Apple tree leaf bumps
Every year my one apple tree (variety unknown) has red and green bumps on the leaves. They show up as the leaves start to bud. My research on the internet seems to indicate it may be some kind of gall mite but I am not sure. They also say it doesn't hurt the tree but my tree is usually weakens so much the tree doesn't produce fruit and the tree looks real bad by the end of the season. I live in the Lakeview area in Carson City, Nevada. Any ideas what it is and how to control it. They say dromant spray may be the only help in the winter which I have not tried but I will try next winter. Thanks for any help!
I suggest reading this extension publication and following the recommendations for chemical, biological, and cultural management: https://extension.usu.edu/files/publications/factsheet/eriophyid-mites2010.pdf. One specific recommendation might be to try predatory mites: Naturally occurring predatory mites often feed on Eriophyid mites and can keep populations at tolerable levels. Avoid the use of broad-spectrum insecticides to preserve predatory mites. Low or extinct populations of predatory mites my be supplemented with predatory mites available for order. One good option for hot arid regions is Galendromus occidentalis (western predatory mite).