Ips beetles, sometimes known as “engraver beetles,” are bark beetles that develop under the bark and tunnel through the tree, damaging and killing pine and spruce trees.
Two factors that contribute to ips beetle problems in Colorado include prolonged drought stress and the creation of freshly cut wood (preferred breeding site). Ips beetles are 1/8 to 3/8-inch long and are reddish brown to black. They are similar in appearance to the mountain pine beetle, and it is important to correctly identify the species in order to prescribe an effective management strategy.
Symptoms of Infestation
Mature ips beetles enter trees and tunnel, producing a yellowish- or reddish-brown boring dust. The dust accumulates in bark crevices or around the base of the tree, and the affected parts of the tree discolor and die. Small round holes in the bark of infested trees indicate the beetles have completed development in that part of the tree and have exited. The presence of woodpeckers, a common predator of the ips beetle, may indicate infestation. These symptoms are similar to mountain pine beetle, so be sure to properly identify the beetles you find associated with your tree.
Logs infested with MPB larvae can be treated in various ways to kill developing beetles before they emerge as adults in summer. For example:
- To prevent attacks, use practices that promote vigorous tree growth. Maintain health and ensure adequate water supply.
- Remove all freshly cut materials that result from pruning or thinning trees, as these attract ips beetles.
- Do not stack infested wood next to living trees.
- Insecticides can be used to prevent infestations, but must be applied prior to an attack. (Always carefully read and follow all label instructions before applying insecticides.)