Last fall I reported on finding what looked to be soldier fly pupae in my compost tumbler (see “DIY Tumber – Revisited“). At the time I wasn’t able to track down any of the suspected adults (large, yellowish flies I’ve frequently found in close proximity to my outdoor composting systems over the years), and my attempts at getting the adults to emerge (from some of the pupae I collected) indoors didn’t end up panning out.
Well, I’m happy to report that I am now finally on the verge of putting the pieces of this puzzle together!
A short time ago I was lucky enough to find one of these adults sitting on a leaf outside on an overcast day (easier to get a nice, clear photo without the glare of the sun) – and it seemed to have no intention of moving, even as I got in super close for some macro shots!
As if this wasn’t cool enough, today when I walked by a bag of (compostable) used cat litter material – waiting to get added to my new litter vermicomposting system – I noticed a bunch of these large, yellow flies hovering around the bag. When I dug around in the material a bit I found some small larvae, so I’m hopeful that these are the young larvae of these flies.
Now that I seem to have this little (accidental) experimental system going, I will likely try to optimize it a bit by adding some moisure, and perhaps some food waste. I really want to see if these are at least semi-comparable to Black Soldier Flies in terms of their waste processing abilities.
I’m also thinking of tracking down a fly expert up here in Canada so I can get an actual ID on this species once and for all.
UPDATE: I e-mailed fly expert, Dr. Stephen Marshal, at the University of Guelph (my former stomping grounds) and received a very quick response, informing me that this is a very common Ptecticus soldier fly species. He suspects that it is Ptecticus trivittatus, but said it would be necessary to key it (i.e. ID it properly using a taxonomic identification key) in order to be sure. Another interesting tidbit Dr. Marshall shared with me was the fact that Black Soldier Flies (Hermetia illucens) ARE found in the southernmost regions of Ontario. So I guess I am not as far out of their range as I thought.