Elderica/Afgan Pines problem
 

I have 4 Elderica or Afgan pines that I planted 4 years ago. They have done
great up until now. I just noticed
that on all 4 trees there are little gooey, gritty white
balls attached to the trunks. Mainly near the base of the tree and the in
joints where limbs are growing out from
the tree. I pulled the ones off that I could reach. One of the white balls
was nearly as big as a golf ball and it
had a small worm in it. I have a Japanese Black Pine
growing right next to the Elderica pines and it is untouched. Maybe this is
an Elderica Pine problem?
If you have any advice, I would appreciate your
help. Thanks