【作者】 徐海云；

【导师】 万方浩；

【作者基本信息】 中国农业科学院 ， 生物安全， 2014， 博士

【摘要】 烟粉虱Middle East-Asia Minor1Bemisia tabaci Gennadius MEAM1（也称生物型B，biotype B）是一种世界性的入侵害虫，在过去的几十年里已在全球范围内造成极大的经济损失。人类对该虫持续的化学防治已导致其产生严重的抗药性，并对生态环境安全和人类健康产生威胁，因而急需发展可持续的防控技术与方法。因此，筛选利用高效的生防作用物，建立有效的生物防治体系已迫在眉睫。传统生物防治是通过从入侵害虫原产地引进其专食性天敌来达到控制其为害的目的。然而，这种单一的生防体系通常会因为缺乏多样性而在害虫治理的过程中难以持续。因此，同时引入两种或多种天敌建立长期有效的害虫生防体系成为研究的重点。不可避免的是，生态位相似或相同的两种或两种以上天敌种群共存时就会发生以抢占寄主资源为目的的竞争作用。本文以烟粉虱的两种优势寄生蜂浅黄恩蚜小蜂Encarsia sophia Girault&Dodd和海氏桨角蚜小蜂Eretmocerus hayati Zolnerowich&Rose为研究对象，针对建立多种天敌联合控制入侵害虫烟粉虱的长期有效的生防体系的需求，围绕两种寄生蜂种间和种内竞争互作关系决定其共存机制这一科学问题，采用发育生物学、昆虫行为学及种群生态学的技术与方法对两种寄生蜂的适生性差异和种间竞争互作关系进行了研究。主要结果和结论如下：1.通过对实验室条件下（温度26±2℃、湿度65%±5%、光周期L14∶D10）两种寄生蜂的年龄-特征两性生命表的组建，明确了两种寄生蜂的适生性差异：浅黄恩蚜小蜂卵-幼虫、预蛹-蛹和成虫的发育历期分别为6.4±0.1、6.5±0.1和16.0±1.3天；海氏桨角蚜小蜂卵-幼虫、预蛹-蛹和成虫的发育历期分别为10.4±0.2、4.6±0.1和9.8±0.8天。浅黄恩蚜小蜂与海氏桨角蚜小蜂的产卵期分别为18.5和15.1天，单雌产卵量分别为101.6和211.4粒，每日最大产卵量分别为22粒和54粒。浅黄恩蚜小蜂和海氏桨角蚜小蜂的种群内禀增长率(r)、周限增长率(λ)、净繁殖率(R0)、平均世代周期(T)分别为0.215d-1、1.2402d-1、57.49后代/个体、18.82天和0.214d-1、1.2383d-1、79.29后代/个体、20.46天。2.通过对两种寄生蜂生殖系统结构与卵巢发育特点研究，明确了两种寄生蜂生殖系统结构的异同和卵子发生发育模式：两种寄生蜂雌性生殖系统均由内生殖系统和外生殖器构成，包括1对卵巢、1对侧输卵管、中输卵管、受精囊、产卵管和产卵鞘；浅黄恩蚜小蜂的产卵器细长笔直较锋利适宜内寄生而海氏桨角蚜小蜂产卵器扁平且尖端向上弯曲适宜外寄生；寄生蜂雌蜂羽化后在保证充足营养的情况下，卵巢内成熟卵子的数量随着时间的推移而显著增加。3.通过对两种寄生蜂寄主处理行为策略的观察，评价了两种寄生蜂成蜂的寄主搜索和寄主识别行为在不同寄主生境和不同引入时间间隔条件下的差异。结果表明：浅黄恩蚜小蜂和海氏桨角蚜小蜂的寄主处理行为呈现出特定的顺序和规律，两种寄生蜂在寄主生境中的行为都包括搜索、评价、产卵、产卵器穿刺、取食、梳理，取食蜜露和站立不动等行为；生境中寄主资源的不同对浅黄恩蚜小蜂的寄主处理行为影响较大，而对海氏桨角蚜小蜂的寄主处理行为影响不大；寄生蜂不同引入时间间隔对两种寄生蜂的寄主处理行为影响不大，但时间间隔为0h的处理中两种寄生蜂对寄主的接受率均大于时间间隔为48h的处理。浅黄恩蚜小蜂对健康寄主和已寄生寄主（同种或异种）的接受率、拒绝率和取食率差异不显著，海氏桨角蚜小蜂对健康寄主的接受率明显高于同种或异种已寄生寄主。4.通过对两种寄生蜂幼虫之间的内竞争的研究，发现二者之间的内竞争结果因寄生蜂雌蜂的引入顺序和引入时间间隔不同而不同：当先引入浅黄恩蚜小蜂时，无论前后两次引入时间间隔如何，浅黄恩蚜小蜂都会在竞争中取胜；当先引入海氏桨角蚜小蜂时，多数情况下浅黄恩蚜小蜂幼虫在竞争中取胜，只有当前后两次引入时间间隔延长到72h时，海氏桨角蚜小蜂幼虫才会在竞争中取胜。较短的卵期发育时间可能是浅黄恩蚜小蜂在内竞争中取胜的主要原因。5.为明确寄主资源条件对寄生蜂种间关系和对寄主控效的影响，评价了不同寄主密度和寄主龄期条件下浅黄恩蚜小蜂和海氏桨角蚜小蜂的种间和种内竞争互作关系。研究结果表明：对于浅黄恩蚜小蜂来说，在寄主密度较低的情况下，同种寄生蜂对其干扰作用较强，而异种寄生蜂海氏桨角蚜小蜂对其干扰作用相对较弱；随着寄主密度的升高，异种寄生蜂海氏桨角蚜小蜂对浅黄恩蚜小蜂的种间干扰作用增强。对于海氏桨角蚜小蜂来说，无论寄主密度高低，异种寄生蜂浅黄恩蚜小蜂对其的种间干扰作用总是强于同种寄生蜂对其的种内干扰作用，而且随着寄主密度的升高，海氏桨角蚜小蜂受到的干扰作用逐渐减弱。寄主龄期对两种寄生蜂种间竞争作用的影响则体现为：在低龄寄主条件（1龄和2龄）下，海氏桨角蚜小蜂具有较强的竞争优势；在高龄寄主条件下，海氏桨角蚜小蜂的竞争优势减弱，浅黄恩蚜小蜂竞争优势增强。更多还原

