Black Soldier Fly in Mount Washington

Subject: Black Flying Thing
Location: Mt Washington, Los Angeles, CA
June 23, 2013 10:59 pm
We have no idea what this is. It just appeared on our office desk at about 10pm, just hanging out staring at the computer. Looks like a wasp, so I caught it to take some pictures in case we need to be weary of getting stung if we see them again.
Thank you!
Signature: Paul and Barb

Black Soldier Fly
Black Soldier Fly

Dear Paul and Barb,
Greetings neighbors.  The offices of What’s That Bug? are on Mount Washington in Los Angeles.  This is a perfectly harmless Black Soldier Fly,
Hermetia illucens.  They are sometimes called Window Flies because of the transparent “windows” on the abdomen.  If you or a neighbor have a compost pile, you can expect to see more Black Soldier Flies as the larvae live in rotting organic materials, including compost piles.  According to BugGuide:  “Very rarely, accidentally ingested larvae cause intestinal myiasis in humans and domestic animals. However, larvae compete with house flies in manure, compost piles, etc., and may thus be beneficial. Adults are harmless and not known to carry any human disease.”

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BugMan aka Daniel Marlos has been identifying bugs since 1999. is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

5 thoughts on “Black Soldier Fly in Mount Washington”

  1. The Black Soldier Fly Blog has set up a Black Soldier Fly Mapping Project (link) displaying the locations of confirmed BSF sightings/wild populations and seasonal data. If you’d like to contribute there’s a ‘Report BSF sighting’ link in the upper left corner of the map or you can use this link. Only locations which are submitted with adequate documentation will be used.


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