Is there any way to outsmart a deer-fly, or are they just on another level?

If you walk the trails at Killarney Lake in June (don't) you'll get swarmed by mosquitos and likely get a pb on the run out of the woods.  If you go in July, you'll get constantly harassed by deer flies.

 

 

Normally, I wear a hat to thwart the buggers, but tonight it was raining and I wore a jacket.  I got hot and removed the jacket.  The deer flies were on to me.  Constantly and annoyingly they flew around in circles just above my head - occasionally trying to land for a free lunch.  Well lads, there's no such thing as a free lunch.  Despite my thwacking and flapping, they persisted.

I tried the following tactics: 

• The dog leash helicopter - just delayed the inevitable.
• The dog leash slash along a vertical plane - see above
• The sudden stop and back step followed by a volleyball serve - occasionally scored an ace
• The crazed sprint - no effect whatsoever, and
• The lucky punch - I need training

But still they hovered and harassed.  What can be done?