Fruit tree spraying
Malathion works very well, but it does not last very long on the fruit. So technically, the interval is around 7 to 10 days, repeating throughout the summer so that your last application is 7 to 10 days before Sept. 15. (If you have not already harvested.)
If you have any other questions, you can contact James Barnhill, who is the agriculture agent in your county.
His contact info:
1181 North Fairgrounds Dr.
Ogden, Utah 84404