Ips Engraver Beetles Prevention
The Colorado Blue Spruce, Pica pungens, is a large tree found in yards and parks across the Denver metro area. They grow tall into a pyramid shape with stiff, horizontal branches forming a dense canopy. Some trees grow up to 100 feet tall. According to the Denver Post, Ips Engraver beetles, are now a problem in Denver. The Denver Parks and Recreation Department identified 74 trees invaded by this beetle, and they believe drought caused this outbreak. The City is removing many of these trees. Homeowners need to remember that the affected trees are not treatable. The cost to remove a large tree is high, so the best option is to protect healthy Spruces now.
Ips Beetle Lifecycle
Ips beetles are small (1/8 to 3/8 inch long), reddish-brown to black beetles. The cavity at the rear end, lined with pairs of tooth-like spines, distinguishes them from other Evergreen beetles. Look for small round holes in the bark of infested trees. These holes show the beetles are moving to another section of the same tree or spreading to adjacent trees in the yard or neighborhood.
Adults overwinter under the bark and emerge in the Spring and look for trees in stress to invade. The males enter a tree and dig a cavity. They use pheromones to attract females to breed. The female beetles excavate galleries forming “Y” or “H”- shaped patterns to lay their eggs. Once the eggs hatch, the small grubs start to tunnel into the tree, looking for food. These tunnels girdle the tree causing dieback and eventually death.
Signs of IPS Beetle Infestation
Ips beetles work fast, so homeowners need to watch for the following signs of infestation. When the larva tunnel affected parts of the tree discolor or fade. Look for reddish boring dust in crevices or at the base of the tree. Below is a list of common Ips symptoms:
- Needle Color Change – At first, needles turn a light shade of yellow. As the Ips spread, the needles turn red and then brown.
- Pitch Tubes – Pitch tubes form as the tree tries to flush out the beetles with resin. Pitch tubes look like popcorn stuck on the side of the tree.
- Woodpeckers – Woodpeckers love to eat Ips beetles and their grubs. The birds remove bark to gain access to the insect and their larvae.
Ips Beetle Management Options
Healthy trees resist most insects commonly found in Denver, including the Ips beetle. (For a list of common tree pests found in Denver, check out the Ross Tree Tree Insect Calendar.) There are three things to keep in mind to promote vigorous tree growth – sunlight, water, and fertilizer. First, make sure high-value trees get good sunlight by thinning out unwanted trees and trimming other trees to open the yard to more sunlight. Make sure the trees obtain adequate water in the summer and winter, especially during droughts. Consider hiring a professional tree service company to water large trees during dry winters. Tree companies possess the equipment needed to water large trees. They also understand how to fertilize established Spruce trees. Below are other important tree management tips:
- Avoid any root damage during any construction or landscaping project.
- Remove or chip any freshly-cut branches, since Ips beetles and larvae do not survive chipping.
- Spread out pruning slash rather than piling it.
- Do not stack firewood near Spruce trees.
Treatment Options
Trees at risk of Ips attack include newly transplanted trees, trees suffering root injuries, and trees surrounded by large breeding populations of Ips beetles. Homeowners with high-value Spruce should get them treated because these insects work fast. Treatment is complicated because:
- The size and density of mature Blue Spruces make treatment difficult.
- Ips merge multiple times each Spring because of overlapping mating cycles.
- Insecticide product concentrations vary based on application.
- There are eleven Ips species found in Colorado. Each species has unique feeding and breeding patterns, which complicates treatment.
- No treatments are available once a tree is infected.
For these reasons, we recommend hiring a professional tree service company, like Ross Tree, for tree maintenance and Evergreen beetle remedies. Ross Tree has three Qualified Supervisors (QS) licensed by the Colorado Department of Agriculture to handle tree pesticide products and is highly qualified to treat trees for Ips beetles. To request an appointment, click here to fill out a request service form or call 303-871-9121.