possibly thrips...

Ah, a new pest to figure out how to handle. I don't see the same damage on my other leaves yet so I'm wondering if I should cut this one off and use an insecticidal soap on the rest of the plant. For now I've moved it away from my other plants.

Not sure how I got the thrips since I've had this plant for 3-4 months now and this is the first sign of anything on it. I did have some potted jasmine plants that I took out when we had some nice weather and brought back in when the weather took a downturn recently. I don't see the same damage on them but I guess it's possible that introduced them into the house?

I treated my plant with Safer insecticidal soap twice now (1 week apart) and used Bonide systemic 2 weeks ago since I read that is can be difficult to get rid of thrips on Monstera's because they can stay in the leaf sheath. (I believe it takes Bonide 2-3 weeks to work).

I haven't seen an improvement in the plant- the new leaves continue to have the same black dots that wipe away easily. None of the older leaves are affected.

I plan to use the insecticidal soap at least 2 more times at one week intervals since that's what helped when I had the spider mite infestation on another plant.

I'm just concerned because I haven't see any actual bugs so I can't tell if this is the result of thrips or not. I've kept the plant in semi-quarantine (I can only keep it somewhat isolated since I have plants in all my rooms) but if this is something that won't be eradicated I'm wondering if I need to get rid of the plant. It cost around $35 and was/is thriving so I'm not excited about throwing it out, but I don't want to wage this battle all summer and definitely don't want to risk infecting my other plants.

Here are some more pictures. I just realized the last one is blurry, I'll try to get a better shot later.

did you ever find out or solve the issue? I'm having the same!! I can't figure it out!

No, I assumed it was thrips and could not get rid of them. They kept showing up in the leaf sheaths. So rather than endanger all my other plants, I tossed it.

Luckily M. deliciosa is easy and cheap to buy around here. My new plant is thriving.

And I no longer take plants in and out of the house. If they go out, they stay outside for the season and they're isolated/treated for a month in the basement before they join my house plants for the winter.