infestation

EAB in Colorado, threatening ash trees

Emerald Ash Borer Detected in Superior, Colo.

SUPERIOR, Colo. – State officials have confirmed the presence of emerald ash borer (EAB), an invasive, highly destructive tree pest, in the Town of Superior in southeast Boulder County. This new detection is still just within a quarantine area established to try and prevent the human-assisted spread of EAB. However, it represents the fifth community with confirmation of EAB in Colorado outside the City of Boulder, where the pest was first detected in 2013.

An estimated 15 percent or more of all urban and community trees in Colorado are ash species susceptible to being killed by EAB – and a majority of these trees are on private land. There are 1.45 million ash trees in Metro Denver, and in the City and County of Denver specifically, one in six trees trees is an ash.

EAB attacks and kills both stressed and healthy ash trees and is so aggressive that trees typically die within two to four years after becoming infested. Additionally, it may be years before an ash tree shows signs of infestation, and by then it may be too late to save. That’s why the Denver City Forester is recommending the preemptive treatment of ash trees in the metro area.

The pest was confirmed in Boulder this week, shortly after Boulder County foresters identified a dead adult EAB on a trap the county had set – along with a dozen others in targeted areas – to detect for early infestation of the pest. This particular trap was located on public property along the Mayhoffer Singletree Trail, near the intersection of West Thomas and Third Avenue in Superior.

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All Eyes On Me: Emerald Ash Borer Emergence

DENVER — It is already June, which means we are at the start of Emerald Ash Borer (EAB) emergence season! Although EAB has not yet been found in the City and County of Denver, we know it is only a matter of time before its discovery.

EAB emergence season means it is time to start looking for the adult borers who leave “D”-shaped holes in the bark of the ash tree, roughly 1/8 inch in diameter. There are also several other telltale signs of EAB infestation like S-shaped tunnels that can be seen on the trunk and tree thinning and bark shedding. Dying ash trees also attract Northern Flickers, a type of large, brown woodpecker. It can take 2-4 years for trees to show signs of infestation.

EAB chews through the tree’s water and nutrient-conducting tissues, strangling the tree. If there is a high population of EAB in the tree, one-third to a half of the branches may die in one year. Most of the canopy will be dead within 2 years of when symptoms are first seen.

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An adult emerald ash borer sitting on an ash tree leaf

Emerald Ash borer discovered in Lyons, Colorado

LYONS, Colo. — State officials have confirmed the presence of emerald ash borer (EAB) – an invasive, highly destructive tree pest – in the Town of Lyons in northern Boulder County. This new detection is still just within a quarantine area established to try and prevent the human-assisted spread of EAB. However, it represents the fourth community with confirmation of EAB in Colorado outside the City of Boulder, where the pest was first detected in 2013.

An estimated 15 percent or more of all urban and community trees in Colorado are ash species susceptible to being killed by EAB – and a majority of these trees are on private land. EAB attacks and kills both stressed and healthy ash trees and is so aggressive that trees typically die within two to four years after becoming infested.

An arborist recently identified an ash tree on private land in the vicinity of 4th Avenue and Broadway Street in Lyons as potentially infested with EAB. The property manager notified members of the interagency Colorado EAB Response Team, which is working to manage the spread and impacts of the pest in Colorado. An adult beetle specimen found in the tree was provided to the Colorado Department of Agriculture (CDA) and then confirmed by Colorado State University experts as being EAB. The infested tree and surrounding trees also are being examined by experts from the CDA and Colorado State University Extension.

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Emerald ash borer discovered in Lafayette, Colorado

LAFAYETTE, Colo. — Emerald ash borer (EAB) has been discovered in Lafayette, the Colorado State Forest Service (CSFS) confirmed on Wednesday. Lafayette is now the third city in Colorado facing an EAB infestation.

Not entirely unlike the mountain pine beetle, which decimated pine trees across hundreds of thousands of acres in Colorado’s high country beginning in 2008, EAB has decimated ash tree populations in more than 25 states and parts of Canada, causing billions of dollars in damage over the last 15 years.

CSFS community forestry program manager Keith Wood also confirmed Wednesday the newly found infestation in Lafayette remains within Colorado’s EAB quarantine zone. That zone includes Boulder, where EAB was discovered in 2013, and Longmont, where EAB was discovered in 2016. Lafayette is less than 13 miles from each city.

“Having a new detection in this area was not unexpected,” Wood said. “But it certainly highlights the need for Front Range communities to be planning now, before EAB arrives.”

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