6 Bugs That Can Harm Or Kill Trees And Plants In The Rocky Mountain Region

Rocky Mountain Region

We all know that insects are a vital part of our environment. But at the same time, it is worth noting that some of these bugs tend to cause a lot of harm to trees and plants and therefore may need to be kept under control. We list down different bugs that can harm or kill trees and plants in the Rocky Mountain region. Read on.

1. Mountain Pine Beetle

This aggressive beetle is renowned for its destructive nature, characterized by major pitch tubes on a tree’s bark. Outbreaks usually happen in mature forests. One sign of mountain pine beetle infestation is gradual fading of trees from yellow-green to red-brown. You can easily tell that a tree is a host of this beetle mainly because you will find woodpeckers digging beneath the barks for larvae. The dark-brown cylindrical insect has been cited as a cause of destruction of lodgepole pine trees in Rocky Mountain National Park since 1996.

2. Eastern Tent Caterpillar

This is a dangerous foliage attacker that has made willows, wild cherry, apple, pear, hawthorn and plum trees its preferred residence. You will find colonies living in conspicuous nests during winter from where they create unsightly silky tents. As the family grows, so does the demand for food – which then means the host tree is stripped off all its twigs. Fortunately, despite weakening trees, these cocoons hardly kill them.

3. Peachtree Borer

The Colorado State University categorizes it as the most destructive insect pest of plum, cherry and other fruit trees. This is because the borer hides under the bark of trees creating massive gouges (also affects upper roots of living trees). Its young larvae dig into the sapwood of the tree causing wounds in the bark. The harm is usually massive during warmer weather as the larvae have to feed more before reaching pupa stage.

4. Tiger Moth

This is not your ordinary moth – it has reddish brown forewings and white hindwings. It spends most of its time around pine trees producing larvae (caterpillars) whose hair causes a skin rash when it comes in contact with some people. While the moth is blamed for the bulk of harmful effects, the larvae is actually the main culprit because it feeds extensively on foliage. This can cause significant injuries if left unchecked although permanent effects are rarely reported.

5. Terminal Weevil

Every April, an army of these marauding creatures emerges creating punctures around trees as it feeds. Two months later, they hatch eggs thereby giving way to formation of larvae, which kill terminal shoots causing loss of 2 years of growth. It’s easy to tell when a tree is under terminal weevil attack as the top begins to droop in midsummer.

6. Spider Mites

Unlike their namesakes (spiders), spider mites eat plants as they are herbivores, not carnivores. They usually devour host plants by piercing and sucking out the fluids – this gradually causes browning or yellowing of leaves. Besides doing that, they create webbing that not is not only unsightly but also can damage the plant leaves. It’s even more challenging to deal with these spider mites because they tend to be fuelled by use of insecticides and fungicides which may kill other organisms that keep the mites under control.


This is by no means an exhaustive list of bugs that can cause permanent harm or even kill your trees/plants. Different weather patterns, foliage and even tree age may determine the kind of insects that attack.  If you have specific questions or notice an infestation, be sure to call your local tree service, if you are in the Denver area feel free to contact TreeRemovalDenver.net at 855-335-1596.

Quick History of the “Free Trees” Movement in Denver

If you read the term “Emerald ash borer” quickly, you might think it was a description of some beautiful place in Ireland. But upon closer look, you’ll see it doesn’t say that at all. Emerald ash borer, also known as EAB, is a pest that’s been plaguing ash trees across the United States since 2002. The larvae eat the bark of ash trees preventing them from transporting water and nutrients throughout its system. So far 25 states have been impacted.

While not yet sighted in Denver, Colorado, in 2013 it was seen in Boulder and last summer it arrived in Longmont. So these destructive beetles are getting closer. But the citizens of Denver aren’t going to wait until they come. In a proactive stance against the primary enemy of the ash tree, Denver launched a free trees program. Spearheaded by The Parks People and supported by Be A Smart Ash, the overall mission of the integrated group is to protect or replace the area’s 330,000 ash trees.

Denver Digs Trees

Denver Digs Trees LogoFounded in 1991, the Denver Digs Trees program has provided Denver with more than 49,000 free or low-cost trees. They dispense a mixture of trees to homeowners and residents in Denver. Sizes range from medium and large shade trees. Precise planting instructions are given with each tree, so it stays healthy.

The program provides excellent options for your free trees. You may ask for a street tree or a yard tree. You can even get both. But plant it according to the specifications provided.The requirements must be followed faithfully.

In 2017 all street trees were free. Free yard trees were available to applicants who may not have been able to get a tree otherwise. If finances are not problem, the cost for yard trees is $35 per tree. Fees vary depending on the neighborhood.

Be A Smart Ash

Be a Smart Ash LogoDenver Digs Trees supports a second program called Be A Smart Ash. This effort is designed to educate Denver about EAB. Right now they fear the EAB has already infiltrated, so they want to spot the parasite before it advances too far. EAB takes up to two years to reveal itself, so identifying it as early as possible helps save more trees.

Be A Smart Ash encourages residents to participate in the free tree program facilitated through Denver Digs Trees. Because it offers a variety of trees, Denver hopes to minimize the damage of the EAB through diversifying its urban canopy.

The Park People

The Park People LogoThe Park People sponsor Denver Digs Trees. The Park People is an organization created in 1969 by dedicated park enthusiasts. This non-profit has grown significantly since then.

The Blue Trees Project

This spring, The Blue Trees Project launched in The Denver Theatre District. It did not give away trees. Instead, using a biologically-safe colorant, it colored 150 trees royal blue. Konstantin Dimopoulos was the performance artist and invited the public to help him. Safe for the trees, the color will fade over time. But the bright blue currently serves as a strong reminder to Denver about the importance of trees, their city’s trees, and their free trees program.

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