Hi BarBalee--You can check for rust take a white Kleenex or paper and fold it around a leaf with spots and pull from the base of the fan to the tip of the leaf. If the kleenex comes up with orange/rust on the cloth, it is rust. If not NO rust. Are your temperatures well over 90? Usually not rust then. I can tell you two things to try if rust, but I am not sure of your temps there. If the Kleenex isn't orange it could be heat damage coupled with insects. I am hoping you will not have to deal with rust.
