This is a JR Gentlemen pen I made today that I am calling "Worm Tracks". The wood is Curly Maple that worm(s) got into and added a little beauty to it. Note the dark spot on both sides of the upper barrel...this is the worm hole.
I have often head this referred to as Ambrosia maple because the Ambrosia Beetle lays the eggs that hatch into the worms that make the tracks. It gives a really outstanding patterns in bowls and other larger turnings, as well as in pens. Nice job!