长翅目成虫口器形态多样性与其演化模式

Mouthparts are closely associated with the feeding behavior and feeding habits of insects. The morphological diversity of mouthparts can provide important traits for evolutionary biologists and systematists. Mecoptera is one of the most primitive orders in holometabolous insects and occupies critical position in Antliophora. Their adults bear unique chewing mouthparts, which bear sucking function and exhibit great morphological and functional diversity among the extant families and genera during long evolutionary process. However, since the study of functional morphology is far from sufficient and the feeding strategies of most groups are just suppositional, making it hard to understand the feeding mechanism and the evolutionary pattern of mouthpart functional morphology. This research project investigates the functional morphology of mouthparts in three representative groups of Mecoptera from morphology, histology, biology, geometric morphometric, and molecular biology aspects, in an attempt to clarify the feeding strategy and feeding mechanism among different groups. By integrating the morphological and molecular data, a phylogenetic tree is reconstructed to clarify the phylogenetic signal of mouthpart morphology and to explore the evolutionary pattern of mouthpart functional morphology. The completion of the project may deepen our understanding of the evolutionary history of Mecoptera and provide important evidence for the origin and evolution of Antliophora and Holometabola.

昆虫口器与昆虫取食行为和取食习性密切相关。口器的形态多样化可为进化生物学家和系统学家提供重要线索。长翅目是原始的全变态类昆虫类群之一，在吸吻总目占据关键地位。该类群在长期的进化过程中，其成虫逐渐演化出极为特殊的具吸收功能的咀嚼式口器，并在仅有的现存科属间表现出极大的形态和食性多样性。然而由于其口器功能形态研究尚不充分，大部分类群取食策略目前均为推测，对进一步理解长翅目昆虫的取食机制和口器功能形态演化模式造成一定的困扰。本项目拟从形态学、组织学、生物学、几何形态测量学、分子生物学等角度，对长翅目3种食性的代表类群口器进行全面的功能形态学研究，以期明确各自的取食策略和取食机制。整合形态和分子数据，构建长翅目系统发育关系树，揭示其口器形态的系统发育信号，探讨其演化模式。本项目的完成，有望加深人们对该类群演化历史的理解，并进一步为吸吻总目乃至全变态类昆虫的起源与演化研究提供重要证据。

口器是昆虫的取食器官，其各组件在形态和功能上呈现出的多样性，是研究进化和系统学的理想材料。本项目从形态学、组织学、生物学、几何形态测量学、分子生物学等角度，对长翅目3种食性的代表类群口器进行了全面的功能形态学研究。研究利用扫描电镜技术，对长翅目3科9属16种的成虫口器形态进行观察，比较了不同科、属的口器形态以及感器类型和分布；通过对口器结构进行组织切片和解剖，研究了不同食性的类群其口器在空间构型上的异同；采用几何形态测量学方法定量分析了口器形态变量；通过解剖消化系统，从内部器官形态、细胞水平上辅助揭示了长翅目成虫食性；联合口器、内部器官以及生物学研究结果，分析不同类群口器的形态功能，揭示其多样化的取食策略和取食机制；获得了以口器形态特征为主的形态学数据和分子生物学数据，分别构建了长翅目系统发育关系树，揭示了长翅目口器形态的系统发育信号，并探讨了长翅目口器功能形态的演化模式。