The other day I noticed these small (~1/4" dia.) swellings on some of the 1yr apple trees in my nursery. I did not see any on nearby pear or prunus trees. I cut one of the swellings through and it has a small black spot inside, I assume dead tissue. Some of the swellings had a scabby spot or crack in the middle. I live in central southern Ontario. Any help in identifying this appreciated!
Need a better closeup photo without the snow causing underexposure. Put a piece of cardboard or something behind the tree trunk to block the view of the snow. It looks like it might be scale insects or perhaps just normal swelling of the buds before they open.
Here are some more pictures, I hope they are more clear. Click on them to enlarge. The raised areas are part of the bark and wood of the tree. They often occur close to a bud but not always.
