果园生境花香物质对梨小食心虫卵寄生蜂的引诱作用及其行为调控机制研究

Parasitoids generally need to visit food sources such as floral nectar for nutrition during the host searching behavior after eclosion. So the color and odor of the flowers play a crucial role on the food search behavior of parasitoids and predators. However, less has been known on the semiochemicals of flowers.Interestingly, our earlier studies demonstrated that floral compositions indeed attract parasitoids, but the active ingredients and the mechanism of attraction are rarely reported. Then, in this project, behaviorally active floral substances emitted from peach and pear orchards habitat to Trichogrammadendrolimi Matsumurawill be identified and synthesized, and the ratio and dosage of the attractive blend will be optimized by lab and field bioassay. The synergistic effect of floral mixture and sex pheromone as well as behaviorallymediated mechanism will be studied. The role of associative learning behavior and pre-exposed experienceon the olfactory and behavioral responses of Trichogrammadendrolimiwill be investigated as well. The associative learning behavior and mechanism of trichogrammadendrolimi on honey and floral attractants and sex pheromones areelucidated. Based on this research proposal, the development of trapping tools for the natural enemy and its technical methods will be applied to domestication of artificial production of natural enemies and monitoring the field population of natural enemies. The establishment of combined technology of monitoring both population of pests and natural enemies in the field provides a theoretical basisfor protection and utilization of parasitoids in the biological control of pests by application of semiochemicals.

寄生蜂羽化后在搜索寄主的过程之前会寻找食物源以补充营养，例如花的蜜源。因此，花的颜色和气味对寄生蜂和捕食性天敌有引诱作用,但对寄生蜂有引诱作用的花香成份研究则较少。我们前期研究表明花香成份、性信息素能引诱寄生蜂，但其活性成份及引诱机理待明确。因此，本项目拟以南方桃、梨果园生境中花香物质为研究对象，通过鉴定、合成能引诱梨小食心虫卵寄生天敌-松毛虫赤眼蜂的花香成份并经配比优化，筛选出最佳的引诱寄生蜂的信息素混合物；研究花香混合物与性信息素类利它素的协同作用及行为调控机理；详细比较联想学习处理和经历处理后，松毛虫赤眼蜂在触角嗅觉反应和行为反应上的差异，阐明松毛虫赤眼蜂对蜜糖、花香引诱物和性信息素的联想学习行为及其机理，据此开发天敌引诱剂并应用于驯化人工繁殖的寄生蜂、田间天敌种群的测报与复壮。建立结合害虫和天敌种群监测的田间测报技术，为害虫控制中合理应用该调控措施改进寄生蜂的控害潜能提供理论依据。

本项目瞄准国家十三五期农药减量增效的发展战略，结合化学生态学与植物保护学科中害虫绿色防控这一交叉学科发展新趋势，针对复壮自然天敌、引诱天敌调控害虫中的科学问题，集中在果园生境中挥发性有机物（VOCs）引诱天敌调控害虫，可否解决定期释放人工驯养寄生蜂存在持效期短，需频繁放蜂等问题开展了研究：以南方桃、梨果园生境中花香物质为研究对象，采用田间动态富集、气质联用鉴定挥发性有机物，通过昆虫触角电位反应（EAG）、Y型嗅觉仪等技术手段筛选出系列能引诱梨小食心虫卵寄生天敌-松毛虫赤眼蜂（Trichogramma dendrolimi Matsumura）的挥发性活性物质，并进一步通过Y型嗅觉仪、风洞试验、田间诱捕等技术和方法筛选优化配方，田间诱捕实验表明，配方以水杨酸甲酯和苯甲醛为主，辅以氧化芳樟醇、法尼醇对松毛虫赤眼蜂引诱效果最好，确定了优良合理的天敌引诱剂配方，经过南北方两地大田试验进一步验证了多个天敌引诱剂配方的活性和稳定性。同时对花香混合物与利它素的协同作用及行为调控机理进行了初步探索，结果表明松毛虫赤眼蜂经过蛹期和成虫期的学习行为和联想记忆后，增强了对化合物的敏感性，提高了化合物对松毛虫赤眼蜂的引诱能力，阐明松毛虫赤眼蜂对花香引诱物等化学信息物质的联想学习和经历有一定的行为反应，初步解析其机理。项目结果明确了化学信息物质对松毛虫赤眼蜂的行为调控的协同作用，也为基于植物挥发物的天敌引诱剂开发用于果园绿色防控提供新思路。研究成果发表国内外期刊论文20篇，国内会议大会主旨报告2次；申报发明专利3项，已授权中国发明专利2项、美国发明专利1项；新晋升教授1人；培养博士2人、硕士3人。项目实施对推动复壮自然天敌种群，实施生态调控，促进化学生态学理论创新，实施绿色防控、促进农业可持续发展具有重要的科学意义和社会经济效益。