1a. Objectives (from AD-416):
Investigate spray timing and the adult activity of the new soft insecticides in pistachios that target navel orangeworm (Amyelois transitella).
1b. Approach (from AD-416):
Pistachios will be sprayed by commercial cooperators using a suggested timing and collected at intervals over a 4-8 week period. These pistachios will be challenged in the lab by infesting them with known numbers of eggs and assessing adult emergence. Additional experiments conducted in the field will assess insecticide efficacy against sentinel eggs and adults. Field infestation estimates will be compared to damage levels determined by the processor. Adult activity will be determined by a combination of studies conducted at industry research farms and by caging adults in the field.
3. Progress Report:
This trust agreement was established to support research Objective 2 B of the parent project, reducing insect pest populations to reduce the need for post harvest treatment as well as promoting the use of selective rather than broad spectrum insecticides to control navel orangeworm. The navel orangeworm is the primary lepidopteran pest of pistachios and almonds in California. It is currently controlled by both broad spectrum and selective insecticides. Shifting the control strategy from broad spectrum to more selective insecticides will benefit the environment, but will require information so that spray timing can be improved. An ARS scientist at Parlier evaluated the duration of control in Madera county provided by four classes of insecticides, with an emphasis on their ability to kill eggs and disrupt the flight pattern of adults. Data from these studies demonstrated that several classes of insecticides kill eggs, and that navel orangeworm control can be improved by treating the pistachios earlier. Preliminary laboratory and field data indicate that several new insecticides have adult activity as well, but the extent of the activity needs to be studied further. This research will improve control of navel orangeworm and decrease damage to pistachios. This in turn will increase nut quality, helping boost exports. Information gathered in these studies will be used to develop a comprehensive control program.