Please help what is this? Pest or fungal?

[chrismende]

Troy, my 2 cents is that your Dendrobium is easily replaced. Toss it and get another healthier one! Agonizing over one sick, new plant isn't worth the trouble!
You will spend far more on the process than the plant is worth.
If your other plants aren't sick too, they would be well served to not be exposed to this one.

 

[chrismende]

Well, maybe I'm overreacting...

 

[gonewild]

Well, maybe I'm overreacting...

No you aren't.

 

[abax]

I don't think you're overreacting at all.

 

[NYEric]

do something to the mites. It looks like secondary fungal/bacterial infection from false mite damages.

Good luck with your $500 flask investment.

This! Keep it isolated from the rest of the plants.

 

[Happypaphy7]

I agree with Chris.
When I see ugly leaf tip starting or a few small spots, I keep a very close eye on. Usually cutting the affected part off is the end of most.

When they return, then it is a challenging case.

When there is a large rot or a whole bunch of little spots all over like this, it is often best to discard the plant IF the plants are easily replaceable mericlone or something that has relatively little variation among clone to clone.

Risk of spreading diseases all over the collection is just not worth it.

My opinion.