# China Mark Moth - watch out for these things !



## Fishfur (Mar 4, 2012)

My earlier post was titled 'Is something eating your plants - alert ?

Well, now I am fairly sure I have identified the critter responsible, and it is a persistent, nasty little insect. It can completely destroy a host plant if its numbers are large enough.

It is a small moth, could easily be mistaken for a pantry moth if you don't see it up close. Rather nice marking on the wings, browns and beiges in a complex pattern. If you see a small moth landing on any plants floating in your tank or pond, kill it ! They do not seem to be afraid, don't fly up when you grab for them, so in a tank are easy to remove, but only if you see them when they land. Active mostly after dusk.

Their larvae do enormous damage to floating plants in particular, and are a huge problem for lily and pond nurseries. They are a pest of water lilies, which they prefer, but clearly can do very well in any aquarium with floating plants of any kind. Plus, they will hook their little cases onto any plant stem at all, several inches below the surface. I have now found them on hornwort, L. Aromatica, guppy grass, frogbit, floating water sprite, salvinia, and several others. I've pulled off every case I see and now I know what the grownups look like, I've managed to destroy a few of them I saw landing.

The larvae fasten their cut leaf cases together with silk and they can use them to float from plant to plant. Though if the case is damaged they will sink and drown, if it is intact they can attach it under water to a stem and live off the plant that way.. it is one way they hibernate for winters, and also how they pupate, to hatch new adults.

Adults live only a few days, spending their time landing on floating leaves and laying eggs underneath the edges, which hatch into voracious little caterpillars that resemble a maggot.

Below, find a link to pics and info on these pests. For ponds, there are few controls; BT or hand removal of infested lily plants. It is not the same kind of BT that you find in mosquito dunks, it's a different strain of BT.

For fish tanks, hand picking seems the only way to remove what's already in the tank without risk to fish or inverts, and BT isn't sold for indoor use, but if you screen the tanks on top the adults will not be able to get in to lay eggs, and if they hatch, will be caught under it where you can destroy them.

They normally overwinter on pond and lake bottoms, but indoor temperatures would likely allow them to be active year round. Only good thing is once you've seen a case, they are easy to recognize and not hard to find.. but it means pulling every plant out and examining the whole thing, stem, leaf and all, for any cases that are attached. Could be very tedious, but it beats having your plants eaten to shreds or death.

http://www.victoria-adventure.org/waterlilies_images/caterpillars/page1.html


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