Phalaenopsis spots on leaves and strange growth

[SouthPark]

Originally Posted by Piao Liang

Thank you for your messages. I’ve had these orchids for a few years. I am very careful with water, sterilized scissors etc. I left my orchid collection to someone else to care for while I was away. I am suspecting that shared water might be the problem although this person will never tell me. These are 3 different orchids are quite valuable. I guess I will have to get rid of them. I have already used Physan.

Thanks for mentioning the above.

Whatever happened - and assuming (just *assuming* not virus-related) ----- you could try (if available to you) system fungicide/bactericide such as copper spray (suitable for orchids) - eg. phyton 27. And can even try some other systematic treatments like monetery garden phos (used to be called agri-fos).

If your plants had abruptly developed this nasty condition, and if it occurred only after a very recent away-trip, then it's possible that the situation is related to the away-trip. Not necessarily the carer's fault.

It also depends on the growing conditions when you were away - and also growing conditions now. Eg. where are the orchids grown? And if grown indoors, then were doors and windows closed - with no air movement, so that fungus activity could start up on the leaves etc? These questions should be considered. They're questions we have to ask ourselves.

But ------ before we throw out orchids, we should at least do something to help them. Physan is a disinfectant - not a systematic treatment that gets into the plant to deal with whatever is causing issues. This just means physan won't necessarily treat this particular health issue.

Do your orchids currently get gentle air-movement in the growing area?

[Piao Liang]

Hello. Finally I discovered that this damage is caused by mites. Not the type that produce webs. I think they are called flat mites. I was inspecting one of the leaves and I saw two tiny (the size of a grain of salt) dark brown specks moving. I have treated my orchids with a miticide with the dose recommended for orchids. Thankfully I didn’t throw away my orchids. We will see how it goes from here.
I am showing photos of the leaf in question.
I was wondering if it could be an insect because the new leaves are more damaged than the older ones and as the leaf grows, the damage decreases.
This is the first time I have problems with mites so I didn’t even think about this possibility!

[Piao Liang]

I also treated them with Captan just in case they also have fungi caused by the weakening of the plant produced by mites.

[estación seca]

Thank you. I've bever seen this kind of mite.

[MJG]

Originally Posted by Piao Liang

Hello. Finally I discovered that this damage is caused by mites. Not the type that produce webs. I think they are called flat mites. I was inspecting one of the leaves and I saw two tiny (the size of a grain of salt) dark brown specks moving. I have treated my orchids with a miticide with the dose recommended for orchids. Thankfully I didn’t throw away my orchids. We will see how it goes from here.
I am showing photos of the leaf in question.
I was wondering if it could be an insect because the new leaves are more damaged than the older ones and as the leaf grows, the damage decreases.
This is the first time I have problems with mites so I didn’t even think about this possibility!

Thanks for posting this. I certainly just learned something new.

[Piao Liang]

I checked if there was anything in the leaves but I couldn’t see anything except for one leaf which had small brown specks. I checked them under the microscope and I couldn’t find insects. I probably washed them away with the miticide? However, I could see fungi mycelium. I think that it was first a flat mite problem followed by (or together with) a fungal infection. We will see after the Captan and fungal treatment.