Abstract: The simulation study under laboratory condition showed that the functional responses of Typhlodromus bambuse to Schizotetranychus bambuse at different development stages could be expressed by the curve of Holling Type Ⅱ.The number of prey consumed by predator quickly increased with initial prey density,but soon leveled off.At 25±0.5 ℃,the handling time (T_h) of T.bambuse to S.bambusae at the stages of egg,larva,protonymph,deurtonymph and female was in order of egg(Q) of T.bambusae to S.bambusae egg,larva,protonymph,deurtonymph and female adult was 1.47,1.34,1.16,0.90 and 0.15,respectively.The numerical response of T.bambusae to S.bambusae revealed that the fecundity of the Phytoseiidae mite was significantly affected by the prey density.When the ratio of predator to prey was 1:1～9,the daily oviposition of the predator varied from 0.5 to 2.0 eggs per female,which was increased with increasing prey density,while if the ratio was 1:15 or more,the daily oviposition decreased to about 1.8 eggs per female,which was probably due to the interference of high prey density to predation.

Key words: Davidia involucrata, Population, Population density, Proteting measures