The present research aimed at evaluating the influence of the water quality in the life cycle and attraction of Aedes aegypti (L.) females to oviposit using different sources of water (raw sewage, effluent of UASB reactor, effluent of polishing lagoon, effluent of anaerobic filter, rain water and de-chlorinated water). The immature development time and survivorship were evaluated on a daily basis in two distinct feeding systems (with and without food). The quality of the water was shown to affect the egg and larval stages, but not the pupal or the adult. In the absence of food, no development was observed in rain water and de-chlorinated water. Immature development was faster in water sources from raw sewage, although with the lowest survivorship (37.3%). Free-choice tests indicated that females preferred to lay most of their eggs on water collected from the effluent of a UASB reactor, achieving the highest oviposition activity index (OAI) of 0.57. In non-choice tests, females laid larger batches of eggs in water collected from anaerobic filters (204.8 eggs), with the lowest number of eggs being laid on de-chlorinated water (37.3 eggs). It can be concluded that A. aegypti does not demonstrate any particular preference to lay eggs on clean water. This has serious implications for developing strategies to manage populations of this important vector in urban areas as it was shown to lay eggs and successfully develop on several different sources of water.

O trabalho teve por objetivo avaliar o efeito da qualidade da água no desenvolvimento de Aedes aegypti (Linnaeus, 1762). O ciclo de vida desse vetor foi estudado em águas de esgoto bruto, efluente de reator UASB, efluente de lagoa de polimento, efluente de filtro anaeróbio, água de chuva e água desclorada. Diariamente avaliaram-se o período de desenvolvimento e as viabilidades de ovo, larva, pupa, longevidade e a fecundidade dos adultos. A duração do período larval variou de 5,6 a 9,1 dias, sendo a sobrevivência baixa em águas de esgoto bruto, efluente de reator UASB, efluente de lagoa de polimento e efluente de filtro anaeróbio. Não foram observadas diferenças nas durações e viabilidades das fases de ovo e pupa, longevidade e fecundidade dos adultos. Constatou-se que, apesar da baixa viabilidade larval, é possível o desenvolvimento do A. aegypti em águas com elevados graus de poluição e que todos os tratamentos permitiram o desenvolvimento desse vetor.

The present work aimed to estimate the effect of water quality in the development of Aedes aegypti (Linnaeus, 1762). The life cycle of this vector was studied in raw sewage water, effluent of UASB reactor, effluent of polishing lagoon, effluent of anaerobic filter, rainwater and de-chlorinated water. The development period, egg viability and larval and pupal survival were evaluated daily as well as the adult longevity and fecundity. The duration of larval period showed a variation of 5.6 to 9.1 days. Survival was considered low in raw sewage water, effluent of UASB reactor, effluent of polishing lagoon and effluent of anaerobic filter. No difference in terms of the duration and egg and pupal viability nor in the adult longevity and fecundity was detected. It was verified that despite a reduction in larval viability, A. aegypti could accomplish total development in waters with high pollution degree and that all the treatments were suitable to the development of this vector.

Resumo Utilizar esgoto tratado para as atividades agrícolas é proporcionar economia de fertilizante e de água de boa qualidade; podendo ser uma alternativa para convivência com a sua escassez. Diversas tecnologias de tratamento de esgotos já foram desenvolvidas na busca de produzir efluente adequado para fertirrigação evitando a contaminação do ambiente com bactérias, parasitas e vírus que criam graves problemas de saúde pública, propagando doenças bacterianas e virulentas, afetando trabalhadores e consumidores das culturas irrigadas. A presente pesquisa objetivou tratar esgotos domésticos utilizando reator UASB seguido de filtro biológico, visando à obtenção de efluente adequado ao reúso. O efluente do filtro continha macro e micronutrientes suficientes para o crescimento da maioria das culturas cultivadas na região semi-árida; no entanto, apresentou concentração de coliformes termotolerantes acima das recomendações da OMS, embora isento de ovos de helmintos. Desta forma, o efluente do filtro anaeróbio só deverá ser utilizado para fertirrigação de culturas restritas.

Abstract The utilization of treated sewage for agricultural purposes means saving of fertilizer and water of good quality, therefore, it may seen as an alternative in its scarcity. Several treatment processes have been developed to produce an effluent with a suitable quality for fertirrigation, while avoiding contamination of the environment with pathogens that may cause serious public health problems and may affect workers consumers of and agricultural product. This research had as its objective to treat sewage in a UASB reactor followed by an anaerobic filter with the aim of obtaining an adequate effluent for agricultural reuse. The filter effluent contained suficiente macro and micro nutrients to grow most crops under the local conditions of the semi arid region. However the concentration of thermo tolerant Coliforms was above the recommend maximum by the WHO, while no helminth eggs were observed in the effluent. Hence the effluent could only be used for restricted irrigation.