Green bumps on a brand new river birch
We just planted this river birch a few weeks ago and these green bumps popped up all over the leaves out of nowhere. We were gone for 10 days - there were none when we left and it’s covered now. Google leads me to believe it might be aphids? On a tree this young, is there something we can or should do to protect it?
District of Columbia County District of Columbia
This looks like a type of leaf gall caused possibly by an eriophyid mite. The gall (abnormal plant growth) is caused by egg laying or feeding of the mite.
There are many types of galls caused by insects, mites, nematodes, fungi, bacteria and viruses.
Insect galls rarely affect plant health and their numbers vary from season to season.
You do not need to control them. Here is more on galls https://extension.umd.edu/hgic/topics/shade-tree-galls