【作者】 高振兴；

【导师】 祝树德；

【作者基本信息】 扬州大学 ， 农业昆虫与害虫防治， 2004， 硕士

【摘要】 印楝素Azadirachtin是一种高效、低毒植物性的生物杀虫剂。印楝素对多种害虫有较高的生物活性，作用方式独特，然而该制剂对水稻螟虫的研究报道很少，为适应无公害水稻发展的需要，寻求适合于水稻螟虫防治的新型生物农药很有必要。本文针对印楝素与常规化学杀虫剂不同的作用方式，探讨了印楝素对水稻二化螟Chilo suppressalis（walker）的生物活性、作用机制、田间应用技术等，主要结果如下： 1．本文系统研究了印楝素对水稻二化螟的生物活性。结果表明：印楝素对二化螟有拒食、生长调节、抑制产卵、忌避、内吸等多种作用方式。印楝素有效成分0.75×10^-3、0.5×10^-3、0.375×10^-3、0.3×10^-3、0.25×10^-3ml／L处理稻茎，对二化螟拒食率分别为70.82％、65.74％、58.64％、36.69％和23.61％。用印楝素有效成分0.75×10^-3ml／L和0.5×10^-3ml／L处理水稻苗饲喂3龄幼虫，幼虫分别于6d、12d全部死亡。用印楝素有效成分0.375×10^-3、0.3×10^-3和0.25×10^-3ml／L低剂量处理稻苗饲喂二化螟幼虫，对其生长发育有明显的抑制作用，处理24d对幼虫发育的抑制率分别为77.63％、63.16％和55.26％。印楝素对二化螟成虫具有较强的产卵忌避作用，10×10^-3ml／L的剂量喷洒稻株，对成虫产卵忌避率达88.60％。室内毒力测定表明：二化螟蚁螟对印楝素比较敏感。同时发现水稻对印楝素有一定的内吸作用，而且根部比叶片更易吸收传导印楝素。 2．研究了印楝素对二化螟的作用机制。印楝素对二化螟幼虫体内几种解毒酶（羧酸酯酶、非特异性酯酶、磷酸酯酶）和乙酰胆碱酯酶活性的影响结果表明：在一定时间内，二化螟幼虫取食印楝素处理的稻苗，处理试虫体内非特异性酯酶和碱性磷酸酯酶有显著抑制作用，在一定的浓度范围内，随着时间的延长抑制能力逐渐增强，24h的比活力分别为0.7737和0.6829；48h的比活力则分别降到0.6981和0.3902。对羧酸酯酶有可逆性抑制作用，处理12h后，其羧酸酯酶的比活力为0.3693，但随着时间的增加，羧酸酯酶的比活力明显开始上升，到48h时甚至超过扬州大学硕士学位论文了正常水平，达到了1.129。结果表明印糠素对梭酸酷酶早期表现为抑制作用，后期表现为诱导作用。对酸性磷酸醋酶和乙酞胆碱酷酶基本没有影响。 3.研究了水稻二化螟成虫对印糠素的触角电位（EAG）反应。结果表明:二化螟成虫触角受印糠素3xlo一ml/L剂量刺激后，雌、雄触角电位分别为10.824mv和62.123mv，分别是对照的2.55和3.79倍，表明印谏素对二化螟成虫有明显的刺激作用。同时发现二化螟雌、雄成虫对印棣素的反应差异显著，雄虫EAG反应明显强于雌虫。当印株素剂量为10xlo一3ml/L时，二化螟雌、雄成虫EAG反应反而被抑制。 4.通过对初孵蚁螟在盆栽水稻上不同施药方式的试验，结果表明:用印棣素防治二化螟，先打药后接虫的保苗效果明显优于先接虫后打药的效果。用印糠素有效成分6xlo一3ml/L处理盆栽稻株，发现打药48h后接虫的保苗效果为90.02%，接虫48h后打药的保苗效果为83.57%。结合田间试验，生产上应用印棣素时，印辣素比化学农药适当提前1一2d喷药防治，以利于提高防治效果。 5.本文对印糠素防治二化螟的田间防治效果进行了评价。试验结果表明:每667m2用0.30，0印株素乳油62.5ml和125ml防治二代二化螟，施药后Zzd保苗效果分别为88.14%、94.13%，防治效果为85.36%、90.76%;而对照药剂三哇磷一ooml/667m2和somlz667mZ，施药后2一d保苗效果为59.670，0、58.54%，防治效果为85.90%、78.20%。印糠素可以作为防治二化螟的有效生物农药。更多还原

