- In the last decades psyllids have increased their geographical range in the US and have been responsible fo the transmission of devastating bacterial plant pathogens ('Candidatus Liberibacter solanacearum' (Lso) and 'Candidatus Liberibacter asiaticus' (CLas)) which cause diseases such as potato Zebra Chip, an emergent disease threatening potato production in theNorth and Central America, and New Zealand or Citrus Greening that has severily affected the citrus industry worldwide. Current control methods rely heavily on the use of chemical insecticides to reduce psyllid populations. The molecular mechanisms of transmission or the consequences of bacterial transmission remain unknown. The purpose of this project is to identify psyllid gene expression changes associated with bacterial transmission and host plant infection. The results of the proposed experiments will lead to a better understanding of psyllid interactions with their host plants and plant-pathogenic bacteria, which in turn can lead to improved crop protection strategies. Expected outcomes are new fundamental knowledge on transmission of plant pathogenic bacteria by insects and change in control methods.