Southern Oregon fruit orchard Bordered plant bug, Largus species infestation. Need effective options.
Need effective treatments that won’t harm beneficial pollinators. Perhaps collers with tanglefoot or spraying. Lost over half crops primarily on about 30 stonefruit and pears. Anyone with experience, please chime in.
Here’s my recommendation for your situation in Grants Pass. It is based on the local ecology, the life cycle of the Bordered plant bug, labeled pesticide use requirements, and Oregon pesticide use law. There are two components for effective control:
The orchard floor and immediate border must be “tightly” mowed from bud break through harvest. This does two things (a) disrupts the instar life-cycle of the Bordered plant bug, and (b) removes pollinators from foraging on the orchard floor later in the season when they would be endangered by tree canopy pesticide sprays. “Tightly” means “up to the trunk, without damaging it”. Once per month might be sufficient depending on the how fast the local flora develop blossoms.
When your fruit sets reach or slightly exceed marble-size: begin periodic spraying of the tree canopy with a tank mix of Evergreen EC + Assail. The purpose of the Evergreen EC is to drive the bugs out of the foliage and increase their metabolism (the piperonyl butoxide does this). It will not kill them. However, it will increase their exposure and consumption of the Assail which will certainly kill them. Note that the Assail is far less effective without it. Of course, you must follow the dosage and frequency directions on the labels. Only a moderate dosage of the Evergreen EC is necessary. The Assail must be used at the maximum concentration listed for Largus plant bugs. Use the permitted spray frequency on the Assail label plus judicious bug-scouting. The latter is recommended for reducing the frequency of sprays.
I write this with great sympathy for your situation and wish you success.
