U.P. Michigan white pine issue
This could be several different things. It is most likely one of our tiny insects with piercing sucking mouthparts (e.g. aphids, adelgids, scale insects). One that we have been seeing a lot of, at least in the lower peninsula is called the pine bark adelgid. Here is an article about it: https://www.canr.msu.edu/news/pine_bark_adelgid_becoming_active_in_white_pines
If you think this matches what you are seeing, then they can probably just let nature run its course. This insect does not usually cause serious problems for white pine. A dormant oil spray in the late winter or early spring can help knock them back if it is deemed necessary. Insecticidal soap in the spring is another option. These treatments would also be somewhat effective against the other tiny piercing-sucking insects that I mentioned. Otherwise, simply ensuring that the tree has adequate water and fertilization (but not too much of either), should be all that is needed. If they do choose to use the oil or insecticidal soap, please remind them to read and follow the label directions to protect the tree and other non-target organisms.