron); adulticide treatments (alfacipermetrin); and cleaning up uncontrolled landfills. The results showed the number of eggs significantly reduced in the areas with intervention. In 2008, the accumulate median of eggs was 175 and 272 in the intervention and control areas, respectively. In 2009, these medians were 884 and 1668 eggs. In total, 3104 households were visited and 683 people were interviewed. During inspections inside the houses, the cooperation of citizens in 2009 was 16% higher than that in 2008 (95% CI 13-19%). These findings suggest that the strategy was effective in reducing the number of eggs. Citizen cooperation, an essential factor for success, was observed through a high level of collaboration by the home owners, who allowed entry into their private dwellings. This study could be a model for controlling the populations of Ae. albopictus in the Mediterranean region.

  12. Spatial distribution and insecticide susceptibility status of Aedes aegypti and Aedes albopictus in dengue affected urban areas of Rawalpindi, Pakistan

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    Ali Arslan

    2016-01-01

    Interpretation & conclusion: The results suggested that all the field populations of Ae. aegypti and Ae. albopictus existed together and showed qualitative changes in their susceptibility status. Resistance against deltamethrin and lambdacyhalothrin was not confirmed and further investigation was recommended to confirm the change in their susceptibility status. This study could help public health authorities to apply simultaneous control activities on both species due to their coexistence and also resistance management strategies should be formulated to slow down the process of development of resistance.

  13. Chemical composition and larvicidal activity of essential oil from Ocimum basilicum (L.) against Culex tritaeniorhynchus, Aedes albopictus and Anopheles subpictus (Diptera: Culicidae).

    Science.gov (United States)

    Govindarajan, M; Sivakumar, R; Rajeswary, M; Yogalakshmi, K

    2013-05-01

    The toxicity of mosquito larvicidal activity of leaf essential oil and their major chemical constituents from Ocimum basilicum were evaluated against Culex tritaeniorhynchus, Aedes albopictus and Anopheles subpictus. The chemical composition of the leaf essential oil was analyzed using gas chromatography-mass spectroscopy. GC-MS revealed that the essential oil of O. basilicum contained 20 compounds. The major chemical components identified were linalool (52.42%), methyl eugenol (18.74%) and 1, 8-cineol (5.61%). The essential oil had a significant toxic effect against late third-stage larvae of Cx. tritaeniorhynchus, Ae. albopictus and An. subpictus with an LC(50) values of 14.01, 11.97 and 9.75 ppm and an LC(90) values of 23.44, 21.17 and 18.56 ppm, respectively. The results could be useful in search for newer, safer, and more effective natural larvicidal agents against Cx. tritaeniorhynchus, Ae. albopictus and An. subpictus.

  14. Isolation, identification, and phylogenetic analysis of a dengue virus strain from Aedes albopictus collected in Mawei town in Guizhou Province, China

    Institute of Scientific and Technical Information of China (English)

    左丽; 舒莉萍

    2004-01-01

    @@ Dengue virus (DEN), a single-stranded RNA virus of the family Flaviviridae, is transmitted from one infected person or animal to another by the mosquitos Aedes albopictus and Aedes aegypti. There are four serotypes of the dengue virus (serotypes 1-4). The virus is responsible for dengue fever (DF), dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). In the recent years, the incidence rate of DF/DHF has been increasing around the world, particularly in tropical and subtropical zones. Dengue is the most significant arthropod-borne viral disease affecting public health.1

  15. Aedes albopictus em área rural do Brasil e implicações na transmissão de febre amarela silvestre

    OpenAIRE

    Almério de Castro Gomes; Marisa Dantas Bitencourt; Délsio Natal; Pedro Luis Silva Pinto; Luis Filipe Mucci; Marcia Bicudo de Paula; Paulo Roberto Urbinatti; José Maria Soares Barata

    1999-01-01

    Durante estudos ecológicos sobre mosquitos anofelíneos no município de Bataguassu, Estado de Mato Grosso do Sul, foram encontradas larvas e adultos de Aedes albopictus. Pela primeira vez sua introdução ocorre numa área enzoótica do vírus selvático da febre amarela no Brasil. Isto sugere risco potencial para transferência desse vírus para área urbana infestada com Aedes aegypti.

  16. Aedes albopictus em área rural do Brasil e implicações na transmissão de febre amarela silvestre

    Directory of Open Access Journals (Sweden)

    Gomes Almério de Castro

    1999-01-01

    Full Text Available Durante estudos ecológicos sobre mosquitos anofelíneos no município de Bataguassu, Estado de Mato Grosso do Sul, foram encontradas larvas e adultos de Aedes albopictus. Pela primeira vez sua introdução ocorre numa área enzoótica do vírus selvático da febre amarela no Brasil. Isto sugere risco potencial para transferência desse vírus para área urbana infestada com Aedes aegypti.

  17. Aedes albopictus em área rural do Brasil e implicações na transmissão de febre amarela silvestre

    Directory of Open Access Journals (Sweden)

    Almério de Castro Gomes

    1999-02-01

    Full Text Available Durante estudos ecológicos sobre mosquitos anofelíneos no município de Bataguassu, Estado de Mato Grosso do Sul, foram encontradas larvas e adultos de Aedes albopictus. Pela primeira vez sua introdução ocorre numa área enzoótica do vírus selvático da febre amarela no Brasil. Isto sugere risco potencial para transferência desse vírus para área urbana infestada com Aedes aegypti.

  18. The Importance of Interspecific Interactions on the Present Range of the Invasive Mosquito Aedes albopictus (Diptera: Culicidae) and Persistence of Resident Container Species in the United States.

    Science.gov (United States)

    Fader, Joseph E

    2016-09-01

    Aedes albopictus (Skuse) established in the United States over 30 yr ago and quickly spread throughout the entire eastern half of the country. It has recently spread into western regions and projected climate change scenarios suggest continued expansion to the west and north. Aedes albopictus has had major impacts on, and been impacted by, a diverse array of resident mosquito species. Laying eggs at the edges of small, water-holding containers, hatched larvae develop within these containers feeding on detritus-based resources. Under limited resource conditions, Ae. albopictus has been shown to be a superior competitor to essentially all native and resident species in the United States. Adult males also mate interspecifically with at least one resident species with significant negative impacts on reproductive output for susceptible females. Despite these strong interference effects on sympatric species, competitor outcomes have been highly variable, ranging from outright local exclusion by Ae. albopictus, to apparent exclusion of Ae. albopictus in the presence of the same species. Context-dependent mechanisms that alter the relative strengths of inter- and intraspecific competition, as well as rapid evolution of satyrization-resistant females, may help explain these patterns of variable coexistence. Although there is a large body of research on interspecific interactions of Ae. albopictus in the United States, there remain substantial gaps in our understanding of the most important species interactions. Addressing these gaps is important in predicting the future distribution of this species and understanding consequences for resident species, including humans, that interact with this highly invasive mosquito.

  19. Wolbachia density and cytoplasmic incompatibility in Aedes albopictus: concerns with using artificial Wolbachia infection as a vector suppression tool.

    Directory of Open Access Journals (Sweden)

    Maurizio Calvitti

    Full Text Available The mosquito Aedes albopictusi is a competent vector of harmful human pathogens, including viruses causing dengue and chikungunya. Cytoplasmic incompatibility (CI induced by endosymbiotic Wolbachia can be used to produce functionally sterile males that can be released in the field as a suppression tool against this mosquito. Because the available sexing methods are not efficient enough to avoid unintentional release of a few transinfected females, we assessed the CI pattern in crosses between wPip Wolbachia-transinfected (ARwP females and wild-type males of Ae. albopictus in this study. Quantitative polymerase chain reaction was used to monitor the titer of the Wolbachia strains that naturally infect Ae. albopictus, that is, wAlbA and wAlbB, in age-controlled males and females. Data were coupled with incompatibility level detected when the above-mentioned males were crossed with ARwP females. Wolbachia infection titer was also monitored in samples of wild caught males. Incompatibility level was positively correlated only with wAlbA density. Crosses between wild-type males having very low wAlbA density (<0.001 wAlbA/actin copy numbers and ARwP females were partially fertile (CIcorr = 68.06 ± 6.20. Individuals with low wAlbA titer were frequently found among sampled wild males (30%-50% depending on the site and period. ARwP males can be as considered as a very promising tool for suppressing Ae. albopictus. However, crosses between wild males having low wAlbA density and ARwP females may be partially fertile. In the case of local establishment of the transinfected mosquito line, this occurrence may favor the replacement of the wild-type mosquitoes with the ARwP line, thus reducing the long-term efficacy of incompatible insect technique. Various alternative strategies have been discussed to prevent this risk and to exploit Wolbachia as a tool to control Ae. albopictus.

  20. High-level gene expression in Aedes albopictus cells using a baculovirus Hr3 enhancer and IE1 transactivator

    Directory of Open Access Journals (Sweden)

    Gray Christine E

    2004-07-01

    Full Text Available Abstract Background Aedes aegypti is the key vector of both the Yellow Fever and Dengue Fever viruses throughout many parts of the world. Low and variable transgene expression levels due to position effect and position effect variegation are problematic to efforts to create transgenic laboratory strains refractory to these viruses. Transformation efficiencies are also less than optimal, likely due to failure to detect expression from all integrated transgenes and potentially due to limited expression of the transposase required for transgene integration. Results Expression plasmids utilizing three heterologous promoters and three heterologous enhancers, in all possible combinations, were tested. The Hr3/IE1 enhancer-transactivator in combination with each of the constitutive heterologous promoters tested increased reporter gene expression significantly in transiently transfected Aedes albopictus C7-10 cells. Conclusions The addition of the Hr3 enhancer to expression cassettes and concomitant expression of the IE1 transactivator gene product is a potential method for increasing the level of transgene expression in insect systems. This mechanism could also potentially be used to increase the level of transiently-expressed transposase in order to increase the number of integration events in transposon-mediated transformation experiments.

  1. Host-feeding patterns of Aedes albopictus (Diptera: Culicidae) in relation to availability of human and domestic animals in suburban landscapes of central North Carolina.

    Science.gov (United States)

    Richards, Stephanie L; Ponnusamy, Loganathan; Unnasch, Thomas R; Hassan, Hassan K; Apperson, Charles S

    2006-05-01

    Aedes albopictus (Skuse) (Diptera: Culicidae) is a major nuisance mosquito and a potential arbovirus vector. The host-feeding patterns of Ae. albopictus were investigated during the 2002 and 2003 mosquito seasons in suburban neighborhoods in Wake County, Raleigh, NC. Hosts of blood-fed Ae. albopictus (n = 1,094) were identified with an indirect enzyme-linked immunosorbent assay, by using antisera made in New Zealand White rabbits to the sera of animals that would commonly occur in peridomestic habitats. Ae. albopictus fed predominantly on mammalian hosts (83%). Common mammalian hosts included humans (24%), cats (21%), and dogs (14%). However, a notable proportion (7%) of bloodmeals also was taken from avian hosts. Some bloodmeals taken from birds were identified to species by a polymerase chain reaction-heteroduplex assay (PCR-HDA). Ae. albopictus fed predominantly on chickens and a northern cardinal. PCR-HDA failed to produce detectable products for 29 (58%) of 50 bloodmeals for which DNA had been amplified, indicating that these mosquitoes took mixed bloodmeals from avian and nonavian hosts. Ae. albopictus preference for humans, dogs, and cats was determined by calculating host-feeding indices for the three host pairs based on the proportion of host specific blood-fed mosquitoes collected in relation to the number of specific hosts per residence as established by a door-to-door survey conducted in 2003. Estimates of the average amount of time that residents and their pets (cats and dogs) spent out of doors were obtained. Host-feeding indices based only on host abundance indicated that Ae. albopictus was more likely to feed on domestic animals. However, when feeding indices were time-weighted, Ae. albopictus fed preferentially upon humans. Ae. albopictus blood feeding on humans was investigated using a STR/PCR-DNA profiling technique that involved amplification of three short tandem repeats loci. Of 40 human bloodmeals, 32 (80%) were from a single human, whereas

  2. Larvicidal activities of hydro-ethanolic extracts of three Cameroonian medicinal plants against Aedes albopictus

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    Tankeu Nzufo Francine

    2016-11-01

    Conclusions: The present study shows that the hydro-ethanolic extracts of S. guineense, Monodora myristica and Z. heitzii tested have significant larvicidal activity. These preliminary results are of great interest and some of these plant species can be proposed for the formulation of new bioinsecticides to control Ae. albopictus populations.

