Don't want to hijack this thread but there is a lot of good info coming from it. Just wanted to know if adding your dusting materials to your ff culture would help gut load the flies with calcium, vitamins ect. or would it crash the culture. Is there any benefit I know I would get tired eating dusted food all the time.
First off, you do not want to mix supplements into your media.. unless you are looking for nutritional problems in your frogs and potentially issues with the cultures.
Fruit flies cannot be gut loaded with calcium as they are extremely efficient in excreting excess calcium as it is taken up in the diet see for example, Dube, K.A.; McDonald, D.G.; O’Donnell, M.J.; 2000; Calcium homeostasis
in larval and adult Drosophila melanogaster; Archives of Insect Biochemistry and Physiology; 44(1) :27-39
In addition they do not uptake and absorb D3 or significant levels of vitamin A, but they do absorb significant levels of vitamin E (which is present in many supplements listed as tocopherols) enough that they can disrupt the absorbtion of D3 and/or A. See the discussion here http://www.dendroboard.com/forum/food-feeding/67766-repashy-superfly-26.html#post608267
They also have a very fast turn over of gut contents.. See tha above linked discussion above.
On top of that, if you are using a supplement that contains amino acids you can push the protien content of the media to the point the cultures do not do well.
Based on the data available, I can't think of a good reason to add old supplements to the fruit fly cultures.