I'm voting Alien Abduction or Pear Rapture. This happens to me about every other year on one particular tree. My neighbors 6 or 7 trees seem to never be affected.
This year I was looking forward to a really nice harvest. The tree was loaded down and very healthy looking. My pears sometimes have a black, dusty looking scum on them but not this year. They never get ripe enough to eat until about the end of October, so they were quite green. I walk my dog by the tree every day. A few days ago I saw that all but about 5 or 6 pears had totally disappeared. There was no fruit on the ground nor debris. This tree is about 70 years old so it's about 30 feet tall. Every pear gone.
Similar things have happened to this tree. If there is a strong thunderstorm, almost always there will be a micro-burst over this tree. A downward blast of wind will strip every pear off the tree and gather it closely to the trunk on the ground. Again the neighbor's tree about 50 yards away remain untouched. This happens about every three years.
irrational as it seems, the supernatural theories are gaining weight.
There are about 2 squirrels that I know of that frequent my 10 acre yard.
I'm stumped.
