Cheyenne Department of Urban Forestry, caring for trees in Cheyenne, Wyoming
F o r    M a p    C l i c k    H e r e

Urban Forestry is a Division of the City of Cheyenne Parks & Recreation Department
Contact Us:
Address: 520 W. 8th Ave.
Cheyenne WY 82001
Phone: 307.637.6428
Office Hours:
Monday - Thursday: 6:30 A.M. - 3:30 P.M.
Friday: 6:30 A.M.- 12:00 noon
Saturday & Sunday: Closed

Mountain Pine Beetle

The Mountain Pine Beetle in our Community - Brochure

1.  ALL species, ages, and sizes of healthy pine tree trunks should be sprayed, from the ground to the top of the tree, with an insecticide labeled for Mountain Pine Beetle (MPB) before June 1st each year.  Spray spruce tree trunks also.

2.  All trees infested with MPB and other bark beetles should be removed and properly disposed of before June 1st each      year.
     a. Assistance is available for removing bark beetle infested trees for lower income, owner occupied, property owners          in the City of Cheyenne. Call the Cheyenne Urban Forestry office at 637-6428 for more information.

3.  Properly dispose of infested wood at the Cheyenne Compost Facility - 3714 Windmill Road.

4.  Do not bring firewood from the mountain forests into Cheyenne until October.  Burn all firewood before April each year.

Mountain Pine Beetle Information from Colorado State Forest Service

Colorado State Forest Service Summary of Products for Use Against Mountain Pine Beetle

Wyoming Certified Pesticide Applicators - Licensed in Cheyenne

Arborists Licensed for Tree Removal and Pruning in Cheyenne

Ten Points on Bark Beetle Management

Detailed Information on Mountain Pine Beetle and Ips Bark Beetle

    All Photos: Cheyenne Urban Forestry

Popcorn like globs of sap or pitch oozing out of entrance holes made by
Mountain Pine Beetle (MPB) in Scotch Pine.

Ponderosa pine showing numerous "hits" by MPB, with sap or pitch oozing out. Not all attacked trees will show pitch or sap around the entrance hole. Sometimes the most visible evidence of MPB attack will be boring dust (looks like saw dust) at the base of trees.  

      Sap oozing out of entrance holes made by MPB.  Open holes in the trunk and wood boring dust mixed with sap may indicate a successful attack.

            Mountain Pine Beetle constructing the new home.

 Woodpecker activity in a tree is a good indicator of the presence of bark beetles.

Even the "bugs" have "bugs". Mites on the back of a Mountain Pine Beetle.

Ten Points about Mountain Pine Beetle Management:

1. Keep your pines healthy.  Water trees year-round, especially evergreens.  Do not cut the tree roots.  Reduce or eliminate the use of weed killers near the tree.  Do not compact the soil around the tree.  Mulch the soil under the tree crown with coarse organic mulch, such as dry wood chips or bark chips. ODC (Organic Disease Control) Colloidal Chitosan can be used to enhance plant vigor.  Avoid pruning pines.  If pruning is required, remove dead, weak and broken limbs in late fall.  Do not prune conifers February through September.

2. All pine trees over 1 inch in trunk diameter are susceptible to attack by bark beetles including Mountain Pine Beetle. The beetles will attack all species and sizes of pine trunks.

3. By June 1st, have the trunks of all your pines greater than 1 inch in diameter, sprayed with an insecticide labeled for killing or repelling mountain pine beetle and other bark beetles (primarily, insecticides with these active ingredients Permethrin, Carbaryl, Bifenthrin and specifically labeled for mountain pine beetle). Spray only green, healthy, pines that have not been attacked by Mountain Pine Beetle.

4. Remove Mountain Pine Beetle and other bark beetle infested pine and spruce trees no later than June 1st each year. Take infested pine trunks and limbs to the City of Cheyenne Compost Facility at 3714 Windmill Road. Limbs and trunks must be cut into lengths of 6 feet long or less with a trunk or limb wood diameter of 12 inches.

5. Removal and Disposal of infested trees: Tree maintenance companies can chip smaller diameter trunk sections and limbs. Trunks too large to chip must either have the bark stripped off or burned by June 1st.

6. Spraying the trunks of already infested pine trees is not an effective method of killing emerging beetles. Standing pine trees that are successfully attacked, but still have green or fading green to yellow needles on the branches, will have many beetles emerge in June through September attacking the same pine or other nearby pines.

7. Mountain pine beetle and other bark beetles can carry blue stain fungus, which assists bark beetles in successfully attacking a pine or spruce tree by possibly clogging the water transport cells in the tree, and possibly providing food or nutrients for the beetle and/or larvae.

