Mountain pine beetle
The mountain pine beetle (Dendroctonus ponderosae) is a small bark beetle native to the forests of western North America. Adults lay eggs beneath the bark and introduce a blue stain fungus to prevent the tree from defending itself with pitch flow. An infestation of beetles will overwhelm a tree, eventually girdling and killing it. Forests badly affected by mountain pine beetle can be spotted overhead by large groupings of dead, rust-colored trees.
Though the mountain pine beetle has not yet reached Minnesota, its severity poses a major threat to the state’s rich pine forests. MITPPC researchers are currently assessing the risk of mountain pine beetle invasion and determining overall susceptibility of local pines.