2010 Annual Report 1a.Objectives (from AD-416) Investigate the length of persistence of the new soft insecticides in pistachios that target navel orangeworm (Amyelois transitella), using bioassay and analytical chemistry,and assess spray coverage. 1b.Approach (from AD-416) Pistachios will be sprayed by commercial cooperators and collected at intervals over a 30-60 day period. These pistachios will be challenged in the lab by infesting them with known numbers of eggs and assessing adult emergence. Samples will be taken from the hull and environment and analyzed to determine insecticide residue, which will be linked to the success of the bioassays. Additional experiments conducted in the field will assess insecticide coverage using sentinel eggs and spray cards. 3.Progress Report This research supports Objective 2 of the in-house project, by providing data necessary to evaluate the coverage and insecticide efficacy in almonds and pistachios. Spray coverage will be assessed using sentinel egg masses and spray cards. The concentration of insecticide on the pistachios will be determined using analytical chemistry. Bioassays will be conducted in the laboratory using egg masses placed in jars containing nuts as well as pinning egg masses onto specific regions of the nut. Information will be collected quantifying the variability in coverage within and between rows. These studies will begin in July 2010 and extend through 2012.