I've picked up two oncidiums this summer, and I don't know much about them at all, but they do have the same spots on their leaves. They're otherwise doing very well. The leaves they've put on since I got them have no spots.

Thanks, Danielle. So yours had the brown spots outlined in yellow and are doing fine? I know there are some spots that were plain brown or yellow, so I wanted to be specific.

I hope you're right and it's just me being paranoid!

I'll take a look when I get home and let you know!

Your plant might have had scale and the grower treated it. It might be nothing. You are right, the yellow around the spots is not the normal freckling. My guess it was insect.

Best to keep an eye on the plant. Look at the leaf axils and the pbulbs for any sign of scale. Wipe the back of the leaves with a white tissue for any coloration.

You could email the grower and ask her if she treated the plant for scale or mites. They are prone to both.

Jane

Could be mite damage. Look on the underside of the leaf. They are hard to see. I use a jewelers loop. Try magnifying glass. Most likely the grower resolved the issue. The damaged leaves will stay damaged. New growth is the canary in the coal mine. Good luck

Thanks, Jane. After I read your message, I looked up scale and mites, then looked much more closely at the plant. I think it has scale. Here's the bump I found:
{{gwi:197075}}

I also saw something white and much smaller than that bump moving on a pseudobulb!

I don't grow many plants and never had pest issues before. When I first got the Onc., the leaves looked dusty/dirty and like they had hard water stains. I wiped them down with a moist paper towel. I only noticed some gray and brown dust. The stains didn't budge:
{{gwi:197077}}
{{gwi:197079}}

There are also a few of these tiny white bumps that are slightly...fuzzy?
{{gwi:197081}}

And there's a dark spot that doesn't look like dirt and didn't brush off easily:
{{gwi:197083}}

Sorry if this is overload - now I'm worried that anything could point to a problem!

So are any of these signs of pests/disease? Can you recommend what I should do?

Or should I just return the plant? Do buyers usually just fix sick plants on their own, or do they return/exchange them? I messaged the vendor yesterday asking her to let me know whether the brown and yellow spotting is harmless and haven't heard back yet. I may message her again about the scale if someone confirms it for me.

On yet another note, I'm also worried that the other plant I received in the same order (Hoya cv. Mathilde) might have problems too. They were separately wrapped in taped-up newspaper and shipped together. Is it likely it has issues too? I'll take a closer look at it tonight.

Cynthia

The spots with the yellow ring is scale. The plant might have mites but you have to identify that. They are hard to see, jewelers loop, magnifying glass. If you wipe with a white tissue you might see some orange stains.

It appears the plant was treated (white stains). I would contact the grower and ask her. Tell her the plant has scale.

If you find any scale, use a q-tip dipped in alcohol and wipe the scale off the leaf. An oil spray is the best to smother them .

You could stick the plant in the sink and spray with water weekly to knock any mites off.

These insects can spread quickly especially in winter with dry air. Keep an eye on them. You don't want to use strong chemicals in the house. An oil/alcohol wipe or spray will work if you do it every 2 weeks. Don't skip or they come back again and again.

The black spot doesn't look important. I can't tell, probably some old mechanical damage or sun burn. The white fluff, maybe mealies. I can't tell. Do some research on these insects and look at images. Google the insect. You can find all sorts of remedies online.

Jane

This is some of the pristine wilderness stuff. Looking at the first set of Photos I would have said that the plant was in pretty good condition.
A long time ago, before cites you could buy wild collected plants, some of them were pretty ratty.
As Jane says a bit of preventative treatment every couple of weeks should keep most bugs at bay. A big danger, especially with this orchid is too much TLC leading to overwatering and death.

I heard back from the seller, who told me the strange spotting was harmless. I told her I found scale and asked if the plant had been treated. I'm waiting for her response. I'm so glad I also consulted everyone here, or I would've trusted her and left the plant alone!

Jane, thanks for all the advice. I actually found an old post of yours about a soap, oil, and alcohol spray. I'll be trying that, or maybe a dip in the same solution, tonight. A dip sounds more effective to me than the spray, and my plants are small.

I want to dip both the orchid and the Hoya cv. Mathilde that was shipped with it, then spray every 2 weeks, like you said, going forward. Does that sound like a good plan?

There's a third plant that was next to these 2 for a day. (Not much plant space left in the room.) It's a Primulina tamiana, which has fuzzy leaves. On second thought, the hoya has hairy stems. How should I treat these plants? I've read oil and alcohol sprays aren't good for fuzzy leaves, but no one recommends an alternative.

How easily/quickly does scale spread to other plants?

Arthurm, I'm not sure what you mean by pristine wilderness stuff...? I thought the plant looked pretty good at first too, especially with the new growth and spikes. I usually convert my plants to semihydro, so don't have overwatering issues.

Speaking of media, will repotting help with the pest situation? Or will the additional stress be too harmful? I actually have some hydroton ready to go. The other plants can wait.

Cynthia

I agree with Arthurm. Don't go overboard. My guess is the grower treated the plant. You have spikes and you risk losing the flowers. I would just wait and keep an eye on things. Your plants do look healthy.

If you use alcohol, keep it away from the buds. I would put things on hold for now.

Jane

You're right, Jane and Arthurm. I got carried away with fear of the scale spreading to other plants and forgot about the spikes. I hate bugs and especially one moving around on the plant...ugh.

I'll remove the scale I can see, maybe use some diluted alcohol on the leaves and pbulbs only. AND watch the plant like a hawk.

Thanks for all the help,
Cynthia

Cynthia,
The best way to control scale is to control ants. Ants "farm" scale. They eat the secretions of the scale. Orchids with the flower nectar attract ants. Control ants and control scale. Mostly.

Some of the bumps you posted about are probably just edema. Check out this site. It does a good job of matching pictures with pest and illness descriptions.

Be care not to kill with kindness.

Here is a link that might be useful: Edema