If they are used, they should be in the outer one or two rows. Ground cover should be cleared around the traps. Traps should be monitored and replaced on a weekly basis, or cleaned and adhesive renewed if needed. These are only useful for detecting relative abundance of the population, and should not be relied upon as the only sampling method. There are no action thresholds based on tarnished plant bug monitoring.
Ground cover sampling usually yields higher populations where flowering weeds are most abundant.
Therefore good weed control accompanied by mowed grass or clean cultivated aisles aides in overall catfacing insect management. Since it is a direct pest, no more than one or two percent fruit injury should be tolerated at any one time. Sprays should be applied during times of adult activity, since this is the damaging stage in orchards.