I hate deer flies. I get terrible welts whenever I get stung by those little buggers. Which is whenever I go outside without long pants on. We never used to have them here in the yard but they moved in over the past few years. I blame the coyotes. They moved in about the same time. Probably not related, but that's my theory and I'm sticking to it!
There's lots of folks out there on the web talking about how they trap deer flies, including the University of Florida, and the consensus seems to be that if you put "tanglefoot", which is clear sticky stuff, on bright blue objects and walk around the yard waving the "bait" around you will attract the deer flies and they'll stick to said blue object. You can use Solo blue cups or plates, or whatever else you can find that's bright blue.
I ordered some of the Tanglefoot sticky stuff today from Amazon. I looked for this locally but couldn't find it, even at ACE Hardware, and they usually have the things I can't find at Home Depot or Lowe's.
Here's an interesting blog on how this woman deals with her deer fly problem! I rarely get bitten above the knees, so I'm not sure this method would work. I'm not even 100% sure that what we have in the back yard are true deer flies. They might be a relation of some sort with the same propensity to bite the crap out of people and leave large itchy welts for a week or two so you can walk around looking like you have the plague. It is NOT pretty!
I can't wait to give it a try! I'll be sure to post the results of this little experiment!