Even though azureus are among the larger dart frogs, in my experience, they seem to prefer the smaller prey items, especially springtails. Although my other frogs, especially the galacs and leucs relish pinheads, my azureus, like yours, seem to eschew them. Maybe it has something to do with the particular way they move. They do take the small melangogaster fruit flies very well, too.
I did read a research paper not long ago on an analysis of stomach contents of wild azureus. The conclusion was that in that particular study, 80% of the stomach contents were springtails. Whether this justified sacrificing wild frogs for this bit of information, I tend to question, but it was done, none-the-less.
For a single frog, I would start a new culture about twice a week or even more often, just in case of some failures, then adjust from there. It's better to over-do it than to run low on food.
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Patty
Pahsimeroi, Idaho
4 D. auratus blue
5 D. galactonotus pumpkin orange splash back
5 D. imitator
6 D. leucomelas
4 D. pumilio Bastimentos
4 D. fantasticus
4 P. terribilis
4 D. reticulatus
4 D. castaneoticus
2 D. azureus
4 P vittatus