2012 Annual Report 1a.Objectives (from AD-416): Develop integrated pest management of the potato psyllid and Liberibacter in a multicrop system (potato, tomato, and pepper). 1b.Approach (from AD-416): Conduct insect transmission studies under laboratory conditions to determine Liberibacter acquisition and inoculation access time required for the potato psyllid to effectively transmit the bacterium and induce diseases. Determine the impact of Liberibacter on different plant growth stages under controlled field cage conditions. Determine density of potato psyllid required for this insect pest to effectively cause diseases in potato, tomato, and pepper. 3.Progress Report: The potato psyllid has recently become a major concern because of its direct feeding and vectoring of diseases caused by the bacterium liberibacter to potato, tomato, and pepper crops in U.S. and other countries. A series of studies assessed liberibacter transmission to potato, tomato, and pepper by the potato psyllid under laboratory conditions and determined density of potato psyllid required for this insect pest to effectively cause diseases in potato, tomato, and pepper. It was confirmed that there are no significant differences in feeding behavior of the potato psyllid on the three host plants. It was also confirmed that as few as one liberibacter-infective potato psyllid per plant is enough to effectively induce the disease after a six-hours exposure to each of the three host plants and, leading to significant yield loss. In addition, it was determined that all the plant growth stages of potato, tomato, and pepper are susceptible to the bacterium. Information from this research will help reduce damage caused by liberibacter to potato, tomato, and pepper by vigorously targeting the potato psyllid for control. The work reported here addresses objectives 2 and 3 of the parent project plan.