基于幼期复变态发育的花绒寄甲逃避松褐天牛幼虫免疫的机理研究

天牛类害虫钻蛀取食致死或携传病原间接造成大量林木死亡，给我国践行“绿水青山就是金山银山”理念和推进林业生态建设造成了极大的困难。花绒寄甲是寄生天牛类害虫的优秀天敌昆虫，在多种重大天牛的防治中发挥着重要作用。花绒寄甲幼虫属外寄生性鞘翅目昆虫，且缺乏寄生因子，其逃避寄主免疫的机理尚不清楚。本项目拟通过建立“花绒寄甲—松褐天牛”寄生系统，弄清花绒寄甲幼期复变态发育过程中形态结构和生活习性的变化，明确其逃避寄主免疫的生物学过程；通过体外分泌物的功能验证和代谢组成分分析，明确寄主对低龄幼虫的免疫识别和抑制效能；采用组织病理学方法追踪其寄生过程，明确大龄幼虫逃避寄主包囊和黑化作用的方式；通过检测寄主免疫功能指标变化和相关免疫基因表达情况，定性和定量地分析寄主的免疫反应特征，为研究花绒寄甲与天牛的互作关系提供理论支撑，为丰富“以虫治虫”的生防基础研究和脊椎动物对外寄生虫的先天性免疫策略提供新思路。

A large number of trees are directly bored by long-horned beetles or indirectly killed by carrying pathogens, which makes it very difficult to practice the conviction that “lucid waters and lush mountains are invaluable assets” and promote the forestry ecological construction. As an excellent parasitic natural enemy, Dstarcus helophoroides plays an important role in the control of many destructive long-horned beetles. The ectoparasitic larva belongs to coleopteran insect lacking parasitic factors and the mechanism of host immune evasion is still unclear. The parasitism system of “D. helophoroides-Monochamus alternatus” was established to clarify the changes of morphological structure and living habits during the development of hypermetamorphosis, and to reveal the biological process of host immune evasion; The immune recognition and inhibition effect of host on the young larvae through the functional validation and metabolic component analysis of external secretions. Histopathological methods were used to track the parasitism process and to determine the ways of older larvae to escape host encapsulation and melanization. The characteristics of host immune response were analyzed qualitatively and quantitatively by detecting the changes of host immune function indexes and the expression of related immune genes. The results would provide theoretical support for the study of the interaction between D. helophoroides and the long-horned beetles, and enrich the fundamental and application research of the bio-control technologies using natural enemies to control pests and present a novel idea for the innate immune strategies of vertebrates.