85 research outputs found
Experimental study of the susceptibility of a European Aedes albopictus strain to dengue virus under a simulated Mediterranean temperature regime
Dengue virus (DENV) has reâemerged in Europe driven by the geographic expansion of the mosquito species Aedes albopictus and Aedes aegypti (Diptera: Culicidae) and the introduction of the virus by viraemic travellers. In the present study, the vector competence (VC) of Ae. albopictus collected in Catalonia (northeast Spain) was evaluated for two different DENV strains, DENVâ1 and DENVâ2, the serotypes responsible for all outbreaks of dengue that have occurred in Europe. Mosquitoes were reared under environmental conditions mimicking the mean temperature and humidity recorded in July on the Mediterranean coast of Catalonia. Mosquitoes were fed on an artificial infectious bloodmeal and, at 14âdays postâexposure, infection, disseminated infection and transmission rates (IR, DIR, TR) and transmission efficiency (TE) were determined by testing the virus in the body, legs and saliva. The tested Ae. albopictus strain was found to be susceptible to both DENVâ1 and DENVâ2 and to be able to transmit DENVâ1. This is the first time that the VC of Ae. albopictus for DENV has been tested in Europe in this specific context (i.e. mimicking the Mediterranean temperature and humidity recorded in Catalonia in July). This study confirms the potential of Ae. albopictus to start autochthonous DENV transmission cycles in the Mediterranean basin.info:eu-repo/semantics/publishedVersio
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Pond dyes are Culex mosquito oviposition attractants
Background
British mosquito population distribution, abundance, species composition and potential for mosquito disease transmission are intimately linked to the physical environment. The presence of ponds and water storage can significantly increase the density of particular mosquito species in the garden. Culex pipiens is the mosquito most commonly found in UK gardens and a potential vector of West Nile Virus WNV, although the current risk of transmission is low. However any factors that significantly change the distribution and population of C. pipiens are likely to impact subsequent risk of disease transmission. Pond dyes are used to control algal growth and improve aesthetics of still water reflecting surrounding planting. However, it is well documented that females of some species of mosquito prefer to lay eggs in dark water and/or containers of different colours and we predict that dyed ponds will be attractive to Culex mosquitoes.
Methods
Black pond dye was used in oviposition choice tests using wild-caught gravid C. pipiens. Larvae from wild-caught C. pipiens were also reared in the pond dye to determine whether it had any impact on survival. An emergence trap caught any adults that emerged from the water. Water butts (80 L) were positioned around university glasshouses and woodland and treated with black pond dye or left undyed. Weekly sampling over a six month period through summer and autumn was performed to quantified numbers of larvae and pupae in each treatment and habitat.
Results
Gravid female Culex mosquitoes preferred to lay eggs in dyed water. This was highly significant in tests conducted under laboratory conditions and in a semi-field choice test. Despite this, survivorship in black dyed water was significantly reduced compared to undyed water. Seasonal analysis of wild larval and pupal numbers in two habitats with and without dye showed no impact of dye but a significant impact of season and habitat. Mosquitoes were more successful, with significantly higher numbers of pupae, in the habitat where they had vegetation cover and shade.
Discussion
Our study has raised some interesting possibilities; one is that where used, pond dyes may be encouraging mosquitoes to breed in gardens in close proximity to people. Considering the concerns over potential future spread of disease in urban environments, this as well as shading of ponds and water butts, should inform future advice over reducing mosquito breeding and spread
Rift Valley fever virus and European mosquitoes vector competence of Culex pipiens and Stegomyia albopicta (= Aedes albopictus)
