There really isn't anyway to breed parasitic wasps without an elaborate setup, or luck. You could breed houseflies, and have the species of parasitic wasp use those, but I don't think it'd be worth it. Your best bet is to go to a biological pest control website there're a lot of them out there. You can get a very large supply of them for cheap. Or, if your in a warmer climate, or your tads wont be morphing until spring or so, I would plant some Spider Plants and ornamental kale to attract cabbage white butterflies, in turn these attract Trichogramma and Ichmeunom parasitic wasps, they lay eggs in the caterpillar or chrysalis, and then eat it from the inside out. They're not very good flier, and you can collect the chrysalises and put them in the froglet tank, and in a few weeks they will hatch.