Insect symbiosis is a rapidly expanding area of interest due to its importance on a basic level and to its emerging significance in applied science. Currently, most reported investigations of symbiosis involving parasitoid-host systems focus on the biology of a single endosymbiont, Wolbachia, and do not address the entire microbial fauna. In this study, the diversity of endosymbionts was examined in the phloem-feeding citrus pest, Diaphorina citri (Kuwayama) [Homoptera: Psyllidae], and two parasitoids, the ectoparasitoid Tamarixia radiata (Waterston) [Hymenoptera: Eulophidae] and the endoparasitoid Diaphorencyrtus aligarhensis (Shafee, Alam and Agarwal) [Hymenoptera: Encrytidae]. Tamarixia radiata and D. aligarhensis were imported from Taiwan and Vietnam in a classical biological control program to reduce D. citri populations in Florida. Genomic DNA was isolated from adult D. citri, T. radiata and D. aligarhensis for use in a high-fidelity PCR assay. Ribosomal DNA from endosymbionts was amplified, cloned and sequenced for phylogenetic analysis. PCR primers based on ribosomal gene sequences obtained from this survey will be used to compare the diversity of endosymbionts in laboratory and field populations of each insect in Florida. This research allows us to study vertical transmission of microbial symbionts from adults to their progeny and to determine if horizontal transfer of endosymbionts occurs between parasitoids and their hosts.