Wolbachia are maternally inherited intracellular bacteria that infect a wide range of arthropods and nematodes and are associated with various reproductive abnormalities in their hosts. The infection by Wolbachia of the psocid, Liposcelis tricolor (Psocoptera: Liposcelididae), was investigated using long PCR amplification of the wsp gene that codes for a Wolbachia surface protein. The results showed that L. tricolor was positive for Wolbachia. Phylogenetic analysis showed that the Wolbachia found in L. tricolor was related to the B-group. Wolbachia infection in L. tricolor could be removed through antibiotic treatment. The results of crosses including ♀^W x ♂ ^W , ♀ ^W− x ♂^W , ♀ ^W x ♂ ^W−, and ♀^W− x ♂ ^W−, suggested that the removal of Wolbachia resulted in lower egg production by L. tricolor. The mean embryonic mortality of offspring produced by L. tricolor without Wolbachia was significantly higher than that of control.