Hi my sister has had this beautiful pine tree (A Bristol Cone Pine?.... ) for about 10 years. We just noticed yellowing needles. When I touch them they, not surprisingly, fall off. After closer examination I see this white goop on some needles and cones. It isn't all over the tree but I do believe it is a problem that needs to be addressed ASAP. I have attached a few photos.

Any advice is very much appreciated. Thank you!