【作者】 蔡双虎；

【导师】 程立生；

【作者基本信息】 华南热带农业大学 ， 农业昆虫与害虫防治， 2003， 硕士

【摘要】 本研究通过对二斑叶螨Tetranychus urticae Koch生命表的制作和分析、对受害寄主植物叶片叶绿素含量变化和与朱砂叶螨T.cinnabarinus(Boisduval)种间竞争研究来全面分析二斑叶螨在我国的危险性。 通过对二斑叶螨在5种寄主植物(四季豆Phaseolus vulgaris、棉花Gossypium hirsutum、苹果Malus pumila、茄子Solanum melongena、辣椒Capsicum annuum)上的实验种群生命表的组建分析，计算出其在这5种寄主植物上内禀增长力r_m分别为0.2634、0.1788、0.2098、0.2280、0.1538；次代种群数量显著增长，在不同寄主植物上每雌产雌数存在极显著差异；在稳定种群年龄分布中，未成熟期在5种植物上分别占总量的88.3335％、85.3052％、85.0386％、87.3787％和86.8404％，成螨期分别占总量的11.6636％、14.6946％、15.0635％、12.6218％和13.1598％；对致死率为99％的不良环境的反应时间都小于30d。 研究发现不同密度的二斑叶螨为害同一寄主植物时叶绿素日减少量差异显著；当害螨密度比较小时，寄主植物叶片存在一定的补偿能力，当二斑叶螨密度过大，每天植物叶片的损耗过大，叶片将丧失补偿能力；相同密度的二斑叶螨为害不同寄主植物时叶绿素日减少量差异极明显，但累计减少总量基本相等，差异不显著。 比较二斑叶螨和朱砂叶螨在4种寄主植物上单种种群和混合种群r_m值来确定二斑叶螨的竞争力的大小，发现不论是单种种群还是混合种群，在四季豆、苹果、茄子上二斑叶螨的竞争力均明显高于朱砂叶螨，但以棉花作为寄主植物时结果刚好相反，这也表明二斑叶螨的竞争力大小与寄主植物种类有关联。 分别从二斑叶螨种群内禀增长力rm的大小和寄主植物受二斑叶螨为害的叶片的叶绿素变化量来看，在4种寄主植物上二斑叶螨对奇主的嗜食性大小顺序为：四季豆＞茄子＞苹果＞棉花。这表明，在所选的4种寄主植物中，二班叶螨最嗜好的是四季豆，其次是茄子，再次是苹果，最不嗜好的是棉花。 从二斑叶螨室内种群生命表、受害叶片的叶绿素变化以及二斑叶螨与朱砂叶螨的种间竞争分析来看，其在棉花上的各项指标均不及其它寄主植物，这表明目前二班叶螨进入我国棉田造成大面积严重为害的可能性不是很大。更多还原

【Abstract】 Experiments were conducted to study the population characteristics of T. urticae Koch and its harming to some crops. The researching process included three facets as follows: analysis of the life tables, chlorophyll variation in the leaves of the host plants and competition with T. cinnabarinus (Boisduval).The life table of experimental population of T. urticae Koch was established at constant temperature of 25 C, illumination time of 16 hours one day and humidity of 50%.The result of the experiment indicated that the value of the innate capacity of increase was 0.2634, 0.1788, 0.2098, 0.2280, 0.1538 on kidney bean, cotton, apple, aubergine and capsicum respectively and the quantity of the offspring obviously increased. When the age distribution of experimental population was steady, the amounts of the immature age were 88.3335%, 85.3052%, 85.0386%, 87.3787% and 86.8404% on five host plants respectively and the amounts of the adults 11.6636%, 14.6946%, 15.0635, 12.6218% and 13.1598% correspondingly. The reaction time to the adverse environment causing 99% death rate of T. ’urticae Koch was less than 30 days on all the four host plants.The diversity of decrement of chlorophyll was distinct with the different densities of T. urticae Koch impacting the same host plants, and the leaves of host plants had the capability of compensating chlorophyll while the density of T. urticae Koch was comparatively low. The total decrement of chlorophyll was basically equal with the same density of T. urticae Koch impacting different hostplants with the diversity of everyday decrement of chlorophyll among different host plants being obvious. The diversity of chlorophyll decrement in different host plants impacted by T. urticae Koch of the same density was obviously distinct.T. urticae Koch had different preference for the four host plants. Inferring from the differences of innate capacity of increase and the diversity of decrement of chlorophyll among different host plants infested by T. urticae Koch, the kidney bean was the best food for T. urticae Koch, the aubergine the better and the cotton the worst among these four host plants.The capacity of competition was positive in relation to the the innate capacity of increase. Compared to T. cinnabarinus (Boisduval), The capacity of competition of T. urticae Koch was obviously higher for both single population and mixed population on the kidney bean, apple, aubergine and capsicum. But the result was opposite on the cotton. This indicated that the capacity of competition of T. urticae Koch was correlative to the host plant species.Above all, the experimental population parameters of T. urticae Koch on cotton was lower than other host plants. This predicted it was impossible that T. urticae Koch enter the cotton fields and harm the cotton seriously at present.更多还原