DRDO-BU Center for Life Sciences, Bharathiar University, Coimbatore 641046, Tamil Nadu, India; Division of Entomology, Department of Zoology, School of Life Sciences, Bharathiar University, Coimbatore 641046, Tamil Nadu, India.
Asian Pac J Trop Med. 2013 Nov;6(11):847-53. doi: 10.1016/S1995-7645(13)60151-0.
To explore the larvicidal activity of Catharanthus roseus (C. roseus) leaf extract and Bacillus thuringiensis (B. thuringiensis) against the malarial vector Anopheles stephensi (An. stephensi), when being used alone or together.
The larvicidal activity was assayed at various concentrations under the laboratory and field conditions. The LC50 and LC90 values of the C. roseus leaf extract were determined by probit analysis.
The plant extract showed larvicidal effects after 24 h of exposure; however, the highest larval mortality was found in the petroleum ether extract of C. roseus against the first to fourth instars larvae with LC50=3.34, 4.48, 5.90 and 8.17 g/L, respectively; B. thuringiensis against the first to fourth instars larvae with LC50=1.72, 1.93, 2.17 and 2.42 g/L, respectively; and the combined treatment with LC50=2.18, 2.41, 2.76 and 3.22 g/L, respectively. No mortality was observed in the control.
The petroleum ether extract of C. roseus extract and B. thuringiensis have potential to be used as ideal eco-friendly agents for the control of An. stephensi in vector control programs. The combined treatment with this plant crude extract and bacterial toxin has better larvicidal efficacy against An. stephensi.
探索夹竹桃叶提取物和苏云金芽孢杆菌（Bacillus thuringiensis，B. thuringiensis）单独或联合使用时对疟疾传播媒介按蚊（Anopheles stephensi，An. stephensi）的杀幼虫活性。
在实验室和现场条件下，用不同浓度测定杀幼虫活性。用概率单位分析法测定夹竹桃叶提取物的 LC50 和 LC90 值。
植物提取物在暴露 24 小时后表现出杀幼虫作用；然而，在石油醚提取物中，最高的幼虫死亡率是针对第一至第四龄幼虫，LC50 值分别为 3.34、4.48、5.90 和 8.17 g/L；苏云金芽孢杆菌针对第一至第四龄幼虫的 LC50 值分别为 1.72、1.93、2.17 和 2.42 g/L；联合处理的 LC50 值分别为 2.18、2.41、2.76 和 3.22 g/L。对照中没有观察到死亡。
夹竹桃叶提取物和苏云金芽孢杆菌的石油醚提取物具有作为控制按蚊传播媒介的理想环保剂的潜力。这种植物粗提取物与细菌毒素联合处理对按蚊具有更好的杀幼虫效果。
