China Mark Moth Larvae

[FountainMan]

About a week after adding the duckweed and azolla to my pond I realized I also inadvertently added China Mark Moth Larvae as well and they've been attacking the water lilies and making taco-like cocoons. Consulted my water garden books and learned they can be killed with a biological agent called Bacillus Thuringiensis Kurstaki. Does anyone have experience with this? How much product should be applied in a 55 gallon pond? Does this work fast? Do I need to reapply or will the bacteria colonize and thrive in the pond?

Thanks.

 

[Mmathis]

I’ve never actually had to use it, but it is completely harmless for the fish and other plants. I think I recall that you dust the leaves with it, and for some reason I want to say it’s best to apply it at dusk. Just be sure that the product you buy is labeled as “safe for use with fish.” The BT itself isn’t harmful, but some products might be a mixture of other ingredients.

 

[FountainMan]

Bought the Thuricide today at Home Depot. My water gardening supplier told me what to get. It's a brownish liquid that looks like chocolate milk. I poured a little bit in the floating skimmer to help distribute the stuff. Looking forward to finally being rid of the caterpillars.

 

[addy1]

I use BT to keep wax moths off the brood comb when we are staring it. It works great.

Hope your caterpillars disappear!

 

[FountainMan]

Sadly this is what's left after the caterpillars ravaged my pond. Now they're going to get their comeuppance. They enjoyed their feast; now they have to pay.

 

[FountainMan]

The BT Thuricide seems to be doing its thing. All the caterpillars I'm finding now are dead. I'm not seeing any alive. The water lilies are pushing up new foliage and so far today nothing seems to be attacking them. I'm hopeful this actually did the trick. I think from now on when I buy aquatic plants I'm going to quarantine them in a separate tub to get rid of nasties before putting them in the pond.

One of the dead caterpillars.

 

[Mmathis]

Your fish will eat them if you throw them in......yummy snack!