Ireri Laban N, Kongoro Jedida, Ngure Peter, Mutai Charles, Langat Bernard, Tonui Willy, Kimutai Albert, Mucheru Obadiah
Division of Vector Borne and Neglected Tropical Diseases, Embu, Eastern Province, Kenya.
J Vector Borne Dis. 2010 Sep;47(3):168-74.
BACKGROUND & OBJECTIVES: Harmful effects of synthetic chemical insecticides including vector resistance, environmental pollution and health hazards have necessitated the current significance in the search for plant-based insecticide products that are environmentally safe and effective to leishmaniases control. The insecticidal activity of Tagetes minuta Linnaeus (Asteraceae), Acalypha fruticosa Forssk (Euphorbiaceae) and Tarchonanthus camphoratus L. (Compositae) extracts were investigated against Phlebotomus duboscqi Neveu Lemaire (Diptera: Psychodidae).
The extracts were prepared from dried aerial parts soaked in methanol and ethyl acetate twice until the filtrates became clear, filtered and dried out by rotary evaporation at 30-35 degrees C. The solid extracts obtained were later prepared into 2.5, 5 and 10 mg/ml. Two millilitres of the solutions were blotted on filter papers, which were dried overnight and placed into jars where adult sandflies were aspirated. Males and females were assayed separately.
RESULTS & CONCLUSION: The extracts had significant mortality (p<0.05) in both males and females bioassays but were not significantly different between sexes. The extracts of Acalypha fruticosa and Tagetes minuta had significantly higher mortality rates than those of Tarchonanthus camphoratus and the different concentrations used showed significantly different mortality rates and 10 mg/ml was the most effective concentration. Cent percent mortality was obtained at 96 h of exposure to 5 and 10 mg/ml concentrations except for Tarchonanthus camphoratus which had a mortality of only 46.7% in 10 mg/ml bioassay. These extracts were found to be insecticidal to adult sandflies.
合成化学杀虫剂存在包括媒介抗性、环境污染和健康危害等有害影响，这使得目前寻找对利什曼病防治环境安全且有效的植物源杀虫剂产品具有重要意义。研究了小花万寿菊（菊科）、灌木铁苋菜（大戟科）和樟脑艾（菊科）提取物对杜氏白蛉（双翅目：毛蠓科）的杀虫活性。
将干燥地上部分浸泡在甲醇和乙酸乙酯中两次，直至滤液变清，过滤后在30 - 35摄氏度下通过旋转蒸发干燥，制备提取物。将得到的固体提取物配制成2.5、5和10毫克/毫升。将两毫升溶液滴在滤纸上，滤纸过夜干燥后放入装有成年白蛉的罐子中。分别对雄性和雌性进行测定。
提取物在雄性和雌性生物测定中均有显著死亡率（p<0.05），但两性之间无显著差异。灌木铁苋菜和小花万寿菊提取物的死亡率显著高于樟脑艾提取物，且不同浓度显示出显著不同的死亡率，10毫克/毫升是最有效浓度。除樟脑艾在浓度为10毫克/毫升的生物测定中死亡率仅为46.7%外，在暴露于5和10毫克/毫升浓度96小时时获得了百分之百的死亡率。这些提取物对成年白蛉具有杀虫作用。
