Maternally inherited Wolbachia bacteria are widely distributed in Chinese populations of the twospotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae). All populations were found to be infected with Wolbachia. Using the Hunan (HN), Liaoning (LN) and Jiangsu (JS) populations of T. urticae as experimental subjects, 100% Wolbachiainfected and 100% uninfected spider mite lines were obtained by screening. This study investigated the dynamics of Wolbachia spread in the twospotted spider mite. Infection frequencies of Wolbachia among the progenies of the artificial populations, initiated with 50% infected and 50% uninfected female adults, were monitored by PCR. The results show 100% maternal transmission in all three populations. The rate of spread was fastest in the HN population in which the infection rate reached 100% by the F7 generation. The infection rate in the LN population reached 100% by the F12 generation but took until the F20 generation to do so in the JS population. Wolbachia appeared to use different strategies to invade and spread in the different populations. In the LN population, Wolbachia invaded and spread by inducing cytoplasmic incompatibility (CI). In the JS population, Wolbachia invaded and spread by enhancing mite survival and host fitness. In the HN population, inducing CI was the dominant strategy. The enhanced fecundity associated with Wolbachia helped to promote the spread of infection. These results could provide a foundation for using Wolbachiabased strategies to control insect pests and disease vectors.