The red turpentine beetle (Dendroctonus valens) is a species of bark beetle native to the forests of North America. The insect is named for its reddish-brown color and for its love of trees in the genus Pinus, which includes the lodgepole pine, ponderosa pine, sugar pine, and whitebark pine. This species is one of the most destructive forest pests in North America.
The adult red turpentine beetle ranges in size from 3 to 5 mm (0.12 to 0.20 in). It is reddish brown in color with dark mottling on its wing covers. The larvae are cream-colored grubs with black heads and legs. They range in size from 6 to 8 mm (0.24 to 0.31 in).
Both adults and larvae feed on the inner bark of pines, boring into the sapwood and heartwood as they go. This feeding causes extensive damage to trees, disrupting the flow of water and nutrients and ultimately killing the tree. Red turpentine beetles often attack weakened or stressed trees first, but healthy trees are not immune to infestation.
The red turpentine beetle has two generations per year; adults overwinter in sheltered locations such as under loose bark or inside cracks in tree trunks before emerging in spring to mate and lay eggs. Females lay an average of 60 eggs per clutch, though this number can vary depending on temperature and food availability . Larvae hatch after about two weeks and begin feeding immediately upon emergence . After completing several molts , they pupate within chambers excavated within the host tree . Adults emerge from these pupal chambers approximately six weeks later .
Red Turpentine Beetle populations can explode rapidly when conditions are favorable for reproduction , leading to significant mortality rates among susceptible trees . In some cases , entire stands have been killed by this pest . Forest management practices that promote tree health such as thinning , pruning , prescribed burning , and removal of dead or dying trees can help reduce losses due to red turpentine beetle activity .