不同植物提取物对台湾乳白蚁的防治效果

本试验以甲醇冷浸法提取苦楝、台湾黄蘖、食茱萸、土肉桂之干材及无患子果实之提取物进行台湾乳白蚁（Coptotermes formosanus）防治效果比较，将提取物配制成不同浓度（mg／mL）浸渍滤纸。各树种提取物以10mg／mL浓度进行试验，于第2天时无患子果实甲醇提取物可达半致死量LD50，于第6天可达致死率100％，滤纸抗白蚁试验以无患子果实之甲醇提取物抗白蚁效果最佳，食茱萸及苦楝材部之甲醇提取物为次等。经真空注入法将浓度10mg／mL之提取物注入于台湾云杉、台湾二叶松之木块，进行喂食试验4周后其结果显示，未处理之木块受白蚁严重啃食，经苦楝、台湾黄蘖、食茱萸之干材及无患子果实浸渍处理之木块白蚁啃食情况较轻微，其两种树种木块之损失率分别降低至55．65％以下。

The effect of different plant exracts against Coptotermes formosanus

In this experiment, methanol extracts of wood from Melia azedarach Linn, Phellodendron amurense, Zanthoxylum ailanthoides Sieb. ＆ Zucc. , Cinnamomum osmophloeum and fruit from Sapindus mukorossi were used to prevent the Coptotermes formosanus. Filter papers were soaked with different concentrations （mg/mL） of extracts, and extracts were to be tested by containing of 10mg/mL. The effect of methanol extract of the fruit from S. mukorossi reached LDs0 in 2 days and reached 100% mortality in 6 days. Filter paper test for prevention of C. formosanus showed that S. mukorossi fruit extracts was the best, Z. ailanthoides Sieb. ＆ Zucc. and M. azedarach Linn wood metha- nol extracts as second-class. The vacuum injection into blocks of Picea morrisonicola and Pinus taiwanensis by con- centration of 10mg/mL after 4 weeks showed that the untreated blocks were most vulnerable by termites attack, whereas the blocks treated by extracts of M. azedarach IJnn, P. amurense, Z. ailanthoides Sieb. ＆ Zucc. , wood of C. osmophloeum and fruit of S. mukorossi were slightly attacked by termites, and weight loss of the two blocks were reduced to 55.65% or less respectively.