"Lotus leaves being fed on by moth larvae"
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.
New Castle County Delaware
We can not make any pesticide recommendations outside of Maryland and suggest that you contact your local county Cooperative Extension office.
Here is that contact information:
New Castle County Office
461 Wyoming Road
Newark, DE 19716
Phone: (302) 831-2667
FAX: (302) 831-8934
This is one of our older publications regarding your problem, but again, you should contact your local Extension agents for best management: https://extension.umd.edu/sites/default/files/_docs/programs/ipmnet/FS818-ControllingTwoAquaticPlant...
Many thanks, that's a great article with a lot of useful information.