I’ve got two indoor containers with king oyster mushroom mycelium in it. Both are infested with fruit flies, as it seems. The mycelium looks fine and healthy, but I don’t want a fruit fly infestation in the house. I’m planning to throw out the worst one (swarming with larvae), but is there some way to prevent this from happening again? Or to get rid of the fruit fly larvae infesting those coffee grounds without throwing out the mycelium? Halp?
The mushroom fly larvae do the damage. Commercial button mushroom farmers use spray to control them. I would toss the substrate. Burn it, bury it, drown it as far from your grow area as possible. Then clean your grow space. When you think its clean; clean it again. What are you using for substrate? Flies usually originate from improperly prepared substrate.
The really badly infested one is coffee grounds. The other one was a mix of coffee grounds and wheat bran. I think I got rid of all the larvae in that one (my kid and I spent a few days picking out the pupae with tweezers), but the other one is in a jar and we can’t get at the bugs as easily. I will toss that one.