Chitolina R F, Anjos F A, Lima T S, Castro E A, Costa-Ribeiro M C V
Laboratório de Parasitologia Molecular, Departamento de Patologia Básica, Centro Politécnico, Universidade Federal do Paraná, Brazil.
Laboratório de Parasitologia Molecular, Departamento de Patologia Básica, Centro Politécnico, Universidade Federal do Paraná, Brazil.
Acta Trop. 2016 Dec;164:290-296. doi: 10.1016/j.actatropica.2016.07.013. Epub 2016 Sep 15.
The selection of oviposition sites by females of Aedes (Stegomyia) aegypti is a key factor for the larval survival and egg dispersion and has a direct influence in vector control programs. In this study, we evaluated the aspects of reproductive physiology of Ae. aegypti mosquitoes tested in the presence of raw sewage. Ae. aegypti females were used in oviposition bioassays according to two methodologies: (i) choice assay, in which three oviposition substrates were offered in the same cage: treatment (raw sewage), positive control (distilled water) and negative control (1% sodium hypochlorite) and; (ii) no choice assay, in which only one substrate was available. The physicochemical and microbiological analysis of the raw sewage used in this study indicated virtually no levels of chlorine, low levels of dissolved oxygen and high levels of nitrogenous compounds as well as the presence of Escherichia coli and total fecal coliforms. After 72h of oviposition, the eggs were counted and there was no statistically significant difference (p>0.05) in the oviposition rate between raw sewage and positive control in both methodologies. In addition, females were dissected to evaluate egg-retention and also there were no appreciable differences in egg retention even when raw sewage was the only substrate offered. The data also showed that egg hatching and larvae development occurred normally in the raw sewage. Therefore, the present study suggests that Ae. aegypti can adapt to new sites and lay eggs in polluted water, such as the raw sewage. These findings are of particular importance for the control and surveillance programs against Ae. aegypti in countries where the conditions of poor infrastructure and lack of basic sanitation are still an issue.
埃及伊蚊（白纹伊蚊）雌蚊对产卵地点的选择是幼虫存活和卵扩散的关键因素，对病媒控制计划有直接影响。在本研究中，我们评估了在未经处理的污水环境下测试的埃及伊蚊的生殖生理方面。埃及伊蚊雌蚊根据两种方法用于产卵生物测定：（i）选择试验，在同一笼子中提供三种产卵基质：处理组（未经处理的污水）、阳性对照组（蒸馏水）和阴性对照组（1%次氯酸钠）；以及（ii）无选择试验，其中只提供一种基质。本研究中使用的未经处理的污水的物理化学和微生物分析表明，几乎没有氯含量，溶解氧含量低，含氮化合物含量高，以及存在大肠杆菌和总粪大肠菌群。产卵72小时后，对卵进行计数，在两种方法中，未经处理的污水和阳性对照组之间的产卵率没有统计学上的显著差异（p>0.05）。此外，解剖雌蚊以评估卵的保留情况，即使仅提供未经处理的污水作为唯一基质时，卵的保留情况也没有明显差异。数据还表明，卵在未经处理的污水中正常孵化和幼虫正常发育。因此，本研究表明埃及伊蚊能够适应新的地点并在污水等污染水中产卵。这些发现对于基础设施差和缺乏基本卫生条件仍是问题的国家的埃及伊蚊控制和监测计划尤为重要。
