‘Candidatus Liberibacter solanacearum’ is the putative causal agent of zebra chip disease of potato, Solanum tuberosum L., and is transmitted by the potato psyllid, Bactericera cockerelli (Sulc). Much work has been done on the association of Liberibacter with the potato psyllid and several laboratories currently use polymerase chain reaction (PCR) to test for the bacterium. We have been testing for the bacterium in individual and composite samples of B. cockerelli as part of an ongoing investigation of the incidence of ‘Ca. L. solanacearum’ in potato psyllids collected in various parts of the US. Here we report that the bacterium can be reliably detected by using conventional and quantitative real-time PCR of nucleic acid extracts prepared from composite samples of one psyllid from a Liberibacterinfected colony combined with either one, two, three, four, five, nine, 14, 19, or 29 psyllids from a Liberibacter-free psyllid colony. This ability makes it possible to more easily test large numbers of psyllids for the presence of ‘Ca. Liberibacter solanacearum’. This, in turn, will aid efforts to predict the threat of developing serious zebra chip disease as a result of psyllid infestations in potato fields.