Titer variability of “Candidatus Liberibacter solanacearum”, an endosymbiont of the potato psyllid Bactericera cockerelli (Sulc) (Heteroptera: Psyllidae)

The potato psyllid vectors the secondary endosymbiont “Candidatus Liberibacter solanacearum” (Lso), the pathogen putatively causing potato zebra chip. Laboratory potato psyllid colonies are routinely tested using real-time PCR to determine Lso titer. High variability in Lso titer levels can be found within and among individual colonies, and this variability changes over time and in response to temperature. No differences in mean titer levels exist between sexes. However, Lso titer levels change as adult psyllids age and in response to host feeding.