【作者】 刘琴；

【导师】 宋从凤；

【作者基本信息】 南京农业大学 ， 种植， 2005， 硕士

【摘要】 茶尺蠖（Ectropis obliqua Prout）是我国浙江、江苏、安徽等主要产茶省份危害茶树的重要害虫。目前生物防治上主要以苏云金杆菌（Bacillus thuringiensis，简称Bt）和茶尺蠖核型多角体病毒（Ectropis oblique Nucleopolyhedogsis Virus，简称EoNPV）等微生物农药防治茶尺蠖危害。苏云金杆菌是研究应用最广泛的微生物杀虫剂，但在田间使用中存在防效不稳定、残效期短等问题。而茶尺蠖核型多角体病毒虽具有杀虫专一性强、杀虫效果好，且能垂直传播、持效期长、对人畜无害的优点，但是存在杀虫速度缓慢问题，使害虫的危害难于控制在经济阈值以下。为了克服苏云金杆菌和茶尺蠖病毒杀虫剂的缺点，本研究分离、筛选了新型Bt、病毒菌株，并对Bt高毒菌株与茶尺蠖病毒的联合作用进行了研究。 影响Bt和EoNPV对茶尺蠖防效的因素试验表明，茶尺蠖对Bt具有较强的耐药性，不同血清型Bt菌株500倍稀释液对茶尺蠖防效在0～41.5％之间；Bt菌株Yz-2对2龄茶尺蠖的致死中浓度LC₅₀高达56.7330uL／mL，是3龄小菜蛾LC₅₀的36.4倍。温度、光照是影响EoNPV应用效果的主要因素。 野外采集菌土，分离接种、感染复壮，筛选出一株对茶尺蠖毒力较高的Bt菌株02-85，对2龄茶尺蠖LC₅₀为6.9043uL／mL，较对照菌株Yz-2毒力高2.15倍。从野外茶尺蠖罹病虫尸上分离筛选了高毒力茶尺蠖病毒EoNPV-A和EoNPV-B，在2×10⁴PIB／mL使用浓度下，茶尺蠖3d开始死亡，10d死亡率达100％。以2龄中期幼虫感染5×10⁵PIB／mLEoNPV的病毒液，病毒产量可达到6.8×10⁸PIB／头，多角体总含量为6.58×10¹⁰PIB。 苏云金杆菌和茶尺蠖核型多角体病毒间具有协同增强作用。Bt与不同含量的EoNPV混合测定，对茶尺蠖的共毒系数在106.02～128.03之间，表明茶尺蠖核型多角体病毒与苏云金杆菌间具有增效作用。1.0×10⁷PIB／mL的EoNPV与2000IU／uL Bt联合作用，对茶尺蠖作用速度加快，致死中时间缩短了2d。杀虫范围较病毒明显扩大，对茶毒蛾等并发害虫兼治效果达85.8％。害虫对混合应用药剂拒食作用加强，保叶效果达92.1％。 利用苏云金杆菌和茶尺蠖核型多角体病毒协同增强作用，研制了茶尺蠖微生物杀虫剂——尺蠖清，属微毒级，无急性致病性，对鱼和鸟均为低毒，对蜜蜂和家蚕均为低风险性农药。研究了产品的加工工艺和产品标准。2004年在江苏、浙江、安徽等省更多还原

【Abstract】 Ectropis obliqua Prout is one of the most important pests which damage the tea-trees in the district of Zhejiang, Jiangsu and Anhui province in China. Bacillus thuringiensis （Bt） and virus are two main bio-pesticides used to control Ectropis obliqua currently. There are some disadvantages of control in practical applications, such as less effective, unstable control effect and short effective period, resulting in the damage caused by E. oblique can not be controlled under the allowable standard. In this study, two new strains with high virulence to E. obliqua have been screened, and the synergistic effect of Bt with EoNPV has also been studied.Different strains of Bt caused larval mortality from 0 to 41.5%, and the LC₅₀ of Bt to E. obliqua was 56.7330uL/mL, 36.4-fold higher than that to Plutella xylostella. Those indicated the pest was not susceptible to Bt. The control effects of EoNPV were mainly influenced by the factors of temperature and light.By collecting virus contained soil, isolation, inoculation and re-isolation, a new Bt strain 02-85 was selected. Its LC₅₀ to E. obliqua was 6.9043uL/mL, the virulence was 2.15 times than that of the strain Yz-2. Two new EoNPV strains named EoNPV-A and EoNPV-B were also screened from virus infected E. obliqua. A total mortality of 100 percent of E. obliqua was obtained after three days when treated with those two isolated viruses at the concentration with 2×10⁴PIB/mL. To replicate the virus, the larvae at second instars was selected to inject EoNPV at concentration of 5×10⁵PIB /mL, and finally total of 6.8×10⁸PIB virus per insect was obtained.There was a combined effect of EoNPV and Bt to control the larvae of Ectropis obliqua. The CTC of 1.0×10⁷ PIB/mL EoNPV+2000IU/uL Bt was 128.03, and the LT₅₀ was about 2 days shorter than using EoNPV only. At the same time, it could control other pests of Lepidoptera and cause feeding resistance action of E. obliqua. The control effect to Iragoides fasciata was up to 85.8%.According to the synergistic effect between Bt and EoNPV, a preparation called Chihoqing has been produced. This product was safe to fish and birds, and did no harm to更多还原