# Is something eating your plants - alert!!



## Fishfur (Mar 4, 2012)

I found a creepy crawler the other day in one of my tanks. At the time I did not think much about it, I just got rid of it. It crawled out of a patch of Salvinia. 

Today I've been rinsing off some new plants, and also trying to reduce the numbers of mini duckweed in my tanks. While I was rinsing off a bunch of plants, I kept finding these odd little green 'cases', stuck firmly to stems or leaves, etc. I have actually seen this 'case' before, but I was so new to water plants at the time, I assumed it was a seed pod of some sort and thought no more of it.

But today I saw another creepy crawler, and he was coming out of one of the little cases I had pulled off a plant stem.

So these things are making very clever disguises for their nasty little plant eating selves. I do believe they make the case out of leaf material they've cut out themselves, hence the big holes in the plants, but then they attach strongly to their chosen host and feed off the juices, as nearly as I can tell from what I observed today. 

They are firmly hooked into the host plant at one end, the other end sticks out. The cases look like live parts of the plant they are stuck to, green colour, size about 3/8" long, 1/4" long, vaguely oval shape but with rather irregular edges. I have pics, I've just got to find a way to get them posted. 

The critters I've seen have been from 1/4" to 1/2" long, whitish/yellowish, and if you pull the green case off the plant, it will crawl out fairly quickly.

They seem to seriously like floaters. Many of my frogbits have just recently been shredded almost to death, so I think it must the time in their life cycle when they hatch and start munching. I should have known it wasn't pond snails !!! 

Also they like mini water lettuce and salvinia, but I've found these green cases stuck to the stems of L. Aromatica, a leaf on a red sword and some other stems, even one just floating, perhaps it got dislodged somehow. I had been blaming the escalating damage to my frogbits on pond snails, but now I know it must be this maggot. It must be some sort of fly or perhaps a moth that is the adult metamorphosed creature.

I will try to get the pics posted.. but if you find a little green case stuck to a plant, pull it off and get rid of it fast.. and if you have holes showing up in all your juicy floaters or other plants, start looking for these darn things !

I'm guessing these must be fairly common. I'll bet there are some of us who have these things in our tanks but don't know they are there.. but if you have them, I'd guess you're going to start seeing damage soon, if you haven't already.

New observation ! They don't cut pieces of leaf, exactly. They skin the leaf they attack and form the case out of the skinned back leaf portion.. it is difficult to say if they actually use the leaf skin as is, or if they eat it and spit it out into the new formation.. but I found some frogbit that had half of a case on them.. as though one wall had been made and then something happened to the maggot to prevent it finishing the job. I've found 2 or 3 unfinished or partly finished cases..and I got a pic of the maggot, that one was on a segment of hornwort, so it's not just flat leaves they go for. Maybe I can find out what they are with a net search but for now, back to cleaning up plants.

Did a quick search anyway. A possible candidate is a Water Lily Leaf Cutter.. or the China Mark moth.. both do the kind of damage I've seen on my frogbit and make little leaf cases for themselves, from cut leaf pieces. Feeding stage begins with small holes, but progresses to eating the whole leaf..and while I am not certain it is either of these is the right insect it is most certainly something very similar. Winters over at the bottom of ponds and such, then climbs up and hatches into the moth form.


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## Gafi (Sep 1, 2011)

Fishfur said:


> I found a creepy crawler the other day in one of my tanks. At the time I did not think much about it, I just got rid of it. It crawled out of a patch of Salvinia.
> 
> Today I've been rinsing off some new plants, and also trying to reduce the numbers of mini duckweed in my tanks. While I was rinsing off a bunch of plants, I kept finding these odd little green 'cases', stuck firmly to stems or leaves, etc. I have actually seen this 'case' before, but I was so new to water plants at the time, I assumed it was a seed pod of some sort and thought no more of it.
> 
> ...


Hopefully the plants I get from you are going to be clean and free from this! haha you're making me worried!


