What is eating my water lilies? China moth larvae

[Pond Guppie]

Can you use this powder on the surface of water lilies to kill these China moth larvae that are in a pond with Koi in it?
Or should I remove the water plants to a temporary location for treatment?

 

[Mmathis]

Can you use this powder on the surface of water lilies to kill these China moth larvae that are in a pond with Koi in it?
Or should I remove the water plants to a temporary location for treatment?

What “powder” are you referencing — the B.T. garden dust? It is supposed to be safe….it’s a biological product rather than a chemical pesticide. But to be safe……look it up and read the label!

 

[Mgessert]

Pesticides must always be used according to label instructions. This is to keep the environment safe and prevent unintended consequences. I would look for one that’s labeled for use in ponds, with fish, for China moths. Is there a natural predator for China moths? Are the moths causing damage? Do the koi eat the larvae?

Never mind, here’s your answer. Pull the plant, treat, then return to pond.

Aquatic Pests: China Mark Moth and Waterlily Leafcutter | University of Maryland Extension

Controlling Two Aquatic Plant Pests: China Mark Moth, Nymphuliella daeckealis (Haimbach) and the Waterlily Leafcutter, Synclita obliteralis (Walker)

extension.umd.edu

 

[j.w]

and welcome @Pond Guppie

You need to start a new thread on here to get more answers and keep things current. Or maybe @addy1 will do it for you?

 

[Pond Guppie]

Pesticides must always be used according to label instructions. This is to keep the environment safe and prevent unintended consequences. I would look for one that’s labeled for use in ponds, with fish, for China moths. Is there a natural predator for China moths? Are the moths causing damage? Do the koi eat the larvae?

Never mind, here’s your answer. Pull the plant, treat, then return to pond.

Aquatic Pests: China Mark Moth and Waterlily Leafcutter | University of Maryland Extension

Controlling Two Aquatic Plant Pests: China Mark Moth, Nymphuliella daeckealis (Haimbach) and the Waterlily Leafcutter, Synclita obliteralis (Walker)

extension.umd.edu

Thank you for sharing the attached information.
And yes, the larvae have been very destructive.
I pulled all my lilies over the winter and treated them separately. BT, hand removal, systemic insecticides, copper. I'm surprised the plants lived. I have changed the water several times over the spring preparing to add the back to my koi pond. But the moth larvae survived all the pesticides, and pruning and we even added perch and minnows for a while hoping they would help eradicate this pest. I may have to discard them and start over with the recommended plants.