Wormlike bugs in Brassia potting medium - Orchid Board

Judi · #1 10-26-2008, 11:34 PM

I'm new to this site--just became a member yesterday. I came across this site while trying to find out what critters are living in my Brassia potting medium. They roll up when poked, are skinny, ~ 3/8th of an inch long and two washed out while I was watering last week--I always inspect the excess water for signs of potential problems; I am attaching a few magnified pictures. This is the first time I saw anything like this, my orchids spend the summer in a screened porch, I last repotted this Brassia last winter. Can anyone identify the critters? I plan on repotting, but I also wonder if some viable unwanted pest eggs aren't included in the bark of the potting mix. Does anyone have experience with this? Is microwaving the medium to kill eggs a good idea?

Sandy4453 · #2 10-26-2008, 11:51 PM

Very strange that you should be posting this when, just today, for the first time ever, I zapped the same exact 'thing' out of my Oncidium plant...just today! I think it's a centepede, not sure though. I had been noticing little chewed up parts on the leaves but couldn't figure out from where it was coming. I sprayed with Neem Oil about a week ago and then again, today I noticed what looked like more damage. I sprayed the entire plant with alcholol and rinsed and then again, Neem Oil and is when I saw "it" between the leaves. As well, a few leaves had fallen off...clean breaks. Had I not found it, it would have ruined the enitre plant.

Definitely unpot and clean the plant and repot it in new medium. It's the only way you'll find every one of them!

Good luck!

P.S. Welcome to the site!

cirillonb · #3 10-26-2008, 11:54 PM

sorry I don't know the name of the but but it looks like the larval phase of some critter. Grubs in the lawn (usually from Japanese Beetles in our area) look and act the same.
I'm not a fan of microwaves. It is difficult to determine how hot it gets inside and in only works on water or water containing material (such as a vegetable or meat, or, for that matter a critter.) People have had fires in microwaves.
If you can stand the stench, you could heat in an over between 275 and 350(F) for about an hour. That kill most things including bacteria, fungi, and viruses. Probably the critter you have as well.
Nick

Undergrounder · #4 10-27-2008, 01:32 AM

I know the critter you might be thinking of cirillon, it doesn't look 'quite' like that, but i wouldn't take chances... certain grubs try to burrow into the fleshy part of a pseudobulb and set up shop there and eat it from the outside. I would do a repot with fresh media, boil the new media in water for 10 mins to kill any nasties. Check the orchid for any small holes in the pseudobulbs, or any small eggs, wash it well and replant.

cirillonb · #5 10-27-2008, 09:42 AM

another solution might be the larvacide BT which is a bacteria that attacks larvae and caterpillars. It is variously available but I got mine from RePotme.com called Gnatrol since it is the first choice in treating a fungus gnat attack. Since it is pricey you may want to use some "home remedies" first.
Nick

BikerDoc5968 · #6 10-27-2008, 10:13 AM

It looks like a grub, larval stage, of an insect. What specific insect really isn't important just now, 'cause this critter will do major damage to the roots of your plant. In my humble opinion the only thing to use on them is a product like Merit (Imidacloprid) or Grubex 2. This is also the active ingredient in Bayer 3-in1 Inscecticide concentrate. So kill the larva and that will kill whatever insect will morph from that and keep it from eating more of your plant....in short use a systemic and/or repot to be sure there are no more critters!

Judi · #7 10-27-2008, 04:34 PM

Thanks for the quick replies and all the good advice! I will try boiling the medium and repot today. You have convinced me it's really important to take care of the critters ASAP. Now I'm getting concerned about the rest of my collection. Maybe I should use Merit or Grubex 2 on all my other orchids. Are these products completely safe for orchids or should I only use them only if I see critters in other pots?

Ross · #8 10-27-2008, 05:14 PM

Sounds like these critters are coming from somewhere and may be in the other pots or may be eggs ready to hatch. I would worry as well.

BikerDoc5968 · #9 10-27-2008, 05:15 PM

I put lots of stuff outside for the summer, including all my succulent plants. For whatever reason, insects love to lay eggs on my succulent plants which go onto grubs (larva) and the larva eat the roots right up into the stems of my succulents. So before they come into the GH, I treat with Merit granules on everything, succulents and orchids and anything else that's been outside and comes inside....EVERYTHING GETS TREATED, PERIOD!

Ross · #10 10-27-2008, 05:18 PM

Quote:

Originally Posted by BikerDoc5968

I put lots of stuff outside for the summer, including all my succulent plants. For whatever reason, insects love to lay eggs on my succulent plants which go onto grubs (larva) and the larva eat the roots right up into the stems of my succulents. So before they come into the GH, I treat with Merit granules on everything, succulents and orchids and anything else that's been outside and comes inside....EVERYTHING GETS TREATED, PERIOD!

Good advice, Doc (as always.) My advice is leave them inside