Took a quick look through SF and noticed this through their Nature section on their website. This is of more concern for users the UK/Europe area than America, but the caterpillars could migrate here or towards other nations eventually. I think there is a solution to have a helicopter mounted with an apparatus to spray a pesticide on the trees and/or areas which the caterpillars burrow on. http://www.dailymail.co.uk/sciencet...ise-poisonous-caterpillars.html#ixzz1tdr4oip2
Yes, they are extremely dangerous and spreading like crazy in Germany these days. Over here they are called "Prozessionsspinner". Their hair and nests can cause serious allergies and asthma. Creepy!