【作者】 徐广春；

【导师】 顾中言；

【作者基本信息】 扬州大学 ， 农药学， 2008， 硕士

【摘要】 本文选用生产上常用的五种药剂:三唑磷、毒死蜱、吡虫啉、高效氯氟氰菊酯和氟虫腈,对灰飞虱成若虫的敏感性变异、繁殖力以及灰飞虱种群的中长期动态影响进行了深入研究。主要结果如下所示:1.五种杀虫剂对灰飞虱1～5龄若虫、成虫的室内活性测定结果表明:灰飞虱低龄若虫到高龄若虫敏感性下降,而1～3龄若虫期差异不显著,4龄后差异较大。如氟虫腈和毒死蜱对灰飞虱成虫LC50的值分别是对灰飞虱1龄若虫LC50的值的17.25倍和21.50倍;同时氟虫腈和毒死蜱对灰飞虱活性较高,防治灰飞虱的最佳时期应为1～3龄若虫期。五种药剂对灰飞虱活性的大小顺序为:氟虫腈>毒死蜱>高效氯氟氰菊酯>吡虫啉>三唑磷。2.玻片浸渍法对灰飞虱天敌大腹圆蛛的室内活性测定试验表明:五种药剂对灰飞虱1龄若虫、成虫和大腹圆蛛的选择性比率VSR均小于1,说明五种药剂对大腹圆蛛的毒性高于对灰飞虱的毒力,五种药剂对大腹圆蛛毒性顺序分别为氟虫腈>毒死蜱>三唑磷、吡虫啉、高效氯氟氰菊酯。3.用五种药剂对灰飞虱3龄若虫室内活性测定获得的LC50、LC75和LC90的剂量分别处理灰飞虱3龄若虫及成虫,将存活的成虫按1:1配对后进行繁殖力测定,结果表明高效氯氟氰菊酯、三唑磷能延长灰飞虱雌成虫的历期,从而增加了灰飞虱产卵的时间,进而使得孵化的若虫总数均多于对照,用高效氯氟氰菊酯对灰飞虱3龄若虫的LC50、LC75的剂量处理灰飞虱3龄若虫及成虫孵化的若虫数均显著高于对照;毒死蜱对雌成虫历期影响不大,但是也能使孵化的若虫数显著高于对照;氟虫腈和吡虫啉能减少灰飞虱雌成虫的历期,使孵化的若虫数少于对照。4.用五种药剂对灰飞虱3龄若虫和成虫室内活性测定获得的亚致死剂量LC10和LC20分别处理灰飞虱3龄若虫及成虫,存活的雌(短翅型)雄(长翅型)按1:1配对配对后进行繁殖力测定,结果表明每种药剂处理的灰飞虱成若虫间对雌成虫历期、卵块数以及卵粒数的影响无显著差异。氟虫腈和吡虫啉处理的,产卵数少于对照,再猖獗比率小于1.00,最小的为0.80;而经高效氯氟氰菊酯、毒死蜱和三唑磷处理的,产卵数均多于对照,再猖獗比率大于1.00,其中最大的为1.53。这就说明氟虫腈和吡虫啉能够抑制灰飞虱种群增长,而高效氯氟氰菊酯、毒死蜱和三唑磷能够刺激灰飞虱的生殖,使得灰飞虱种群数量增长。5.五种药剂对灰飞虱种群中长期影响的试验表明:氟虫腈(39.9mL/667m2、0.15mg/L)和毒死蜱(59.9mL/667m2、0.96mg/L)在用药初期均有较好的防治效果,同时经氟虫腈处理的灰飞虱种群数量低于对照,但是水泥池和盆栽试验均表明用药后期毒死蜱能够促进灰飞虱种群的增长;高效氯氟氰菊酯(99.8mL/667m2、12.95mg/L)和三唑磷(98.6mL/667m2、29.67mg/L)处理用药初期灰飞虱种群有所下降,但不久就表现出促进灰飞虱种群增长的趋势,使得后期其数量均多于对照;吡虫啉(53.2mL/667m2、34.96mg/L)处理的灰飞虱种群数量稍少于对照。毒死蜱、高效氯氟氰菊酯和三唑磷导致灰飞虱再猖獗的可能原因为这三种药剂能刺激灰飞虱的生殖以及对天敌的毒性远远大于对灰飞虱成若虫的毒性。更多还原

