Abstract Environmental concerns and insecticide resistance threaten the sustained efficacy of mosquito control approaches which remain reliant on synthetic chemicals. Plant-based extracts may be an environmentally sustainable and effective alternative to contemporary mosquito control approaches; however, the efficacies of many possible plant-based extracts remain untested. The present study examines the effects of extracts from three floating and three submerged aquatic plants on larval mosquito Culex pipiens mortality, and development to pupal and adult stages. Physical impacts of floating plant species on mosquito mortality and development are also examined. Extracts of Lagarosiphon major and Lemna minuta were toxic, causing significantly increased mosquito mortality compared to plant-free controls. Effects of Azolla filiculoides, Crassula helmsii, Elodea canadensis and Lemna minor were statistically unclear, yet in some cases tended to increase pupal and larval numbers at high extract concentrations. Surface coverage of all floating Lemna species drove significant mosquito mortality through mechanical processes which likely impeded surface respiration by larval mosquitoes. In particular, high-density mats of L. minuta consistently caused total larval mortality. The present study thus suggests that targeted use of specific aquatic plants could assist in mosquito control protocols. However, as the chemical composition of botanic material will differ across spatial and temporal gradients, even for a singular species, localised assessment of the efficacy of plant-based extracts from within areas experiencing problematic mosquito control is required. The application of aquatic plants that are both toxic to larvae and are effective physical control agents presents an economic and effective method of mosquito control.

中文翻译：

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水生植物提取物和覆盖范围介导幼虫蚊子的存活和发育

摘要 环境问题和杀虫剂耐药性威胁到仍然依赖合成化学品的蚊子控制方法的持续有效性。植物提取物可能是当代蚊虫控制方法的一种环境可持续且有效的替代品；然而，许多可能的植物提取物的功效仍未经过测试。本研究考察了三种漂浮植物和三种沉水植物的提取物对幼蚊库蚊死亡率以及发育至蛹和成虫阶段的影响。还研究了漂浮植物物种对蚊子死亡率和发育的物理影响。Lagarosiphon Major 和 Lemna minuta 的提取物是有毒的，与无植物对照相比，导致蚊子死亡率显着增加。红花的作用，Crassula helmsii、Elodea canadensis 和 Lemna minor 在统计上不清楚，但在某些情况下，在高提取物浓度下往往会增加蛹和幼虫的数量。所有漂浮的 Lemna 物种的表面覆盖通过机械过程导致显着的蚊子死亡，这可能阻碍幼虫蚊子的表面呼吸。特别是，L. minuta 的高密度垫一直导致总幼虫死亡率。因此，本研究表明，有针对性地使用特定的水生植物可以帮助蚊子控制协议。然而，由于植物材料的化学成分在空间和时间梯度上会有所不同，即使对于单一物种，也需要对来自蚊子控制有问题的区域内的植物提取物的功效进行局部评估。