On my property I have 5-6 white spruce trees that are infected with eastern spruce gall, and 9-10 spruce trees that are not infected. These spruce trees are 15-20 years old. One tree seems to be infected much worse than the others, but is more than 50 feet away from any other spruce tree. Some of the trees that are infected are near others that are not. I understand that it is primarily an aesthetic issue, but is there anything I can do to prevent this from spreading to other trees or to prevent further infestations? If there is a different form I should use for this question, please let me know. Thank you for your help!