Phal leaf damage identification

[shadowteme]

Hi everyone, I'm new to the forum and need a little help with one of my phalenopsis orchids. I noticed these weird circular spots on an older leaf:







They are a little pressed in but I never saw any insects or pests and they seem a little too perfectly ring shaped anyway, I don't think it's pest related. I cut the most damaged leaf off and I'm monitoring the other one that also has the beginnings of the issue.

Can anyone help identify this? The orchid is otherwise perfectly ok, has healthy roots and is in bloom.

[estación seca]

I wonder about spider mites under the leaf. Is there very fine cobwebbing, or does it look silvery? Take a tissue and rub it under the leaf from stem to tip. Do you see brown or red streaks?

What are your growing conditions? Temperatures, humidity, light?

[shadowteme]

Originally Posted by estación seca

I wonder about spider mites under the leaf. Is there very fine cobwebbing, or does it look silvery? Take a tissue and rub it under the leaf from stem to tip. Do you see brown or red streaks?

What are your growing conditions? Temperatures, humidity, light?

No cobwebbing and no red or brown dots, no mealybugs or scales or any other living thing on the leaves. I've actually very recently battled with false spider mites on a miltonia, so that's the first thing I checked, but nothing on this phal (thank god).

Growing conditions are on the drier side right now with the heating on, humidity about 50%, temperature ranges between 21-17°C. The orchid is in an east facing window with good natural light but not in strong direct sun. I never mist, I know phals are sensitive to stagnant water. I water with rain water when the media (bark and sphagnum mix) is dry and the roots are white.

[estación seca]

This looks something like a problem camille1585 had in the past year. Perhaps if you search on her username you might find her posts. At one time she thought it was some kind of mite, so perhaps use "mite" as a search term.

[shadowteme]

Wow, thanks so much, I managed to find it! But boy do I hope it's not that virus, even though it seems very likely unfortunately...

[camille1585]

That does look similar to what I see on my plants, though I don't really see those circular spots much. I had several of the affected plants tested for 6-7 common orchid viruses, and everything came back negative. Opinion of the lab (where I worked at the time) was that it was likely due to insects. Indeed I have been battling mealy buds for many years (can never fully eradicate them) and what I have noticed is that it is usually plants which had mealies at some point which develop symptoms. I don't know if it's mealies themselves causing issues or if they somehow transfer bacterial/fungal pathogens.

I have learned to live with the unsightly markings (and insects unfortunately), and occasionally have to trash a badly affected plant.

[shadowteme]

Originally Posted by camille1585

That does look similar to what I see on my plants, though I don't really see those circular spots much. I had several of the affected plants tested for 6-7 common orchid viruses, and everything came back negative. Opinion of the lab (where I worked at the time) was that it was likely due to insects. Indeed I have been battling mealy buds for many years (can never fully eradicate them) and what I have noticed is that it is usually plants which had mealies at some point which develop symptoms. I don't know if it's mealies themselves causing issues or if they somehow transfer bacterial/fungal pathogens.

I have learned to live with the unsightly markings (and insects unfortunately), and occasionally have to trash a badly affected plant.

This gives me so much hope you have no idea In any case I can only wait and see for now, maybe it won't spread further... fingers crossed none of my other orchids will be affected. Thank you so much for the quick reply!