茶皂素对几种农药的增效作用测定

Tests of Synergistic Actions of Tea Saponin on Several Pesticides

试验分别测定了茶皂素与Bt、鱼藤酮和乐果的联合毒力作用．结果显示，茶皂素对这几种农药具有明显的增效作用．加入1000和2000mg／L的茶皂素后，与Bt对小菜蛾3龄和4龄幼虫的共毒系数（CTC）分别达到168．10、260．93和408．15、543．68；而鱼藤酮和乐果对萝卜蚜的LC50则分别降低了34．88％、58．10％和18．13％、53. 70％．

The co-toxicities of tea saponin mixed with pesticides Bt, rotenone and dimethoae were testedrespectively. Results showed that tea saponin had significant synergistic actions on these pesticides. Afteradded tea saponin at concentrations of 1 000 and 2 000 mg/L into pesticide dilutions, the co-toxicity co-efficients of Bt admixtures on the third and fourth instar larvae of diamondback moth Plutella xylostella(L.) were 168. 10, 260. 93 and 408. 15, 543. 68, respectively, while the LC50 s of rotenone anddimethoate to turnip aphid Lipaphis erysimi (Kaltenbach) were reduced by 34. 88%, 58. 10% and 18.1 3 %, 53. 70% respectively.