A healthy tree can fight off plagues and diseases using a combination of methods. A tree can not repair damage, but isolates it from the sap stream, and then grows around it. This process is called CODIT, compartmentalization of decay in trees. A healthy tree can also use resin or latex to distribute chemicals that repel insects or pests.
Ips typographus is an unattractive looking beetle. It lays its eggs in tree bark, preferably of spruce or pine trees. The larvae dig themselves out, leaving a distinct tunnel pattern resembling an alien alphabet: hence its name, Letterzetter, Buchdrucker, Bostryche typographe, Корое́д-типо́граф.
The bark beetle in general can develop into a serious threat to conifer forests.
The Compositor Composing
Using an online image to audio converter, the image above was turned into sound. Of course, the image is not optimized for tunnel-reading. This is a test. Listen to the unfiltered audio file below: