【作者】 弓淑芬；

【导师】 戴华国；

【作者基本信息】 南京农业大学 ， 农业昆虫与害虫防治， 2004， 硕士

【摘要】 本文以亚洲玉米螟的适宜、次适与不适寄主--玉米螟赤眼蜂、拟澳洲赤眼与松毛虫赤眼蜂为主要研究对象，从三种赤眼蜂雌蜂触角上化学感器的形态及分布、三种赤眼蜂与亚洲玉米螟的化学通讯中植物源和寄主源化学信息素的影响、玉米螟赤眼蜂与亚洲玉米螟在生理上的相互防御与激素调控等几个方面，探讨了赤眼蜂的寄主搜索与寄生后对寄主的发育调控机制，以进一步了解赤眼蜂与亚洲玉米螟的协同进化关系。 运用扫描电子显微镜分别对玉米螟赤眼蜂、拟澳洲赤眼蜂、松毛虫赤眼蜂雌蜂触角上的化学感器进行了观察，描述了它们的外部形态，并比较了感器的数目和着生位置。研究发现了镰刀形感器腹面的特殊形态，并确定了其嗅觉功能。发现位于触角端部的毛形感器顶端具单孔，从而确定单孔毛形感器为味觉器。发现三种赤眼蜂棒节腹面的镰刀形感器数目及棒节背面板状感器的形态和嗅孔密度存在差异。并发现玉米螟赤眼蜂的坛形感器具有两种形态，而其他二个种的坛形感器只有一种形态。 利用嗅觉仪和培养皿法研究了玉米螟赤眼蜂、拟澳洲赤眼蜂、松毛虫赤眼蜂对被玉米螟幼虫取食过的玉米叶片、茎杆和玉米螟雌蛾腹末鳞片的四种试剂不同浓度抽提液的趋向反应。结果表明，亚洲玉米螟雌虫腹末鳞片、玉米健茎、健叶、虫伤茎和虫伤叶提取物对三种赤眼蜂有不同程度的他感作用。就提取物而言，其引诱能力：玉米螟雌虫腹末＞虫伤株＞玉米茎、叶；就他感作用而言，其作用的明显程度：玉米螟赤眼蜂＞拟澳洲赤眼蜂＞松毛虫赤眼蜂。两种方法相比较，嗅觉仪法较为精确。 采用放射化学法(RC)和放射免疫法(RIA)分别测定了亚洲玉米螟卵在不同发育时期被玉米螟赤眼蜂寄生后卵内保幼激素酯酶活力和蜕皮激素滴度的变化。结果发现，玉米螟胚胎发育早期(即在胚胎发育72h之前)被寄生，则正在发育的玉米螟胚胎停止发育，而赤眼蜂卵得到正常发育。卵内保幼激素滴度和蜕皮激素滴度的变化与赤眼蜂胚胎发育过程中激素动态变化相吻合。玉米螟胚胎发育晚期(即在胚胎发育72h之后)被寄生，则赤眼蜂胚胎不能正常发育。说明玉米螟卵胚胎发育72h是玉米螟赤眼蜂寄生成功与否的关键时期。更多还原

【Abstract】 Some aspects of the chemical communication and physiological accommodation between Trichogramma spp. and Ostrinia furnacalis were studied in the laboratory. First, the external morphology of antennal sensillum of female species of T. ostriniae, T. confusum and T. dendrolimi were observed by scanning electron microscopy(SEM); Next, the behavioural responses of the three Trichogramma species to different extracts of plant volatiles and host volatiles were examined by choice tests using "Y" tube and culture dish; Finally, the juvenile hormone esterase activity and molting hormone titer in 0. furnacalis eggs parasitized in their different development phases by T. ostriniae were measured by RC method and RIA method. The results aresummarized as follows:The external morphology of antennal sensillum were observed and described by SEM for female species of the three kinds of Trichogramma. The numbers and the relative positions of these sensillum were depicted. The special structure on the ventro-lateral margin of falcate sensilla was discovered and its function was confirmed. A single pore at the tip of trichoid sensilla on the apex of the antenna was discovered, which indicated that the trichoid sensilla may perform gustatory function. The differences in the numbers of falcate sensillum , the densities of olfactory pores and shapes of placoid sensillum and the shapes of ampullaceum sensillum among the three species of Trichogramma, were also discussed.The effect of the allelochemicals on T. ostriniae, T. confusum and T. dendrolimi in host searching behaviour was studied, and "Y’-tube olfactometer system and culture utensil method were used. The results demonstrated: The extract of the last abdomen of the female moth, the host-damaged and the healthy stem and leaf of maize were attractive to three trichogramma species. As far as the extract was concerned, the attractive ability were: the last abdomen of Trichogramma> the host-damaged> the stem and the leaf of maize; as far as the allelopathy was concerned, the attractive ability were: T. ostriniae> T. confusum> T. dendrolimi. Compared to the two methods, the olfactometer system was more accurate.The juvenile hormone esterase activity in O. furnacalis eggs parasitized in their different growth phases by T. ostriniae were measured by RC method. The moltinghormone titer in O. furnacalis eggs parasitized in their different development phases by T. ostriniae were measured by RIA method. It was discovered that if parasitization occurred in early stage of host embryonic development (before 72h), T. ostriniae egg would develop, and embryonic development of O. furnacalis would be suppressed. The change pattern of juvenile hormone esterase activity and molting hormone titer of eggs parasitized were according with that of the developing process of T. ostriniae from egg to pupa. If parasitization occurred after 72h, the development of T. ostriniae were suppressed. The result showed that about 72h of the development of O. furnacalis embryo is the key period for T. ostriniae to parasitize successfully.更多还原