  3. Llegada de Aedes albopictus a España: un nuevo reto para la salud pública Introduction of Aedes albopictus in Spain: a new challenge for public health

    Directory of Open Access Journals (Sweden)

    Nuria Giménez

    2007-02-01

    Full Text Available Introducción: En el Centro de Atención Primaria de Sant Cugat del Vallès (Barcelona se detectó un espectacular aumento de consultas por picaduras de insectos. El posterior estudio de las especies del área permitió identificar a Aedes albopictus. Objetivo: Analizar las consultas por picaduras de insecto (1998-2004. Métodos: Estudio descriptivo transversal retrospectivo. Consultaron 2.760 pacientes durante el período 1998-2004. Resultados: Se detectó un continuo aumento de consultas por picaduras, hasta alcanzar las 16 consultas por 1.000 habitantes. Los pacientes tenían una media de edad de 32 años, y un 62% eran mujeres. El 71% de las lesiones se localizaron en las extremidades y se infectaron el 19% de ellas. El 67% de los pacientes recibió tratamiento sistémico. Conclusiones: La atención primaria alertó sobre el llamativo aumento de consultas por picaduras de insecto. El colectivo de pacientes que consultó por este motivo fue mayoritariamente femenino, joven, recibió con frecuencia tratamiento sistémico y presentó un elevado porcentaje de complicaciones locales.Introduction: A spectacular increase was noticed in the number of consultations for insect stings at the Sant Cugat Primary Care Center (Barcelona, Spain. Subsequent study of the species in the area identified Aedes albopictus. Objective: To analyze consultations for insect stings in this center (1998-2004. Methods: A descriptive, cross sectional study with a 7-year retrospective review was performed. A total of 2,760 patients consulted. Results: A continual increase in the number of consultations for insect stings was detected, reaching 16 consultations per 1,000 inhabitants. The mean age of the patients was 32 years and 62% were women. Seventy-one percent of the stings were located on the extremities and 19% were infected. Sixty-seven percent of the patients received systemic treatment. Conclusions: Primary care alerted the town council of the significant increase

  4. Effect of triflumuron, a chitin synthesis inhibitor, on Aedes aegypti, Aedes albopictus and Culex quinquefasciatus under laboratory conditions

    OpenAIRE

    Belinato,Thiago Affonso; Martins,Ademir Jesus; Lima, José Bento Pereira; Valle,Denise

    2013-01-01

    Background Resistance to traditional insecticides represents a threat to the control of disease vectors. The insect growth regulators (IGR) are a potential alternative to control mosquitoes, including resistant populations. The chitin synthesis inhibitors (CSI) are IGRs, which interfere with the insect molting process and represent one major class of compounds against Aedes aegypti populations resistant to the larvicide organophosphate temephos. In the present study, we evaluated the efficacy...

  5. Climatic factors driving invasion of the tiger mosquito (Aedes albopictus into new areas of Trentino, northern Italy.

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    David Roiz

    Full Text Available BACKGROUND: The tiger mosquito (Aedes albopictus, vector of several emerging diseases, is expanding into more northerly latitudes as well as into higher altitudes in northern Italy. Changes in the pattern of distribution of the tiger mosquito may affect the potential spread of infectious diseases transmitted by this species in Europe. Therefore, predicting suitable areas of future establishment and spread is essential for planning early prevention and control strategies. METHODOLOGY/PRINCIPAL FINDINGS: To identify the areas currently most suitable for the occurrence of the tiger mosquito in the Province of Trento, we combined field entomological observations with analyses of satellite temperature data (MODIS Land Surface Temperature: LST and human population data. We determine threshold conditions for the survival of overwintering eggs and for adult survival using both January mean temperatures and annual mean temperatures. We show that the 0°C LST threshold for January mean temperatures and the 11°C threshold for annual mean temperatures provide the best predictors for identifying the areas that could potentially support populations of this mosquito. In fact, human population density and distance to human settlements appear to be less important variables affecting mosquito distribution in this area. Finally, we evaluated the future establishment and spread of this species in relation to predicted climate warming by considering the A2 scenario for 2050 statistically downscaled at regional level in which winter and annual temperatures increase by 1.5 and 1°C, respectively. CONCLUSIONS/SIGNIFICANCE: MODIS satellite LST data are useful for accurately predicting potential areas of tiger mosquito distribution and for revealing the range limits of this species in mountainous areas, predictions which could be extended to an European scale. We show that the observed trend of increasing temperatures due to climate change could facilitate further

  6. Dissemination and transmission of the E1-226V variant of chikungunya virus in Aedes albopictus are controlled at the midgut barrier level.

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    Camilo Arias-Goeta

    Full Text Available Emergence of arboviruses could result from their ability to exploit new environments, for example a new host. This ability is facilitated by the high mutation rate occurring during viral genome replication. The last emergence of chikungunya in the Indian Ocean region corroborates this statement since a single viral mutation at the position 226 on the E1 glycoprotein (E1-A226V was associated with enhanced transmission by the mosquito Aedes albopictus in regions where the major mosquito vector, Aedes aegypti, is absent.We used direct competition assays in vivo to dissect out the mechanisms underlying the selection of E1-226V by Ae. albopictus. When the original variant E1-226A and the newly emerged E1-226V were provided in the same blood-meal at equal titers to both species of mosquitoes, we found that the proportion of both variants was drastically different in the two mosquito species. Following ingestion of the infectious blood-meal, the E1-226V variant was preferentially selected in Ae. albopictus, whereas the E1-226A variant was sometimes favored in Ae. aegypti. Interestingly, when the two variants were introduced into the mosquitoes by intrathoracic inoculations, E1-226V was no longer favored for dissemination and transmission in Ae. albopictus, showing that the midgut barrier plays a key role in E1-226V selection.This study sheds light on the role of the midgut barrier in the selection of novel arbovirus emerging variants. We also bring new insight into how the pre-existing variant E1-226V was selected among other viral variants including E1-226A. Indeed the E1-226V variant present at low levels in natural viral populations could rapidly emerge after being selected in Ae. albopictus at the midgut barrier level.

  7. Spatial and Temporal Hot Spots of Aedes albopictus Abundance inside and outside a South European Metropolitan Area.

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    Mattia Manica

    2016-06-01

    Full Text Available Aedes albopictus is a tropical invasive species which in the last decades spread worldwide, also colonizing temperate regions of Europe and US, where it has become a public health concern due to its ability to transmit exotic arboviruses, as well as severe nuisance problems due to its aggressive daytime outdoor biting behaviour. While several studies have been carried out in order to predict the potential limits of the species expansions based on eco-climatic parameters, few studies have so far focused on the specific effects of these variables in shaping its micro-geographic abundance and dynamics. The present study investigated eco-climatic factors affecting Ae. albopictus abundance and dynamics in metropolitan and sub-urban/rural sites in Rome (Italy, which was colonized in 1997 and is nowadays one of the most infested metropolitan areas in Southern Europe. To this aim, longitudinal adult monitoring was carried out along a 70 km-transect across and beyond the most urbanized and densely populated metropolitan area. Two fine scale spatiotemporal datasets (one with reference to a 20m circular buffer around sticky traps used to collect mosquitoes and the second to a 300m circular buffer within each sampling site were exploited to analyze the effect of climatic and socio-environmental variables on Ae. albopictus abundance and dynamics along the transect. Results showed an association between highly anthropized habitats and high adult abundance both in metropolitan and sub-urban/rural areas, with "small green islands" corresponding to hot spots of abundance in the metropolitan areas only, and a bimodal seasonal dynamics with a second peak of abundance in autumn, due to heavy rains occurring in the preceding weeks in association with permissive temperatures. The results provide useful indications to prioritize public mosquito control measures in temperate urban areas where nuisance, human-mosquito contact and risk of local arbovirus transmission are

  8. Avaliação da influência da temperatura sobre o desenvolvimento de Aedes albopictus

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    Daniéla Cristina Calado

    2002-04-01

    Full Text Available OBJETIVO: Verificar a influência da temperatura sobre os estágios de desenvolvimento de Aedes albopictus sob condições de laboratório. MÉTODOS: Foi avaliado o período de desenvolvimento dos estágios de ovo, larva e pupa em quatro temperaturas constantes de 15ºC, 20ºC, 25ºC e 30ºC em câmaras climatizadas com umidade relativa do ar oscilando entre 70% e 85% e fotoperíodo de CE 12:12 horas. Pela análise de variância, foram testados os efeitos das quatro temperaturas constantes. RESULTADOS: O período de incubação dos ovos compreendeu 38,38; 19,09; 13,10; e 10,44 dias; o período larval dos indivíduos machos atingiu 30,13; 13,83; 7,36; e 5,57 dias; o período larval para fêmeas apresentou duração de 33,22; 15,00; 8,06; e 6,16 dias; o período pupal em machos compreendeu 8,01; 4,92; 2,40; e 1,76 dias, enquanto nas fêmeas foi de 8,15; 5,11; 2,60; e 1,88 dias sob as temperaturas de 15ºC, 20ºC, 25ºC e 30ºC, respectivamente. Em todos os estágios de desenvolvimento, foram encontradas diferenças significativas, entre as temperaturas avaliadas, em torno de 5% no tempo de desenvolvimento. O período de desenvolvimento foi inversamente relacionado à temperatura, com o período larval mais breve em machos que em fêmeas. Nas temperaturas de 20ºC a 30ºC, o desenvolvimento foi mais breve e com maior viabilidade que a 15ºC. CONCLUSÕES: Nas condições em que foram realizados os experimentos, a temperatura afetou de forma significativa e inversamente proporcional os estágios imaturos de Aedes albopictus. Esses resultados mostram que os estágios imaturos são mais suscetíveis durante os períodos de baixas temperaturas devido ao maior tempo necessário para completar o desenvolvimento, informação que pode ser utilizada em estratégias de controle.

  9. Plano amostral para cálculo de densidade larvária de Aedes aegypti e Aedes albopictus no Estado de São Paulo, Brasil Sampling desing for larval density computation of Aedes Aegypti and Aedes albopictus in the State of S. Paulo, Brazil

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    Maria Cecília G.P. Alves

    1991-08-01

    Full Text Available O Programa de Controle de Vetores de Febre Amarela e Dengue, desenvolvido pela Superintendência de Controle de Endemias do Estado de São Paulo, Brasil, prevê a realização de pesquisa para avaliação da densidade larvária de Aedes aegypti e Aedes albopictus em edificações de municípios com infestação domiciliar. Descreve-se o plano amostral que vem sendo aplicado, desde outubro de 1987, nos municípios da Região de Presidente Prudente. Para acompanhamento da densidade está sendo utilizado o índice de Breteau. São sorteados, nos municípios infestados, mensalmente e de forma independente, amostras de edificações para a obtenção das estimativas do índice. O plano amostral prevê a seleção de conglomerados em 2 estágios: quadras e edificações. O tamanho da amostra foi definido estimando-se o coeficiente da correlação intraconglomerado e variância relativa por elemento através de pesquisas realizadas anteriormente em municípios do Serviço Regional de São José do Rio Preto. O plano propõe que os valores relativos ao tamanho da amostra sejam atualizados periodicamente em função dos valores obtidos para o estimador do Índice de Breteau e sua variância, em meses anteriores.The Yellow Fever and Dengue Vector Control Program developed by the Superintendency for the Control of Endemic Diseases in the State of S. Paulo recommends Aedes aegypti and Aedes albopictus larval density monitoring in cities with domiciliar infestation. The sampling plan which has been applied in the countries of the Presidente Prudente region (SP- Brazil since 1987 is described. The infestation is measured by using the Breteau Index. A sample of buildings is drawn, monthly and independently, in the infested cities, in which measurements are to be made. The sample is stratified and the elementary unit selection is made by using two-stage cluster sampling: of blocks and buildings. The sample sizes were defined using the coefficient of variation

  10. Evaluation of different formulations of IGRs against Aedes albopictus and Culex quinquefasciatus (Diptera: Culicidae

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    Gul Zamin Khan

    2016-06-01

    Conclusions: It is thus concluded that IGRs can be utilized as environment friendly control measures for Culex and Aedes spp. of mosquitoes on small and large scale. This will reduce the use of conventional insecticides by the public health authorities and help in reducing selection pressure of insecticides.

  11. Serum concentration and increased temperature alter Mayaro virus RNA and protein synthesis in Aedes albopictus (mosquito)-infected cells.

