Yellow bumps on night blooming cereus leaf

Question

I have been rooting a night blooming cereus for about three months now. It is finally showing new growth. However, there are hard yelliwish bumps on the underside of the largest leaf. Some appear to have tracks going to them. I’ve looked at it under magnification and cannot see any insects. So I would appreciate being told what these are, if they are a danger, and if so, how do I get rid of them?

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Answer 1

I think this may be leaf damage from scale pests.

Treat the plant with Neem Oil or insecticidal soap.
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/control-plant-scale.htm