叶蝉科昆虫是半翅目种类最丰富的类群，广泛分布于世界各地，主要刺吸植物汁液掠夺营养，许多种类传播植物病毒病，是重要的农林害虫。由于该科类群众多、以往研究均未能包含所有类群，缺乏世界范围全面的系统发育关系研究，而且有些亚科、族的地位和关系存在争议，导致叶蝉科高级阶元分类系统分歧较大，亟需开展国际合作，重建系统发育关系并修订分类系统。合作双方在各自地域和领域均取得了显著研究进展，而且长期务实合作。本项目拟在以往研究和合作基础上，通过研究材料和技术的相互补充，综合运用比较形态学和分子系统学方法，基于形态和分子数据，结合生物地理分布等多方面信息，重建叶蝉科各类群间的系统发育关系，对亚科、族等高级阶元分类单元进行重新划分和定位，建立叶蝉科的自然分类系统，明确各阶元间界限，确定疑难亚科、族和属的归属问题，为重建头喙亚目乃至半翅目昆虫分类系统提供依据，使我们在这一领域的研究居于世界前列。

Cicadellidae (leafhoppers), the largest hemipteroid family of exclusively herbivorous insects, are an important component of biodiversity in nearly every terrestrial habitat. Leafhoppers are major agricultural pests that feed on plant fluids. Some of them injure plants either by direct feeding or through transmitting plant pathogens that result in massive yield losses. The higher classification of Cicadellidae remains controversial and its phylogeny has remained problematic. Because most current and previous cicadellid systematic work has been regional in scope, and many cicadellid subfamilies and tribes have been confirmed as paraphyletic or polyphyletic, their relationship with other groups needs to be clarified based on more comprehensive morphological and molecular phylogenetic analyses worldwide. There is a pressing need to provide synthetic treatments of entire cicadellid clades through greater international coordination. This project will be undertaken by a joint international team that includes most of the world’s taxonomic experts on Cicadellidae who have been intensively cooperating together for a long time and achieved great progress in this and related fields. We propose to solve the problems defined above using methods of comparative morphology, molecular phylogenetics, and zoogeography, etc., based on accelerated collaborative investigation of the cicadellid fauna worldwide. In addition, we will also focus on revising the classification systems of these and related taxa with definitions and/or systematic status that remains problematic, based on the more comprehensive phylogenetic analyses. These results will significantly expandour knowledge of the cicadellid fauna worldwide and provide a more secure and productive phylogenetic framework for future pure and applied research of Auchenorrhyncha and related Hemiptera.