Vector borne diseases can be controlled by managing the mosquito population. So the present study was done to evaluate larvicidal activities of Cajanus cajan mature leaf extracts against the Japanese encephalitis vector Culex vishnui. Crude and three different solvent extracts of C. cajan leaves were applied for larvicidal bioassay against the all instars larvae of Cx. vishnui. For statistical justifications log probit, regression and ANOVA analyses were performed. Non-target organisms were also evaluated against crude and ethyl acetate solvent extract of mature leaves. The IR analysis and GC-MS analyses were carried out to find out the active ingredient. 0.5% concentration of crude extract showed highest larval mortality after 72 h of exposure. Amongst the three tested solvent extracts namely n-Hexane, ethyl acetate and chloroform: methanol (1:1 v/v), ethyl acetate extract exhibited the most potent larvicidal activity. In ethyl acetate extract 100% mortality was found in 100 ppm concentration against 1st instar larvae after 72 h of exposure. Chemical characterization revealed that the active ingredient belongs to the flavonoids group of compound which might be responsible for larval toxicity. However, the bioassay against the non-target organisms revealed that, they were mostly safe to the extracts. The results support that C. cajan mature leaves can be used as an ecofriendly larvicidal agent against the Cx. vishnui in near future.

中文翻译：

---

Cajanus cajan成熟叶提取物对日本脑炎病媒的杀幼虫作用

媒介传播的疾病可以通过控制蚊子数量来控制。因此，本研究旨在评估 Cajanus cajan 成熟叶提取物对日本脑炎载体 Culex vishnui 的杀幼虫活性。将 C. cajan 叶的粗制和三种不同溶剂提取物用于针对 Cx 全龄幼虫的杀幼虫生物测定。毗湿奴。对于统计理由，进行了对数概率、回归和方差分析。还针对成熟叶的粗制和乙酸乙酯溶剂提取物评估了非目标生物。进行IR分析和GC-MS分析以找出活性成分。0.5% 浓度的粗提取物在暴露 72 小时后表现出最高的幼虫死亡率。在三种测试的溶剂萃取物中，即正己烷、乙酸乙酯和氯仿：甲醇 (1: 1 v/v)，乙酸乙酯提取物表现出最有效的杀幼虫活性。在乙酸乙酯提取物中发现 100 ppm 浓度的 1 龄幼虫在暴露 72 小时后死亡率为 100%。化学表征表明，该活性成分属于可能导致幼虫毒性的黄酮类化合物。然而，针对非目标生物的生物测定表明，它们对提取物大多是安全的。结果支持 C. cajan 成熟叶可用作针对 Cx 的环保杀幼虫剂。vishnui 在不久的将来。化学表征表明，该活性成分属于可能导致幼虫毒性的黄酮类化合物。然而，针对非目标生物的生物测定表明，它们对提取物大多是安全的。结果支持 C. cajan 成熟叶可用作针对 Cx 的环保杀幼虫剂。vishnui 在不久的将来。化学表征表明，该活性成分属于可能导致幼虫毒性的黄酮类化合物。然而，针对非目标生物的生物测定表明，它们对提取物大多是安全的。结果支持 C. cajan 成熟叶可用作针对 Cx 的环保杀幼虫剂。vishnui 在不久的将来。