Blue-stain-fungus
Guides
Dendroctonus rufipennis
spruce beetle, great spruce bark beetle
Dendroctonus rufipennis, the spruce beetle, is a bark beetle native to North America and a major pest of spruce forests. Adults measure 4–7 mm in length and are among the larger bark beetles in spruce. The species undergoes a facultative life cycle of 1, 2, or 3 years, with 2-year cycles being most common. Outbreaks have caused extensive tree mortality across western North America, particularly affecting Engelmann and white spruce. Climate warming and drought stress are key factors driving population increases.
Dendroctonus terebrans
Black Turpentine Beetle
Dendroctonus terebrans, the black turpentine beetle, is the largest bark beetle in the southeastern United States. It attacks pine trees near the base of the trunk and in stumps, typically targeting stressed or freshly cut trees. Unlike the more destructive southern pine beetle (D. frontalis), it rarely kills healthy trees outright but can contribute to tree mortality through sustained feeding damage and by vectoring blue-stain fungi. The species produces and responds to complex semiochemicals, including frontalin and brevicomin, which facilitate mass attack behavior and may mediate interactions with other bark beetle species.
Orthotomicus
Orthotomicus is a genus of bark beetles in the family Curculionidae, subfamily Scolytinae, containing approximately nine described species. The genus is primarily associated with coniferous trees, particularly pines (Pinus spp.) and cedars (Cedrus spp.). Several species, notably Orthotomicus erosus (Mediterranean pine engraver) and O. laricis, have become significant forest pests through native population outbreaks and invasive range expansions. Species in this genus are known for their associations with ophiostomatoid fungi, which they vector and which contribute to tree decline.