Q.pest prevention on apple trees
Did not know when or with what (preferably organic) I could spray on my apple trees to prevent pest problems this spring. My first year to have apples on my trees and I am losing most of them to insects eating holes in them (as well as birds) or stinging them making them start to rot. Do not see any bugs on them. What can I spray on them while they are dormant and when should this be done? Have a Gala, Honeycrisp and Pixie Crunch.

These articles and links will help you with a schedule of treatment against pests and disease.
http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-3084/EPP-7319web15.pdf
https://www.gardeningknowhow.com/edible/fruits/apples/apple-tree-diseases.htm
https://www.gardeningknowhow.com/edible/fruits/fegen/fruit-tree-spraying.htm