几种植物源杀虫剂对螺旋粉虱的生物活性及田间防治效果

采用室内生物测定和大田药效试验等方法,测定印楝素、苦参碱和烟碱对螺旋粉虱的室内生物活性与田间防治效果.结果表明,这3种杀虫剂均对螺旋粉虱具有较高的生物活性.其中在对螺旋粉虱成虫的毒力测定中,印楝素、苦参碱和烟碱LC_(50)值分别为0.0998、0.013 3、0.0023mg/L,对3龄若虫的LC_(50)值分别为1.6724、0.0593、0.031 5mg/L,对卵的LC_(50)值分别为1.2117、0.0340和0.011 3mg/L.大田药效结果表明,3种植物源杀虫剂对螺旋粉虱均有很好的防治效果和持效性,其中在1.00 mg/L的浓度下,药后5 d的防治效果仍在80%左右.

Bioactivities of Several Botanical Pesticides Against Spiraling Whitefly(Aleurodicus dispersus Russell)

Azadirachtin, Matrine and Nicotinamide were detected indoor and in the field to observe their indoor bioactivities and their field control effect against spiraling whitefly(Aleurodicus dispersus Russell). The results indicated that these 3 botanical pesticides all had high bioactivities against the spiraling whitefly. The lethal concentrations(LC_(50)) for Azadirachtin, Matrine and Nicotinamide againts adults of the spiraling whitefly were 0.099 8 mg/L, 0.0133 mg/L and 0.002 3 mg/L, respectively; the LC_(50) for 3~(rd) instar nymphs were 1.672 4, 0.059 3, 0.031 5 mg/L, respectively; and the LC_(50) for eggs were 1.211 7, 0.034 0, 0.011 3 mg/L, respectively. The field trial results indicated that Azadirachtin, Matrine and Nicotinamide had a good control and persistent effect against the spiraling whitefly, and still controlled about 80% of the spiraling whitefly at day 5 after treatment at the rate of 1 mg/L.