Crab apple tree has series of small holes in trunk.
This is not an insect creating these holes but a sapsucker.
The feeding holes are fairly shallow and some trees can sustain a fair amount of damage and be just fine. When the damage is extensive to the trunk, though, a tree may be weakened and become more sensitive to other problems, such as disease, pest insects, or drought. https://extension.umd.edu/hgic/woodpeckers-and-sapsuckers