Experiências em divulgação científica e sensibilização da população: importância do controle mecânico do vetor Aedes aegypti / Experiences in scientific outreach and public awareness: the importance of mechanical control of the Aedes aegypti vector / Experiencias en divulgación científica y sensibilización de la población: importancia del control mecánico del vector Aedes aegypti

Aedes aegypti é o principal vetor dos agentes etiológicos de dengue, zika e chikungunya, doenças para as quais não existem vacinas totalmente eficazes. Alternativas de controle visando mitigar essas arboviroses são primordiais. Entre essas, o controle mecânico aborda práticas de eliminação e/ou limpeza de criadouros do vetor. Neste relato, apresentamos e avaliamos criticamente ações realizadas pelo grupo, ocorridas entre 2016 e 2019, nas quais divulgamos informação científica clara através do diálogo com a população. Os métodos utilizados foram: 1) palestras em escolas (público infantojuvenil) utilizando slides, fotos e vídeos; 2) oficinas (público misto), estande com material in vivo do ciclo de vida do Aedes, jogos e desenhos. Analisamos dez palestras em escolas do ensino fundamental e médio e vinte oficinas realizadas em diferentes regiões do Brasil. Concluímos que tais ações e suas análises críticas devem ser realizadas continuamente para que sejam bem-sucedidas

Aedes aegypti is the main vector of dengue, zika, and chikungunya etiological agents, diseases for which no effective vaccines are available. Control alternatives aimed at mitigating these arboviruses are essential. Among such, mechanical control addresses practices of elimination and/or cleaning of vector breeding sites. Here, we presented and critically evaluated actions carried out by ourselves. These actions took place between 2016 and 2019, where we disseminated clear scientific information through dialogue with the population. The following methods were employed: 1) lectures in schools (children and youth audiences) using slides, photos, and videos; 2) workshops (mixed audience), stand with in vivo material from the Aedeslife cycle, games, and drawings. Ten lectures in elementary and high schools and twenty workshops held in different regions of Brazil were analyzed. It was concluded that such actions and their critical analyzes must be carried out continuously to be successful

Aedes aegypti es el principal vector de los agentes etiológicos del dengue, zika y chikungunya, enfermedades para las que no existen vacunas totalmente eficaces. Las alternativas de control para mitigar estas arbovirosis son fundamentales. El control mecánico, representa una de estas alternativas, aborda prácticas de eliminación y/o limpieza de criaderos del vector. En este informe presentamos y evaluamos de manera crítica las acciones realizadas por el grupo entre los años 2016 y 2019. Presentamos información científica clara a través del diálogo con la población mediante los siguientes métodos: 1) conferencias en escuelas (público infantil) utilizando diapositivas, fotos y videos; 2) Talleres (público mixto), stand con material in vivo del ciclo de vida del Aedes, juegos y dibujos. Analizamos diez conferencias en escuelas (primarias y secundarias) y veinte talleres realizados en diferentes regiones de Brasil. Concluimos que tales acciones y el análisis crítico de las mismas deben llevarse a cabo de manera continua para que resulten exitosas.

Zika infection decreases Aedes aegypti locomotor activity but does not influence egg production or viability

BACKGROUND Zika has emerged as a new public health threat after the explosive epidemic in Brazil in 2015. It is an arbovirus transmitted mainly by Aedes aegypti mosquitoes. The knowledge of physiological, behavioural and biological features in virus-infected vectors may help the understanding of arbovirus transmission dynamics and elucidate their influence in vector capacity. OBJECTIVES We aimed to investigate the effects of Zika virus (ZIKV) infection in the behaviour of Ae. aegypti females by analysing the locomotor activity, egg production and viability. METHODOLOGY Ae. aegypti females were orally infected with ZIKV through an artificial feeder to access egg production, egg viability and locomotor activity. For egg production and viability assays, females were kept in cages containing an artificial site for oviposition and eggs were counted. Locomotor activity assays were performed in activity monitors and an average of 5th, 6th and 7th days after infective feeding was calculated. FINDINGS No significant difference in the number of eggs laid per females neither in their viability were found between ZIKV infected and non-infected females, regardless the tested pair of mosquito population and virus strain and the gonotrophic cycles. Locomotor activity assays were performed regardless of the locomotor activity in ZIKV infected females was observed, in both LD and DD conditions. MAIN CONCLUSIONS The lower locomotor activity may reduce the mobility of the mosquitoes and may explain case clustering within households reported during Zika outbreaks such as in Rio de Janeiro 2015. Nevertheless, the mosquitoes infected with ZIKV are still able to disseminate and to transmit the disease, especially in places where there are many oviposition sites.

The influence of a light and dark cycle on the egg laying activity of Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae)

BACKGROUND The epidemiological importance of the mosquito Aedes aegypti as a vector of multiple human pathogens has generated a growing number of studies on the physiology and behaviour of its blood-feeding females. The activity of oviposition is one of the critical elements contributing to the expansion of Ae. aegypti's populations. Although there is a vast literature about oviposition behaviour, significant specific knowledge about egg viability and female fertility under light and dark conditions is still lacking. OBJECTIVES We studied, in controlled laboratory conditions, the effect that light and dark cycles have on the efficiency of oviposition by Ae. aegypti females. METHODS Physiological assays were performed using synchronised eggs obtained from forced egg laying. The number and viability of eggs was analysed under three different light/dark regimes: LD12:12 (12 h of light and 12 h of dark), DD (constant darkness) and LL (constant light). FINDINGS and CONCLUSIONS Our results show that females prefer to lay their eggs in dark conditions, but maximising the number and viability of eggs requires the occurrence of a light/dark cycle. Ongoing research on this theme has the potential of contributing to the proposition of new strategies for control based on the failure of egg laying and hatching.

Embryonic development of Aedes aegypti (Diptera: Culicidae): influence of different constant temperatures

Despite its vector importance little attention is given to Aedes aegypti embryonic development. In this study, temperature influence on time course of Ae. aegypti larvae hatching and egg viability were evaluated. The dormancy state at the end of embryogenesis could be interrupted with a proper stimulus. Temperatures tested ranged between 12-36°C; the maximum temperature limit is 35°C and the minimum one is below 12°C. Egg viability between 16-31°C was above 80 percent. The definition of physiological embryonic parameters at this temperature range corroborates Ae. aegypti presence on tropical and subtropical world regions.