Small Black Insects

[Faan]

When looking for snails a few minutes ago in my greenhouse I saw small insects on the roots of my Mystacidium capense. At first I thought these to be eggs of some sort, but when I had a closer look I discovered that these eggs move.

These little insects are about, or not even 1/2 mm in size and I only saw them on the roots. They are black in colour and shiny in the light.

I have not been able to spot them on any other plant.

If I know what they are I may check to see whether they can do any harm. This is the first time ever that I have seen something like this.

Any comments?

 

[Stone]

Faan, I have definately seen these very small black and shiny insects from time to time. I have not identified them (some kind of aphid?) as they have not realy caused much of a problem so far. But I spray them just to be sure. They seem to be easy to get rid of. Be careful spraying roots though, maybe try basting them off with water first?

 

[Lanmark]

Probably they're Oribatid Mites which are generally considered harmless. They usually only consume bits of dead and decaying organic matter. They play a role in nature's system of decomposition.

 

[Stone]

Probably they're Oribatid Mites which are generally considered harmless. They usually only consume bits of dead and decaying organic matter. They play a role in nature's system of decomposition.

Thanks Lanmark, I didn't think they looked to dangerous but I've only ever seen them on Cattleya leaves.

 

[Lanmark]

Thanks Lanmark, I didn't think they looked too dangerous but I've only ever seen them on Cattleya leaves.

They tend to live down by the pseudobulbs and roots, but they like to come out and sun themselves by day. :wink: I've been growing a happy, healthy mounted Meiracyllium trinasutum since the late 1990s and Oribatids have been living on it the entire time. They've never caused any harm. I think of them as pets.

 

[SlipperFan]

You have strange pets, Mark! oke:

 

[FlowerFaerie]

I think of them as pets.

Your plants have pets???

 

[Faan]

Well, I think I got rid of my "pets" by giving them lots of water. They were only on this particular plant and nothing on any of the other plants standing right next to this one. I was a bit concerned as the capense has three new flower stems developing and I did not want my pets to chew the flowers away before they even there.
I must say I feel a bit more relaxed after all the feedback.
Thanks

 

[Lanmark]

Your plants have pets???

Oribatid mites live happily in symbiosis on exactly five of my orchids, all of which are healthy and robust plants. Four of these plants are mounted on or potted in wood products, and one is a rupicolous Lc hybrid. The oribatids don't seem to like living on any of my other plants, at least as far as I have been able to determine in multiple detailed examinations over the years using 10x magnification. I don't have any explanation for this. Oribatids are ubiquitous in the environment and would be nearly impossible to permanently eradicate from any orchid collection of more than a few plants. Doing so would be pointless for me anyway since I'm not a commercial grower and the oribatids do no harm -- they never have and I doubt they ever will. Someone who is determined enough to kill them all off within a small collection of orchids might possibly succeed with repeated applications of alternated powerful chemicals combined with oft-repeated dustings of diatomaceous earth. Be aware that forest oribatid mite populations explode after fires, so bringing in new, fresh heat-treated wood products (pine bark chunks in potting media, for example) is almost a sure-fire way to reintroduce oribatid mites into your plant collection.

The only harm I've ever heard of being attributed to any species of oribatid mites is that they can play a role in equine acquisitions of tapeworm infections. Philip J. Johnson, BVSc, MRCVS, MS College of Veterinary Medicine, University of Missouri-Columbia states,

"Tapeworm eggs leave the horse in feces and contaminate the pasture. Tapeworm eggs are eaten by free-living (non-parasitic) mites (oribatid mites) which are particularly prevalent on permanent pastures. The tapeworm undergoes an essential maturation stage inside the mite. Horses inadvertently ingest the oribatid mite when grazing.

Following digestion by the horse's intestinal tract, the tapeworm is able to infect the horse."

Moral of the story: Don't graze in the fields and don't eat your orchids. oke: