Chansang Uruyakorn, Zahiri Nayer S, Bansiddhi Jaree, Boonruad Thidarat, Thongsrirak Pratom, Mingmuang Jiranuch, Benjapong Nipa, Mulla Mir S
Division of Medical Entomology, National Institute ofHealth, Department of Medical Sciences, Ministry of Public Health, 88/7 Tiwanon Road, Nonthaburi 11000, Thailand.
J Vector Ecol. 2005 Dec;30(2):195-200.
Aqueous extracts of nine medicinal plants were bioassayed against larvae of Culex quinquefasciatus Say and Aedes aegypt (L.). Among these plants, the long pepper, Piper retrofractum Vahl (Piperaceae), showed the highest level of activity against mosquito larvae. To gain more information on larvicidal activity of P. retrofractum, fresh fruits of this plant were extracted in water and the extracts made into powder and bioassayed against 3rd and 4th instar larvae of Cx. quinquefasciatus and Ae. aegypti in the laboratory. Extracts of unripe (001/3) and ripe (002/3 and 001/4) fruits showed different levels of activity against Cx. quinquefasciatus larvae. Extracts 001/3 and 002/3 were equi-toxic to a Bacillus sphaericus resistant and susceptible strains, both from Thailand. The ripe fruit extract 002/3 was somewhat more active against Ae. aegypti than Cx. quinquefasciatus. Another ripe fruit extract (001/4) was much more toxic to both mosquito species. Diluted solutions of the solid extract (002/3) in distilled water lost their larvicidal activity upon aging. Loss of activity at 25 degrees C was greater than that stored at 4 degrees C, and greater in water than in acetone solution.
对9种药用植物的水提取物针对致倦库蚊（Culex quinquefasciatus Say）和埃及伊蚊（Aedes aegypt (L.)）幼虫进行了生物测定。在这些植物中，荜拨（Piper retrofractum Vahl，胡椒科）对蚊虫幼虫表现出最高水平的活性。为了获取更多关于荜拨杀幼虫活性的信息，将这种植物的新鲜果实用水提取，提取物制成粉末，并在实验室中针对致倦库蚊和埃及伊蚊的3龄和4龄幼虫进行生物测定。未成熟果实（001/3）和成熟果实（002/3和001/4）的提取物对致倦库蚊幼虫表现出不同水平的活性。提取物001/3和002/3对来自泰国的球形芽孢杆菌抗性和敏感菌株具有同等毒性。成熟果实提取物002/3对埃及伊蚊的活性略高于对致倦库蚊的活性。另一种成熟果实提取物（001/4）对两种蚊虫的毒性都大得多。固体提取物（002/3）在蒸馏水中的稀释溶液老化后失去其杀幼虫活性。在25摄氏度下活性丧失大于在4摄氏度下储存的情况，并且在水中比在丙酮溶液中丧失得更多
