Hi Ed,
I know this isn't published due to literature being confined to commonly available food insects in cultivation. But this is more of a farmed versus wild salmon mentality for using field sweepings.
The JWPT (Jersey Zoo) used field sweepings to supplement their frog diets.
And like I said, I don't live in the US where there is the great convenience of commercial fruit fly and other feeder insect supply companies. I maintain my own FF cultures and when they crash (as they do sometimes or are overwhelmed by mould); I have to replentish my seed population by importing new ones. And this is not always as easy as it sounds when living in a culture which views bugs as pests.
I had the one escapee azureus from a group of her siblings which were of a uniform size when she disappeared and 2 months later she was 30% larger compared directly to her littermates. I guess she survived entirely on wild insects and grubs in the leaf litter. And now she's still doing well but lightened up in colour. (she was a much darker, duller shade when we found her)
I'm not saying that it is totally safe but it works for me. Plus I have at hand, mebendazole, fenbenazole and metronidazole. So far, so good.