Native to the western United States.
This is a common beetle in dead hardwood trees, and commonly occurs in homes when infested firewood is brought into the house in the fall. The warming of the wood signals springtime to the beetles in the wood, and they may emerge in large numbers. They do not infest structural wood members once they appear. There is one generation each year, and the pupa stage over-winters. It is not a pest species.
The adult beetle is about ¾ of an inch long, and is dark gray with two wavy white lines across each elytron. The prothorax is narrow in front and much wider at the back, and the elytra are much wider at the anterior than the posterior. It has long legs and long antennae, and looks much like a large, black spider as it runs across the floor. Adults are attracted to light once they emerge from the wood.
Evidence of their origin will be emergence holes in the firewood, typically the round holes of this family and about ¼ inch in diameter.
Characteristicts Important to Control:
Since these beetles are present in structures almost exclusively in firewood, prevention lies with not bringing the firewood into the structure until it is ready to be burned, or removing it to the outside if beetle emergence begins.