Abstract: Nested polymerase chain reaction (PCR) and standard PCR amplification of the Wolbachia surface protein (wsp) gene were used to assay the infection of the population of Liposcelis tricolor by endosymbiotic Wolbachia.The sensitivity of standard PCR was compared with that of nested PCR in monitoring Wolbachia in L.tricolor by using the universial primers of wsp gene and the primers of A and B subgroup.About 610 bp region of Wolbachia wsp gene,500 bp region of Wolbachia A subgroup wsp gene and 450 bp region of Wolbachia B subgroup wsp gene were sequenced from this host population.The result suggested that this tested population of L.tricolor was infected by two strains of Wolbachia and nested PCR possessed a higher sensitivity.