几种无公害药剂对球果花蝇的控制作用及其机理

The Controlling Efficacy and Their Mechanism of Some Insecticides on Strobilomyia spp.

为了更加安全、有效地控制落叶松球果花蝇的危害 ,选用 5 %除虫脲乳油、2 0 %除虫脲悬浮剂等 6种无公害药剂 ,在落叶松球果花蝇产卵盛期进行了树冠喷雾防治。同时 ,利用GC -MS分析了喷洒药剂后落叶松球果挥发性气味的变化 ,探讨 6种药剂的防治机理。在此基础上 ,于幼虫脱果期选用 5 %杀铃脲乳油、5 %伏虫灵乳油等 7种药剂 ,进行了室内杀幼虫试验。花蝇产卵盛期防治试验表明 ,喷施 50 0、1 0 0 0、1 50 0倍液的百草一号防治效果分别达到 97.50 %、96 .95 %、82 .2 3 %。喷施稀释 50 0、1 0 0 0倍的百草一号 ,后可使球果被害率降低 82 .79%和71 .1 2 %。利用百草一号水溶液处理的球果 ,对花蝇产卵的驱避率分别达到 37.71 %、61 .71 %和 2 7.71 %,同时也表现出较强的抑制卵孵化作用。防治机理分析表明 :5 %除虫脲乳油、2 0 %除虫脲悬浮剂、2 5 %除虫脲可湿性粉剂、1 0 %吡虫啉可湿性粉剂、蛾螨灵和百草一号的 50 0～ 1 50 0倍水溶液处理落叶松球果 ,可以对落叶松球果花蝇的产卵产生一定的驱避作用 ,驱避率可达到 2 7.71 %～ 95 .71 %。驱避机制试验表明 ,施用 50 0倍的 2 0 %降虫脲等使α-蒎烯的相对含量明显增加 ,β -蒎烯、月桂烯等 5种组分的相对含量有所降低。脱果幼虫的室内防治试验发现 ,以 30

To control the damage of Strobilomyia spp. effectively and safely, several kinds of environmental safe insecticides were used to determine the controlling ability and their processing mechanism. Six kinds of insecticides were used in the treatment of Larix cone in the filed. Those insecticides used in treating of larvae came out of cone are 5% trilumuron emulsifiable concentrate, 5% hexaflumuron emulsifiable concentrate, etc. The change of volatile components after spraying insecticides on crown of treees was also been studied with GC-MS to determine the working mechanism of those insecticides. Spraying on the crown of tree experiments shows that 0.36% matrine aqueous solution is the most effective one among those used pesticides. Spraying 0.36% matrine aqueous solution diluted 500,1000 or 1500 times with water can observably reduce the damage rate of seeds. The controlling efficacies of those dilutions are 97.50%, 96.95% and 82.23% respectively. Spraying them on the crown of Larix can also significantly reduce the damage of cones. After spraying 0.36% matrine aqueons solution, those treated cones show remarkably rebelling effect for those Strobilomyia spp. adults trying to laid eggs on them. Some of those eggs laid on the treated cones have restricted from hatching. The processing mechanism of efficacy studies shows that spraying any sort of those 6 kinds pesticides on Larix crown would evidently change the main volatile components of treated cones. The content of α-pinene increased after treatment but the content of β-pinene,β-ocimene, phellandrene, myrcene and 3-carene reduced. The percentage of those 6 kinds of volatile in the compositions detected by GC-MS also increased. Experiment on the killing of larvae came out of cone shows that 30% phoxin and benzoylphenol Ⅲ emulsifiable concentrate, 0.36% matrine aqueous solution and 10% imidacloprid wettable powder were better than the others. The controlling efficacy of 30% phoxin and benzoylphenol Ⅲ emulsifiable concentrate diluted 500, 1000, 1500 times with water was 60.0%, 72.7% and 71.9% respectively.