It's possible but not practical. Lets start with the ecological rule of 10 that says for every gram of frog, you will have to feed 10 grams of insect, which will require 100 grams of plant matter for food. Now that's just the food the frog actually eats. Obviously if you supply enough plant matter to support 10 grams of insect per gram of frog, the frog is going to eat all the insects and they will go extinct. So next you will have to turn to a set of equations known as the Lotka-Voltera equations that model populations under different scenarios. You need to use an equation that accounts for 1 predator with however many prey species you will have and, if you can design your viv correctly, you can include a refugium where predation cannot occur to reduce the population of insects needed to sustain predation. You will also need to know some information about the longevity, reproductive rates, predation rates, and non-predation mortality of the insects. Once you have all of those pieces, you should be able to calculate the size of the insect populations you would need to sustain the estimated predation. Add a little cushion for error. Then calculate the number of grams that population of insect would represent. Multiply by 10 to calculate the edible plant mass needed to support those insects. And finally figure out how large of an enclosure you need to support that plant mass. Piece of cake, right? My guess is that you would figure on something the size of a medium greenhouse to support one frog. Let us know how it turns out!