    Science.gov (United States)

    Motta, M C; Fournier, M V; Carvalho, M G

    1995-01-01

    We have previously shown the inhibition of Mayaro virus multiplication in Aedes albopictus-infected cells maintained at a supraoptimal temperature for growth (37 degrees C) and a stimulation of virus production in response to high serum concentrations in the incubation medium. In the present study, we addressed the question of how the effect of continuous heat stress and high serum concentration soon after infection interfere with virus macromolecule synthesis. Cells maintained at 28 degrees C in the presence of 2% serum synthesized a viral genomic RNA of 12 kb and a subgenomic RNA of 5.2 kb 6 h postinfection. Analysis of the protein profile showed the presence of the viral nucleocapsid protein of 34 kDa (P34). However, if infected cells were maintained at 37 degrees C, a smear starting immediately below the 5.2-kb RNA was noticed and the viral P34 was not detected by SDS-PAGE. Addition of 10% serum to the growth medium of infected cells maintained at 37 degrees C results in a viral RNA profile and protein synthesis similar to those observed in cultures kept at 28 degrees C, i.e., the smear was not observed and the P34 protein was detected. The results suggest that the inhibition of virus multiplication by temperature may be related to the inhibition of viral nonstructural protein synthesis early during infection. The presence of high serum levels in the incubation medium protects macromolecule synthesis against heat stress.

  12. Laboratory studies of a Brazilian strain of Aedes albopictus as a potential vector of Mayaro and Oropouche viruses.

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    Smith, G C; Francy, D B

    1991-03-01

    The vector efficiency of colonized Aedes albopictus from Brazil was assessed for Mayaro (MAY) and Oropouche (ORO) viruses. Female mosquitoes, 3-4 days old, were fed on a MAY-infected hamster with a viremia level of 5.3 log10 Vero cell plaque-forming units (PFU) of virus/ml or an ORO-infected hamster circulating 7.3 log10 PFU/ml. Mayaro infection rates among fed mosquitoes were 16.9 and 11% at 6, 13 and 20 days postfeeding, respectively, and 1/2 and 2/2 infected mosquitoes transmitted virus on days 13 and 20, respectively. Only 13, 5 and 3% of mosquitoes were infected with ORO virus at 6, 13 and 20 days, respectively, and no transmission occurred. Mosquitoes were also fed on 3 dilutions of MAY virus-blood suspensions in membrane feeders. The infection rate among mosquitoes fed the highest concentration (7.7 log10 PFU/ml) was 11/13 (85%), and 5/11 (46%) infected mosquitoes transmitted virus.

  13. Climatic suitability of Aedes albopictus in Europe referring to climate change projections: comparison of mechanistic and correlative niche modelling approaches.

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    Fischer, D; Thomas, S M; Neteler, M; Tjaden, N B; Beierkuhnlein, C

    2014-02-13

    The Asian tiger mosquito, Aedes albopictus, is capable of transmitting a broad range of viruses to humans. Since its introduction at the end of the 20th century, it has become well established in large parts of southern Europe. As future expansion as a result of climate change can be expected, determining the current and projected future climatic suitability of this invasive mosquito in Europe is of interest. Several studies have tried to detect the potential habitats for this species, but differing data sources and modelling approaches must be considered when interpreting the findings. Here, various modelling methodologies are compared with special emphasis on model set-up and study design. Basic approaches and model algorithms for the projection of spatio-temporal trends within the 21st century differ substantially. Applied methods range from mechanistic models (e.g. overlay of climatic constraints based on geographic information systems or rather process-based approaches) to correlative niche models. We conclude that spatial characteristics such as introduction gateways and dispersal pathways need to be considered. Laboratory experiments addressing the climatic constraints of the mosquito are required for improved modelling results. However, the main source of uncertainty remains the insufficient knowledge about the species' ability to adapt to novel environments.

  14. Olfaction in Asian tiger mosquito Aedes albopictus: flight orientation response to certain saturated carboxylic acids in human skin emanations.

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    Seenivasagan, T; Guha, Lopamudra; Parashar, B D; Agrawal, O P; Sukumaran, D

    2014-05-01

    The flight orientation response of nonblood-fed and hungry Aedes albopictus females was studied in a Y-tube olfactometer at 10(-6) to 10(-2) g odor plumes of saturated carboxylic acids (C1-C20), in which C2-C18 were the main constituents of human skin emanations. Thirteen acids viz C1, C2, C3, C5, C6, C8 C9, C10, C12, C14, C16, C18, and C20 showed attractance at odor plumes ranging from 10(-5) to 10(-3) g doses, while five acids viz C4, C7, C11, C15, and C19 showed repellence at 10(-4) to 10(-2) g to test mosquitoes. Tridecanoic acid (C13) showed attractance only at 10(-4) g dose while higher doses caused repellence. Dose-dependent reversal of orientation behavior from attractance to repellence was observed at 10(-2) g plumes of C5, C9, C10, C13, C17, C19, and C20 acids. The outcome of the study will help in the identification of odoriferous acids as potential attractants, repellents, or attraction inhibitors, which may find their application in the repellent formulations and odor-baited traps for surveillance and control of mosquitoes.

  15. Essential oil composition, adult repellency and larvicidal activity of eight Cupressaceae species from Greece against Aedes albopictus (Diptera: Culicidae).

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    Giatropoulos, Athanassios; Pitarokili, Danae; Papaioannou, Fotini; Papachristos, Dimitrios P; Koliopoulos, George; Emmanouel, Nickolaos; Tzakou, Olga; Michaelakis, Antonios

    2013-03-01

    The present study evaluated leaf essential oils from eight Cupresaceae species; Cupressus arizonica, Cupressus benthamii, Cupressus macrocarpa, Cupressus sempervirens, Cupressus torulosa, Chamaecyparis lawsoniana, Juniperus phoenicea, and Tetraclinis articulata for their larvicidal and repellent properties against Aedes albopictus, a mosquito of great ecological and medical importance. Based on the LC(50) values, C. benthamii essential oil was the most active (LC(50) = 37.5 mg/L) while the other tested Cupressaceae essential oils provided rather moderate toxicity against larvae (LC(50) = 47.9 to 70.6 mg/L). Under the used laboratory conditions, three of the essential oils (C. benthamii, C. lawsoniana, and C. macrocarpa) provided sufficient protection against mosquito adults, equivalent to the standard repellent "Deet" in the 0.2 mg/cm(2) dose, while C. macrocarpa assigned as the superior repellent oil in the 0.08 mg/cm(2) dose. Chemical analysis of the essential oils using gas chromatography and gas chromatography-mass spectrometry revealed the presence of 125 components.

  16. Molecular Tracing with Mitochondrial ND5 of the Invasive Mosquito Aedes (Stegomyia albopictus (Skuse in Northern South America

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    Adriana Zorrilla

    2013-08-01

    Full Text Available The widespread invasive Aedes albopictus, the Asian tiger mosquito, a vector of Dengue, Chikungunya and other arboviruses were discovered in Caracas (Venezuela in 2009 and, separately in Colombia (Leticia 1998, Buenaventura 2001 and Cali 2007. The possible geographic origins were examined using mtDNA sequences NADH 5 (ND5. Sequences were aligned with those from GenBank. Venezuelan populations contained both unique (H14 and Asian-native haplotypes (H3, while the Colombian populations contain one unique (H15 and two common haplotypes (H1, H11 shared with the Brazilian, Hawaian, and Cameroon populations. Haplotype network analyses suggested: 1 Independent introduction into both countries; 2 two independent invasions into Colombia: from the Amazon River (H1 with evidence of founder effect or genetic bottleneck in Leticia, and, another via the Pacific port of Buenaventura from Hawaii (H11; 3 introduction to Venezuela directly from any Asian native range. Potential factors leading to limited genetic variation in mtND5 in the Columbian and Venezuelan populations were also discussed.

  17. Seasonal variation and bioactivity of the essential oils of two Juniperus species against Aedes (Stegomyia) albopictus (Skuse, 1894).

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    Evergetis, E; Michaelakis, A; Papachristos, D P; Badieritakis, E; Kapsaski-Kanelli, V N; Haroutounian, S A

    2016-06-01

    The seasonal variation in respect to the yield and chemical composition of 24 essential oils (EOs) isolated from various parts (leaves and fruits) of two indigenous Greece Juniperus species (family Cupressaceae), namely Juniperus drupacea and Juniperus phoenica, were determined by GC and GC/MS analysis. The larvicidal properties of these EOs were evaluated against 3rd and early 4th instar larvae of Aedes (Stegomyia) albopictus (Skuse, 1894) at one screening dose (29 mg L(-1)). Moreover, the repellent activity against adult mosquitoes was also evaluated at one screening dose. The analytical data indicated that the EOs mainly consisted of monoterpenes, mostly cyclic and only occasionally aliphatic and to a lesser percent diterpenes. The EOs yield was sharply increased when the plant material was subjected to pre-treatment before steam distillation. Finally, the influence of plant material collection period on their yield and chemical content was also determined. Bioactivity assessments indicated that three EOs possess very potent larvicidal properties and 12 EOs display significant repellent activities since they were proved to be "DEET-like." Therefore, they represent an inexpensive source of natural mixtures of larvicidal and repellent mixture of natural compounds, with potentials for application for utilization in mosquito control schemes in order to prevent the expansion of viral infections.

  18. Evaluation of larvicidal activity of the essential oil of Allium macrostemon Bunge and its selected major constituent compounds against Aedes albopictus (Diptera: Culicidae).

    Science.gov (United States)

    Liu, Xin Chao; Liu, Qiyong; Zhou, Ligang; Liu, Zhi Long

    2014-04-15

    During the screening programme for new agrochemicals from Chinese medicinal herbs and local wild plants, the essential oil of dried bulbs of Allium macrostemon Bunge (Liliaceae) was found to possess larvicidal activity against mosquitoes. The aim of this research was to determine the larvicidal activity of the essential oil and its major constituent compounds against the larvae of the Culicidae mosquito, Aedes albopictus. Essential oil of A. macrostemon was obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromaotography-mass spectrometry (GC-MS). The activity of the essential oil and its two major constituents were evaluated, using World Health Organization (WHO) procedures, against the fourth instar larvae of Ae. albopictus for 24 h and larval mortalities were recorded at various essential oil/compound concentrations ranging from 9.0 - 150 μg/ml. The essential oil of A. macrostemon exhibited larvicidal activity against the early fourth instar larvae of Ae. albopictus with an LC₅₀ value of 72.86 μg/ml. The two constituent compounds, dimethyl trisulfide and methyl propyl disulfide possessed strong larvicidal activity against the early fourth instar larvae of Ae. albopictus with LC50 values of 36.36 μg/ml and 86.16 μg/ml, respectively. The results indicated that the essential oil of A. macrostemon and its major constituents have good potential as a source for natural larvicides.

  19. Larvicidal and repellent activity of the essential oil of Coriandrum sativum L. (Apiaceae) fruits against the filariasis vector Aedes albopictus Skuse (Diptera: Culicidae).

    Science.gov (United States)

    Benelli, Giovanni; Flamini, Guido; Fiore, Giulia; Cioni, Pier Luigi; Conti, Barbara

    2013-03-01

    The essential oils of many Apiaceae species have been already studied for their insecticidal and repellent properties against insect pests. In this research, the essential oil (EO) extracted from the fruits of Coriandrum sativum L. (Apiaceae) was evaluated for the first time for its larvicidal and repellent activities against the most invasive mosquito worldwide, Aedes albopictus Skuse (Diptera: Culicidae). The chemical composition of C. sativum EO was investigated by gas chromatography with electron impact mass spectrometry analysis. Coriander EO was mainly composed by monoterpene hydrocarbons and oxygenated monoterpenes, with linalool (83.6 %) as the major constituent. C. sativum EO exerted toxic activity against A. albopictus larvae: LC(50) was 421 ppm, while LC(90) was 531.7 ppm. Repellence trials highlighted that C. sativum EO was a good repellent against A. albopictus, also at lower dosages: RD(50) was 0.0001565 μL/cm(2) of skin, while RD(90) was 0.002004 μL/cm(2). At the highest dosage (0.2 μL/cm(2) of skin), the protection time achieved with C. sativum essential oil was higher than 60 min. This study adds knowledge about the chemical composition of C. sativum EO as well as to the larvicidal and repellent activity exerted by this EO against A. albopictus. On this basis, we believe that our findings could be useful for the development of new and safer products against the Asian tiger mosquito.

  20. Ipomoea batatas (Convolvulaceae)-mediated synthesis of silver nanoparticles for controlling mosquito vectors of Aedes albopictus, Anopheles stephensi, and Culex quinquefasciatus (Diptera:Culicidae).

