Mountain Pine Beetle Update
Map of 2008 “Beetle Busters” Inspection Results Shows 502 Mountain Pine Beetle Infested Trees Locally
The volunteer “Beetle Busters” corps, administered by the Town of Estes Park Public Works Department, completed 183 inspections for pine beetle infestation in the Estes Valley and found 502 infestations in the area in 2008. The results of these inspections have been compiled into this map, created by the Town of Estes Park GIS department in January of this year.
The map indicates the heaviest infestations were in the Little Valley area and near the end of McGraw Ranch Road; however, significant beetle activity has been found throughout the valley. This map only includes the results of the volunteer inspection program, available free of charge to Estes Valley residents.
The current Mountain Pine Beetle (MPB) infestation in the Rocky Mountains is unprecedented for Colorado, according to the Colorado State Forest Service (CFSF). The CSFS predicts the majority of Colorado’s mature lodgepole forests will succumb to the beetle infestation by 2013 (source, csfs.colostate.edu/pdfs/MPB_AllForestSpecies.pdf). According to the “Beetle Buster” inspections, MPB infestation has also been found in ponderosa pine in the Estes Valley.
At the recent Tree Symposium, held by the Estes Park Tree Board on May 6 at the Estes Park Conference Center, various tree experts and governmental agencies weighed in on their opinions and experience with the beetle infestation. It is uncertain whether the current Western Slope lodgepole pine epidemic poses the same threat to Estes Valley ponderosa pines. “Historically, the epidemic MPB ‘jump’ from lodgepole to ponderosa pine is not automatic. Sometimes it happens, sometimes is does not,” said Dave Leatherman, Forest Entomologist. The current infestation is unprecedented so it is difficult to predict what might happen to the Estes-area ponderosa forests.
Attacked trees usually turn color in late spring, 9-10 months after having been attacked the previous summer, Leatherman said – the only time a red tree is likely to still harbor beetles is in June, July and early August. Otherwise, red trees are usually OK to cut and transport to new locations, he added. MPB infestation starts with females boring into the trunk of a mature tree (generally, those trees under 8 inches in diameter are spared) then attracting mates and hundreds of other pine beetles. After they lay their eggs – approximately 100 eggs per female – the parental generation dies and the larvae develop under the tree’s bark, feeding on the tree’s phloem. When this next generation is fully developed – a year after their parents attacked – the beetles fly to neighboring trees. Normally they only fly a mile or less, but under exceptional weather conditions beetles can blow up to 60 miles away in a day. Once they find suitable new green trees, the process begins again. The beetles carry “bluestain fungi” which provide food for the beetles and aid in the tree-killing process, Leatherman said.
Various opinions on how to protect trees that have not yet been “hit” were also presented at the Tree Symposium. Generally, an integrated pest-management approach is considered to be the most effective which includes removing and effectively disposing of “green hit trees” – those tree infested with beetles, but showing no visible signs – which are a threat to other trees once they emerge. Then, having a licensed pesticide contractor preventively spray green, un-attacked, high-value trees (be sure to stay away from water sources), and applying natural repellents such as Verbenone on green, un-attacked tree areas. Verbenone is a pheromone that tells beetles the tree is “used up” and they should move on to another tree. Thinning stands, removing and treating infested trees, and preventive spraying are the standard techniques. Of the newer alternatives, Leatherman said verbenone packs (nailed directly to the tree before the beetle fly) show the most promise but users should not expect quite the same level of protection as standard spraying. Leatherman suggests at times when there is a local beetle threat, a reasonable approach might be preventively spraying 5-10 high-value trees near a home, and using verbenone in the zone immediately surrounding this. At times when the local beetle population is low (that is, between epidemics), thinning to improve the vigor and growth of the forest is the preferred activity, he said.
Generally, the beetles “fly” in mid July-August, said Leatherman, although dry and warm weather may affect this cycle.
In May of 2008, the Town of Estes Park adopted an ordinance requiring Town residents to remove any beetle-infested trees on their property. This ordinance is similar to county and state regulations in place and can be enforced simultaneously. If the Town ordinance is violated, the beetle-infested trees can be removed by the Town and a lien for 200 percent of the cost of the removal can be levied against the property. In addition, municipal court may assess a daily fine of up to $300 from the day of the court order to remove the tree through the day it is actually removed. (source, Town of Estes Park Police Department, Code Enforcement)
The Town of Estes Park’s volunteer “Beetle Busters” will inspect Estes Valley properties and give you advice on how to protect your trees. The Town also has a free beetle-killed tree disposal site, the air curtain burner at 666 Elm Road (look for the yellow gate, open between 8 a.m. and 4 p.m. weekdays). The trees must be prepared by cutting off all limbs and cut into sections of either 8-foot, 6-inch – OR, 2-foot or shorter sections. The burner site will not accept tree branches or other slash.
For more information on the Town of Estes Park’s free beetle inspection program and air curtain burner site, please contact the Public Works Department at 577-3588. To view Dave Leatherman’s presentations given at the Tree Symposium, and the “Beetle Busters” map, visit: www.estesnet.com/publicworks/Parks/TreeBoardPage.aspx.