The larvae won’t harm the worms. They are faster than the worms though. So if a large enough colony forms they will outcompete the worms for food. however, they’ll produce an ash that non-scientific evidence has shown to help worms grow larger. This isn’t proven, so it’d be great if you’re someone who likes to experiment.

If not, If you don’t want to deal with picking the larvae out, use the butter tub method. Or, alternately just wait til it gets cold again. The larvae have to “hibernate” and are very inactive once temperatures drop.

I just discovered maggots in my compost in Eugene, OR. I googled compost maggots and discovered the maggots are black soldier fly larva. I cover the compost pit with black plastic and add kitchen waste, garden cleanings, and coffee grounds. These creatures are devouring waste at an astonishing rate.

Today it is a bit cooler and I dumped ten pounds of coffee waste on what looks to be several cups of squirming larva. I looked a few hours later and they were either dead or dormant. Could the coffee have poisoned the larva?

How soon will they pupate? Do I need to do anything to encourage the BSF to lay eggs in the same compost pit? I have two pits, one I am building while the other is cooking? Will these BSF larva increase the speed of composting?

Thanks for any information on encouraging these larva for a garden compost project.

Bob k