I've been searching for data for insect feed conversion ratios, and it is difficult to find. I am wondering if someone else has data like this, maybe we can put together a table for different species.
So far, I've found the following:
Mealworms : 2.2 (from the mealworm excel file on this forum)
BSFL on chicken manure: 3
BSFL on pig manure: 4.8 (I've seen this confirmed by a few sources)
BSFL on cattle manure: 7.8
BSFL data from "From organic waste to biodiesel: Black soldier fly, Hermetia illucens, makes it feasible" http://bbrc.hzau.edu.cn/upload/file/From organic waste to biodiesel Black soldier fly_ Hermetia illucens_ makes it feasible.pdf
Crickets: .9 - 1.6, depending on feed, from http://labs.russell.wisc.edu/insectsasfood/files/2012/09/12_ComparDietsLvstk.pdf
Earthworms: 10 or more, from http://www.sciencedirect.com/science/article/pii/S0960852499000553
I think the mealworm and bsf data is accurate, as I've seen similar results from other areas. I don't know about the crickets, because I've seen results anywhere from 1 to 5, and a lot depends on the feed. In that study above, .9 was on cricket chow and 1.6 was on rabbit feed (mostly alfalfa with some grain, ~15% protein). For earthworms, I have seen people talk about FCRs close to 1, but I couldn't find any studies or actual data to support that. I had no idea their efficiency was so low, but 10 makes me want to use BSF or crickets for decomposing animal waste.
I am interested in converting rabbit manures and bedding into protein for pigs and chickens. I currently use earthworms, but I'm not getting a lot of biomass out of them for protein. BSFL would be a lot better, and I think rabbit manure would be inbetween cattle and pig manure on FC, probably around 6-7.
I have seen at least one source include dried rabbit manure (50/50 with wheat bran) in the diet of mealworms without any adverse effects. I don't know the FCR for that, though.
Crickets might do really well, as rabbit manure is very similar to rabbit feed in composition, so the 1.6 figure might hold, or at worst, looking at 2.
Does anyone have any additional data or input they could share?