Oncidium twinkle leaves with spotting
 

The same oncidium twinkle orchid regarding which I posted about browning leaf tips earlier last week is now having some other issues. Some leaves have tiny black spots and one of the leaves has tiny scabs and another one has brown line along the middle of the leaf. I'm attaching the pictures. Could this be scale? I'm dealing with scale issues on some of my other orchids that are currently quarantined so I'm so paranoid as I have other seedlings that I dont want them to get infected.
This seedling is grown in bark and sphagnum moss, watered once a week, fertilized once every 2 weeks. Temperatures at home is 70F and dry. Please suggest what can I do if this is indeed scale and if its not ,could it be some fungal infection?
I spot treated the leaves with some horticultural oil but not sure if that will be sufficient if its indeed scale.

The brown edges are probably scrapes and mechanical damage. The first photo is concerning for spider mites. They are common in low humidity, and prefer to attack thin-leafed plants. They can be controlled by wetting all surfaces of the leaves frequently.

I don't think once a week is enough to water a Twinkle in medium to large bark. They should not dry out. The last photo shows a pleated leaf, which happens with insufficient watering of Oncidiums.

Adult scale are hard, hemispherical, brown to black things on the leaves. I don't see that. Juveniles look like a collection of cotton stuck to a leaf. I don't see that.

Thank you estación for the response. Glad that it doesnt like scale. I will make sure to wet the leaves frequently to get rid of mites. I think horticultural oil also should help with controlling mites. I will increase frequency of waterings for all.my oncidiums

Horticultural oil will suffocate plants as well if used too often. It's hard to give a maximum frequency, but small thin-leafed plants will be much more susceptible.

I don't use oil much because I have good results with soapy water and alcohol. However, I mail ordered a Passiflora two years ago and it came with a type of scale I hadn't seen, Florida citrus scale. This is reported to be susceptible to neem oil. Online reading about treating passion flowers suggested not to use oil more than twice in a month.

Good to know that will keep this in mind Estación

When I use horticultural oil or neem oil for indoor pest management I like to rotate with another type, be it a soap or something else. Used outdoor, oils leave minimal residue and the environment helps degrade and remove what is left, but indoor plants don’t get the same sun/wind/dirt/rain activity.

That makes sense👍Soap or alcohol is not always sufficient to manage severe pest infestations