Thanks for the interesting question.

I suspect that this is a type of aphid known as a Pine Bark Adelgid (Pineus strobe). They are covered by a white woolly-looking material. This is probably what you referred to as “white dust”. It almost looks like there are snowflakes on the bark. It derives its name by its attraction to pine bark (especially that of white pine), and because it belongs to the insect family known as Adelgidae. It feeds on the sap of white pine. It is at this time of the year (late spring, 2022) when sap is actively flowing, that this aphid is often observed. As the season progresses into the summer, these aphids disappear as you have probably observed.

These aphids produce a very sweet substance known as honey dew that attracts ants and various wasps. Perhaps you have observed these latter two insects on your white pine at this time of the year?

These aphids are now mating, probably have even done so. Eggs are laid in the woolly tufts. After laying eggs, the adult aphids die. These eggs hatch into an immature form known as “crawlers”. These crawlers overwinter on the bark of your white pine. Early next spring (April 2023?), these crawlers develop into the white adults that you are now seeing. This is why they keep visiting you every spring.

For healthy, well established white pines there is generally no damage to the tree. In extreme cases, especially among young trees, detrimental stress can be placed on the tree. For this reason chemical treatments are neither recommended nor used. If you wanted do something of a cosmetic nature, a high powered spray of water could be employed to wash off the aphids. However even doing this will not guarantee that they won’t appear in the following spring, as the adults would already have produced and laid eggs. I would also suspect that over the years you may have observed varying amounts of these aphids. Their populations wax and wane with each season.

The following should give you further information on these and related points:

https://homeguides.sfgate.com/white-stuff-pine-trees-80077.html

https://pnwhandbooks.org/insect/hort/landscape/hosts-pests-landscape-plants/pine-pinus-pine-bark-adelgid - :~:text=They appear woolly and may,on the trunks of trees.

https://apps.extension.umn.edu/garden/diagnose/insect/trees-shrubs/not-obvious/pinebarkadelgid.html

https://bugguide.net/node/view/486535

https://hortnews.extension.iastate.edu/pine-bark-adelgid

Interesting insect. Thanks for bringing it to our attention.