Abstract: The effect of mutual interference and heterogeneity on Coccinella septempunctata was investigated. It was found that the more wheat stalks the adult ladybugs encountered, which meant more interference was met during predation, the lower the predation efficiency was observed.The interspecific mutual interference had more influence on predation of adult ladybug than the intraspecific mutual interference did in C. septempunctata and Harmonia axyricis. The correlation of intraspecific competition strength (I) and the number of ladybug (P) in H. axyricis could be described as I=0.0012+1.4072lgP for female, I=0.0058+1.3942 lgP for male and I=-0.0072+0.7234lgP for female C. septempunctata. The correlation of interspecific competition strength between C. septempunctata and H. axyricis (I) and the number of natural enemies (P) could be described as I=0.0539+1.1167lgP for female C. septempunctata and female H. axyricis, I=0.0018+1.1944lgP for female H. axyricis and male C. septempunctata.

Key words: mutual interference, spacial heterogeneity, Coccinella septempunctata, predation