JEFFERSON COUNTY —As Mary Mahaffey scraped various insects, leaves and other debris off a three-sided purple triangle that sat in an ash tree for about two months, she had good news for her companions with the Foothills Park and Recreation District.
“No emerald ash borer here,” she said.
Mahaffey didn’t expect to find any of the highly destructive pests that have tormented the Midwest and parts of the Eastern U.S.; nothing has been found in Colorado .
But that hasn’t stopped the U.S. Department of Agriculture from placing traps around the Denver metro area to detect any early signs of emerald ash borer when it’s still possible to save an ash tree.
On July 17, Mahaffey, a plant protection and quarantine officer with the USDA, inspected three traps set up around the southern part of Jefferson County in ash trees in Columbine Hills and Marker parks and in a tree along the East Woodmar Greenbelt.
The traps — which are purple, 24 inches long and sit about 15 feet up on an ash tree — have a lure meant to attract male emerald ash borers. If the pests approach the trap, they get stuck on an adhesive that coats the outside.
The traps were placed in trees in late May or early June and the lure lasts 60 days. Mahaffey changed the lure and said she will return to remove the traps in late August or early September when the borers are rarely seen.
The traps have been placed in the area for the past three years, said Mahaffey, who also lives in the area. Other traps are located in Littleton, Centennial and at Chatfield State Park.
“I knew from living here that the area wasn’t being served, so I got in touch with (the USDA),” she said. “We’re happy to have them up.”
Brenda Nix, parks operations and planning coordinator with the Foothills Park and Recreation District, said she did not expect to find any emerald ash borer, but if any are found and the district has to replace ash trees, it would try to vary the types of trees planted to avoid having any one pest decimate the system.
For south Jeffco residents, seeing the trap is no cause for alarm and it remains highly unlikely that any residential ash trees contain emerald ash borer.
People can take action such as using insecticide, but even that is premature.
“In south Jeffco, it’s a little too early to be using preventive insecticide based on what we know,” said Laura Pottorff with the Colorado Department of Agriculture.
Boulder County is under quarantine, which should limit any wood from leaving the county. Emerald ash borers are able to move when wood is transported between towns as crates or firewood.
, but so far has had no luck trapping any ash borers.
“I guess it’s an honest disclosure that traps don’t work as well as we would like them to,” Pottorff said.
The U.S. Department of Agriculture and Colorado State Forest Service have put up more than 250 traps around the state with 41 of them in Jefferson County.
Joe Vaccarelli: 303-954-2396, jvaccarelli@denverpost.com or twitter.com/joe_vacc
Emerald ash borer traps in jefferson county
Apple Ridge: 2
Arvada: 10
Chatfield State Park: 1
Foothills Metro District: 3
Golden: 6
Lakewood: 12
Westminster: 4
Wheat Ridge: 3
