Report for period ending 6/2016 Over the past year, studies using electropenetrography (EPG) studies have been conducted with the goal of determining how much imidacloprid is needed in leaf tissues to control ACP, in particular to disrupt psyllid phloem-feeding behaviors. During these studies, we have continued to increase the dose of imidacloprid delivered to plants in order to reach the point where 100% of psyllids are incapable of reaching the phloem. However, the results obtained to date using EPG suggest that even at unrealistically high levels of imidacloprid applied to the plant, an average of 2% of the psyllids are still likely to perform some feeding behaviors in phloem. However, our data suggests that because the proportion is so low, and not every feeding bout by a psyllid results in infection, this use of imidacloprid to reduce infection in young tree plantings is still a very useful tool. However, some results obtained here suggest that the soil-applied neonics ability to prevent infection may be due more to feeding deterrence rather than direct mortality. Thus, we initiated experiments using an artificial diet-based bioassay to develop a dose-response curve for the three neonics versus the asian citrus psyllid. The majority of time spent this quarter was in perfecting the artifical diet system building upon the success of other researchers who have used such diets for studying ACP. Our goal here is to develop a feeding-based LC50 and LC90 for imidacloprid, clothianidin and thiamethoxam. THese LC50/90 values will then be compared to those previously reported values for contact bioassays using either leaf dip or vial assays. Concurrent with this work, we are continuing to analyze the large backlog of leaf samples gathered from our ongoing field studies where we are investigating the uptake of the three neonics at different times of the year, distribution of the three neonics within a tree, and appropriate rate of product applied based on tree size. We literally have thousands of samples in the freezer awaiting analysis. We continue to run samples as fast as the machine can analyze them.