Garden Pests and Diseases: What is causing these issues on Pittosporum tobira?, 4 by SavvyDaze

SavvyDaze wrote:
We have 2 Pittosporum tobira planted about 20 feet apart in our front yard under some Oak trees.They were here when we bought the house in 2006.They have always grown beautifully and never had any issues until about a month or so ago.

Shrub #1: I noticed yellow spots on the leaves and they have gradually gotten worse. Recently, I noticed that, along with yellow spots, some of the leaves were turning brown on the tips. There is also what appears to be sooty mold on some of the leaves but you can't really see in the pictures.

Shrub #2: The older growth doesn't seem to be affected (yet), but the newest growth is dying back. The leaf tips and some edges are almost translucent...kind of looking as if they had been burned. There are also some white, near translucent, spots in the center of the leaves. This shrub doesn't have the yellow spots like the other one has, nor have I noticed any sooty mold.

I looked intensely all over both shrubs, on the stems, under the leaves, and on the trunks and see no pests. I showed pictures of Shrub #1 to the owner of a local plant nursery the other day and his first thought was Mealy Bugs. However, there is nothing white, fuzzy, or cotton-like on the bark or leaves of either shrub. I don't see any aphids, spider mites or webbing either. I looked for ants and see no sign of them. I see no scale either. I am at a loss.

Whoever planted these shrubs many moons ago, planted them in pure sand, and I almost never intentionally water them. They get rain water and that is about it, so I know it isn't root rot, nor are they being over-watered.

Any idea what are causing these problems? Any suggestions?

Thanks!