Abstract: The succession of insect community in wheat fields in the south of Shaiixi was studied by using the principal component analysis method. There were three stages. The main trend of succession was as follows; Pest insects and their natural predators existed in small numbers in early spring. The species in the community were evenly distributed. It is not necessary to take control measures. Most of the insects were in their peak phases. The distribution of species were not even in the unstable community. The insect community was in the decline. In the meantime, the principal component analysis revealed the main insect species, affecting insect community succession, and their dynamics. Analysis also revealed the influence of pest management measures on the insect community in wheat fields. The abundance, diversity, and rate of even distribution of the community decreased with chemical applications.

Key words: Wheat field, Insect, Cornmunity succession, Time alignment, Management measure