Appears to be slug damage

[TheLorax]

I have some jewel orchids growing in a contained terrarium. There appears to be what looks like slug damage on the leaves. The plants are all growing in long fiber sphagnum moss and are otherwise healthy.

I have taken the plants out and used a 5x magnifying glass to try to see mites or who knows what and couldn't see anything. I then put some of the leaves under a 20x stereoscope and couldn't find the culprit. I've set my alarm clock for 3am and gotten up with a flash light to sneak up on that case to see if something was coming up out of the sphagnum at night to feed on my plants and came up empty handed.

It was suggested that I probably had slugs. I placed a small tray of beer in the terrarium and so far I have not caught anything.

Suggestions please? I've been unable to identify my foe so can't select a pesticide.

Does anyone want photos to see the holes in the leaves?

 

[Eric Muehlbauer]

My guess is bush snails. They are tiny (2-5mm) snails that can cause an astounding amount of damage for their size. While snails are killed by the same things that kill slugs, they are not attracted to the same things. So, beer, yeast solutions, and slug bait (whether metaldehyde or the safer,"organic" iron phosphate stuff like Sluggo or Escar-Go) won't work. They are just not attracted to the bait. A chemical solution could be with metaldehyde liquid...the snails will die when they cross a "line in the sand", but if you don't want to use that kind of stuff I don't blame you. Diatomaceous earth is useless...slugs and snails just slime their way over it...I have witnessed it too many times...maybe the best thing is a total change of media....Take care, Eric

 

[TheLorax]

Thanks for commenting because I had discounted bush snails. I thought those only fed on roots. I'll try a change of medium tomorrow and see if that provides relief.

I've got Diatomaceous earth however you say that won't work so that's out.

Tell me more about metaldehyde liquid? I found this information-
Trade and Other Names: Some trade names include Antimilace, Antimitace, Ariotox, Cekumeta, Deadline, Halizan, Limatox, Meta, Metason, Namekil, Ortho Metaldehyde 4% Bait, Slug Death, Slug Pellets, Slug-Tox and Slugit Pellets.

What do you think of Methiocarb pellets?

 

[CLMoss]

Hi,

I am a windowsill grower; however, I take advantage of the warm months and grow out-of-doors until the weather changes. If I suspect slug or any other pest that my be in my media, I submerge the pot, up to the top, in water. If a slug is hiding in the media it will have to reach the surface for air. It always works.

Claudia

 

[NYEric]

I find that my jewel orchids sometimes suffer from fungus gnat larvae just below the surface of the plant. I'm treating w/ the dreaded phytotoxin Safer soap spray.

 

[TheLorax]

Hi CLMoss, that's what I do with some carnivorous plants. It does work. I've just repotted into fresh LFS so let's see if I need to go that route next. I was somewhat concerned about doing that because I didn't know if those plants could handle being submerged. Much better option for me than going chemical.

Hey EricNY, have you ever considered Gnatrol for fungus gnats, it's a biological control-

http://www.hydroempire.com/store/product_info.php/cPath/11/products_id/1101
Comes in a more economical 16oz size too for around $15.

http://www.cdms.net/ldat/ld4CD005.pdf

 

[NYEric]

Hadn't heard of it before, thanx.

 

[goldenrose]

I find that my jewel orchids sometimes suffer from fungus gnat larvae just below the surface of the plant. I'm treating w/ the dreaded phytotoxin Safer soap spray.

BTI as a soil drench is suppose to take care of fungus gnat larvae as well.

 

[NYEric]

Haha, TheLorax sent me the MSDS sheets for the chemicals; hasn't she read Blake and my competition to exterminate ourselves?! :rollhappy:

 

[goldenrose]

Poor Blake, we do give him a hard time on chemical use don't we! (but for good reason!).
Years ago I got hit by the mealies & that was one of the reasons I took an eight year absence. Since coming back, I use alot more non chemical means & improved my overall culture & haven't had too much of a problem. One will never get rid of them, some plants (phals) they really seem to favor & if worse comes to worse, I won't have phals or a very limited number.

 

[Eric Muehlbauer]

Deadline is the brand of metaldehyde liquid that I have seen sold here. It is an ugly, thick black liquid...I have a container but I rarely use it, maybe once every year or 2. Turns snails and slugs into black slime. Too bad the iron phosphate stuff isn't attractive to snails, because I find it better on slugs than metaldehyde, and its safe too! Eric

 

[TheLorax]

The Gnatrol is target specific. It's a BTI. That's about as safe as you can get and it will knock out the fungus gnats. Truly a wonderful product particularly when you understand how it works. Gosh, it's like slapping mosquitoes then dropping them down the tube of a pitcher plant only better.

I missed the little Y chromosome friendly competition. I've read a lot of old threads but somehow that escaped one me. Provide a link please.

 

[NYEric]

This is my contribution:
http://www.slippertalk.com/forum/showthread.php?t=3299&highlight=Scrubbing+bubbles

 

[NYEric]

This was Blake's!
http://www.slippertalk.com/forum/showthread.php?t=4882&highlight=malathion

 

[TheLorax]

It was slug damage. I repotted all the plants a few days ago and placed the spent LFS in a 3 gallon zip lock bag that I tossed on the counter. I added a few salad scraps to the bag over the last few days. Normally, I start a bag and walk it out to the composter when it's full. This morning I saw a little 3/4" slug on the lettuce in the bag. That little stinker! It must have been gorging then crawling back down into my LFS for a siesta. And here we were just talking about lettuce being a better bait than beer for a terrarium situation this past Saturday.

 

[Eric Muehlbauer]

Toss in the iron phosphate! That is one natural pest control that actually outperforms the chemicals. Eric

 

[TheLorax]

I can do that but do you still recommend doing it right now being as how I completely changed out the LFS they were all potted in?

 

[CLMoss]

Hi, What is LFS? Lettuce is good bait...do the slugs get lost in the bag?

C

 

[goldenrose]

LFS = long fiber sphagnum

 

[TheLorax]

I keep that bag on the counter until it is full. All I had in it was the spent LFS and some salad scraps that were tossed in after the LFS. I saw the slug through the ziplock baggie hanging out on top of a piece of lettuce. Had to look twice to be sure. He WAS a happy slug until I squished him. I suppose he could have gotten lost in the zip lock. It was that slug's misfortune that he didn't go to the underside of that piece of lettuce.