广义半翅目是昆虫纲不完全变态类昆虫的最大目及昆虫纲中第五大目，包括蚜虫、介壳虫、粉虱、木虱、飞虱、叶蝉、盲蝽、臭虫、锥猎蝽等农林与卫生害虫及紫胶虫、五倍子蚜、大部分猎蝽、姬蝽、花蝽等益虫，在农业生产和人类日常生活中起着重要作用。其形态多样，习性复杂。近百年来，该类群高级阶元的系统发育及进化主要是基于比较形态学或是少量基因片段的分子系统学方法推断的，对该类群高级阶元的分类至今仍存在不同的观点。近年来，虽然有些关于该类群线粒体基因组的研究，但不少科级阶元的相关研究仍属空白。申请者拟测定半翅目部分关键类群（蚧总科、蝉总科、角蝉总科、奇蝽次目、鞭蝽次目及鞘喙亚目）代表种的线粒体基因组序列，通过生物信息学的方法分析半翅目昆虫线粒体基因组的基因重排、RNA二级结构、密码子使用、控制区的结构以及核苷酸组成偏好性等，探讨其基因组结构进化的趋势与机制，构建系统进化树，分析该类群昆虫高级阶元系统发育关系。

Hemiptera （s. l.） is the largest order in the incomplete metamorphism insects and the fifth largest in Insecta. Mostly they are agricultural and medical pests, such as aphids, scales, whiteflies, psyllids, planthoppers, leafhoppers, mirids, bed bugs, triatomine bugs and so on. Others are beneficial bugs, such as lac insects, Melaphis spp., most assassin bugs, damsel bugs, anthocorids and so on. These insects play an important role in agriculture and our daily life. The higher phylogeny of this order was reconstructed mainly based on morphological characters or few molecular markers and there are no uniform opinion on the phylogeny and evolution of this order during past century. Although some works have been published on the mitochondrial genomes of the Hemiptera, but leaves the corresponding data blank on some families. We try to sequence the mitochondrial genomes of representatives of key groups, Coccoidea, Cicadoidea, Membracioidea, Enicocephalomorpha, and Dipsocoromorpha, analyze the gene rearrangements, secondary structures of RNA, codon usage, structure of control region and nucleotide composition in the mitochondrial genomes known, explore the trends and mechanism of gene structural evolution, reconstruct the higher phylogeny and classification of Hemiptera.