【Abstract】 Bemisia tabaci (Gennadius)(Hemiptera: Aleyrodidae) Middle East-Asia Minor1(MEAM1, alsocalled biotype B), a serious invasive pest in vegetables and broad-acre crops worldwide, has causedextremely serious economic losses during the last decades. The extensive use of chemical insecticides infood crops has resulted in the development of resistance against several insecticides, increasing threatsto the environment and human health. Thus, developing long-term integrated B. tabaci populationmanagement, with a strong natural enemy component, is a promising alternative. The classicalbiological control is a way to control invasive alien species by introducing specific natural enemiesfrom the original areas of the invasive pests. However, introducing single species might be difficult toachieve sustainable management of insect pests because of the lack of biodiversity. Therefore,introducing two or multiple species of natural enemy to establish a long-term management system hasbeen emphasized by numerous scientists. Unavoidably, when two or even more species with similarecological niche coexist in a biological control system, the competition for resource utilization mightoccur.Regarding the demand of establish sustainable biological control system of B. tabaci byintroducing multiple natural enemies, here we investigated the fitness differences and interspecificcompetitive interactions between Encarsia sophia (Girault&Dodd) and Eretmocerus hayati(Zolnerowich&Rose)(Hymenoptera: Aphelinidae), two prominent parasitoids of B. tabaci, and try tounderstand the concomitant mechanism affected by inter-and intraspecific interactions between thesetwo parasitoids. The main results and conclusions are as follows:1. The age-stage, two-sex life table were studied under laboratory condition (26°C±2°C,65±5%RH, and14L:10D regime) to evaluate the fitness difference between these two parasitoids. For En.sophia, the developmental time from egg to larva, from prepupa to pupa, and the longevity of adultswere6.4±0.1,6.5±0.1and16.0±1.3days, respectively; for Er. hayati, they were10.4±0.2,4.6±0.1and9.8±0.8days respectively. The oviposition period, fecundity, as well as maximum number ofoviposition per day for En. sophia and Er. hayati were18.5and15.1days,101.6and211.4eggs, as wellas22and54eggs, respectively. The population intrinsic rate of increase (r), finite rate of increase (λ),net reproduction rate (R-10)、mean generation time (T) of En. sophia were0.215d-1,1.2402d,57.49progeny/individual and18.82day, respectively; for Er. hayati, were0.214d-1,1.2383d-1,79.29progeny/individual and20.46day, respectively.2. The reproductive system structure and ovary developmental traits of these two parasitoids werestudied. Both parasitoid females’ reproductive system consisted of internal and external reproductiveorgans, including a pair of ovaries, six ovarioles, spermatheca, ovipositor and ovipositor sheath. Theovipositor of En. sophia is straight, has an apparently hard and sharply pointed upper valve, and appearswell-suited to penetrating a hard substrate, while that of Er. hayati is curved, thick-walled, but has ablunt and apparently flexible tip. These features correlate well with the mode of oviposition that En. sophia and Er. hayati ovipositing internally and externally respectively. Mature ova increased with theage of adult female when the available nutrition was enough.3. The host handling behaviors of these two parasitoids under various host habitats and in differentfemale introduction sequences were studied. Results showed that host handling behaviors of bothparasitoids, which included searching, accessing, oviposition, drilling by ovipositor, hostfeeding,preening, feeding on honey and standing still, showed particular phases and sequences. The differenthost types in the habitats showed more significant effect on En. sophia than Er. hayati. The femaleintroduction sequences did not affect the host handling behaviors of both parasitoids significantly.However, host acceptance rates of two parasitoids when time interval is0h were higher than when timeinterval is48h. The acceptance rates, rejection rates and host-feeding rates of En. sophia on heathy hostsand parasitized hosts (conspecific or heterospecific) were not significantly different. However,acceptance rate of Er. hayati on healthy hosts was significant higher than on conspecific orheterospecific hosts.4. Results of intrinsic competition between the immature of the two parasitoids indicated that thecompetition outcome varied with the introduction sequence and time intervals of different female adults.When En. sophia was introduced first, it outcompeted the competition regardless of the time intervals (0,24,48h). When Er. hayati was introduced first, it prevailed at the time interval72h. This result might beexplained by shorter development time of egg of En. sophia when compared to Er. hayati.5. To understand the effect of host resources availablity on interspecific interaction of twoparasitoids and host suppression, the inter-and intraspecific competitive interactions between En.sophia and Er. hayati under different host densities and host instars were evaluated. For En. sophia,while the host density was low, intraspecific interference was stronger than interspecific interference.What’s more, the interspecific interference increased with host densities. For Er. hayati, the interspecificinterference were always stronger than intraspecific interference, and decreased with increasing hostdensity. Host instars also affected the outcome of interspecific competition of these two parasitoids. Er.hayati won the competition while provided with young host instars (first and second instar nymphs),and this advantage decreased while provided with older host instars.更多还原