The white cottony material is an insect. You can control it with Horticulture Oil. You can find Horticulture Oil at any garden center, but be sure to mix it in a new sprayer unless the sprayer you have has been used for contring insect. Don't use a sprayer that has been used to control weeds. Please read all directions! Mode of action for horticulture oil , the oil smothers the insect and nothing else is harmed

Thank you for the tip. What is the name of the insect?

White pine adelgid