I've used the Rescue fly traps for several years no. The flies that go into them are those Green Blow Flies and what look like the tachinid flies, too. The only problem is that they stink.
From what I am hearing, the fly problem is international. They are have the same problem in Canada.
This is one reason that I try to capture a female and let her lay eggs.
Herndon, VA (USA)
Take care of the small things....