Fungus Fly Larvae in Flake Soil

[BugOnABender]

My flake soil got infested with fungus fly larvae is it still usable as a breeding substrate for goliath beetles and food for the L1 grubs?

 

[Goliathus]

My flake soil got infested with fungus fly larvae is it still usable as a breeding substrate for goliath beetles and food for the L1 grubs?

So long as it is not too broken down, it should be ok to use.  Substrate that has become paste-like or soil-like in consistency, is too decomposed.