These Hydrangea Leaf Rollers are pretty smooth criminals.
They are tiny caterpillars that live inside a little pod that looks quite a bit like flower buds. I've only ever seen them on Annabelle Hydrangeas, but that's just me. When you crack the pod open, you really just see a lot of little black specks (caterpillar poop) and you have to really look hard for the worm. Gross out factor: 3
Because the nests are pretty crafty, sometimes you don't notice you have them until you REALLY have a problem. And the nests are so tightly built that it's really hard to spray them with BT (or Sevin), no spray penetrates that little wigwam. You can hand pick them, but you have to stay up on it- and even then it sometimes doesn't work. Systemics work, but if you're organic, you're back to hand picking and BT.
I'd recommend getting a sleeping bag and sleeping under the Annabelles so you can really keep an eye on them- then you can hand pick them and submerge the pods in cheap whiskey, to make sure they are really dead- and that they died in style. That's organic, right?