植物病原媒介昆虫——角顶叶蝉亚科的系统发育和分类系统重建

The Deltocephalinae is presently the largest subfamily of leafhoppers, including at least 6500 described species. Deltocephalines feed on phloem sap from numerous angiosperm plant families. Some deltocephaline species are important agricultural pests which transmit plant pathogens, especially to gramineous crops (Deltocephalines account for 127 of 151, or 84%, of cicadellid vector species). Deltocephalinae is poorly defined and its higher classification is unstable. Classification of the group has not been based on explicit phylogenetic hypotheses; therefore relationships among tribes remain obscure. It is an ill-defined collection of hundreds of genera, many of which are included simply because they cannot be placed in any other subfamily with certainty. Conversely, many closely-related genera are excluded from the subfamily for little apparent reason. Furthermore, the natural relationships among the many deltocephaline genera is poorly understood, and has not been taken into account in the segregation of tribes, many of which were erected for single variant genera. Based on our previous research, including the classificaton and phylogeny of Deltocephalinae from China and revision of Deltocephalinae from the American region, this project will provide more detailed phylogenetic analyses and examine relationships within this lineage of deltocephalinae using a large number of morphological characters and molecular data, as well as biogeographic data. It will also investigate relationships among different groups, redefine the deltocephaline tribes and genera based on natural relationships as well as on phenetic criteria, and build a natural system of classification in conformity with the phylogenetic relationships and evolutional history. The resulting phylogenetic framework will form the basis for a revised classification of Cicadellidae and establish a basis for testing hypotheses concerning the roles of host and biogeography in the evolutionary history and diversification of the group.

角顶叶蝉亚科Deltocephalinae昆虫刺吸植物汁液掠夺寄主营养，许多种类传播植物病原（151种叶蝉病原介体中，127种隶属于该亚科），对农林生产造成严重危害。角顶叶蝉亚科的分类研究虽取得一些成果，但高级分类单元迄今比较混乱，族的划分及范围不断变化，许多属的归属缺乏依据，常被称为"叶蝉科的垃圾堆"，严重制约了叶蝉科昆虫分类和系统发育研究，亟需对该亚科昆虫进行族、属级分类单元的重新划分和订正。本项目在前一项基金"中国角顶叶蝉亚科昆虫分类订正和系统发育研究"及对美洲地区角顶叶蝉种类订正的基础上，结合角顶叶蝉形态学（包括口器及内部器官系统）、生物地理学及分子生物学等特征，对世界角顶叶蝉亚科的族、属进行重新划分，并探讨各类群间的亲缘关系，建立符合该亚科进化历史的自然分类体系，对于查清叶蝉科昆虫的种类及其分布格局、促进叶蝉科昆虫分类研究的进展具有重要意义，并为防控病病原传播介体提供理论基础。

角顶叶蝉亚科昆虫许多种类传播植物病原，严重为害农林业生产。角顶叶蝉亚科的高级分类单元迄今比较混乱，族的划分及范围不断变化，严重制约了叶蝉科昆虫分类和系统发育研究。本项目采用形态学、生物地理学、分子生物学等方法，研究了世界角顶叶蝉亚科昆虫的种类及其分布。我们采用光学显微镜和扫描电镜，研究了角顶叶蝉亚科及其近缘类群昆虫的口器、触角和足的超微形态，通过扫描和透射电镜，观察了雌、雄性生殖系统的超微结构、精子超微结构等特征，发现不同类群间口器、生殖系统和精子存在一些差异，其形态和超微结构为该亚科分类鉴定提供依据。采用分子生物学方法，在测定215种基于5个分子标记基因（H2A, H3, 28S, 16S, COI）的DNA序列，组建了基于多基因序列的数据集，采用最大简约法MP和最大似然法ML分别构建系统发育树，分析了角顶叶蝉亚科的系统发育关系，并结合线粒体基因组数据，确认传统的角顶叶蝉亚科不是单系群，支持将传统的7个亚科归入角顶叶蝉亚科。确认刻纹叶蝉族、乌叶蝉族、隆脊叶蝉族、铲头叶蝉族、二点叶蝉族、带叶蝉族、角顶叶蝉族和径槽叶蝉族的单系性。在系统发育分析的基础上，提出了角顶叶蝉亚科合理的族级分类体系，部分澄清了目前角顶叶蝉亚科属级分类单元的混乱，建立1新族6个新属，并描述了一些新种。其中在对中国、印度、泰国和斐济的黑色标本进行鉴定时，发现该类叶蝉其体表被有大量刻点、头冠前缘有棱脊、腹部第二节内突发达且长、雌虫尾节稍短而与角顶叶蝉亚科其它族相区分，进而结合形态和分子数据，合作发表1新族，包括3新属5新种，分别为Punctulus gen. nov.（P. tumidifrons sp. nov.分布于中国, P. manipurensis分布于印度, P. lobatus sp. nov.分布于泰国）、Hirsutula gen. nov.（仅1种，H. rubrifrons sp. nov.分布于泰国）、Taveunius gen. nov.（仅1种T. megapunctatus sp. nov.分布于斐济）。本研究对于完善世界叶蝉科昆虫的分类奠定了良好的基础。