To study the ecological effect of genetic diversity of wheat cultivars on Sitobion avenae, the population dynamics of S. avenae and its natural enemies was investigated in wheat fields. The spatial distribution of S. avenae was also analysed. Compared with monocultures, Beijing 837, the number of S. avenae apterae per 100 plants in intercropping patterns was significantly lower during the aphid peak period, and the cascade of population densities was: Beijing 837 monoculture (7422.0) > intercropped with KOK (5796.7) > intercropped with Hongmanghong (5406.7) > intercropped with Zhengzhou831 (5291.7) > intercropped with JP2 (4493.4) > intercropped with Zhongsiwumang (4155.0). The spatial distribution of S. avenae was changed from aggregated to uniform pattern. In the aphid parasitoid peak period, there were higher population densities of the aphid parasitoids in each intercropping field with a very significant level of P