【Abstract】 The five insecticides which were used frequently in the paddy were used in the experiments.Five insecticides were fipronil chlorpyrifos triazophos imidacloprid and cyhalothrin.The effects of five insecticides on the sensivity variation and productivity of the small brown planthopper(SBPH), Laodelphax striatellus(Fallén) were researched.We also studied the SBPH population dynamic influenced by five insecticides for middle and long period.The main results were showed as follows.1 We mensurated the five insecticides’susceptibilities of different instar nymphs of the SBPH in the laboratory.The results revealed that the susceptibilities decreased from the lower instar nymphs to the bigger ones.There was no difference among 1～3 instar nymphs,and the latter’s mutation was significiant.For example,the LC50 values of fipronil and chlorpyrifos to the adult SBPH were as 17.25 and 21.50 times as to the 1st instar nymphs.The toxicity of fipronil and chlorpyrifos to SBPH was higher than others,and high-point for prevention and cure was during 1～3 instar nymphs’period.The order of five insecticides’toxic activity to SBPH from big to small was fipronil> chlorpyrifos>cyhalothrin>imidacloprid>triazophos.2 Laboratory deterimenation of the toxic activity of five insecticides to Araneus ventricosus was done by the slip-slide method.The results showed that the vertebrate selectivity ratios(VSR) were less than 1.00. That is to say, the five insecticides’toxicity to the spiders was higher than to SBPH. The order of five insecticides’toxic activity to spider from big to small was fipronil> chlorpyrifos>cyhalothrin imidacloprid triazophos.3 The five insecticides’toxic activity to the 3rd instar nymphs was determined by rice-stem-dipping method.Both the 3rd instar nymphs and adults of SBPH were treated with the doseages.The doseages which were used in the experiment were LC50 LC75 and LC90 of the 3rd instar nymphs.The surivivals were reared on the rice seeding which was treated with the same doses above.And then divided into single pair.We could see that cyhalothrin and triazophos were able to prolong the span of the female adults and increased the number of eggs. So the total number of instar nymphs’hatching was more than the control and treated by cyhalothrin was more than the control significiantly. The effect on the span by chlorpyrifos was not clear, but it also could make the total number of instar nymphs’hatching greater.Fipronil and imidacloprid could cut down the the span of the female adult so that the total number of instar nymphs’hatching was less than the control.4 The sublethal doses, LC10 and LC20 of the 3rd instar nymphs and adults, were got from the experiment. We treated the 3rd instar nymphs and adults with the doses above. The surivivals were reared on the rice seeding and divided into single pair which the male adults were macropterous and the female were brachypterous. It could be seen that both the span and total number of eggs or egg-masses had no difference between the 3rd instar nymphs and adults which were treated by five insecticides. The total numbers of eggs treated by fipronil and imidacloprid were less than the control. That is to say,the resurgence ratios were less than 1.00.5 From the experiment of the SBPH population dynamic influenced by five insecticides for middle and long period, we could see that the prevention and cure effect of fipronil(39.9mL/667m2、0.15mg/L)and chlorpyrifos(59.9mL/667m2、0.96mg/L) was better than others at the beginning. The quantity of SBPH population which was treated by fipronil was less than the control all the time. But the quantity of SBPH population which was treated by chlorpyrifos mounted up and was more than the control form the experiment of concrete pool and potter plant. The quantity’s trend of SBPH population which was treated by cyhalothrin (99.8mL/667m2、12.95mg/L) and triazophos (98.6mL/667m2、29.67mg/L)was the same as the one treated by chlorpyrifos. The quantity of SBPH population which was treated by imidacloprid (53.2mL/667m2、34.96mg/L) was less than the control in some sort. There were two main reasons for the SBPH’s resurgence by using the pesticides , chlorpyrifos cyhalothrin and triazophos. The first one was these three insecticides could stimulate the productivity of both instar nymphs and adults of SBPH. The second one was the toxicity of these three insecticides to the nature enemy, Araneus ventricosus, was more than the toxicity to SBPH out and away.更多还原