I have a fresh water pond that has Water Lilly's and Lotus growing in it. Last week I noticed that the Lotus leaves had fleshy brown and green Lepidopteran larvae feeding on them causing a highly visible skeletonizing symptom that is getting worse as the areas coalesce. From my research it looks like I have a worm known as China mark Moth. The area involved is quite large covering about a third of the pond. Can I treat with a sprayer mixed with Bt kurstaki or Conserve (Spinosad)? There are fresh water fish, frogs and turtles in the pond so I'm not sure if I have any treatment options.