Looking at your pics, I would say Drosophila hydei (fruit flies), bean weevils, and 1/4" or smaller crickets. Remember to dust your feeder insects and feed them to your frogs just before putting the lights out for the evening. Since you will be feeding very small feeder insect, most of which can climb glass, I would cut a piece of cloth a little bit bigger to the width and length of the tank. I would tape it down tightly to the frame to prevent escape.