Those are mites. You need to treat all your orchids. They will mostly be on the underside of the leaves. Try to find an insecticide that claims to kill mites. Spray all parts of the plant and the top of the medium and in a week, do it again.
I actually start by using an insecticide soap. I like it because it's not poisonous and I can really clean the orchid with it and not worry about getting it all over my hands. I repeat it in a week to kill newly hatched mites and then a month later. After that I just keep an eye on the plants. I don't know what insecticides are available in your country or if you can get insecticide soap. If you have a good plant store or garden supply store they can probably tell you what's good for mites.
I dont see any mites right now in any plant. I guess they are so small or their eggs haven't hatched yet. I will try to find a good one! Thank you again!!!!!!! Very much!
Nope, those are mites! Devastating if you can't get rid of them. You don't need to buy insecticidal soap, you can make it with some dish soap and water. The biggest enemy of mites is water. Just keep at it...do some research on line about the life cycle of the spider mites and it will help you in knowing how long to treat them for it. You do need to treat just about every plant in your house! They travel quickly!
No not in the roots. However, in the winter they take a nap in the soil so it's a constant battle. I've had lots of luck with Rose RX 3 in 1. I have a problem with mites in the summer on my roses pretty bad. It really knocks them down pretty quick. Just get the concentrate, you will use a lot. I'm sure if it's safe for roses, it's safer for Orchids.