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## matti2uude (Jan 10, 2009)

I guess I should check the plants I got from you.


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## Kooka (Feb 8, 2011)

I hope you didn't get those buggers from me, I didn't have any of the problems that you're having now 

I wonder if there is anything you can do to get rid of this pest, maybe lowering the temperature in the tank or just physically trying to remove them.


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## Jaysan (Dec 19, 2011)

Since you said they love floaters, I checked all my floaters and they all look good with no holes (phew)


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## Fishfur (Mar 4, 2012)

This is a recent problem.. only in the past two to three weeks. Matt, so far as I know, everything I gave you was clean.. I did not give you any frobits that had been chewed on at all, but if you want to toss them I'll give you the money back. But I always pick over any plants I'm selling beforehand, and pull off dead or damaged leaves. Had I seen a case I'd have removed that too, but I also would not have sold that plant to anyone. But by all means,please look.. I'm afraid I'd forgotten I'd just sold you stuff when I discovered I have this problem. 

But that's one reason I posted this, so everyone would be aware. If you see a little green case like the one in the pics on the link, pull it off and toss it or flush it. The darn things go through, I forget if it's 4 or 5, stages, called instars, basically size increases and each one requires a new case of more chewed up leaves, which will be a bit larger than the previous one. I've now seen them stuck onto roots, stems and leaves of a least a dozen species, none of which are usual hosts for this pest.

I won't be selling any more plants until I am certain I have dealt with the problem.. fortunately, the cases are a fair size. They are easy to see, and easy to remove if you are looking at a plant closely, though you do pretty much have to pull it out of the water first, I'm afraid. The cases are good camouflage and harder to see among all the shades of green inside a tank. But a simple, temporary, screen top will prevent any adult moth from laying eggs on any floaters or escaping if it hatches in a tank.

I am guessing, and only guessing, that at least one adult moth found my little pond on the balcony and laid eggs on the frogbits there, but I've also seen them on plants from at least 3 other sources I have purchased from, at least one of them a store. I am not blaming anyone at all for anything. As I mentioned, I have seen the cases before myself, but not knowing what they were, did not think anything about them at the time.

Phil, so far as I know, nothing was on the plants I got from you, not that I noticed, but I'm in the process of removing every single plant I have from every tank I have and inspecting them carefully to find and remove any cases that may still be present, as well as checking to see if there are any more adult moths around, after dark, which is when they tend to show up.. I've only seen a few. I've also tossed all the frogbits that were chewed on, in case they had eggs on them. I won't be happy until I have a month of clear sailing after I finish this task. 

This is a seriously annoying problem, but the sad fact is, these critters are a common pest of ponds, especially water lilies. They could come from any source that sells pond plants. They could be in anyone's tank that has purchased plants from a place that sells pond plants, which includes many of the LFSs, without anyone being aware of it, particularly since the moths show up after dark, are small and not very noticeable unless you know what they are. They also are not an all summer problem. Early autumn is when they start to show up.

Unless the numbers of larvae are fairly high, I think most folks would put any damage they see down to snails.. which is exactly what I thought was the problem and I'd been hunting snails with a vengeance lately.. and it wasn't them at all.

But I hope the warning will ensure if anyone does find them that they will know what they are and be able to get rid of them fast. Just check the pic on the link.. it's exactly what I found.. and they'll be in places where they just don't belong.. on roots, stems and stuck to leaves as well. If you have any floaters that look chewed, be on the lookout for these things.


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## Scotmando (Jul 10, 2011)

They're just bugs! Squish 'em & feed 'em to the fish!


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## Fishfur (Mar 4, 2012)

Trouble is, they are too big for all my fish ! They drown if you rip their cases off.. the air bubble gets out and they sink.. but the ones I catch are too big for my fishies to munch. I t would only be justice if the fish could eat them ! I would not mind so much but they have eaten most of my frogbits down to nubs, except for one tank, which I think they just haven't got much of a toehold in yet. Got one tank half done.. two and a half to go.


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