Sixtoothed spruce bark beetle (Pityogenes chalcographus) is an insect pest. It is a native of Europe and Asia and was first detected in Maryland in 2007.
Norway spruce is the preferred host but fir, Douglas-fir, pine and other spruce species are also be attacked. This beetle prefers the thin bark of branches and trunk of young trees and concentrates on stressed trees, causing death by destruction of sap conducting tissues.
This is just one of many forest pests that are moved to un-infested forests by humans moving firewood. Help protect our forests: don't move firewood!