Abstract: [Objective] The bamboo shoot-boring noctuid is a joint name for several species of moths which are hamful to bamboo shoot stage in southern China. There are four dominant species that have sympatric distribution and the same host. Their biological and ecological characteristics are similar. However,the classification status and evolutionary approach are still controversial. To determine their classification status and provide a molecular theory foundation for the system evolution, their genetic relationship was studied in the paper.[Method] The bamboo shoot borers, distributing in the bamboo production areas surrounding in Hangzhou, Zhejiang Province, were used as the research object, and four 709 bp segments of cytochrome C oxidase subunit Ⅰ(COⅠ) gene were cloned, using universal primers, from mitochondrial DNA of different bamboo shoot borers' individuals and compared with homologous sequences from other lepidopterous insects to analyze their base composition characteristics and the genetic relationship for accurate identification of bamboo shoot borers at molecular level by building system evolutionary trees.[Result] 1)The results indicated that the genetic distance between the four kinds of bamboo shoot borers was small.2)Three phylogenetic trees showed that they got 100% support on the branch.[Conclusion] The four bamboo shoot borers have closed genetic relationship,among which three species can be classified into one genus except Sapporia repetita.Furthermore, the four kinds of bamboo shoot borers could be used as ideal samples for sympatric speciation research for its similarity in body and habits and distribution.This study provides preliminary molecular basis for the genetic relationship and DNA barcoding technology of the 4 kinds of bamboo shoot moths at the same time.

Key words: shoot-boring noctuids, mitochondrial cytochrome oxidaseⅠgene, sequence comparison, genetic relationship