What are these bugs on my Dieffenbachia?

[VanillaSugar2021]

The plant is not healthy and leaves are turning brown. I have removed the plant from other houseplants (which seem healthy).

Does anyone know what these bugs are and will they kill off my plant completely? Thanks.

Eek

They look like black fly. They’ll suck the sap, but won’t kill the plant unless you have a heavy infestation. Squash them with your fingers, wash them off under the tap, or spray with water with a dash of washing up liquid

Odd place to have them, and odd that they’re not all clustering at the leaf tip, so they might be something else.