[Pescador]

My 2 year old Strelitzia has these white powdery spots on all but the newest leaf. When brushed off they show a pale discolouration of the leaf which later goes necrotic.
Any ideas on cause and how to treat?

[Yorkie]

Can you tell if it's a powdery fungal type disease, or a small fluffy pest / a small pest under a fluffy blanket?

[Pescador]

Cant see any wee beasties, even with a magnifying glass.