Unit of Entomotoxicity, Department of Zoology, Govt. Thirumagal Mills College, Vellore-632607 Tamilnadu, India.
Asian Pac J Trop Med. 2012 Aug;5(8):598-604. doi: 10.1016/S1995-7645(12)60124-2.
To investigate the potentiality of mosquitocidal activity of Gliricidia sepium (G. sepium) (Jacq.) (Leguminosae).
Twenty five early third instar larvae of Anopheles stephensi (An. stephensi) were exposed to various concentrations (50-250 ppm) and the 24 h LC(50) values of the G. sepium extract was determined by probit analysis. The ovicidal activity was determined against An. stephensi to various concentrations ranging from 25-100 ppm under laboratory conditions. The eggs hatchability was assessed 48 h post treatment. The pupicidal activity was determined against An. stephensi to various concentrations ranging from 25-100 ppm. Mortality of each pupa was recorded after 24 h of exposure to the extract.
Results pertaining to the experiment clearly revealed that ethanol extract showed significant larvicidal, ovicidal and pupicidal activity against the An. stephensi. Larvicidal activity of ethanol extracts of G. sepium showed maximum mortality in 250 ppm concentration (96.0±2.4)%. Furthermore, the LC(50) was found to be 121.79 and the LC(90) value was recorded to be 231.98 ppm. Ovicidal activity of ethanol extract was assessed by assessing the egg hatchability. Highest concentration of both solvent extracts exhibited 100% ovicidal activity. Similarly, pupae exposed to different concentrations of ethanol extract were found dead with 58.10% adult emergence when it was treated with 25 ppm concentration. Similarly, 18.36 (n=30; 61.20%); 21.28(70.93) and 27.33(91.10) pupal mortality was recorded from the experimental pupae treated with 50, 75 and 100 ppm concentration of extracts. Three fractions have been tested for their larvicidal activity of which the Fraction 3 showed the LC(50) and LC(90) values of 23.23 and 40.39 ppm. With regard to the ovicidal effect fraction 3 showed highest ovicidal activities than the other two fractions. Furthermore, there were no hatchability was recorded above 50 ppm (100% egg mortality) in the experimental group. Statistically significant pupicidal activity was recorded from 75 ppm concentration.
From the results it can be concluded the crude extract of G. sepium is an excellent potential for controlling An. stephensi mosquito. It is apparent that, fraction 3 possess a novel and active principle which could be responsible for those biological activities.
研究吉贝（Gliricidia sepium）（Jacq.）（豆科）的杀蚊活性潜力。
将 25 只早期三龄幼虫的按蚊（An. stephensi）暴露于不同浓度（50-250 ppm）下，并通过概率分析确定 G. sepium 提取物的 24 小时 LC（50）值。在实验室条件下，用不同浓度（25-100 ppm）测定对按蚊的杀卵活性。处理后 48 小时评估卵的孵化率。用不同浓度（25-100 ppm）测定对按蚊的杀蛹活性。暴露于提取物 24 小时后，记录每只蛹的死亡率。
实验结果清楚地表明，乙醇提取物对按蚊表现出显著的杀幼虫、杀卵和杀蛹活性。乙醇提取物对 G. sepium 的杀幼虫活性在 250 ppm 浓度下表现出最高死亡率（96.0±2.4）%。此外，LC（50）为 121.79，LC（90）值为 231.98 ppm。通过评估卵的孵化率来评估乙醇提取物的杀卵活性。两种溶剂提取物的最高浓度均表现出 100%的杀卵活性。同样，用 25 ppm 浓度处理时，暴露于不同浓度乙醇提取物的蛹全部死亡，成虫出现率为 58.10%。同样，从用 50、75 和 100 ppm 浓度提取物处理的实验蛹中记录到 18.36（n=30；61.20%）；21.28（70.93）和 27.33（91.10）的蛹死亡率。已测试了三个馏分的杀幼虫活性，其中馏分 3 的 LC（50）和 LC（90）值分别为 23.23 和 40.39 ppm。就杀卵效果而言，馏分 3 显示出比其他两个馏分更高的杀卵活性。此外，实验组中未记录到 50 ppm 以上的孵化率（100%卵死亡）。从 75 ppm 浓度开始记录到具有统计学意义的杀蛹活性。
从结果可以得出结论，吉贝的粗提物是控制按蚊的潜在优秀物质。显然，馏分 3 具有一种新的活性成分，可能是这些生物活性的原因。