    Science.gov (United States)

    Pavithra Bharathi, V; Ragavendran, C; Murugan, N; Natarajan, D

    2016-12-08

    We proposed an effective and eco-friendly control of dengue, malaria, and filariasis-causing vectors. We tested Ipomoea batatas leaves-mediated silver nanoparticles (AgNPs) against first to fourth instar larvae and adults of Aedes albopictus, Anopheles stephensi, and Culex quinquefasciatus at different concentrations. The synthesized AgNPs showed broad spectrum of larvicidal and adulticidal effects after 48 h of exposure. The characterization of synthesized AgNPs was done using various spectral and microscopy analyses. The maximum efficacy was observed in synthesized AgNPs against the adult of Ae. albopictus with the LC50 and LC90 values were 10.069 and 15.657 μg/mL, respectively, followed by others.

  1. 香茅醛对白纹伊蚊空间驱避作用的研究%The space repellency of citronellal on Aedes albopictus

    Institute of Scientific and Technical Information of China (English)

    郝蕙玲; 孙锦程

    2011-01-01

    目的 探讨香茅醛作为一种可能的空间驱避剂的应用价值.方法 在风洞系统内测试香茅醛不同剂量浓度诱导的白纹伊蚊(Aedes albopictus)行为反应及对宿主定向行为的影响.在密闭窄间中,分别以0.013~0.250μg/cm3浓度的香茅醛处理白纹伊蚊24~96 h后测定其感受、定向寄主的能力.结果 香茅醛高浓度(96%)对白纹伊蚊有一定的驱避作用,低浓度(3.0%~6.0%)则有一定的引诱作用.12.0%~96.0%浓度的香茅醛溶液对白纹伊蚊正常感受宿主气味均有一定的抑制作用,低于此浓度,抑制效果明显下降.白纹伊蚊在0.013~0.250μg/cm3浓度的香茅醛气味空间处理24~96 h后未影响其正常感受宿主气味的能力.结论 香茅醛只有达到一定浓度时,才对白纹伊蚊定向宿主有一定的抑制效果,而且这种抑制具瞬时性.%Objective In order to study citronellal' s repellency action and judge its prospects. Citronellal could be a spatial repellent against Aedes albopictus and play a major role in new repellent technology. Methods Olfactory behavior and host seeking ability of Aedes albopictus were tested with a olfactometer, and the inhibation of their host seeking ability following treatments at dosages of 0.013 - 0. 250 μg/cm3 for 24 - 96 h were observed too. Results Citronellal at dosage of 96% could be an effective spatial repellent to Aedes albopictus,and at dosages of 3.0% -6.0%could be an effective attractant. It was observed that mosquitoes at dosages of 12.0% -96.0% all showed different degrees of reduction in host seeking ability,and the reduction were lost under the dosage of 12.0%. But citronellal was ineffective on reducing the host seeking ability of Aedes albopictus following treatments with dosages of 0.013 -0. 250 μg/cm3 for 24 - 96 h. Conclusion Citronellal can be a spatial repellent against Aedes albopictus at a higher dosages ,and the inhibation is momentary.

  2. Laboratory and Simulated Field Bioassays to Evaluate Larvicidal Activity of Pinus densiflora Hydrodistillate, Its Constituents and Structurally Related Compounds against Aedes albopictus, Aedes aegypti and Culex pipiens pallens in Relation to Their Inhibitory Effects on Acetylcholinesterase Activity

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    Young-Joon Ahn

    2013-05-01

    Full Text Available The toxicity of Pinus densiflora (red pine hydrodistillate, its 19 constituents and 28 structurally related compounds against early third-instar larvae of Aedes albopictus (Ae. albopictus, Aedes aegypti (Ae. aegypti and Culex pipiens palles (Cx. p. pallens was examined using direct-contact bioassays. The efficacy of active compounds was further evaluated in semi-field bioassays using field-collected larval Cx. p. pallens. Results were compared with those of two synthetic larvicides, temephos and fenthion. In laboratory bioassays, Pinus densiflora hydrodistillate was found to have 24 h LC50 values of 20.33, 21.01 and 22.36 mg/L against larval Ae. albopictus, Ae. aegypti and Cx. p. pallens respectively. Among the identified compounds, thymol, δ-3-carene and (+-limonene exhibited the highest toxicity against all three mosquito species. These active compounds were found to be nearly equally effective in field trials as well. In vitro bioassays were conducted to examine the acetylcholinesterase (AChE inhibitory activity of 10 selected compounds. Results showed that there is a noticeable correlation between larvicidal activity and AChE inhibitory activity. In light of global efforts to find alternatives for currently used insecticides against disease vector mosquitoes, Pinus densiflora hydrodistillate and its constituents merit further research as potential mosquito larvicides.

  3. Laboratory and Simulated Field Bioassays to Evaluate Larvicidal Activity of Pinus densiflora Hydrodistillate, Its Constituents and Structurally Related Compounds against Aedes albopictus, Aedes aegypti and Culex pipiens pallens in Relation to Their Inhibitory Effects on Acetylcholinesterase Activity.

    Science.gov (United States)

    Lee, Dong Chan; Ahn, Young-Joon

    2013-05-30

    The toxicity of Pinus densiflora (red pine) hydrodistillate, its 19 constituents and 28 structurally related compounds against early third-instar larvae of Aedes albopictus (Ae. albopictus), Aedes aegypti (Ae. aegypti) and Culex pipiens palles (Cx. p. pallens) was examined using direct-contact bioassays. The efficacy of active compounds was further evaluated in semi-field bioassays using field-collected larval Cx. p. pallens. Results were compared with those of two synthetic larvicides, temephos and fenthion. In laboratory bioassays, Pinus densiflora hydrodistillate was found to have 24 h LC50 values of 20.33, 21.01 and 22.36 mg/L against larval Ae. albopictus, Ae. aegypti and Cx. p. pallens respectively. Among the identified compounds, thymol, δ-3-carene and (+)-limonene exhibited the highest toxicity against all three mosquito species. These active compounds were found to be nearly equally effective in field trials as well. In vitro bioassays were conducted to examine the acetylcholinesterase (AChE) inhibitory activity of 10 selected compounds. Results showed that there is a noticeable correlation between larvicidal activity and AChE inhibitory activity. In light of global efforts to find alternatives for currently used insecticides against disease vector mosquitoes, Pinus densiflora hydrodistillate and its constituents merit further research as potential mosquito larvicides.

  4. Bromeliad-inhabiting mosquitoes in an urban botanical garden of dengue endemic Rio de Janeiro--are bromeliads productive habitats for the invasive vectors Aedes aegypti and Aedes albopictus?

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    Mocellin, Márcio Goulart; Simões, Taynãna César; Nascimento, Teresa Fernandes Silva do; Teixeira, Maria Lucia França; Lounibos, Leon Philip; Oliveira, Ricardo Lourenço de

    2009-12-01

    Immatures of both Aedes aegypti and Aedes albopictus have been found in water-holding bromeliad axils in Brazil. Removal of these plants or their treatment with insecticides in public and private gardens have been undertaken during dengue outbreaks in Brazil despite uncertainty as to their importance as productive habitats for dengue vectors. From March 2005-February 2006, we sampled 120 randomly selected bromeliads belonging to 10 species in a public garden less than 200 m from houses in a dengue-endemic neighborhood in Rio de Janeiro. A total of 2,816 mosquito larvae and pupae was collected, with an average of 5.87 immatures per plant per collection. Culex (Microculex) pleuristriatus and Culex spp of the Ocellatus Group were the most abundant culicid species, found in all species of bromeliads; next in relative abundance were species of the genus Wyeomyia. Only two individuals of Ae. aegypti (0.07%) and five of Ae. albopictus(0.18%) were collected from bromeliads. By contrast, immatures of Ae. aegypti were found in manmade containers in nearly 5% of nearby houses. These results demonstrate that bromeliads are not important producers of Ae. aegypti and Ae. albopictus and, hence, should not be a focus for dengue control. However, the results of this study of only one year in a single area may not represent outcomes in other urban localities where bromeliads, Ae. aegypti and dengue coincide in more disturbed habitats.

  5. Avaliação da produtividade dos criadouros do Aedes aegypti (L. e Aedes albopictus (Skuse através dos dados da vigilância em Parati – RJ.

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    Eduardo Wermelinger

    2012-12-01

    Abstract. This study evaluated the pupa-productivity of the entomologic surveillance according methodology used by the official Program for Dengue Control in Brazil (PDCB for Aedes aegypti (Linnaeus and Aedes albopictus (Skuse in Parati, RJ, Brazil. The highest number of A. aegypti pupae were found in drains (31%, bottles and cans (23%; and the highest number of A. albopictus pupae were found in bottles and cans (24%, and plant vases (21%. Of the total pupae identified 84.3% and 79.3% of A. aegypti and A. albopictus respectively were collected in small receptacles: bottles, plants vase, tires, bromeliads and tree holes. These productivities are not supported by literature and can be explained by the restrictions of access for the bigger receptacles and lack of training of the agents. The study points out the importance which the small receptacles can have on vector densities in urban environment despite of their productivity and conclude that the entomology surveillance methodology for dengue used in PDCB has no efficacy to identify the bigger and more productive receptacles. This conclusion suggests that this inefficacy can be an important factor for the failures on dengue vector control in Brazil.

  6. Potential for sublethal insecticide exposure to impact vector competence of Aedes albopictus (Diptera: Culicidae for dengue and Zika viruses

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    Richards SL

    2017-05-01

    Full Text Available Stephanie L Richards, Avian V White, Jo Anne G Balanay Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC, USA Abstract: Chikungunya, dengue, and Zika viruses (CHIKV, family Togaviridae, genus Alphavirus; DENV and ZIKV, family Flaviviridae, genus Flavivirus are arboviruses that cause human epidemics. Due to the lack of vaccines for many mosquito-borne diseases, there is a need for mosquito control. In the US and other regions, residual barrier insecticide sprays are applied to foliage where female mosquitoes rest and/or sugar feed between blood meals. Residual sprays are an important control method for anthropogenic day-active sylvan mosquitoes such as Aedes albopictus (vector of CHIKV, DENV, and ZIKV that are difficult to control using ultralow-volume sprays applied only at dusk or dawn when these mosquitoes are not active. In this exploratory study, we analyzed the extent to which ingestion of a sublethal dose of the active ingredient bifenthrin affected vector competence (i.e., infection, dissemination, and transmission of Ae. albopictus for DENV and ZIKV. Two incubation periods (IPs; 7 and 14 d were tested at 28°C for insecticide-fed and sugar-fed mosquitoes. We show that mosquitoes that were fed bifenthrin (0.128 µg/mL mixed with sucrose solution exhibited significantly lower DENV infection rates and body titers after a 14-d IP. During the 7-d IP, one mosquito (sugar group transmitted ZIKV. During the 14-d IP, 100% of mosquitoes showed body and leg ZIKV infections, and one mosquito (sugar+bifenthrin group transmitted ZIKV. This is a preliminary communication, and more studies will be required to further investigate these findings. We expect the findings of this small-scale study to spur larger-scale investigations of the impacts of insecticides on mechanisms regulating vector competence, and exposure to other active ingredients, and aid in development of new

  7. Evaluation of Pioneer eco-backpack sprayer and Twister XL backpack sprayer using Aqualuer against caged adult Aedes albopictus and Culex quinquefasciatus.

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    Xue, Rui-De; Qualls, Whitney A; Smith, Mike L; Zhao, Tong-Yan; Brown, James R

    2012-12-01

    A Pioneer Eco-Backpack electric cold ultra-low volume (ULV) sprayer and a gas-powered Twister XL 3950 series 2 motorized knapsack ULV sprayer with Aqualuer (20.6% permethrin AI) were evaluated against caged adult Aedes albopictus and Culex quinquefasciatus in St. Augustine, FL. The Pioneer Eco-Backpack sprayer provided 100% knockdown of both species of mosquitoes at 15 min; the Twister XL backpack sprayer resulted in 17-23% knockdown at 15 min. Both backpack sprayers with Aqualuer resulted in 100% mortality of both species at 24 h. The new Pioneer Eco-Backpack sprayer powered by electricity could be a potential tool for mosquito control.

