中国大蚊属分类修订及系统发育研究

The crane fly genus Tipula Linnaeus, 1758 belongs to Tipulidae, Tipuloidea, Nematocera, Diptera, which is one of the largest genera of Tipulidae with worldwide distribution and rich biodiversity. The larvae of most Tipula species feed on decayed plant tissue, while some others on roots of plants. Meanwhile, both adults and larvae could be important food of many predators. Thus, it is meaningful and necessary for ecological study and pest control to investigate this group of insects. Since the fauna of Chinese Tipula had not been studied systematically, a great number of species had not been determined or described, and the phylogenetic relationships within the genus or those between the genus and other related genera were not clear, this project aims to research on the taxonomy and phylogeny of Chinese Tipula. In this research, a taxonomic revision of the Chinese fauna of this genus will be carried out, and new taxa will be discovered and described; diagnostic characters of Tipula and some groups in the genus will be summarized after a comparative morphological study, while keys to species or subgenera will be provided; a phylogenetic study will be did to reveal the phylogeny of Tipula, and to resolve the monophyly and validity of the genus or some of the subgenera or species groups within the genus; then a better system of the genus will be reconstructed. The results would provide the available data for a future survey of biodiversity of crane flies in China, which would be also important for the future study of the systematics of Tipulidae in the world.

大蚊属隶属于双翅目、长角亚目、大蚊总科、大蚊科，世界性分布，种类繁多，生境复杂；本属幼虫多取食水中或土中的腐败植物组织，少数取食植物根系，成虫和幼虫均为多种捕食性生物的食物。开展对该类昆虫的研究具有重要的生态学意义和一定的经济意义。但目前大蚊属在中国的种类缺少系统的区系研究和修订工作，属内系统发育关系以及该属与其近缘属的系统关系尚不明确，因此，本项目拟开展中国大蚊属的分类修订及系统发育研究。项目组将系统厘定中国大蚊属的种类，发现并描述新分类单元；通过比较形态学研究，归纳大蚊属及属内各类群的鉴别特征，建立检索表；通过系统发育研究，探讨属内系统发育关系，解决该属及部分亚属或种团的单系性和有效性问题；进而建立和完善中国大蚊属的分类系统。本项目研究结果将丰富中国大蚊属物种多样性，并对大蚊属世界性的修订工作，以及大蚊科的系统研究提供重要资料。

大蚊属是双翅目大蚊科的模式属，也是大蚊科最大的属之一，在大蚊科的系统分类中占有举足轻重的地位。而其前期基础分类研究较弱，目前大蚊属在中国的种类缺少系统的区系研究和修订工作，属内系统发育关系以及该属与其近缘属的系统关系尚不明确。基于此，本项目的研究内容和相关成果主要包括：（1）大蚊属比较形态学研究，针对大蚊属亚属、种级阶元，以雄、雌外生殖器形态特征为主要突破点，探索不同亚属、不同种间形态差异，发现除传统上常用的雄性第9背板、第8腹板、生殖叶和抱握器的形态特征以外，雄性生殖基节与生殖桥、精泵与射精管、阳茎与阳基侧突，雌性尾须、生殖叉、产卵瓣和第8腹板悬骨等，这些结构形态在种间或亚属间也存在差异，但在不同亚属间差异程度不同，进而总结各亚属及种的特征。（2）中国大蚊属种类系统厘定，通过参考现有文献，比对项目组采集到的和从国内外各科研院校及标本馆借到的大蚊属模式与非模式标本，发现大蚊属15个新种、4个中国新记录种、9个同物异名，经过系统修订，目前我国大蚊属昆虫已知21亚属，319种。（3）大蚊属系统发育研究，主要基于成虫形态特征，尤其雄性形态特征的比较形态学研究结果，选取大蚊属部分亚属代表种，进行支序系统学分析，初步结果显示大蚊属及尖大蚊亚属的单系性存疑，但仍需进一步的分析验证和完善。项目研究结果丰富了中国大蚊属的物种多样性，为大蚊属及大蚊科的系统学和演化研究提供了新的证据，也对大蚊科昆虫资源的保护和利用及害虫防治提供了理论基础。