Fly Predators

As the summer sets in, the flies have become a serious issue on our 1/4 acre microfarm. Just ask the rabbits, or the dogs, or my husband for that matter. Yes we have fly strips, and I try to keep the various forms of manure and organic matter under control, but flies are a large part of nature here in Western KY. my question is regarding the marketed "Fly Predators" that are for sale.
When I brought up this miraculous, seemingly circle-of-life minded solution, Hubby said No Way, Do not bring any bugs from some far away land into our ecosystem.

Dang... he's really got a point there.
Any input on the validity of this concern? As research continues, I plan to track down origins of each species on the market. Maybe somebody on here has some information that would expedite this process, as well as provide forum for this possibly wonderful -slash- possibly catastrophic method

I understand the fly issue believe me, not just a western ky problem by any means lol. Given I currently have no livestock I've been the target of attacks, add in the ridiculous (even by ky standards) humidity we've had and I've been a walking, breathing fly bait while working on my set-up.

Can't speak directly to the "predator" thing, but I'd proceed with caution. One, I'm sure it's an expensive option, the use of purchased parasitic or predatory controls usually is. Two, you're introducing something that could have greater effect than you realize. Does it specifically target houseflies, black flies, etc. or just flies? Flies in and of themselves are a diverse group with some functioning as helpful pollinators.

Try some fly traps. I bought a few at Walmart that resemble the disposable wasp traps you see. It's basically a bag containing bait and a one way gate for the flies to enter. They come in, can't find a way out, then drown in the liquid bait. Waiting for the storm system we're supposed to have the next few days to pass to use them, but they seem promising. Like any trap, obviously position them where you won't come in much contact with them (they do attract flies after all). Especially on no larger than 1/4 acre a couple of them should do the trick. At the very least it'll knock the numbers back to a manageable number, and should only attract problem flies.