By Jesse Lee
What does it look like?
Conifer bark beetles consist of a large group of insects that feed on the inner bark of spruce, fir, pine and other conifers. Some of the most devastating members of the conifer bark beetle family include the Mountain Pine Beetle, Southern Pine Beetle, Pine-Engraver Beetle and Spruce Beetle.
These beetles are tiny, usually less than 1/6 inch long, and are brown or black in color.
Host material and range
Bark beetles generally attack weakened or dying trees, as healthy conifers can usually withstand infestation. The beetles will attack all parts of the tree but do the most damage when attacking the trunk.
The beetles are not limited by geography, and attack trees throughout the United States. Once a tree is under attack, the beetles will release an aggregation pheromone to attract more beetles to the infested tree.
Bark beetles kill by chewing into the bark and boring into the phloem layer, where they feed and reproduce. Trees under attack will show signs of sawdust from boring beetles, and will begin to waste or fade, with needles turning from healthy green to yellow.
Because these beetles leave a wake of dead trees in their path, there is not only immediate danger to individual trees and to forests, but also secondary danger in providing fuel to wildfires like those devastating California.
With the proximity of homes to forested areas, the dead trees are becoming a threat to the property and lives of people living in these areas.
Prevention and treatment tips
Healthy trees can often stave off the attack of conifer bark beetles, and trees should be treated with proper nutrition and fertilization treatments to ensure health and vigor.
Traditional treatment for beetle infestation includes whole-trunk sprays. However, these treatments are expensive, are prone to drift and exposure, and can be tough to administer due to the height and size of the trees.
Tree injection chemistry is a less risky alternative that can provide multi-season protection for high-value trees.
What can you do?
Ensure that trees are maintained through proper health and nutrition treatments, including fertilizer treatments. Infested trees should be treated with an insecticide treatment as soon as infestation is discovered.
Jesse Lee is with Epic Creative, Wis. Article provided by Mauget, a leader in micro-injection and micro-infusion tree care. Contact Mauget or visit www.Mauget.com to learn more about different species of conifer bark beetles, steps taken to prevent and control them, and proper treatment application and use.