You want to wait till that first frost kills the warbles.
That's an old wives tale but if it makes you feel better then more power to you. I have very seldom found a warble/wolves on a squirrel. I have found them much more often on rabbits.
Yeah, frost doesn't kill them, by then most have hatched and left their hosts....
"...the left considers you vermin, and they'll kill you given the chance..." Bristoe
