Today @ Colorado State has been replaced by SOURCE. This site exists as an archive of Today @ Colorado State stories between January 1, 2009 and September 8, 2014.

Environment / Sustainability

An emerging tree pest discovered in Colorado

June 2, 2014
By Joanne Littlefield

It was the morning of September 27 and Boulder County residents were still reeling from floodwaters that swamped the area and displaced hundreds of people.

Carol O'MearaCarol O'Meara, a Colorado State University Extension agent, was in the parking lot at the fairgrounds where the Boulder County Extension Office was relocated after the flood, when her cell phone rang.

It was Kathleen Alexander, the forester for the city of Boulder.

“Something’s happened and I wanted to give you a heads up so you can prepare before of it goes down, Alexander said. “We’ve found emerald ash borer in Boulder.”

They were words O’Meara and others on the front line of protecting Colorado’s trees dreaded hearing.

EAB adults have an emerals-green head/back and coppery reddish purple abdomen. Photo: David Cappaert, Michigan State UniversityWhat is an emerald ash borer?

The emerald ash borer is an exotic beetle native to Asia.

Like the name implies, the insect feeds primarily on ash trees. Adult beetles munch on foliage but generally cause little lasting damage to the trees.

It’s their offspring that are the problem. 

The larvae consume the inner bark, interfering with the tree’s ability to transport nutrients and water. The tree eventually dies.

The beetle was first discovered in 2002 in Michigan where it decimated millions of ash trees.

Adult emerald ash borers are approximately 1/2-inch long. Photo: David Cappaert, Michigan State UniversityExperts believe the emerald ash borer was likely transported to the United State on wood materials shipped from Asia.

The beetle infestation has since spread into Ontario and both east and west of Michigan.  The U.S. Department of Agriculture (USDA) and other regulatory agencies quarantined trees, logs and other wood products to prevent them from leaving infested areas.

Confirming the find

Before announcing the devastating find, Boulder County called in experts.

Staff from the Colorado Department of Agriculture (CDA) and the USDA’s Animal, Plant Health Inspection Service staff travelled to Boulder to gather samples. 

Emerald ash borer larva. Photo David Cappaert, Michigan State UniversityThe samples were then sent to Colorado State University’s BioAgricultural Sciences and Pest Management Department and CSU Professor Boris Kondratieff, a renowned taxonomist, for initial confirmation.   

From there, the specimens were sent to Michigan State University and then the Smithsonian Institute. 

All three labs confirmed Alexander’s suspicions – emerald ash borer had made its way to Colorado.

A call to action

Vertical splits in the bark are one of the signs that EAB has infested the tree. Photo Joseph O'Brien, International Society of ArboricultureThe discovery spurred an array of meetings between county, state and federal officials.

O’Meara, who works for the county, was in the midst of it all.  She helped arrange meetings between the various entities and because she has a degree in entomology, was assigned the roles of outreach and subject matter expert.

“It was the beginning of the strategy for holding a series of meeting with all groups who could be affected by a quarantine of the county,” O’Meara said. “These included arborists, city foresters, waste haulers and nursery owners.”

CDA acted as the lead agency with regulatory responsibilities, used an organizational structure developed by the federal government for disaster response. 

USDA staff assisted - until the federal government shut down last October.

Colorado was alone in its fight for several weeks.

A Colorado State Forest Service forester and CSU Extension staff person assess the branch of an ash tree to determine the presence of EAB. Photo Ryan Lockwood, CSFSPinpointing a pest

Once the USDA staff returned to work, the Boulder-based emerald ash borer response team faced a daunting task – find the pest and determine the extent of the infestation.

Skilled staff was needed to help organize and conduct the delimitation survey of the city of Boulder.

The team had divided the city into 38 square-mile grids. Ten ash trees from each grid were selected for sampling. Two limbs were removed from each and taken to a shed on the Boulder Forestry ground where the bark was stripped so experts could examine the wood.

CSU Extension organized an army of trained volunteers to help with the effort and O’Meara’s role once again evolved. She assembled and scheduled volunteers and coordinated the peeling of the samples. 

It took volunteers more than two-and-a-half months to peel 866 branches.

Emerald ash borer was found in four of the square miles tested.  

Preventing the spread

O’Meara continues to work as part of Boulder County’s emerald ash borer response committee, which commissioners formed to develop a comprehensive plan to deal with the pest.

She sits on the city of Boulder’s Interdepartmental Working Group to help coordinate efforts between agencies and serves on Emerging Pest Issues in Colorado (EPIC), a statewide forestry group whose mission is to educate foresters about new problems on the horizon.

Ash trees comprise an estimated 15 to 20 percent of all trees in Colorado cities, neighborhoods, parks and backyards. Photo: Colorado State University Facilities

O’Meara has learned a lot since September, including strategies for dealing with this insect, learning to work within a structured response plan, and balancing the demands with the tasks of her everyday job.

“I seriously underestimated how it would consume my time,” she said.

Dealing with emerald ash borer and advising citizens on this pest is just one part of O’Meara’s job. Many residents are uncertain whether they should treat their trees – which can be expensive – and call her for advice.

“My role is to help them navigate their options, and give them the information they can use to make their decisions,” she said.

Did you know?

CSU Extension agents and staff in Boulder and Broomfield counties have developed an emerald ash borer manual for front-line responders and landowners. You can find the manual by clicking here.