Hey Lynn - I wouldn't think dusting other feeders with freeze-dried flies would be all that beneficial; essentially just adding more insect to the meal. It would probably be more beneficial to the animal to dust with a limiting nutrient of some kind that is lacking in the already insectivorous diet. Calcium is useful because insects are notoriously phosphorus heavy, and multivitamin supplementation is useful as well. I'm sure you could incorporate this idea into the diets of nectar feeding or fruit feeding herps as a protein supplement to the diet though = )

Keep us posted on your flies Christopher - I wish you the best in trying out this new feeder!