I temporarily had some painted reed frogs, which are very similar in size and habits to the argus.. I fed them on very large flies.. like the blowfly/bluefly type, which I caught wild as no feeder bugs for sale in my country. They loved them and swallowed 2 or 3 in rapid succession. I kept them for about 2 months and then released them as I didn't have a large tank setup that they deserved. They were nice and fat when I let them goMy 5cents lol