Huanglongbing, a globally devastating citrus disease, is associated withCandidatusLiberibacter asiaticus (CLas) and is mainly transmitted byDiaphorina citri. Verification of the distribution and dynamics ofCLas inD. citriis critical to understandingCLas transmitted by vectors in nature. Here, the distribution and titers ofCLas in different sexes and tissues ofD. citriadults were investigated by fluorescence in-situ hybridization (FISH) and quantitative real-time PCR (qRT-PCR). Results showed thatCLas had widespread distribution in the brain, salivary glands, digestive system, and reproductive system of both females and males, indicating a systemic infection ofCLas inD. citri. Moreover,CLas fluorescence intensity and titers were significantly increased in both the digestive system and the female reproductive system with development and there was a marked decreased in both the salivary glands and the male brain, but there was no significant change in the female brain or the male reproductive system. Furthermore, the distribution and dynamics ofCLas in embryos and nymphs were investigated.CLas was observed in all laid eggs and subsequent first–second-instar nymphs, indicating that a high percentage of embryos and nymphs resulting from infectedD. citrimothers were infected with CLas.