II. Injury: Adults first feed on developing buds, flowers, shucks, and setting fruit. Adults will often feed on the developing shuck (left photo below) and young peach during the bloom to petal fall periods. Egg-laying scars are the most common injury and will be most easily found on fruit from outside rows near overwintering sites. Larvae (right photo below) tunnel into developing fruit and feed near the pit. First brood larval injury will cause fruit drop. Second brood injury will usually not cause drop, but will provide a wounded fruit source for brown rot and other diseases to develop.

III. Monitoring: Monitoring of PC should be concentrated from bloom through two weeks after shuck-fall. Monitoring can be done with a beating tray by holding a large square yard cloth beneath the tree and beating on a branch three times with a rubber mallet or rubber-wrapped stick. Fruit should also be examined by counting a minimum of 200 fruit per block for egg-laying scars or feeding injury. Early control of the overwintering generation is critical so that egg laying is avoided.

Additional monitoring for the second adult PC emergence should be done during July. Monitoring can be done with a beating tray by holding a large square yard cloth beneath the tree and beating on a branch three times with a rubber mallet or rubber-wrapped stick. Fruit should also be examined by counting a minimum of 200 fruit per block for egg-laying scars or feeding injury.

No economic threshold levels have been established. However since PC is a direct pest, no more than 1/2 to 1 percent fruit injury should be tolerated.