Abstract: Chrysolina aeruginosa (Coleoptera, Chrysomelidae) is one of main pests of Artemisia ordosica. In recent years, this phytophagous beetle has spread rapidly throughout Northwest China, which has led to mass mortalities of A. ordosica. This pest has produced great damage to the local ecology. Three habitats of A. ordosica (siltyloam hilly land, mobile and semimobile sandy land, and manuallyfixed sandy land) in Ningdong region of Ningxia were selected as study sites to investigate the population dynamics and  vertical distribution of C. aeruginosa. The results showed that the average population densities of C. aeruginosa in three habitats were 10.54, 1155 and 8.53 individuals pear clump, respectively. The victimization rates of A. ordosica were 81.54%, 85.15% and 85.92%, respectively, but the population of C. aeruginosa had not significant difference in three habitats. All population curves showed a single peak and the largest population occurred in late July to midAugust in 2012 in the three habitats. The vertical distribution of C. aeruginosa was mainly in the canopy layer and middle layer (40-70 cm). There was a highly significant correlation between the population density of C. aeruginosa and its vertical distribution in different height ranges of A. ordosica. Correlation analysis showed that the population dynamics of C. aeruginosa were closely related to diameter and burgeon length of A. ordosica and the altitude. Based on principal component analysis and gray correlation analysis, population dynamics of C. aeruginosa was positively correlated with the mean temperature and increasing temperature could promote its population growth within a certain range.

Key words: population structure, point pattern analysis, interspecific association.