Worm circus

The last few days have seen a zillion minute delicately pale green worms rappelling on gossamer filaments from the fruit trees.  Collectively, they make a shimmering curtain that leans in the breeze and catches the light from the right angle.  It’s a beautiful thing.  Unphotographable.From the wrong angle, the trapeze show is totally invisible, and when you stride through it, you’re festooned by a dozen sticky threads and instantly remember you meant to skirt the tree.Today I noticed a development.  Instead of the 100s of lines almost reaching the grass with one worm on the end of each, there’s a reduction in numbers of lines, but that the ones that remained had dozens of riders.  Tiny green bodies tip to tail like a beaded string on one lifeline.I’m fascinated at the process.  Do these worms spin out their lines to ride to the earth, over a few days?  Then what?  Do they eat the spring leaves on the tree then go to the ground to transform?  Or travel back up the tree to inflict for damage come fruit time?  I know nothing about these insects. As beautiful an effect they create, I’m horrified at the obvious infestation.What can be done about them?