If they are aphids - need photo to confirm - don't panic! White pine aphids seldom do any permanent damage and I seriously doubt aphids were the cause of the death of your previous pines. There are other issues which can be much more serious to the health of these trees but it is only speculation at this point exactly what caused the problem....unreasonable to blame the aphids however. While ants do hang out with - an even 'farm' - aphids for their sweet honeydew, they are also attracted to the sweetish sap or resin the pines can emit for any number of reasons, some, like pine borers - quite serious. Try hosing off - usually a strong stream of water will dislodge/remove the bulk of the problem. If stronger stuff needed, try a horticultural oil. and fwiw, your other conifers are safe. White pine aphids feed only on white pines. No probs with the leylands or green giants.

arent they actually dark green with a black head?? anyway .. any lightweight house plant hand spray will work .. just a little spritz ... but.. in reality .. they eat last years needles... which would be falling off anyway [sooner or later] .. and frankly .. though they change the appearance of the plant.. they have no real long term effect on the plant.. as the new flush.. which is extending right now.. will take care of the plant.. and hide the damage ... this is NOT something that you need to go nuclear on .... as they will be turning into sawfly very soon.. and will be gone... this year.. they are in plague proportions in SE MI... near me... though i can hand spray the small plants in my collection.. there really isnt anything i can do about the 25 to 40 foot pine trees all around the yard ... ken

Guess you effectively snapped it up out from its (going) dormancy, GOOD JOB! George (NJ).

I have a wonderful contorted pine in my front garden. One of the unique things I found is it's needles brown & drop off twice a year - not all, just some of them. In the early spring & then again in the fall. It isn't dead - this is just a natural trait for this specific evergreen. It's a conversation piece in my community - most people here have never seen them before. We love it! We keep the needles raked up because they have a tendency to change the PH of your garden soil for other flowers, etc. We too thought it was dying but it is more beautiful when the brown disappears. Take heart & enjoy it! Regards, Pat