[Insect community and its relationship with Ceroplastes japonicus occurrence in jujube orchards]

Employing community character indices and canonical correlation analysis, this paper studied the insect communi structure and its relationship with the occurrence degree of Ceroplastes japonicus in jujube orchards. The results showed that based on the community discrepancy coefficient of 0.20, the insect community in various sampling fields could be categorized into two groups, i. e. , plain and hill. The occurrence of C. japonicus in plain region was heavier, with lower insect community diversity, smaller species number, and higher dominance of phytophagous insects, while that in hill region was lighter, with higher insect community diversity, more abundant species, and higher dominance of natural enemy insects. Canonical correlation analysis indicated that at the significant level of 0.05, the first and second pairs of canonical correlation coefficients of C. japonicus occurrence characters and insect community characters were 0. 9904 and 0.8538, respectively, suggesting that the occurrence of C.japonicus was significantly correlated with the characters of insect community. Community diversity (with the coefficient of 3. 4893), species number (with the coefficient of 5.8060), and dominance (with the coefficient of 6.9353) had most important effects on the occurrence of C. japonicus.