Abstract:

Tetranychus truncatus is a mite pest of Sophora japonical in the district of Beijing.It occurs from last May to early November, with a peak harmful time from July to August.In the urban district, about 70% of the leaf was injured, and in the suburb, it was over 90%.there are 15-17 generations a year. Each generation lasts 6.7 days on an average at 28℃, RH 67%.The average life-span is 7.5 days for the males and 10.7 days for the females at 27℃, RH 72%.It overwinters as adult in the creack of trunk and limb, quite few are in the branchlet, grass and soil layer of the root. Using 25% Nivkomycin at a dilution of 1:1000, 10% Zeng xiao lui yang mei su of 1:2000, 73% propargite of 1:2000, washing powder of 1:400, pellet NH₄HCO₃ of 1:100 in spring, significant effectiveness was obtained.

Key words: Tetranychus truncatus, Hibernation, Biological insecticide, Acaricide