中国迈金小蜂属分类与系统发育研究（膜翅目：小蜂总科）

The genus Mesopolobus Westwood, 1833 belongs to the family Pteromalidae (Hymenoptera), and distributes worldwide. 125 species are currently recorded in the genus, the majority of which are important parasitoids of eggs, larvae and pupae of Diptera, Lepidoptera, Hymenoptera, Coleoptera and Hemiptera. Most of the pests have hidden leaf, stem boring, stem borers, gall and development in the seed. Therefore, these parasites are potentially important enemies of many pest insects. However, there are only reported 27 species form China, and had been no systematic study on the genus in China. In this project, species of Mesopolobus from China will be systematically studied for their taxonomy, distribution and host. We try to build phylogenetic trees by combined analyses of morphological characters, gene sequences and parasitic habits of representative species in order to analyze the relationships between taxa, and how the relationship between parasitoids and their hosts were established and evolved. This proposal is not only a taxonomic study and species diversity, but also providing scientific basis for study of insect fauna, management of natural resources, as well as biological control of insect pests in China.

迈金小蜂属隶属于膜翅目、小蜂总科、金小蜂科，是金小蜂科中一个大属。目前已知125种，广泛分布于世界各动物地理区，绝大部分种类分布在全北界。主要寄生于其它昆虫的卵、幼虫、蛹甚至成虫，寄主涉及双翅目、鳞翅目、同翅目、膜翅目、鞘翅目的多种昆虫；很多被寄生的昆虫是重要农林业害虫（如瘿蚊、小蠹虫等），且大多具有潜叶、蛀干、蛀茎、造瘿及在种子中发育的习性。而迈金小蜂大多是这些寄主的致死初寄生者，对控制害虫的种群密度，维护生态平衡发挥着重要作用。中国地跨古北区和东洋区，仅记录27种；因此有必要进行深入的系统学研究，摸清我国该类寄生蜂资源、记录和发现新的分类单元、探讨迈金小蜂属在中国的分布格局；同时，充分利用分子数据，鉴别隐存种；结合外部形态比较、寄生习性、多基因分子数据的分析，探讨迈金小蜂种间系统发育关系、分族体系及可能的寄生习性的演化，为害虫的生物防治、天敌资源的开发和利用提供理论依据和科学指导。

迈金小蜂属Mesopolobus隶属于膜翅目金小蜂科，是金小蜂科中的一个大属，已知125种，形态多样，分布广泛，绝大部分种类分布在全北界。迈金小蜂主要寄生于其它昆虫的卵、幼虫、蛹甚至成虫，寄主涉及双翅目、鳞翅目、同翅目、膜翅目、鞘翅目, 对控制害虫的种群密度，维护生态平衡发挥着重要作用。本研究执行期间，整理鉴定动物研究所昆虫标本馆金小蜂科标本15,000号（其中迈金小蜂2000号），野外采集小蜂标本9,000余号（鉴定获得迈金小蜂300余号）；基于外部形态，共鉴定出迈金小蜂68种，其中17个新种，26个中国新纪录种，初步摸清了迈金小蜂在中国的物种多样性；通过采集地信息得出迈金小蜂在中国的分布从北向南物种丰富度逐渐减少，青藏区、蒙新区特有种记录最多的特点。同时，获得迈金小蜂及相关金小蜂类群800余条分子序列，初步探讨了中国迈金小蜂种间系统发育关系；确定迈金小蜂属不是单系，认为属下分种团目前还不可行，可参照Bouček（1988）建议的3个种团划分，不能归入的属则建议按照外部形态特征辨识度高的性状进行区分；Mesopolobus nobilis (Walker)、Mesopolobus semenis Askew不是单系；Mesopolobus tongi Xiao、Mesopolobus sp. indet 4和Mesopolobus keralensis Sureshan & Narendran关系较近；经过试验认为选用COI和ITS2作为金小蜂的分子标记，对于发现隐存种，解决种内遗传距离界定问题是比较好的分子标记。