Azalea leaf miner Caloptilia azaleella is a minor pest originally from Japan but now fully established in QLD. It targets Azaleas and Rhododendrons and causes brown patches on the leaves as the larvae feed inside their mines.
When they reach half grown, they burrow to the surface and migrate to the leaf tip, curl it over themselves and web it in to place creating a shelter in which to pupate to an adult moth.
Keeping plants healthy is a great preventative, also squashing any caterpillars in their mines and pruning off affected leaves. You can put the leaves in the compost as long as the leaf miners are dead, leaving the leaves in a plastic bag in the sun should do it. Any contact pesticides will not work as they are safe inside the leaf.
For natural control, look out for spiders, ladybirds and lacewings which would predate on the larvae.