  8. Low-temperature threshold for egg survival of a post-diapause and non-diapause European aedine strain, Aedes albopictus (Diptera: Culicidae

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    Thomas Stephanie

    2012-05-01

    Full Text Available Abstract Background The interplay between global warming and invasive arthropods in temperate zones is of utmost interest in terms of the potential expansions of vector-borne diseases. Up to now, investigations on the recent establishment of mosquito vectors have focused on temperatures during their phases of activity. However, cold temperatures may also act as a strong ecological constraint. Projected changes in winter climate indicate an increase of mean minimum temperatures of the coldest quarter, less frequent days with frost and a shorter frost-season in Europe at the end of the century. Nevertheless, single cold extremes are also expected to persist under warming scenarios, which have a strong impact on reproduction success. Methods Here, the temperature constraints of European Aedes albopictus eggs, which had passed through a diapause, compared to non-diapausing eggs were examined systematically under controlled laboratory conditions. Additionally, one tropical strain of Ae. albopictus and of Ae. aegypti was used in the comparison. Results The lower temperature threshold tolerated by the European eggs of Ae. albopictus which have undergone a diapause, was -10°C for long term exposures (12 and 24h and -12°C for 1h exposure. Non-diapausing eggs of European Ae. albopictus were found to hatch after a -7°C cold treatment (8, 12 and 24h exposure. Both tropical aedine species only tolerated the long term treatment at -2°C. Neither Ae. albopictus nor Ae. aegypti eggs hatched after being exposed to -15°C. Survival was mainly influenced by temperature (F = 329.2, df = 1, p  Conclusions Here, low temperature thresholds for aedine mosquito egg survival were detected. The compilation of risk maps for temperate regions can substantially be improved by considering areas where an establishment of a vector population is unlikely due to winter conditions.

  9. Surveillance and Control of Aedes albopictus in the Swiss-Italian Border Region: Differences in Egg Densities between Intervention and Non-intervention Areas

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    Suter, Tobias T.; Flacio, Eleonora; Feijoó Fariña, Begoña; Engeler, Lukas; Tonolla, Mauro; Regis, Lêda N.; de Melo Santos, Maria A. V.; Müller, Pie

    2016-01-01

    Background Aedes albopictus, the Asian tiger mosquito, originates from the tropical and subtropical regions of Southeast Asia. Over the recent decades it has been passively spread across the globe, primarily through the used tyre trade and passive transportation along major traffic routes. A. albopictus is a proven vector for many arboviruses, most notably chikungunya and dengue, with recent outbreaks also in continental Europe. In southern Switzerland, in the Canton of Ticino A. albopictus was spotted for the first time in 2003. Since then the local authorities have implemented a control programme based on larval source reduction. Despite these efforts, mosquito densities have increased over the last decade, casting doubts on the effectiveness of such larval control programmes. Methodology/Principal Findings The Italian communities just across the Swiss-Italian border lack a control programme. This motivated us to compare the intervention and the non-intervention areas side by side in an attempt to find evidence for, or against, the effectiveness of larval A. albopictus control. Using ovitraps and a randomised sampling scheme, we examined the seasonal and spatial abundance of A. albopictus in sylvatic and urban environments across the Swiss-Italian border in 2012 and 2013. In the urban environments of the non-intervention area, egg densities were 2.26 times higher as compared to the intervention area. In the sylvatic environments, as compared to the urban environments, egg densities were 36% in the intervention area and 18% in the non-intervention area. Conclusions/Significance Though alternative explanations are also valid, the results support the hypothesis that the Ticino intervention programme does have an impact. At the same time the data also suggest that current larval interventions fall short in gaining full control over the mosquito, calling for the evaluation of additional, or alternative, approaches. Ideally, these should also consider inclusion of the

  10. Detecção de Aedes aegypti e Aedes albopictus, na zona urbana do município de Catanduva-SP, após controle de epidemia de dengue

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    Rubens Pinto Cardoso Junior

    1997-02-01

    Full Text Available Após a realização dos trabalhos de controle visando à interrupção da transmissão do vírus do dengue, iniciou-se um trabalho de monitorização de Aedes aegypti e Aedes albopictus com dois métodos de vigilância entomológica: Índice de Breteau (IB e ovitrampas. Pretendeu-se avaliar o tempo necessário para que as espécies envolvidas fossem novamente detectadas na área urbana do município de Catanduva, SP. As ovitrampas apresentaram positividade para Aedes aegypti dois meses após os trabalhos de controle, enquanto o Índice de Breteau veio a positivar-se somente no quarto mês após o término dos referidos trabalhos.After the realization of control research that had in view the transmition of dengue virus, we started to monitor two kinds of entomological vigilance, Breteau Index and ovitrap. We intended to evaluate the necessary time elapsed before Aedes sp mosquitoes were again detected at the urban area of Catanduva s town (SP. The ovitraps showed positiviness for the Aedes aegypti two months after the control research, while the Breteau Index became positive only at the fourth month after the end of the refered research.

  11. Functional and immunohistochemical characterization of CCEae3a, a carboxylesterase associated with temephos resistance in the major arbovirus vectors Aedes aegypti and Ae. albopictus.

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    Grigoraki, Linda; Balabanidou, Vassileia; Meristoudis, Christos; Miridakis, Antonis; Ranson, Hilary; Swevers, Luc; Vontas, John

    2016-07-01

    Temephos is a major organophosphate (OP) larvicide that has been used extensively for the control of Aedes albopictus and Aedes aegypti, the major vectors for viral diseases, such as dengue fever, zika and chikungunya. Resistance to temephos has been recently detected and associated with the upregulation of carboxylesterases (CCEs) through gene amplification, in both species. Here, we expressed the CCEae3a genes which showed the most striking up-regulation in resistant Aedes strains, using the baculovirus system. All CCEae3a variants encoded functional enzymes, with high activity and preference for p-nitrophenyl butyrate, a substrate that was shown capable to differentiate temephos resistant from susceptible Aedes larvae. Enzyme kinetic studies showed that CCEae3as from both Ae. aegypti and Ae. albopictus (CCEae3a_aeg and CCEae3a_alb, respectively) strongly interact with temephos oxon and slowly released the OP molecule, indicating a sequestration resistance mechanism. No difference was detected between resistant and susceptible CCEae3a_aeg variants (CCEae3a_aegR and CCEae3a_aegS, respectively), indicating that previously reported polymorphism is unlikely to play a role in temephos resistance. HPLC/MS showed that CCEae3as were able to metabolize temephos oxon to the temephos monoester [(4-hydroxyphenyl) sulfanyl] phenyl O,O-dimethylphosphorothioate. Western blot and immunolocalization studies, based on a specific antibody raised against the CCEae3a_alb showed that the enzyme is expressed at higher levels in resistant insects, primarily in malpighian tubules (MT) and nerve tissues.

  12. Molecular characterization of Chikungunya virus isolates from clinical samples and adult Aedes albopictus mosquitoes emerged from larvae from Kerala, South India.

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    Niyas, Kudukkil P; Abraham, Rachy; Unnikrishnan, Ramakrishnan Nair; Mathew, Thomas; Nair, Sajith; Manakkadan, Anoop; Issac, Aneesh; Sreekumar, Easwaran

    2010-08-13

    Chikungunya virus (CHIKV), an arthritogenic alphavirus, is transmitted to humans by infected Aedes (Ae.) aegypti and Ae.albopictus mosquitoes. In the study, reverse-transcription PCR (RT PCR) and virus isolation detected CHIKV in patient samples and also in adult Ae.albopictus mosquitoes that was derived from larvae collected during a chikungunya (CHIK) outbreak in Kerala in 2009. The CHIKV strains involved in the outbreak were the East, Central and South African (ECSA) genotype that had the E1 A226V mutation. The viral strains from the mosquitoes and CHIK patients from the same area showed a close relationship based on phylogenetic analysis. Genetic characterization by partial sequencing of non-structural protein 2 (nsP2; 378 bp), envelope E1 (505 bp) and E2 (428 bp) identified one critical mutation in the E2 protein coding region of these CHIKV strains. This novel, non-conservative mutation, L210Q, consistently present in both human and mosquito-derived samples studied, was within the region of the E2 protein (amino acids E2 200-220) that determines mosquito cell infectivity in many alpha viruses. Our results show the involvement of Ae. albopictus in this outbreak in Kerala and appearance of CHIKV with novel genetic changes. Detection of virus in adult mosquitoes, emerged in the laboratory from larvae, also points to the possibility of transovarial transmission (TOT) of mutant CHIKV strains in mosquitoes.

  13. Molecular characterization of Chikungunya virus isolates from clinical samples and adult Aedes albopictus mosquitoes emerged from larvae from Kerala, South India

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    Niyas Kudukkil P

    2010-08-01

    Full Text Available Abstract Chikungunya virus (CHIKV, an arthritogenic alphavirus, is transmitted to humans by infected Aedes (Ae. aegypti and Ae.albopictus mosquitoes. In the study, reverse-transcription PCR (RT PCR and virus isolation detected CHIKV in patient samples and also in adult Ae.albopictus mosquitoes that was derived from larvae collected during a chikungunya (CHIK outbreak in Kerala in 2009. The CHIKV strains involved in the outbreak were the East, Central and South African (ECSA genotype that had the E1 A226V mutation. The viral strains from the mosquitoes and CHIK patients from the same area showed a close relationship based on phylogenetic analysis. Genetic characterization by partial sequencing of non-structural protein 2 (nsP2; 378 bp, envelope E1 (505 bp and E2 (428 bp identified one critical mutation in the E2 protein coding region of these CHIKV strains. This novel, non-conservative mutation, L210Q, consistently present in both human and mosquito-derived samples studied, was within the region of the E2 protein (amino acids E2 200-220 that determines mosquito cell infectivity in many alpha viruses. Our results show the involvement of Ae. albopictus in this outbreak in Kerala and appearance of CHIKV with novel genetic changes. Detection of virus in adult mosquitoes, emerged in the laboratory from larvae, also points to the possibility of transovarial transmission (TOT of mutant CHIKV strains in mosquitoes.

  14. Density-Dependent Oviposition by Female Aedes albopictus (Diptera: Culicidae) Spreads Eggs Among Containers During the Summer but Accumulates Them in the Fall.

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    Fonseca, D M; Kaplan, L R; Heiry, R A; Strickman, D

    2015-07-01

    When possible, oviparous females should deposit eggs in sites that maximize the future performance of their offspring. Therefore, studies of oviposition behavior may uncover parameters important to offspring fitness. Gravid female Aedes albopictus (Skuse) were given a choice of containers with leaf infusion or plain water, either open or with a cover with a small opening, and their behavior was compared under summer (long day, higher temperature) or fall (short day, lower temperature) regimes. Open containers with leaf infusion were always preferred, but over time, summer females expanded their choices to oviposit in all containers and follow-up experiments indicated that the number of eggs laid was inversely correlated to the number of eggs present. In contrast, fall females laying diapausing eggs that do not hatch until the spring, accumulated eggs in open containers with food resulting in high egg densities. Combined, these results demonstrate a seasonal shift that suggests either high winter egg mortality or safety in numbers. It also demonstrates that female Ae. albopictus change their behavior based on cues associated with expected added risk, which varies across time and space. The wide distribution of summer eggs across container types may contribute to the fast expansion of Ae. albopictus across its invasive range, but egg accumulation in the fall may be exploited for control. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Larvicidal and repellent activity of essential oils from wild and cultivated Ruta chalepensis L. (Rutaceae) against Aedes albopictus Skuse (Diptera: Culicidae), an arbovirus vector.

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    Conti, Barbara; Leonardi, Michele; Pistelli, Luisa; Profeti, Raffaele; Ouerghemmi, Ines; Benelli, Giovanni

    2013-03-01

    Rutaceae are widely recognized for their toxic and repellent activity exerted against mosquitoes. In our research, the essential oils extracted from fresh leaves of wild and cultivated plants of Ruta chalepensis L. (Rutaceae) were evaluated for larvicidal and repellent activity against the Asian tiger mosquito, Aedes albopictus Skuse (Diptera: Culicidae), currently the most invasive mosquito worldwide. In this research, gas chromatography and gas chromatography-mass spectrometry analyses of the essential oils from wild and cultivated plants showed only quantitative differences, in particular relatively to the amounts of ketone derivatives, while the qualitative profile evidenced a similar chemical composition. Both essential oils from wild and cultivated R. chalepensis plants were able to exert a very good toxic activity against A. albopictus larvae (wild plants, LC(50) = 35.66 ppm; cultivated plants, LC(50) = 33.18 ppm), and mortality was dosage dependent. These data are the first evidence of the toxicity of R. chalepensis against mosquitoes. Furthermore, the R. chalepensis essential oil from wild plants was an effective repellent against A. albopictus, also at lower dosages: RD(50) was 0.000215 μL/cm(2) of skin, while RD(90) was 0.007613 μL/cm(2). Our results clearly evidenced that the larvicidal and repellent activity of R. chalepensis essential oil could be used for the development of new and safer products against the Asian tiger mosquito.

