You could try microworms, but mine never really took to them, it was mainly the live bbs, mosquito larvae, daphnia and live bloodworm (which I found in one of my mozzie buckets, in the sludgey (decaying leaf) bit at the bottom. Do you have a compost heap, if you do might be able to use baby earthworms (look for little olive coloured eggs and you'll pretty much have a few baby worms round them, if you do). Also, I've hatched my brineshrimp in a small 10litre tank, and large glass coffee jars and they've hatched within 24-48 hours. I just siphoned them out using a turkey baster and squirted them into a mans white hanky (as I don't have a brineshrimp net) then rinsed and fed them.
Axolotl larvae will not eat dead food until they start developing their back legs.
Basically you have to have livefood, otherwise you'll notice your larvae dying from hunger and attempting to nibble on their siblings.
So, if you can't find any you should order some online (ie TM), daphnia, bloodworm and the mozzie larvae (if they were alive) are great as they don't foul the tank/containers. Whereas, microworms and bbs, you have to clean up any uneaten food daily to avoid fouling their tank/s, which could result in deaths if you don't.