Has anyone out there developed any strategies to minimize the number of maggots in their mushrooms grown outdoors on logs? I assume the first response will be to create habitat for the natural predators of the flying insect that lay their eggs in/on the fruit or somehow irritating them so that they would rather go somewhere else. Harvesting the fruit while young, as well as moving the fruiting sites to different locations (crop rotation technique), or just accepting that maggots are an additional source of protein are all strategies that I am prepared to attempt to varying degrees. I personally chew less well when I know that there are maggots, cooked and dead, in my mouth.
What kind of mushrooms are you growing? In my experience, shiitake are generally maggot free, while oysters attract fungus gnats like crazy. I grew mushrooms outdoors on my patio in Portland, Oregon for nine months out of the year (not on logs but on sawdust blocks and on cardboard boxes and paper) and I had some problems with other creatures wanting to eat my mushrooms.
At first, my outdoor mushrooms were free of pests. But then, the word got out. Hundreds of slugs showed up, and thousands of fruit flies. My oysters (especially my king oysters) were riddled with holes and full of squirming maggots. I hung up fly paper around my sawdust blocks, and that helped, but only a little. (The fly paper works really well indoors, though.)
And then, after about a month of maggot-filled mushrooms, a funny thing happened. The spiders showed up. Thousands of spiders. And my gnat/maggot problem pretty much went away, not completely, but to the point where it wasn't a problem anymore. Nature saw that there was a problem (surplus gnats) and sent predators there to restore balance. I didn't have to do anything.
The slugs, well, I had to go out every night around midnight and pick them off by hand. Perhaps given enough time, Mother Nature would have come up with a solution there, too. (Maybe something that likes to eat slugs, like ducks?)
frankenstoen wrote: Nature saw that there was a problem (surplus gnats) and sent predators there to restore balance.
Nature did not see it as a problem, it was a problem for you, for nature it was an opportunity (well specifically for the spiders that we are calling nature it was an opportunity). Perhaps the OP could change his habits to make it more of an opportunity for spiders in his area, and they would come in and fix his problem.
Give the spiders cover overhead to keep the rain off the webs and a lattice work to drape their webs from and they will reduce your fungus gnat problem.