  16. Failure to demonstrate experimental vertical transmission of the epidemic strain of Chikungunya virus in Aedes albopictus from La Réunion Island, Indian Ocean

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    Marie Vazeille

    2009-07-01

    Full Text Available Aedes albopictus was responsible for transmission in the first outbreak of chikungunya (CHIK on La Réunion Island, Indian Ocean, in 2005-2006. The magnitude of the outbreak on this island, which had been free of arboviral diseases for over 30 years, as well as the efficiency of Ae. albopictus as the main vector, raises questions about the maintenance of the CHIK virus (CHIKV through vertical transmission mechanisms. Few specimens collected from the field as larvae were found to be infected. In this study, Ae. albopictus originating from La Réunion were orally infected with a blood-meal containing 10(8 pfu/mL of the CHIKV epidemic strain (CHIKV 06.21. Eggs from the first and second gonotrophic cycles were collected and raised to the adult stage. The infectious status of the progeny was checked (i by immunofluorescence on head squashes of individual mosquitoes to detect the presence of viral particles or (ii by quantitative RT-PCR on mosquito pools to detect viral RNA. We analysed a total of 1,675 specimens from the first gonotrophic cycle and 1,709 from the second gonotrophic cycle without detecting any viral particles or viral RNA. These laboratory results are compared to field records.

  17. Effectiveness of ultra-low volume nighttime applications of an adulticide against diurnal Aedes albopictus, a critical vector of dengue and chikungunya viruses.

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    Ary Farajollahi

    Full Text Available Aedes albopictus, the Asian tiger mosquito, continues expanding its geographic range and involvement in mosquito-borne diseases such as chikungunya and dengue. Vector control programs rarely attempt to suppress this diurnal species with an ultra-low volume (ULV adulticide because for maximum efficacy applications are conducted at night. During 2009-2011 we performed experimental nighttime applications of a novel adulticide (DUET® against field populations of Ae. albopictus within an urban site composed of approximately 1,000 parcels (home and yard in northeastern USA. Dual applications at mid label rate of the adulticide spaced one or two days apart accomplished significantly higher control (85.0 ± 5.4% average reduction than single full rate applications (73.0 ± 5.4%. Our results demonstrate that nighttime ULV adulticiding is effective in reducing Ae. albopictus abundance and highlight its potential for use as part of integrated pest management programs and during disease epidemics when reducing human illness is of paramount importance.

  18. Quality control and data validation procedure in large-scale quantitative monitoring of mosquito density: the case of Aedes albopictus in Emilia-Romagna region, Italy.

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    Carrieri, Marco; Albieri, Alessandro; Urbanelli, Sandra; Angelini, Paola; Venturelli, Claudio; Matrangolo, Carmela; Bellini, Romeo

    2017-03-01

    The risk of local transmission of chikungunya, dengue, and Zika viruses from viremic travelers arriving from affected areas is a real possibility in southern Europe, due to the large presence of the vector Aedes albopictus. The first chikungunya outbreak in Europe occurred in the Emilia-Romagna region, Italy, in 2007, prompting the regional public health department to implement an Ae. albopictus monitoring and control plan. This paper presents the procedure developed for the quality control of the data collected by the regional ovitrap monitoring network. The quality control procedure consists of four successive steps; the first step is data acquisition and the second is an automatic data processing step, while skilled technicians according to specific procedures perform the third and fourth steps by checking the exact position of the ovitraps and by conducting human landing collections, respectively. The paper also presents the results of this quality control procedure applied to the data collected through the large-scale Ae. albopictus monitoring operation performed in Emilia-Romagna in 2015.

  19. Larvicidal activity and influence of Bacillus thuringiensis var. israelensis on Aedes albopictus oviposition in ovitraps during a two-week check interval protocol.

    Science.gov (United States)

    Carrieri, Marco; Masetti, Antonio; Albieri, Alessandro; Maccagnani, Bettina; Bellini, Romeo

    2009-06-01

    Toxicity persistence of Bacillus thuringiensis var. israelensis (Bti) was evaluated in laboratory and field trials to develop a new protocol for Aedes albopictus monitoring. In the laboratory, the residual toxicity of 5 Bti formulations was compared using the percentage mortality at days 4, 8, 12, and 16 of Culex pipiens larvae exposed for 24 h to Bti treatments. The results showed a good performance of all tested formulations (>97% mortality at day 14, for all the formulations), but only Vectobac 12AS at the concentration of 1 ml/liter showed an efficacy of 100% for 2 wk. A field study was designed to test the effect of Bti on the ovitrap check interval or influence of ovipositional response of gravid Ae. albopictus females. Three different ovitrap treatments were used: ovitraps with tap water checked weekly; ovitraps with tap water checked every 2 wk; ovitraps with Bti (Vectobac 12AS, dose of 1 ml/liter) checked every 2 wk. Our study demonstrated that in the ovitrap, the toxic action of a 1% solution of Bti was maintained for at least 14 days with mortality of 100% and that rainfall did not seem to negatively influence the residual action of Bti. Therefore the probability that the larvae may complete the developmental cycle in ovitraps with Bti seems to be very low. The oviposition activity index showed that Bti enhances the oviposition rate of Ae. albopictus by 17.4%.

  20. How Diverse Detrital Environments Influence Nutrient Stoichiometry between Males and Females of the Co-Occurring Container Mosquitoes Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus

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    Yee, Donald A.; Kaufman, Michael G.; Ezeakacha, Nnaemeka F.

    2015-01-01

    Allocation patterns of carbon and nitrogen in animals are influenced by food quality and quantity, as well as by inherent metabolic and physiological constraints within organisms. Whole body stoichiometry also may vary between the sexes who differ in development rates and reproductive allocation patterns. In aquatic containers, such as tree holes and tires, detrital inputs, which vary in amounts of carbon and nitrogen, form the basis of the mosquito-dominated food web. Differences in development times and mass between male and female mosquitoes may be the result of different reproductive constraints, which could also influence patterns of nutrient allocation. We examined development time, survival, and adult mass for males and females of three co-occurring species, Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus, across environments with different ratios of animal and leaf detritus. We quantified the contribution of detritus to biomass using stable isotope analysis and measured tissue carbon and nitrogen concentrations among species and between the sexes. Development times were shorter and adults were heavier for Aedes in animal versus leaf-only environments, whereas Culex development times were invariant across detritus types. Aedes displayed similar survival across detritus types whereas C. quinquefasciatus showed decreased survival with increasing leaf detritus. All species had lower values of 15N and 13C in leaf-only detritus compared to animal, however, Aedes generally had lower tissue nitrogen compared to C. quinquefasciatus. There were no differences in the C:N ratio between male and female Aedes, however, Aedes were different than C. quinquefasciatus adults, with male C. quinquefasciatus significantly higher than females. Culex quinquefasciatus was homeostatic across detrital environments. These results allow us to hypothesize an underlying stoichiometric explanation for the variation in performance of different container species under similar

  1. How Diverse Detrital Environments Influence Nutrient Stoichiometry between Males and Females of the Co-Occurring Container Mosquitoes Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus.

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    Donald A Yee

    Full Text Available Allocation patterns of carbon and nitrogen in animals are influenced by food quality and quantity, as well as by inherent metabolic and physiological constraints within organisms. Whole body stoichiometry also may vary between the sexes who differ in development rates and reproductive allocation patterns. In aquatic containers, such as tree holes and tires, detrital inputs, which vary in amounts of carbon and nitrogen, form the basis of the mosquito-dominated food web. Differences in development times and mass between male and female mosquitoes may be the result of different reproductive constraints, which could also influence patterns of nutrient allocation. We examined development time, survival, and adult mass for males and females of three co-occurring species, Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus, across environments with different ratios of animal and leaf detritus. We quantified the contribution of detritus to biomass using stable isotope analysis and measured tissue carbon and nitrogen concentrations among species and between the sexes. Development times were shorter and adults were heavier for Aedes in animal versus leaf-only environments, whereas Culex development times were invariant across detritus types. Aedes displayed similar survival across detritus types whereas C. quinquefasciatus showed decreased survival with increasing leaf detritus. All species had lower values of 15N and 13C in leaf-only detritus compared to animal, however, Aedes generally had lower tissue nitrogen compared to C. quinquefasciatus. There were no differences in the C:N ratio between male and female Aedes, however, Aedes were different than C. quinquefasciatus adults, with male C. quinquefasciatus significantly higher than females. Culex quinquefasciatus was homeostatic across detrital environments. These results allow us to hypothesize an underlying stoichiometric explanation for the variation in performance of different container

  2. How Diverse Detrital Environments Influence Nutrient Stoichiometry between Males and Females of the Co-Occurring Container Mosquitoes Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus.

    Science.gov (United States)

    Yee, Donald A; Kaufman, Michael G; Ezeakacha, Nnaemeka F

    2015-01-01

    Allocation patterns of carbon and nitrogen in animals are influenced by food quality and quantity, as well as by inherent metabolic and physiological constraints within organisms. Whole body stoichiometry also may vary between the sexes who differ in development rates and reproductive allocation patterns. In aquatic containers, such as tree holes and tires, detrital inputs, which vary in amounts of carbon and nitrogen, form the basis of the mosquito-dominated food web. Differences in development times and mass between male and female mosquitoes may be the result of different reproductive constraints, which could also influence patterns of nutrient allocation. We examined development time, survival, and adult mass for males and females of three co-occurring species, Aedes albopictus, Ae. aegypti, and Culex quinquefasciatus, across environments with different ratios of animal and leaf detritus. We quantified the contribution of detritus to biomass using stable isotope analysis and measured tissue carbon and nitrogen concentrations among species and between the sexes. Development times were shorter and adults were heavier for Aedes in animal versus leaf-only environments, whereas Culex development times were invariant across detritus types. Aedes displayed similar survival across detritus types whereas C. quinquefasciatus showed decreased survival with increasing leaf detritus. All species had lower values of 15N and 13C in leaf-only detritus compared to animal, however, Aedes generally had lower tissue nitrogen compared to C. quinquefasciatus. There were no differences in the C:N ratio between male and female Aedes, however, Aedes were different than C. quinquefasciatus adults, with male C. quinquefasciatus significantly higher than females. Culex quinquefasciatus was homeostatic across detrital environments. These results allow us to hypothesize an underlying stoichiometric explanation for the variation in performance of different container species under similar

  3. Efficacy of seed extracts of Annona squamosa and Annona muricata (Annonaceae) for the control of Aedes albopictus and Culex quinquefasciatus (Culicidae)

    Institute of Scientific and Technical Information of China (English)

    Fara Nantenaina Raharimalala; Beby Rasoahantaveloniaina; Pierre Herv Ravelonandro; Patrick Mavingui

    2014-01-01

    Objective: To evaluate the potential efficacy of seed extracts of Annona squamosa and Annona muricata used as natural insecticides to control adult and larvae of the vectors Aedes albopictus and Culex quinquefasciatus under laboratory conditions. Methods:Aqueous and oil extracts of the two plants were prepared from dried seeds. Preliminary identifications of the chemical components of each seed extracts were performed using micro-reactional and GCP techniques. Larvae and adults of Aedes albopictus and Culex quinquefasciatus were collected from the breeding sites in coastal and highlands regions of Madagascar. WHO standardized tests of susceptibility for larvae and imaginal stage of mosquitoes were realized to determine mortality and LC50 of mosquitoes. Results: Chemical identifications showed that these extracts contain alkaloids and flavonoids compounds that probably confer their biological insecticidal proprieties. CPG analysis showed also the presence of various fatty acids. On adult mosquitoes, significant insecticidal effects were observed with both aqueous and oil extracts of the two plant seeds compared to mortality induced by deltamethrin, an insecticide used as reference. Extracts of Annona muricata induced high mortality rate to both species of mosquito compared to extracts of Annona squamosa at all concentrations tested. The LC50 of seed extracts ranged from 1% to 5% for adults and 0.5% to 1% for larvae. Conclusions: The seed extracts of these two plants may be used as mosquito controlling agents and offer a new approach to a less costly, practical and environmentally friendly control of vector borne diseases.

