ABSTRACT The present research aimed to determine the lowest levels of three heavy metals (Pb, Cd and Cu) to which the larvae of Southern House Mosquito, Culex quinquefasciatus are susceptible in water. The study also aimed to investigate the effects of these heavy metals on the development of Cx. quinquefasciatus at concentrations set by Pakistan Environmental Protection Agency (Pak-EPA) as permissible levels for liquid industrial effluents. The 2nd instar larvae of Cx. quinquefasciatus were exposed to different concentrations of Pb, Cd and Cu and their effects on oviposition preference, egg hatching rate and larval development were studied. The LC50 values of Pb, Cd and Cu were 12.6, 6.3 and 2.6 ppm, respectively. Gravid female mosquito adults deposited a significantly lower number of egg rafts in containers containing 0.50 ppm Pb or 1.0 ppm Cu in water. Each of the heavy metals in water resulted in significantly (p < 0.05) lower egg hatching rate, prolonged time to pupation, lower pupation rate, prolonged time to adult emergence, lower adult emergence rate and higher female to male ratio. It is concluded that the 2nd instar larvae of Cx. quinquefasciatus are susceptible to Pak-EPA permissible levels of Pb, Cd and Cu in municipal and liquid industrial effluents.

中文翻译：

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Pb、Cd和Cu对库蚊（双翅目：库蚊科）存活和发育的影响

摘要 本研究旨在确定南屋蚊幼虫库蚊在水中易感的三种重金属（铅、镉和铜）的最低水平。该研究还旨在调查这些重金属对 Cx 发展的影响。quinquefasciatus 的浓度由巴基斯坦环境保护局 (Pak-EPA) 设定为液体工业废水的允许水平。Cx的二龄幼虫。quinquefasciatus 暴露于不同浓度的 Pb、Cd 和 Cu 并研究它们对产卵偏好、卵孵化率和幼虫发育的影响。Pb、Cd 和 Cu 的 LC50 值分别为 12.6、6.3 和 2.6 ppm。妊娠雌性蚊子成虫在含有 0.50 ppm Pb 或 1 的容器中放置的卵筏数量明显减少。水中的 0 ppm Cu。水中的每种重金属都显着（p < 0.05）降低了卵孵化率，延长了化蛹时间，降低了化蛹率，延长了成虫羽化时间，降低了成虫羽化率和更高的雌雄比。结论是Cx的2龄幼虫。quinquefasciatus 对市政和液体工业废水中 Pak-EPA 允许水平的 Pb、Cd 和 Cu 敏感。