Do you have *anything* that would reach that tent? Pole pruner? Access to high pressure waterhose or a tree sprayer with jet attachment? If you can wash the caterpillars off the tree, I'm sure your "girls" will be more than happy to search them out on the ground
If you could just tear up the tent, it'll make life uncomfortable for them and expose the caterpillars to predatory wasps and birds. They'll also be forced to repair or make another tent -- all that silk comes out of them and (I think) would help to weaken them.