Wounded plums typically ooze sap. Eggs are laid in some of the fruit and the young beetle grubs develop on the pit of the fruit. Effective controls have not been identified for these Insects. They will often drop from plants when disturbed, so some beetles can be collected by shaking branches over a sheet during blossoming and fruit set. Damage is caused by the maggot-stage larvae that tunnel the fruit, making it susceptible to spoilage.
Winter is spent in the pupal stage around the base of cherry trees.
The adult flies emerge in early summer, typically between late June and early July, and lay eggs on the fruit. There is only one generation per year. Western cherry fruit flies can be trapped using yellow sticky boards. Although some control is possible by this trapping, sticky traps are best used to determine when flies are present so sprays can be timed appropriately. Twig dieback from peach twig borer tunneling.