  4. Effect of food types on competitive interaction between Aedes aegypti (LINNAEUS, 1762 and Ae. albopictus (SKUSE, 1894 (Diptera, Culicidae: a proximate level appraisal

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    Banerjee Sampa

    2017-06-01

    Full Text Available Competitive interactions between coexisting Aedes aegypti and Ae. albopictus have been implied as a crucial factor shaping life history traits and population characteristics. The overlap in resource requirements and similarities in the life history strategies of the two Aedes mosquitoes form a basis for competitive interactions. In the present study, the role of the food quality of the larval habitats in influencing the outcome of competition between Ae. aegypti and Ae. albopictus is evaluated to highlight food quality as a basis for asymmetric competitive outcomes. Instar I larvae of the two mosquitoes were reared using conspecifics or heterospecifics of constant size and equal ratio with four different food types: boiled rice, boiled pulses, a mixture of boiled rice and pulses, and fish food. Competitive interactions were evaluated using age at pupation (AP, pupal weight (PW, dry adult weight (AW and wing length (WL with respect to intra- and interspecific competition for the two sexes of each mosquito species. The results show that Ae. albopictus developed faster but achieved a smaller size compared to Ae. aegypti under interspecific competition conditions, the extent of the difference varying significantly with the food type. Given the variety of food resources available in the small container larval habitats, the results of the study imply that food quality may act differentially with respect to larval development and adult body size, depending on the conspecifics or heterospecifics and on the sex of the species concerned. The dominance of one species over the other may also be a consequence of the resource utilization pattern that varies in the larval habitats.

  5. Area-Wide Ground Applications of Bacillus thuringiensis var. israelensis for the Control of Aedes albopictus in Residential Neighborhoods: From Optimization to Operation

    Science.gov (United States)

    Williams, Gregory M.; Faraji, Ary; Unlu, Isik; Healy, Sean P.; Farooq, Muhammad; Gaugler, Randy; Hamilton, George; Fonseca, Dina M.

    2014-01-01

    The increasing range of Aedes albopictus, the Asian tiger mosquito, in the USA and the threat of chikungunya and dengue outbreaks vectored by this species have necessitated novel approaches to control this peridomestic mosquito. Conventional methods such as adulticiding provide temporary relief, but fail to manage this pest on a sustained basis. We explored the use of cold aerosol foggers and misting machines for area-wide applications of Bacillus thuringiensis var. israelensis (VectoBac WDG) as a larvicide targeting Aedes albopictus. During 2010–2013 we performed initially open field trials and then 19 operational area-wide applications in urban and suburban residential areas in northeastern USA to test three truck-mounted sprayers at two application rates. Area-wide applications of WDG in open field conditions at 400 and 800 g/ha killed on average 87% of tested larvae. Once techniques were optimized in residential areas, applications with a Buffalo Turbine Mist Sprayer at a rate of 800 g/ha, the best combination, consistently provided over 90% mortality. Importantly, there was no significant decrease in efficacy with distance from the spray line even in blocks of row homes with trees and bushes in the backyards. Under laboratory conditions Bti deposition in bioassay cups during the operational trials resulted in over 6 weeks of residual control. Our results demonstrate that area-wide truck mounted applications of WDG can effectively suppress Ae. albopictus larvae and should be used in integrated mosquito management approaches to control this nuisance pest and disease vector. PMID:25329314

  6. Cross-Mating Compatibility and Competitiveness among Aedes albopictus Strains from Distinct Geographic Origins - Implications for Future Application of SIT Programs in the South West Indian Ocean Islands.

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    Damiens, David; Lebon, Cyrille; Wilkinson, David A; Dijoux-Millet, Damien; Le Goff, Gilbert; Bheecarry, Ambicadutt; Gouagna, Louis Clément

    2016-01-01

    The production of large numbers of males needed for a sustainable sterile insect technique (SIT) control program requires significant developmental and operational costs. This may constitute a significant economic barrier to the installation of large scale rearing facilities in countries that are undergoing a transition from being largely dependent on insecticide use to be in a position to integrate the SIT against Aedes albopictus. Alternative options available for those countries could be to rely on outsourcing of sterile males from a foreign supplier, or for one centralised facility to produce mosquitoes for several countries, thus increasing the efficiency of the mass-rearing effort. However, demonstration of strain compatibility is a prerequisite for the export of mosquitoes for transborder SIT applications. Here, we compared mating compatibility among Ae. albopictus populations originating from three islands of the South Western Indian Ocean, and assessed both insemination rates and egg fertility in all possible cross-mating combinations. Furthermore, competitiveness between irradiated and non-irradiated males from the three studied strains, and the subsequent effect on female fertility were also examined. Although morphometric analysis of wing shapes suggested phenoptypic differences between Ae. albopictus strains, perfect reproductive compatibility between them was observed. Furthermore, irradiated males from the different islands demonstrated similar levels of competitiveness and induced sterility when confronted with fertile males from any of the other island populations tested. In conclusion, despite the evidence of inter-strain differences based on male wing morphology, collectively, our results provide a new set of expectations for the use of a single candidate strain of mass-reared sterile males for area-wide scale application of SIT against Ae. albopictus populations in different islands across the South Western Indian Ocean. Cross

  7. Cross-Mating Compatibility and Competitiveness among Aedes albopictus Strains from Distinct Geographic Origins - Implications for Future Application of SIT Programs in the South West Indian Ocean Islands

    Science.gov (United States)

    Damiens, David; Lebon, Cyrille; Wilkinson, David A.; Dijoux-Millet, Damien; Le Goff, Gilbert; Bheecarry, Ambicadutt; Gouagna, Louis Clément

    2016-01-01

    The production of large numbers of males needed for a sustainable sterile insect technique (SIT) control program requires significant developmental and operational costs. This may constitute a significant economic barrier to the installation of large scale rearing facilities in countries that are undergoing a transition from being largely dependent on insecticide use to be in a position to integrate the SIT against Aedes albopictus. Alternative options available for those countries could be to rely on outsourcing of sterile males from a foreign supplier, or for one centralised facility to produce mosquitoes for several countries, thus increasing the efficiency of the mass-rearing effort. However, demonstration of strain compatibility is a prerequisite for the export of mosquitoes for transborder SIT applications. Here, we compared mating compatibility among Ae. albopictus populations originating from three islands of the South Western Indian Ocean, and assessed both insemination rates and egg fertility in all possible cross-mating combinations. Furthermore, competitiveness between irradiated and non-irradiated males from the three studied strains, and the subsequent effect on female fertility were also examined. Although morphometric analysis of wing shapes suggested phenoptypic differences between Ae. albopictus strains, perfect reproductive compatibility between them was observed. Furthermore, irradiated males from the different islands demonstrated similar levels of competitiveness and induced sterility when confronted with fertile males from any of the other island populations tested. In conclusion, despite the evidence of inter-strain differences based on male wing morphology, collectively, our results provide a new set of expectations for the use of a single candidate strain of mass-reared sterile males for area-wide scale application of SIT against Ae. albopictus populations in different islands across the South Western Indian Ocean. Cross

  8. Biosynthesis, characterization, and acute toxicity of Berberis tinctoria-fabricated silver nanoparticles against the Asian tiger mosquito, Aedes albopictus, and the mosquito predators Toxorhynchites splendens and Mesocyclops thermocyclopoides.

    Science.gov (United States)

    Kumar, Palanisamy Mahesh; Murugan, Kadarkarai; Madhiyazhagan, Pari; Kovendan, Kalimuthu; Amerasan, Duraisamy; Chandramohan, Balamurugan; Dinesh, Devakumar; Suresh, Udaiyan; Nicoletti, Marcello; Alsalhi, Mohamad Saleh; Devanesan, Sandhanasamy; Wei, Hui; Kalimuthu, Kandasamy; Hwang, Jiang-Shiou; Lo Iacono, Annalisa; Benelli, Giovanni

    2016-02-01

    Aedes albopictus is an important arbovirus vector, including dengue. Currently, there is no specific treatment for dengue. Its prevention solely depends on effective vector control measures. In this study, silver nanoparticles (AgNPs) were biosynthesized using a cheap leaf extract of Berberis tinctoria as reducing and stabilizing agent and tested against Ae. albopictus and two mosquito natural enemies. AgNPs were characterized by using UV–vis spectrophotometry, X-ray diffraction, and scanning electron microscopy. In laboratory conditions, the toxicity of AgNPs was evaluated on larvae and pupae of Ae. albopictus. Suitability Index/Predator Safety Factor was assessed on Toxorhynchites splendens and Mesocyclops thermocyclopoides. The leaf extract of B. tinctoria was toxic against larval instars (I–IV) and pupae of Ae. albopictus; LC50 was 182.72 ppm (I instar), 230.99 ppm (II), 269.65 ppm (III), 321.75 ppm (IV), and 359.71 ppm (pupa). B. tinctoria-synthesized AgNPs were highly effective, with LC50 of 4.97 ppm (I instar), 5.97 ppm (II), 7.60 ppm (III), 9.65 ppm (IV), and 14.87 ppm (pupa). Both the leaf extract and AgNPs showed reduced toxicity against the mosquito natural enemies M. thermocyclopoides and T. splendens. Overall, this study firstly shed light on effectiveness of B. tinctoria-synthesized AgNPs as an eco-friendly nanopesticide, highlighting the concrete possibility to employ this newer and safer tool in arbovirus vector control programs.

  9. Laboratory evaluation of aqueous leaf extract of Tephrosia vogelii against larvae of Aedes albopictus (Diptera: Culicidae) and non-target aquatic organisms.

    Science.gov (United States)

    Li, Weisheng; Huang, Congling; Wang, Kun; Fu, Jiantao; Cheng, Dongmei; Zhang, Zhixiang

    2015-06-01

    Mosquito control using insecticides has been the most successful intervention known to reduce malaria prevalence or incidence. However, vector control is facing a threat due to the emergence of resistance to synthetic insecticides. Insecticides of botanical origin may serve as suitable alternative biocontrol techniques in the future. In this research, the leaf aqueous leachate of Tephrosia vogelii was evaluated for its toxicity against larvae of the most invasive mosquito worldwide, Aedes albopictus (Diptera: Culicidae), and toward adults of the water flea, Daphnia magna (Cladocera: Crustacea) and Oreochromis niloticus, two non-target aquatic organisms that share the same ecological niche of A. albopictus. The leaf aqueous leachate of T. vogelii was evaluated against fourth-instar larvae, non-blood fed 3-5 days old laboratory strains of A. albopictus under laboratory condition. In addition, the objective of the present work was to study the environmental safety evaluation for aquatic ecosystem. Mortality was then recorded after 7d exposure. The leaf aqueous leachate of T. vogelii showed high mosquitocidal activity against larvae of A. albopictus, with a LC50=1.18μg/mL. However, it had a remarkable acute toxicity also toward adults of the non-target arthropod D. magna, with a LC50=0.47μg/L and O. niloticus with a LC50=5.31μg/L. The present findings have important implications in the practical control of mosquito larvae in the aquatic ecosystem, as the medicinal plants studied are commonly available in large quantities. The extract could be used in stagnant water bodies for the control of mosquitoes acting as vector for many communicable diseases.

  10. Larvicidal and ovideterrent properties of neem oil and fractions against the filariasis vector Aedes albopictus (Diptera: Culicidae): a bioactivity survey across production sites.

    Science.gov (United States)

    Benelli, Giovanni; Bedini, Stefano; Cosci, Francesca; Toniolo, Chiara; Conti, Barbara; Nicoletti, Marcello

    2015-01-01

    Neem seed oil (NSO) of Azadirachta indica (Meliaceae) contains more than 100 determined biologically active compounds, and many formulations deriving from them showed toxicity, antifeedancy and repellence against a number of arthropod pests. However, it is widely known that botanical products can differ in their chemical composition and bioactivity, as function of the production site and production process. We used high-performance thin layer chromatography (HPTLC) to investigate differences in chemical constituents of NSOs from three production sites. HPTLC analyses showed several differences in chemical abundance and diversity among NSOs, with special reference to limonoids. Furthermore, the three NSOs and their fractions of increasing polarities [i.e. ethyl acetate (EA) fraction and butanol (BU) fraction] were evaluated for larvicidal toxicity and field oviposition deterrence against the Asian tiger mosquito, Aedes albopictus, currently the most invasive mosquito worldwide. Results from bioactivity experiments showed good toxicity of NSOs and EA fractions against A. albopictus fourth instar larvae (with LC50 values ranging from 142.28 to 209.73 ppm), while little toxicity was exerted by BU fractions. A significant effect of the production site and dosage was also found and is probably linked to differences in abundance of constituents among samples, as highlighted by HPTLC analyses. NSOs and EAs were also able to deter A. albopictus oviposition in the field (effective repellence values ranging from 98.55 to 70.10%), while little effectiveness of BU fractions was found. Concerning ovideterrent activity, no difference due to the production site was found. This is the first report concerning larvicidal toxicity of NSO against A. albopictus and ovideterrence against Culicidae in the field. The chance to use chemicals from the NSO EA fraction seems promising, since they are effective at lower doses, if compared to synthetic products currently marketed, and could be

  11. Efficacy of attractive toxic sugar baits (ATSB) against Aedes albopictus with garlic oil encapsulated in beta-cyclodextrin as the active ingredient.

