Beating tray monitoring and sweep net sampling of true bugs should be initiated. The native vegetation surrounding pistachios is still green, so the migratory plant bugs have no reason to move…yet. That will quickly change as we move into April and early May.
Navel orangeworm (NOW) traps should be in place. The NOW adult pheromone lure, has proven to be very effective in catching adults, so much so that some consultants wish to dispense with the high maintenance egg traps.
Running egg traps assists in the interpretation of the wing or delta adult trap data, since we do not (and may never) have treatment thresholds for either development stage.
Research suggests pistachios compensate for nuts lost to Phytocoris and Lygus feeding, so early chemical treatment specifically for these pests may not be needed unless you have significant BOT, and Calacoris is your predominant plant bug present prior to shell hardening.
Most growers routinely add a pyrethroid to their mid-April nutrition spray to cover this issue.
Donnie Thomas, private pest consultant, also likes to assess the presence of Gill’s pistachio mealybug at green tip using his beating tray. He beats ten trees per area with his tray beneath the shoot tips, then surveys the tray for grey, immature mealybug stages that have crawled up the trunk during the warm February weather.
Donnie says this has really helped him determine if he is going to have a problem in June. I would appreciate feedback from others who experiment with this.