What is this on my dieffenbachia?

Question

It’s tiny and dust like, almost like saw dust. The plant is otherwise very healthy.

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Answer 1

Those are aphids and they suck sap from your plant. You can wipe them off with a wet paper towel or rinse them under water. You can also use insecticidal soap or Neem oil. This article should help:

https://www.gardeningknowhow.com/houseplants/hpgen/common-bugs-and-pests-on-houseplants.htm