Abstract: In order to analyze the insect distributional law in China and provide scientific basis of insect geographical division, in 2008 we created a new method, i.e., the multivariate similarity clustering analysis (MSCA). The key difference of this method from traditional similarity clustering analysis methods is directly computing the similarity coefficient of multiregion and throwing away the old merged steps. By using the MSCA, distribution information of total 93 662 insect species belonging to 17 018 genera of 823 families in 64 basic geographical units (BGUs) of China was analyzed. The results showed that 9 large unit groups and 20 small unit groups are clustered by 64 BGUs when similarity levels are 0.14 and 0.19, respectively. First insect fauna geographical division plan of China was putted forward by quantitative analysis, in which the insect fauna of China is divided into 9 regions and 20 sub-regions. The 9 regions were named as Northwestern China, Northeastern China, Northern China, Qinghai-Xizang, Changjiang-Huaihe, Central China, Southwestern China, Eastern China and Southern China insect region. A northern large region was clustered by the preceding 4 regions and a southern large region by the others stably. Taiwan was clustered to East China, but not to South China, because its similarity degree with Fujian is closer than that with Guangdong, Guangxi or Hainan. Several important aspects in quantitative analysis on insect biogeography are discussed, and some suggestions about insect fauna investigation are given. This study proves that the MSCA method is very applicable, simple and quick, and can be used in a wider range. It is presaged that bio-geographical study will get from qualitative analysis into a quantitative stage.

Key words: Insect, fauna, distribution, zoogeography, geographical division, multivariate similarity clustering analysis, China