Garden Pests and Diseases: Spots on avocado tree leaves, 2 by nealdt

nealdt wrote:
Hello,

I planted a Holiday avocado in my back yard last year, and for the past 2-3 months I've noticed small spots on the leaves that I'm having trouble identifying.

The first and third picture attached show small brown spots on the underside of the leaves, and how it looks from the topside as well. I thought they might be persea mites or similar, but all the material I've read about those mites says that the spots would be aligned along the veins like this: http://www.ipm.ucdavis.edu/PMG/O/I-AC-OPER-CD.012.html . Also, I haven't found any of the characteristic "silky web" nests that the mites are supposed to make. Am I being too literal in interpreting "along the veins"? Or is this some other pest/disease?

Also, the second picture shows (probably) unrelated damage on some of the upper leaves, large brown blotchy spots. The tips I know are just leaf tip burn, but the spots are more worrying and don't match anything I can find on Google. Does anyone know what this might be?

Thank you for all your help.