Abstract: Based on the analysis of the data obtained from apple orchards in Beijing area between April and September,1989,the Iwao regression method,the Taylor power principle and 4 aggregated indices were used to test the spatial patterns and dynamics of hawthorn spider mites (Tetranychus viennensis Zacher) at the movable stages (larva,nymph and adult).The results showed that the mites distributed in an aggregative pattern and the basic component of distribution was individual colonies.The annual occurrence of this mite could be divided into three periods (April,May-June and July-Sept.).In April, mites emerged after overwintering and distributed at the highest in the east quadrant,the upper stratum and the inner part of the canopy.The number of mites increased between May and June,and decreased between July and September.In the 2nd and 3rd peneds,little difference was found in distribution density in the 4 quadrants and the density was higher in the lower and middle strata and in the periphery part of the canopy.

Key words: Hawthorn spider mites, Movable mites, Spatial patterns, Dynamics.patterns

CLC Number: 

• S433.7