Rift Valley fever (RVF) is a mosquito-borne disease caused by the Rift Valley fever virus (RVFV). Rift Valley fever affects a large number of species, including human, and has severe impact on public health and the economy, especially in African countries. The present study examined the vector competence of three different European mosquito species, Culex pipiens (Linnaeus, 1758) form molestus (Diptera Culicidae), Culex pipiens hybrid form and Stegomyia albopicta (= Aedes albopictus) (Skuse, 1894) (Diptera Culicidae). Mosquitoes were artificially fed with blood containing RVFV. Infection, disseminated infection and transmission efficiency were evaluated. This is the first study to assess the transmission efficiency of European mosquito species using a virulent RVFV strain. The virus disseminated in Cx. pipiens hybrid form and in S. albopicta. Moreover, infectious viral particles were isolated from saliva of both species, showing their RVFV transmission capacity. The presence of competent Cx. pipiens and S. albopicta in Spain indicates that an autochthonous outbreak of RVF may occur if the virus is introduced. These findings provide information that will help health authorities to set up efficient entomological surveillance and RVFV vector control programmes. © 2017 The Authors. Medical and Veterinary Entomology published by John Wiley & Sons Ltd on behalf of Royal Entomological Society
Estudos paleoambientais interdisciplinares: dinĂąmica da vegetação, do ambiente marinho e inferĂȘncias climĂĄticas milenares a atuais na Costa Norte do EspĂrito Santo, Brasil
Estudos paleoambientais desde ~50.000 anos na costa do Brasil e, em particular, no litoral do EspĂrito Santo, sĂŁo ainda insuficientes para servir de base a reconstituiçÔes da dinĂąmica da vegetação, de oscilaçÔes do nĂvel relativo do mar e de flutuaçÔes climĂĄticas e respectivas influĂȘncias sobre a ação humana milenar. Para obter essas informaçÔes, uma equipe interdisciplinar, financiada por projetos temĂĄticos FAPESP e CNPq, desenvolveu pesquisas correlatas na Reserva Natural Vale (RNV) e regiĂŁo. Para a caracterização da dinĂąmica da vegetação e marinha, com inferĂȘncias climĂĄticas, em locais de floresta de tabuleiros e campos naturais da RNV e regiĂŁo desde ~16.000 anos, utilizaram-se isĂłtopos do C (12C, 13C e 14C) da matĂ©ria orgĂąnica do solo e sedimentar, alĂ©m de palinologia em sedimentos lacustres e terrestres. No estudo da dinĂąmica do ecĂłtono floresta â campo, apresentam-se inferĂȘncias preliminares sobre a evolução pedogenĂ©tica dos Espodossolos associados ao campo, com ĂȘnfase Ă s suas caracterĂsticas fĂsico-quĂmicas, e tambĂ©m dos Argissolos, encontrados sob floresta. Finaliza-se com o estĂĄgio inicial de uma coleção de referĂȘncia de fitĂłlitos, bioindicador de vegetação utilizado em estudos paleoambientais, extraĂdos de plantas da floresta de tabuleiros da RNV.A equipe agradece todo o empenho dos funcionĂĄrios e apoio logĂstico da Reserva Natural Vale, Linhares, EspĂrito Santo; Ă FAPESP atravĂ©s do projeto TemĂĄtico 2011/00995-7 (ProjES); e ao CNPq â Universal 2012-5/470210, pelo aporte financeiro e a colaboração dos tĂ©cnicos do LaboratĂłrio 14C, Liz Mary Bueno de Moraes e Thiago Casemiro Barrios de Campos, na preparação de amostras gasosas para a datação 14C.Peer Reviewe
Incidence of thyroid cancer in Italian contaminated sites
Some human literature suggests a possible role of endocrine disruptors (EDs) exposure in thyroid cancer (TC) development. We investigated TC incidence in selected Italian National Priority Contaminated Sites (NPCS) with documented presence of EDs considered thyroid carcinogens. Adjusted Standardized Incidence Ratios (SIRs), with their 90% confidence intervals, were computed by gender, and age-specific groups (aged 15-39 years, and 40 years or over) for each NPCS in the period 2006 to 2013. In the age group of 15-39 years, a significant excess of TC risk was found in two NPCSs in males; non-significant excess risks were observed in four NPCSs in males, and in five in females. In the age group of 40 years and over, significant excess risks were found in six NPCSs in males and in seven NPCSs in females; non-significant excess risks were identified in two NPCSs in males and females. The findings of several excesses in incidence, mainly observed in adults aged 40 years or over, are suggestive of a possible adverse effect associated with residence in NPCSs, even if a role of other factors cannot be excluded, due to the adoption of an ecological study design. Future analytical studies are needed to clarify if EDs are a TC risk factor for individuals living in NPCSs
Lambda-cyhalothrin efficiency on fruit borer control and quali-quantitative spraying aspects in a pinecone crop
EficiĂȘncia de fungicidas para controle de mofo-branco (Sclerotinia sclerotiorum) em soja, na safra 2019/2020: resultados sumarizados dos experimentos cooperativos.
bitstream/item/217684/1/Circ-Tec-165.pd
EficiĂȘncia de fungicidas para controle de mofo-branco (Sclerotinia sclerotiorum) em soja, na safra 2020/2021: resultados sumarizados dos experimentos cooperativos.
bitstream/item/224971/1/CT-173.pd
EficiĂȘncia de fungicidas para controle de mofo-branco (Sclerotinia sclerotiorum) em soja, na safra 2021/2022: resultados sumarizados dos experimentos cooperativos.
Experimentos cooperativos de controle biolĂłgico de Sclerotinia sclerotiorum na cultura da soja: resultados sumarizados da safra 2019/2020.
bitstream/item/216581/1/CIRCULAR-TECNICA-163-online.pd
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