white leaf-cutting worms on water lilies

Question
An infestation of tiny white leaf-cutting worms is decimating my water lilies. they are only a few millimeters long, and cut a portion of leaf, then glue it over themselves on the leaf or stem. I've removed every leaf that had a worm on it--most were in really bad shape-- as well as what appeared to be a mess of eggs/babies, and scooped out every stray bit of leaf I could--the little nasties hide under them, and apparently move from plant to plant.
Is there any way to treat the pond to kill these without harming my goldfish & mosquito fish or otherwise totally mucking up my pond's flora & fauna?

Answer
They are probably China mark moths.  Here's my section on them:  http://fishpondinfo.com/plants/plantpests.htm#moths

Hand removal works best for minor infestations but adding mosquito dunks (Bt) to the pond should kill them.  Bt is safe for non-insects.  I have more on mosquito dunks on my mosquito page at http://www.fishpondinfo.com/mosquito.htm

Good luck!

Robyn