【Abstract】 Azadirachtin is a kind of botanical insecticide with high effect and low toxicity. It has high biological activity and unique functional mechanism to many kinds of pests. But there were rare report in the efficacy of azadirachtin on paddy stem borer. In order to meet the need of the development of no-polluted paddy, it’ s quite necessary to find out a new biological pesticides which can perfectly control paddy stem borer. This paper studied the biological activity, action mechanism, application technology of azadirachtin for Chilo suppressalis (walker), in view of the different action of azadirachtin from conventional chemical insecticides. The main results were as following:1. The biological activity and functional mechanism of azadirachtin for rice stem borer, Chilo suppressalis, were systematiclly studied in this paper. The results showed that azadirachtin had many functional patterns for Chilo suppressalis as antifeedant, growth regulation, oviposition deterrent , sucking toxieity and others. The antifeedant rates of the newly-hatched larvae reached 70.82%, 65.74%, 58.64% 36.69% and 23.61% after feeding on paddy that treated with 0.75x10-3 0.5 10-3, 0.375x10-3, 0.3x10-3 and 0.25x10-3ml/L azadirachtin concentration. The 3th-instar larvae completely died in 6 days, 12 days respectively after feeding on paddy that were treated with the effective element of 0.75x10-3 and 0.5x10-3ml/L azadirachtin. The larvae development was obviously suppressed when it was feed on the paddy which was treated with 0.375 x 10-3 , 0.3 10-3 and 0.25 10-3ml/L azadirachtin respectively. The restrained rate of larvae development were 77.63%, 66.16% and 55.26% after 24 days. Azadirachtin deterred adults from standing on the paddy sprayed with azadirachtin. The oviposition deterrence rate reached 88.60% when paddy were treated with 10 10-3ml/L azadirachtin. Results of toxicity determined in laboratory indicated that newly-hatched larvae weresensitive to azadirachtin and the root of the paddy was more likely to absorb andtransmit azadiractin than the leaves.2. Action mechanisms of azadirachtin to stem borer were researched in this thesis. According to the effects of azadirachtin on metabolic esterase,’ which including caboxylesterase, total esterase, phosphatase and AchE, the resuts showed that the total esterase and alkaline phosphatase were significantly restrained in a period when the larvae of chilo suppressalis was feed on the paddy treated with azadirachtin. Under certain concentration of azadirachtin, the restraining ability to them is stronger along with the time elongating. Their activity ratio were 0.7737 and 0.6829 after treatment in 24 hours. Their activity ratio were 0.6981 and 0.3902 after treatment in 48 hours. There was a reversibly restrain action to carboxylesterase. The activity ratio of carboxylesterase was 0.3693 after treatment in 12 hours. When the time was longer, the active ratio was increased significantly. The active ratio of enzyme reached 1.129 in 48 hours. The results showed that azadirachtin may restrain carboxylesterase at early stage but induced it at later stage. Besides these, azadirachtin didn’t effect acid phosphatase and AchE.3. The EAG response of the adult of chilo suppressalis to azadirachtin was studied in the paper. The result indicated that the EAG of the male and female of chilo suppressalis reached 10.824mv and 62.123mv respectively, which was 2.55 and 3.79 times of CK, when the antenna was stimulated by 3 X 10"3ml/L azadirachtin. This results demonsrated that azadirachtin had stimulated effect on the adult of chilo suppressalis. Antenna electric response of the male and female adult to azadirachtin was significantly different. The antenna electric response of the male is stronger than that of female. When the concentration was 10 10-3ml/L, the EAG response of the male and female adult were restrained.4. Based on the experiment of different application method for the newly-hatched chilo suppressalis, the results showed that the better control effect would be get if azadirach更多还原