How do i keep worms out of my fruit?

every year our plum tree has worms in the fruit; how can i resovle this problem?

How do i keep worms out of my fruit?
Spray the trees with approved fruit tree bug spray. It depends on what type of fruit worms you have, and where you are located. Apple maggot is a very destructive pest that is quite widespread in the US. To help control it, clean up all leaves and fruit every fall and destroy the infected pieces. The life cycle of the fruit fly is found on line and the treatments from several authorities.

Also call your local county agriculture agent if in the US.