What are the “beetle” and the “blue” in: Beetle kill blue pine?

Sham S. Misri

When the mountain pine beetle attacks a pine tree it’s got an assistant, an accomplice in the blue stain fungus travelling with the beetle inside what silviculturists call “ a special structure in the beetle’s mouthparts.”

That’s how the fungus gets from tree to tree. What does the fungus do for the beetle in this classic example of symbiosis?

When a pine tree is attacked it produces a protective resin. The fungus works to stop that, allowing the beetle to wreak havoc and lay eggs. The fungus also serves the beetle by creating resin free environment for eggs and larvae. If that is not enough, adults and larvae use the fungus as a food source.

Source: Forest Business Network.