以支系和进化主干的视角看待某一类群的系统发育地位更有利于将前进进化与分支进化的认识相结合。关于蝽类昆虫在生命树中的支系位置，近年来积累的证据已经在对于若干节点的认识上有了新的观点。随着现生类群生命树的构建以及化石类群与现生类群系统发育关系的整合，每个支系所经过的系统发育历程将逐渐变得清晰，并对相关的个体发育研究具有一定参考价值。本文致力于将近10年来的各种主流意见更迭完整地体现在对于蝽类昆虫支系地位的认识上。

作为确定分子数据初组同源性（primary homology）的过程，比对的重要性在于后续算法的选择。本文对基在生物系统发译研究中的作用及其基本步骤与算法做了简要说明：从理论与实践相结合的角度介绍了使用最为广泛的软件，讨论了其中的空位（gap）问题，参数问题和比对结果校正等问题；并且对此领域中前沿的基因组对研究进展做了概述。

作为一类重要的信息和功能分子，RNA在分子系统学研究中有着特殊有重要作用。RNA除了其一级结构以外，其二级结构亦可用于同源性比较。由于高级结构与功能的关系更为密切，比较的结果可以揭示一些在一级结构比较中难以发现的现象。

The first complete mitochondrial genome of pentatomomorphan bug, Stictopleurus subviridis Hsiao, 1977 (Insecta, Hemiptera-Heterolxera, Rhopalidae) was sequenced in this study. The genome was a circular molecule of 15319 bp containing the typical 37 genes that arranged in the same order as that of the putative ancestor of hexapods. Sequences overlaps were observed between several neighbor genes, which made the genome relatively compact. An unusual non-coding spacer was found between tRNA-Ile and tRNA-GIn. The tRNA-Ser (C, GT) could not be folded into typical secondary structure because its DHU arm was replaced with a simple loop. CO2 and CO3 were terminated with a single T adjacent to a downstream tRNA gene in the same strand. The genome was AT-biased with a total A+T content of 75.7% which was also demomtrated by the codon usage. Protein genes of two strands presented opposite CG-skew trends which was also reflected by the codon usage. For most of the amino adds, the protein coding sequences did not prefer to use the cognate codons of corresponding tRNAs and the codon usage of the protein genes was not random. The most frequently used codons were NNA and the most infrequendy were NNG. Compared with another complete mitochondrial genome of Heteroptera, Triatoma dimidiata, AIP8 was the fastest evolving protein and COl was the slowest, while tRNAs and rRNAs were slower than all the proteins.