Insects and diseases are the two biggest threat to tree health in residential areas in the Colorado area. Once you notice any abnormalities to your trees health it’s important to begin an analysis in order to gain an understanding of what’s affecting your tree and prevent further damage.

Some of the Most Common Ailments

The Mountain Pine Beetle

(aka, the Black Hills beetle or the Rocky Mountain pine beetle)

This infestation primarily develops in pine trees such as Lodgepole, Ponderosa, Scotch and Limber. It’s less commonly found in Bristlecone and Pinon 

Pines but has been known to occur. From 1996-2013 there was a Mountain Pine Beetle epidemic that affected 3.4 million acres of Colorado pine forest land leaving a gray cast from all the dead trees that still stand erect on the eastern slope of the Sangre de Cristo Mountain Range.

Symptoms include popcorn-shaped masses of resin called “pitch-tubes” that can be found on the trunk where the beetle has tunneled into the tree. These pitch-tubes may be brown, pink, or white in color. Dust may also be found in bark crevices or on the ground near the tree base. Another sign that the Mountain Pine Beetle has infested your tree is that there will be evidence of woodpeckers feeding on beetles living in the bark. Bits of bark may be missing and flakes of bark may be found on the ground below the tree. These symptoms can be similar to the other beetle infestations so be sure to properly identify your beetle before deciding on a treatment.

Treatment methods involve pyrethroid insecticides that work as a protective chemical to trees that are particularly susceptible to Mountain Beetle infestation. Systemic, bark-penetrating pesticides can be used to treat trees that have been infested. Tree mortality will probably be the end result of a Mountain Beetle infestation.

The Ips Beetle (aka the engraver beetle)

The Ips Beetle is a bark beetle the delves under tree bark and tunnels through the tree bringing death to many pine and spruce trees in the Colorado area. The beetle enjoys freshly cut wood for breeding so avoid leaving freshly cut wood near the base of healthy trees. They are 1/8th to 3/8th inches long and are a reddish brown to black color. They are similar in appearance and character to the Mountain Pine Beetle but not treated in the same way so its important to properly identify the species as to apply effective treatment.

Like the Mountain Pine Been, the Ips Beetle enters into the tree and tunnels, producing a yellow or reddish dust that accumulates in the bark and crevices around the base of the tree. The presence of woodpeckers is often an indication of infestation.

To prevent Ips Beetle infestation its important to maintain the health of your tree with adequate water and pruning methods. Remove downed wood from your yard. Avoid placing infested wood near healthy trees. If necessary infesticide can be used to prevent infestation but usually is harmful to a trees mortality.


Dwarf Mistletoe

Dwarf Mistletoe is a type of parasite that can cause severe damage to native coniferous and pine 

The amazing

trees and are a common problem in Colorado forests. It mostly affects Ponderosa and Lodgepole pines, but can affect Douglas-fir, Pinon, Limber and Bristledone. Infection can slow growth and limit seed production and wood quality. Heavy infection can kill trees. Dwarf Mistletoe can be identified by abnormal tree growth known as a “witches’ broom” characterized by a swelling of the branch. This disrupts the normal branching pattern of the tree and thus negatively affect the trees health.

Pruning is the best treatment for trees infected with Dwarf Mistletoe which can easily be done with a quick call to Colorado Tree Services.

Various Aspen Ailments


These insects occur on most trees and shrubs and are a healthy part of the ecosystem. They become a problem when they are not controlled by natural predators and can sometimes cause leaf curl on ash, plum, and honey sickle.   

Marssonina Blight

This fungus causes the most common disease on aspen foliage. Although there is leaf discoloration, this condition is usually not damaging though heavy infestation can cause early leaf drop.


Western Tent Caterpillar

These little guys have been known to swarm entire forest destroying everything in their hungry hungry path. When found seek immediate help from professionals

Oystershell Scale

Common throughout Colorado this destructive pest suck the sap out of trees and will eventually kill the tree if not treated.

Western Spruce Budworm

In Colorado the Western Spruce Budworm can affect many different douglass fur, white fur, and spruce trees. These insects create ideal conditions for other pesky bugs and fugues by creating a less than healthy tree. Trees that have been infested can be identified by dead leaves and branches or just general decline in health. Chemical treatment options exist.