Frangipani Leaves. It is most noticeable in late summer and early autumn. There is a new disease attacking frangipanis in australia called frangipani rust or plumeria rust.
Frangipanis normally drop their leaves in the fall they are deciduous. Frangipani are drought tolerant once established but younger plants will require regular watering and care. Rake up all the dead and fallen leaves on the ground surrounding your frangipani and then bin all of the leaves in your garbage bin not compost as the rust spores can re infect other frangipani from the reuse of the compost.
Add seaweed fertilizer or fish emulsion a few times a year to the soil.
Frangipani trees are easy to care for and can do very well in areas with extreme heat and droughts. Frangipanis need to be placed somewhere that gets at least 6 hours of sunlight a day. Top dressing with compost and organic mulch will help but make sure it is kept clear of the trunk to avoid rot and fungus. The scaling is formed when leaves drop in winter leaving small semi circular marks on the bark.