    Science.gov (United States)

    Junnila, Amy; Revay, Edita E; Müller, Gunter C; Kravchenko, Vasiliy; Qualls, Whitney A; Xue, Rui-de; Allen, Sandra A; Beier, John C; Schlein, Yosef

    2015-12-01

    We tested the efficacy of attractive toxic sugar bait (ATSB) with garlic oil microencapsulated in beta-cyclodextrin as active ingredient against Aedes albopictus in suburban Haifa, Israel. Two three-acre gardens with high numbers of Ae. albopictus were selected for perimeter spray treatment with ATSB and ASB (bait containing no active ingredient). Baits were colored with food dye to verify feeding of the mosquitoes. The mosquito population was monitored by human landing catches and sweep net catches in the surrounding vegetation. Experiments lasted for 44 days. Treatment occurred on day 13. The mosquito population collapsed about 4 days after treatment and continued to drop steadily for 27 days until the end of the study. At the experimental site the average pre-treatment landing rate was 17.2 per 5mins. Two days post-treatment, the landing rate dropped to 11.4, and continued to drop to an average of 2.6 during the following 26 days. During the same period, the control population was stable. Few sugar fed females (8-10%) approached a human bait and anthrone tests showed relatively small amounts of sugar within their crop/gut. Around 60-70 % of males caught near our human bait were sugar positive which may indicate that the males were feeding on sugar for mating related behavior. From the vegetation treated with the toxic bait, we recovered significantly fewer (about 10-14%) males and females stained by ATSB than at the ASB-treated control. This may indicate that the toxic baits alter the resting behavior of the poisoned mosquitoes within the vegetation. Almost no Ae. albopictus females (5.2±1.4) approached human bait after treatment with ATSB. It therefore appears that microencapsulated garlic oil is an effective pesticide against Ae. albopictus when used in an ATSB system.

  12. Multi-country Survey Revealed Prevalent and Novel F1534S Mutation in Voltage-Gated Sodium Channel (VGSC Gene in Aedes albopictus.

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    Jiabao Xu

    2016-05-01

    Full Text Available Aedes albopictus is an important dengue vector because of its aggressive biting behavior and rapid spread out of its native home range in Southeast Asia. Pyrethroids are widely used for adult mosquito control, and resistance to pyrethroids should be carefully monitored because vector control is the only effective method currently available to prevent dengue transmission. The voltage-gated sodium channel gene is the target site of pyrethroids, and mutations in this gene cause knockdown resistance (kdr. Previous studies reported various mutations in the voltage-gated sodium channel (VGSC gene, but the spatial distribution of kdr mutations in Ae. albopictus has not been systematically examined, and the association between kdr mutation and phenotypic resistance has not been established.A total of 597 Ae. albopictus individuals from 12 populations across Asia, Africa, America and Europe were examined for mutations in the voltage-gated sodium channel gene. Three domains for a total of 1,107 bp were sequenced for every individual. Two populations from southern China were examined for pyrethroid resistance using the World Health Organization standard tube bioassay, and the association between kdr mutations and phenotypic resistance was tested.A total of 29 synonymous mutations were found across domain II, III and IV of the VGSC gene. Non-synonymous mutations in two codons of the VGSC gene were detected in 5 populations from 4 countries. A novel mutation at 1532 codon (I1532T was found in Rome, Italy with a frequency of 19.7%. The second novel mutation at codon 1534 (F1534S was detected in southern China and Florida, USA with a frequency ranging from 9.5-22.6%. The WHO insecticide susceptibility bioassay found 90.1% and 96.1% mortality in the two populations from southern China, suggesting resistance and probable resistance. Positive association between kdr mutations with deltamethrin resistance was established in these two populations.Two novel kdr

  13. Two Chikungunya isolates from the outbreak of La Reunion (Indian Ocean exhibit different patterns of infection in the mosquito, Aedes albopictus.

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    Marie Vazeille

    Full Text Available BACKGROUND: A Chikungunya (CHIK outbreak hit La Réunion Island in 2005-2006. The implicated vector was Aedes albopictus. Here, we present the first study on the susceptibility of Ae. albopictus populations to sympatric CHIKV isolates from La Réunion Island and compare it to other virus/vector combinations. METHODOLOGY AND FINDINGS: We orally infected 8 Ae. albopictus collections from La Réunion and 3 from Mayotte collected in March 2006 with two Chikungunya virus (CHIKV from La Réunion: (i strain 05.115 collected in June 2005 with an Alanine at the position 226 of the glycoprotein E1 and (ii strain 06.21 collected in November 2005 with a substitution A226V. Two other CHIKV isolates and four additional mosquito strains/species were also tested. The viral titer of the infectious blood-meal was 10(7 plaque forming units (pfu/mL. Dissemination rates were assessed by immunofluorescent staining on head squashes of surviving females 14 days after infection. Rates were at least two times higher with CHIKV 06.21 compared to CHIKV 05.115. In addition, 10 individuals were analyzed every day by quantitative RT-PCR. Viral RNA was quantified on (i whole females and (ii midguts and salivary glands of infected females. When comparing profiles, CHIKV 06.21 produced nearly 2 log more viral RNA copies than CHIKV 05.115. Furthermore, females infected with CHIKV 05.115 could be divided in two categories: weakly susceptible or strongly susceptible, comparable to those infected by CHIKV 06.21. Histological analysis detected the presence of CHIKV in salivary glands two days after infection. In addition, Ae. albopictus from La Réunion was as efficient vector as Ae. aegypti and Ae. albopictus from Vietnam when infected with the CHIKV 06.21. CONCLUSIONS: Our findings support the hypothesis that the CHIK outbreak in La Réunion Island was due to a highly competent vector Ae. albopictus which allowed an efficient replication and dissemination of CHIKV 06.21.

  14. Insecticide resistance and, efficacy of space spraying and larviciding in the control of dengue vectors Aedes aegypti and Aedes albopictus in Sri Lanka.

    Science.gov (United States)

    Karunaratne, S H P P; Weeraratne, T C; Perera, M D B; Surendran, S N

    2013-09-01

    Unprecedented incidence of dengue has been recorded in Sri Lanka in recent times. Source reduction and use of insecticides in space spraying/fogging and larviciding, are the primary means of controlling the vector mosquitoes Aedes aegypti and Ae. albopictus in the island nation. A study was carried out to understand insecticide cross-resistance spectra and mechanisms of insecticide resistance of both these vectors from six administrative districts, i.e. Kandy, Kurunegala, Puttalam, Gampaha, Ratnapura and Jaffna, of Sri Lanka. Efficacy of the recommended dosages of frequently used insecticides in space spraying and larviciding in dengue vector control programmes was also tested. Insecticide bioassay results revealed that, in general, both mosquito species were highly resistant to DDT but susceptible to propoxur and malathion except Jaffna Ae. aegypti population. Moderate resistance to malathion shown by Jaffna Ae. aegypti population correlated with esterase and malathion carboxylesterase activities of the population. High levels of acetylcholinesterase (AChE) insensitivity in the absence of malathion and propoxur resistance may be due to non-synaptic forms of AChE proteins. Moderate pyrethroid resistance in the absence of high monooxygenase levels indicated the possible involvement of 'kdr' type resistance mechanism in Sri Lankan dengue vectors. Results of the space spraying experiments revealed that 100% mortality at a 10 m distance and >50% mortality at a 50 m distance can be achieved with malathion, pesguard and deltacide even in a ground with dense vegetation. Pesguard and deltacide spraying gave 100% mortality up to 50 m distance in open area and areas with little vegetation. Both species gave >50% mortalities for deltacide at a distance of 75 m in a dense vegetation area. Larval bioassays conducted in the laboratory showed that a 1 ppm temephos solution can maintain a larval mortality rate of 100% for ten months, and the mortality rate declined to 0% in the

  15. Diet and density dependent competition affect larval performance and oviposition site selection in the mosquito species Aedes albopictus (Diptera: Culicidae

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    Yoshioka Miho

    2012-10-01

    Full Text Available Abstract Background Oviposition-site choice is an essential component of the life history of all mosquito species. According to the oviposition-preference offspring-performance (P-P hypothesis, if optimizing offspring performance and fitness ensures high overall reproductive fitness for a given species, the female should accurately assess details of the heterogeneous environment and lay her eggs preferentially in sites with conditions more suitable to offspring. Methods We empirically tested the P-P hypothesis using the mosquito species Aedes albopictus by artificially manipulating two habitat conditions: diet (measured as mg of food added to a container and conspecific density (CD; number of pre-existing larvae of the same species. Immature development (larval mortality, development time to pupation and time to emergence and fitness (measured as wing length were monitored from first instar through adult emergence using a factorial experimental design over two ascending gradients of diet (2.0, 3.6, 7.2 and 20 mg food/300 ml water and CD (0, 20, 40 and 80 larvae/300 ml water. Treatments that exerted the most contrasting values of larval performance were recreated in a second experiment consisting of single-female oviposition site selection assay. Results Development time decreased as food concentration increased, except from 7.2 mg to 20.0 mg (Two-Way CR ANOVA Post-Hoc test, P > 0.1. Development time decreased also as conspecific density increased from zero to 80 larvae (Two-Way CR ANOVA Post-Hoc test, P . Combined, these results support the role of density-dependent competition for resources as a limiting factor for mosquito larval performance. Oviposition assays indicated that female mosquitoes select for larval habitats with conspecifics and that larval density was more important than diet in driving selection for oviposition sites. Conclusions This study supports predictions of the P-P hypothesis and provides a mechanistic understanding

  16. Development of a novel sticky trap for container-breeding mosquitoes and evaluation of its sampling properties to monitor urban populations of Aedes albopictus.

    Science.gov (United States)

    Facchinelli, L; Valerio, L; Pombi, M; Reiter, P; Costantini, C; Della Torre, A

    2007-06-01

    Collection methods currently used for large-scale sampling of adult Stegomyia mosquitoes (Diptera: Culicidae) present several operational limitations, which constitute major drawbacks to the epidemiological surveillance of arboviruses, the evaluation of the impact of control strategies, and the surveillance of the spreading of allochthonous species into non-endemic regions. Here, we describe a new sticky trap designed to capture adult container-breeding mosquitoes and to monitor their population dynamics. We tested the sampling properties of the sticky trap in Rome, Italy, where Aedes (Stegomyia) albopictus is common. The results of our observations, and the comparison between sticky trap catches and catches made with the standard oviposition trap, are presented. The sticky trap collected significantly larger numbers of Ae. albopictus females than any other Culicidae species representing >90% of the total catches. A maximum of 83 An. albopictus females was collected in a single week. A high correlation (Pearson correlation coefficient r= 0.96) was found between the number of females and the number of eggs collected by the traps. The functional relationship between the number of eggs and the number of adult females was assessed by major axis regression fitted to log(1 +x)-transformed trap counts as y= 0.065 + 1.695x. Trap samples significantly departed from a random distribution; Taylor's power law was fitted to the trap samples to quantify the degree of aggregation in the catches, returning the equations s(2)= 2.401 m(1.325) for the sticky trap and s(2)= 13.068 m(1.441) for the ovitrap, with s(2) and m denoting the weekly catch variance and mean, respectively, indicating that eggs were significantly more aggregated than mosquitoes (P ovitrap. At low population densities (c. ovitrap was more sensitive at detecting the presence of this species. Overall, our results indicate that our new model of sticky trap can be used to sample Ae. albopictus females in urban

  17. Characterization of Aedes albopictus (Skuse, 1894 (Diptera:Culicidae larval habitats near the Amazon River in Colombia Caracterización preliminar de los sitios de cría de Aedes (Stegomyia albopictus (Skuse, 1894 (Diptera: Culicidae en el municipio de Leticia, Amazonas, Colombia

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    Víctor Albert