Subject:  What’s this bug/worm in standing water?
Geographic location of the bug:  Northern CA – Mendocino Coast
Date: 11/11/2017
Time: 04:59 PM EDT
I’ve been seeing a lot of these worm bugs floating/swimming in the standing water on top of my composter.  They are alive and move around slowly in the water.  They’re almost an inch long and kind of skinny if you see them sideways (2nd photo).  Can you tell me what this is?
Thanks so much!
How you want your letter signed:  Laurie York

Black Soldier Fly Pupa

Dear Laurie,
This is a Black Soldier Fly Pupa, and their presence in your compost pile is a sign that it is healthy.  According to Daily Dump:  “The Black Soldier Fly Maggots are prolific creatures that appear in all compost heaps – they are nature’s scavengers and good for composting. They love a very wet pile. …  If it’s too much and you want to avoid them coming out and crawling on your floor, you can put your composter in a plastic tub with high sides. They usually cannot crawl out of that slippery vertical surface. If they crawl out and wander all over, then sweep them up, collect them in a container and drop them under a tree – birds love them!  Remember that these BSF maggots suppress the lifecycle of the pest carrying housefly. The Soldier flies have no mouth and cannot transmit pathogens, so they are harmless. Appreciate them. They are even a fried delicacy in some cultures as they are very rich in protein!” 

Black Soldier Fly Pupa

Hi Daniel,
Thanks so much for writing me with this info about the Black Soldier Fly Pupa.  Now when I see them I’ll not be frightened and know that they are beneficial in my compost pile.
I appreciate the helpful info you sent me.
Be well,

Location: Mendocino Coast, California

One Response to Black Soldier Fly Pupa

  1. Jim Harrison says:

    A friend of mine is an ichthyologist who is trying to farm sturgeon in order to produce caviar. He uses soldier fly larvae as fish food.

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