I use turkish glider mels as I find these the most productive. Have made up stunted cultures before to see if those refusing normal mels will take stunted ones - some do and some stick to the springs so generally feed both. They will also take 1st and 2nd instar milkweed bugs without any problem.

Btw John those "Rio Saladillo" look lovely - might get some of those myself. Have a couple of empty vivs im just growing in!