The plant must be a Strelitzia nicolai and the pest is scale. Just rub as much of the scale as you can off the plant,getting in the leaf crevices as well with a tool. Then,use used coffee grounds on the soil of the pot and water in well. This acts systemically i many plants and kills the scale. You can also place a couple of used coffee grounds disks in a bottle,fill it with water,shake and leave it in the sun for some hours. Then,soak with this all the areas where the scale was or still is and you cant reach. The used coffee grounds and that treatment will take care of the scale for good. If you place the plant outside,in a well ventilated spot in the sun and water it correctly,it should come back on its own and be fine from there on
Good luck with it!!!