British Columbia: Garry Oak getting eaten alive

Something is destroying my Garry Oak. I thought it might be mites or thrips, and I see no galls of any type. Does anyone have any idea of what this might be and a possible treatment?

Thanks for any assistance you may offer.

 

I searched up "Yellow spots on garry oak leaves" and got this:
"The damage from oak leaf phylloxera is first visible as yellow spots on the leaves..."
http://www.bing.com/search?q=yellow+spots+on+garry+oak+leaves&form=MOZSBR

"Oak leaf phylloxeran: The damage from oak leaf phylloxera is first visible as yellow spots on the leaves in May and June. This gradually progresses to complete browning and defoliation of some trees by late July. By late July or early August, heavily affected trees lose their leaves, although the trees often produce a second flush of leaves in August.

Most trees with phylloxera seem to have light infestations without damage, while a few trees are heavily attacked year after year, becoming severely weakened and eventually dying. At least 10 species of predators have been recorded feeding on the phylloxeran, but they do not appear to control it." ~ http://www.goert.ca/gardeners_restoration/garryoak_trees.php

I'd say seek out a Professional Arborist at your (and their) earliest convenience.