Last spring I noticed multiple white spots all over the fronds of several pups on a sago in a friend's yard. The spots were only on pups on one side of the sago not the pups on the other side. Nor were there any spots on the main sago. Eventually the white spots disappeared but the fronds now have tiny yellow spots where the white spots were. The fronds are otherwise green and healthy looking, as is the rest of the plant and pups.
Is this scurf or scale insect? I figured if it was scale, it would have spread to the whole plant and the leaves would be showing some death by now. However, I can't find any info about scurf causing discoloration on the leaves after falling off. Can any one confirm this condition? Unfortunately, I do not have any photos.