If you have fruit flies coming to the fruit as soon as you put it in the cage, you need to eliminate any place they could be breeding.
Always remove any fruit dropped in the pan under the glider cage every morning.
Do not let scraps of fruit stay in a kitchen disposal - run it and rinse the drain well with hot water.
Do not leave fruit peel, leftovers from the glider plates or other fruit scraps in a garbage can in the house! Take it outside to a covered garbage can.
If you are careful about taking the glider plates out of the cage each morning and making sure there are no scraps of fruit anywhere for the fruit flies to breed they should be gone pretty quickly.