keeping caterpillars out of trees?

I remember growing up in Maine there was a year or two of severe gypsy moth explosion and seeing trees with flashing wrapped around them.
Not sure if this was to stop squirrels or caterpillars.
Part of a big white oak overhangs my pool and I'm getting really tired of caterpillar droppings in the shallow end - anything I can do to limit them would be nice

Does flashing, or maybe putting something sticky on the flashing stop caterpillars?

 

Here ya go.
http://www.dnr.state.mn.us/treecare/forest_health/ftc/homeownertips.html

 

Thanks SM. I don't have tent caterpillars(should have elaborated) there are varying types of insects pooping from above.
Katydids are probably most of the problem, but I find all kinds of drowned caterpillars on a regular basis.
If you didn't know what they look like:


2-3" long they make a racket when the sun goes down - dogs like the crunch they make this time of year

 

I ran some duct tape inside out around my trees when we had gypsy moths real bad a few years ago. It worked great until they filled the tape up or it rained. Just change the tape out and your good to go

 

I have a weeping cherry tree that got a few tents in it with a bunch of leaf damage. I knew I had to ignore it this year. A couple days ago I looked over to that tree and the tents were gone. I didn't interfere with them. No idea what happened to them, much less, what happened to the tents. I haven't used a lick of pesticide or herbicide this year.

 

The gypsy moths hit here the year before we bought our home. I ended up with plenty of oak firewood due to those buggers.

No clue what folks used, in my yard it is apparent they used nothing.

 

Now that's an idear. Added to my arsenal Smokin. Thanks.

 

I use Bt to keep both the regular caterpillars at bay and especially those tomato horn worms.