2011 Annual Report 1a.Objectives (from AD-416) To determine the differences in potato psyllid gene expression in psyllids harboring Liberibacter solanacearum reared at different temperatures. 1b.Approach (from AD-416) DNA sequencing of psyllid ESTs, annotation, and organization in a PAVE database for mining. 3.Progress Report The potato psyllid transmits a bacterium, Candidatus liberibacter, to potatoes, tomatoes, and peppers. This bacterium causes the “zebra chip” disease in potatoes due to severe discoloration in the tuber flesh when they are processed into potato chips. We have previously found that the bacterium is sensitive to high and low temperatures. Using the hypothesis of this temperature sensitivity, we have constructed a “library”, or copy, of the genes of the psyllid and are evaluating these genes for changes caused by these temperature extremes. If specific genes can be associated with this temperature sensitivity, then these gene products may provide an alternate control strategy for this emerging insect pest. This project studies the effects of temperature upon gene expression in the potato psyllid, the vector of the zebra chip bacterium, and contributes to objective 2 of the in-house project. Progress research on this project was monitored by email and phone conversations.