On closer examination I saw these:
|These growths are galls. Masses of plant tissue that grow over nesting insects. I wasn't sure if it was an aphid or mite which caused this. Turns out it's an aphid.|
|Unfortunately, this tree has other issues - some dying branches and peeling bark. The leaves show a bit of stress with perhaps a form of rust. These galls won't kill off the tree, but certainly don't help matters.|
There you'll find the contents inside the gall and the aphid's life cycle. Well done, MAF&RI!