Tree "spider webs"

I have two beautiful red maple trees my Dad planted for me a couple of years ago. They are lush, red and a wonderful addition to our yard.

One of them, however seems to have a "spider web" like substance crawling over it. I've noticed this on other trees throughout the area. I've been told this can kill of the portion of the tree this "web" covers. Does anyone know what this is and what is a good and safe way to get rid of it? I'd really hate to see anything happen to these trees.

Thats tent caterpillars not much you can do the trees will be ok next year
http://www.pmra-arla.gc.ca/english/consum/tentcaterpillars-e.html

They started in my lilac (small tents) and I hit em with "End-All" from Ryerse's ...dead in seconds...the caterpillars that is...

you can introduce a small flame (assuming you can get to the "tent") and it will kill off the catapillers and burn off the 'tent'

We found that cutting off the affected branch(es) and then burning the tents worked effectively.

I believe you will find that they are "fall web worms". They have been bad the last few years. Because they appear later in the year when the tree is already starting to prepare for winter, they do no permanent damage and are actually a good source of food for some birds. They look worse than they are. I have heard of people having success by spraying the "webs" with sunlight dish soap. I presume the soap will break the surface tension on the "web" and it then won't be able to protect the caterpillars from the elements.................

Thanks everyone...not only was I worrying about damage, it looks kinda gross!