8. Do not bring into the Cheyenne area any firewood or store firewood from beetle killed forest trees or local trees during the growing season, April - October.

9. Burn all firewood from beetle killed trees before April each year.

10. Any left over firewood should have the bark removed by June 1st.  Destroy bark containing mountain pine beetle life stages.

Detailed Information on Mountain Pine Beetle:

Mountain pine beetle (MPB) attacks Scotch or Scots pine, Lodgepole pine, Ponderosa pine, Limber pine, pinyon, bristlecone, and Austrian pine.  A Norway spruce found in Cheyenne, late summer 2007, had been heavily attacked by a bark beetle. Several spruce trees succumbed to bark beetle attack in 2010. Initially trees are attacked by MPB and Ips bark beetle that are under stress from drought, root or trunk damage, soil compaction, or herbicide damage.  Healthier trees are being attacked as the insect population increases in the Cheyenne area. 

Keep your coniferous evergreen trees healthy, water them year-round.

Life Cycle:

Adult beetles emerge from attacked trees in mid-June through early-October.  Mid-August on average seems to be the peak emergence time for beetles in Cheyenne.  The adults fly to green pine trees and chew a hole into the bark. Sometimes the sap oozing out of the tree "pitches-out" the beetle.  Trees under drought stress or in poor health may not ooze sap. If the bark beetle attack is successful, a beetle pair mates and the female chews a vertical tunnel under the bark where up to 75 eggs are laid.  The eggs hatch and the larvae feed horizontally away from the vertical egg gallery.  The feeding of hundreds if not thousands of larvae will girdle the tree, cutting off the flow of food and water throughout the tree trunk.  MPB adults typically carry spores of blue stain fungus on their bodies.  The blue stain fungus helps weaken the tree by growing in tree cells that function in water transport.  Blue stain fungus may also provide food or nutrients to the beetles and/or their larvae.  The growth of the fungus aids a successful beetle attack by possibly slowing or stopping the sap flow in the tree.  Heavily attacked pines will not be visibly dead immediately.  A dying tree can have a green or a fading green color for up to 8 to 12 months after a MPB attack. MPB spends the winter protected under the bark in larvae stage and sometimes in adult stage.  In the spring the larvae begin to feed again.  The larvae enter pupae stage in June and July.  Adult beetles emerge from the pupae stage and chew their way out of the tree and fly to green pines.  Several adult beetles may use the same exit hole.  In Cheyenne, Mountain Pine Beetles seem to have one generation per year.  

Water your evergreen trees year-round to help keep them healthy.


Hire a commercial pesticide applicator to spray all living pines and spruces not attacked by MPB by June 1st with carbaryl (Sevin SL or XLR ®, and others), permethrin (Astro®, Dragnet®, and others), or bifenthrin (Onyx®, and others). The formulation of the pesticide used needs to be specifically labeled for Mountain Pine Beetle control. Thoroughly coat the tree trunk top to bottom and around the entire circumference with the insecticide spray to the point of runoff.  Some insecticides labeled for Mountain Pine Beetle are restricted use and must be applied by a professional spray applicator licensed by the State of Wyoming.  A spray application by June 1st should provide protection for one adult flight period or one growing season. Permethrin insecticides may require a second application of spray in mid to late July.   Read the entire insecticide label and follow the directions closely before using any pesticide.

 Water evergreen trees year-round to help keep them healthy

Dispose of Infested Wood:

Take beetle infested tree trunks and limbs to the City of Cheyenne Compost Facility at 3714 Windmill Road to be chipped, destroying the beetle habitat and most of the beetle larvae in the process.  Limbs and trunks must be cut into lengths of 6 feet long or less with a trunk or limb wood diameter of 12 inches.

Storing or Transporting Firewood:

Ideally, pine and spruce tree trunks destined to be firewood should have stood in place in the forest for at least one year after the needles have fallen off of the tree (two years after bark beetle attack), or be well seasoned or dry.  Otherwise, it should be assumed that any pine tree or spruce wood has a possible life stage of MPB or other bark beetle under the bark. Pine and spruce trunks with the bark peeled off can be stored as firewood without being covered.  Transporting firewood during the adult beetle flight period, mid-June through early October, could spread the beetle from the mountain forest to your yard.

To help keep evergreen trees healthy, water them year-round.

Take all necessary precautions from spraying your pine tree trunks to carefully selecting and storing your firewood, or next year's firewood may come from your own yard.

Information adapted from Cheyenne Urban Forestry experience and from articles by: Colorado State University Extension


Colorado State University Extension

USDA Forest Service

Questions? E-Mail Forestry Division
If possible, take a couple of digital photos of your tree or shrub and include them with your questions. One photo should be a close up of the problem area. The second photo should be of the entire tree if possible.




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