【作者】 王飞；

【导师】 吴进才；

【作者基本信息】 扬州大学 ， 农业昆虫与害虫防治， 2008， 硕士

【摘要】 褐飞虱Nilaparvata lugens (St?l) (Hemiptera:Delphacidae)是影响水稻产量和品质的重要害虫,近年来在亚洲地区的猖獗危害呈加重趋势。目前防治褐飞虱为害的主要手段仍是化学防治,而很多研究指出滥用农药是诱导褐飞虱再猖獗的重要原因,尤其在农药对褐飞虱生殖的影响方面。本文在测定四种常用选择性杀虫剂(吡虫啉,扑虱灵,溴氰菊酯和三唑磷)对褐飞虱的毒力系数基础上,分别研究了水稻感抗品种(TN1和协优963)上,不同浓度和施药次数的四种杀虫剂处理对褐飞虱产卵相关指标的影响,主要包括产卵雌虫率,产卵前期,产卵期、雌成虫寿命,产卵量,卵块数、产卵级别,和卵孵化率等。研究结果如下:采用稻茎浸渍法,测定了四种常用杀虫剂(吡虫啉,扑虱灵,溴氰菊酯和三唑磷)对褐飞虱的毒力效应,结果表明:吡虫啉对褐飞虱的毒力最高(供试种群为室内长期饲养的敏感种群),LC50仅为0.0848 mg·L-1,扑虱灵次之。溴氰菊酯和三唑磷对褐飞虱的毒力较低,LC50分别为33.71 mg·L-1和42.59 mg·L-1,表明褐飞虱对吡虫啉和扑虱灵敏感性较高,而对溴氰菊酯和三唑磷的敏感性较低。生殖刺激实验表明,褐飞虱的产卵雌虫率,产卵前期,产卵期,雌成虫寿命,产卵量,卵块数,产卵级别和卵孵化率与药剂,浓度,施药次数和水稻品种有关。吡虫啉和扑虱灵处理,随着浓度的增加褐飞虱的产卵雌虫率,产卵量,卵块数和卵孵化率显著降低,产卵前期显著延长,产卵期和雌成虫寿命显著缩短,且产卵级别主要集中在第Ⅲ级上。而溴氰菊酯和三唑磷处理的实验结果与吡虫啉和扑虱灵恰好相反,随着浓度的增加褐飞虱的产卵前期显著缩短,产卵雌虫率,产卵期,雌成虫寿命,产卵量,卵块数和卵孵化率显著增大,产卵级别主要集中在第Ⅳ级上。农药是影响褐飞虱产卵的主要因素,但因种类不同对各项指标所产生的影响差异较大,属于不稳定因素。不同水稻品种也对上述各产卵指标表现出显著的影响,并且品种差异对褐飞虱产卵指标造成的影响较稳定,属于稳定因素。例如,在相同浓度和相同施药次数条件下,TN1上的褐飞虱产卵量显著大于协优963。除了TN1上扑虱灵单次施药处理的卵孵化率和TN1上溴氰菊酯单次施药雌成虫寿命之外,可以根据实验结果为两个品种上的四种农药处理建立各个产卵指标和不同药剂浓度间的二次回归模型并得到相关系数。此外,多次施药加大了四种农药对以上各产卵指标的影响。在相同水稻品种条件下吡虫啉和扑虱灵多次施药处理的产卵雌虫率,产卵期,雌成虫寿命,产卵量,卵块数和卵孵化率显著显著小于单次施药处理,产卵前期显著大于单次施药处理,而且单次施药的产卵级别在高级别的比率大于多次施药处理;溴氰菊酯和三唑磷多次施药处理的产卵雌虫率,产卵期,雌成虫寿命,产卵量,卵块数和卵孵化率显著大于单次施药处理,产卵前期显著小于单次施药处理,且单次施药的产卵级别在高级别的比率小于多次施药处理。本研究的结果,再次印证了溴氰菊酯和三唑磷两种药剂对褐飞虱生殖的刺激诱导作用,说明实际生产中杀虫剂的选择和适当使用时间,正确使用方法都是避免褐飞虱暴发及猖獗的关键因素。同时品种作为一个稳定的影响因素,抗虫品种的推广使用也是褐飞虱治理的重要手段。本研究结果对于研究褐飞虱在猖獗的内在机制和实际生产中对褐飞虱为害的控制和管理具有非常重要的意义。更多还原

【Abstract】 The brown planthopper (BPH) Nilaparvata lugens (St?l) (Hemiptera:Delphacidae) is an important pest that impacts rice development and grain quality. Outbreaks of the pest frequently occur in Asia. Chemical control is the main method to reduce the damage of N. lugens, and the use of pesticide was considered an important factor for resurgence occurrence, especially, the effect of insecticide on reproduction of N. lugens. The present study tested the toxicity of imidacloprid, buprofezin, deltamethrin and triazophos to third instar nymphs of N. lugens, and established the toxicity regression equations of four insecticides; The present study investigated effects of series of concentrations of four insecticides on laid-eggs female ratio (LFR), preoviposition and oviposition durations (POD and OD), longevity of female (LOF), number of laid-eggs (NLE), number of egg-masses (NEM), grade of egg-production (GEP) and egg hatchability of N. lugens on two rice varieties, TN1 and Xieyou 963. The quadratic regression equations with significant correlation coefficients between each index and insecticide concentrations could be established for four insecticides on both rice varieties. The results showed as follow:The toxicity of imidacloprid to third instar nymphs of N. lugens was maximum, LC50 was 0.0848 mg·L-1, followed by buprofezin. The toxicity of deltamethrin and triazophos was less than buprofezin, LC50 was 33.71 mg·L-1 and 42.59 mg·L-1, respectively. The susceptibility of N. lugens to imidacloprid and buprofezin was more than deltamethrin and triazophos.The indices of N. lugens, LFR, POD, OD, LOF, NLE, NEM, GEP and hatchability varied with insecticides, their concentrations, spray times and rice varieties. For imidacloprid and buprofezin, LFR, NLE, NEM and hatchability decreased, POD elongated, and OD and LOF shortened with increase of concentrations significantly, and the GEP was mainly in gradeⅢ. In contrast, for deltamethrin and triazophos, POD shortened, LFR, OD, LOF, NLE, NEM and hatchability increased with increase of concentrations significantly, and the GEP was mainly in gradeⅣ.Rice variety also showed a significant influence on the indices. For example, NLE on TN1 significantly increased compared to on Xieyou 963 under the same concentrations and spray times. Regression equations with significant correlation coefficients between each index and insecticide concentrations could be established for four insecticides on both rice varieties except for hatchability for single spray of buprofezin on TN1 and for LOF for single of deltamethrin on TN1. In addition, increase of spray times for the four insecticides amplified effects on these indices. For example, three sprays of deltamethrin significantly increased NLE compared to single spray under the same concentrations and rice variety.The present study demonstrated that deltamethrin and triazophos stimulated fecundity of N. lugens. The type of insecticide, applicathion time and method were key fators for control of the pest. The present findings have very important significance for the understanding of mechanisms of N. lugens resurgence and for management of the pest in commercial rice production.更多还原