Metallic-green beetles about the size of sunflower seeds have wreaked havoc across the Great Lakes states, killing more than 50 million ash trees.
While the tiny emerald ash borers have not been seen in Colorado yet, federal officials have enlisted Front Range cities, Loveland included, in a search for them.
Large purple traps that look like box kites are being hoisted into ash trees to see if the beetles are still being held at bay.
“We have no evidence that they are in Colorado,” said Rob MacDonald, forestry specialist with Loveland's Department of Parks and Recreation. “This is a step we're taking to make sure of that.”
The stakes are high. The insect is the most destructive forest pest ever seen in North America, according to the U.S. Department of Agriculture.
$25 Billion Tab
The cost of treating, removing and replacing the millions of stricken ash trees in the emerald ash borer's 25-state range is estimated at more than $25 billion.
No one knows precisely how the Asian native got to suburban Detroit in 2002. It probably arrived in hardwood packing materials on a cargo ship.
But that is where the beetle began its rapacious run through ash trees in the upper Midwest, spreading north to Canada, east to New England, south to Tennessee and west to extreme eastern Kansas.
But, for now, that's where its range stops. About 580 miles of prairie separate the Colorado Front Range from the dreaded pest.
“The Great Plains is a great barrier for us,” said Lisa Peraino, a Denver-based plant health specialist with the U.S. Department of Agriculture.
Peraino's agency, the USDA's Animal and Plant Health Inspection Service, is coordinating the emerald ash borer trapping project in Colorado.
Twenty-seven Front Range towns and cities are placing 103 traps in mature ash trees, Peraino said. Fifty of them are in predetermined locations where computer models show infestations would be most likely to occur.
MacDonald on Friday hung one in a tree along Eisenhower Boulevard on the south shore of Lake Loveland.
The 2 ½-foot tall triangular purple box — “they like purple,” MacDonald said — is coated with a sticky resin to catch insects, and baited with small swaths of fabric that carry the scent of distressed ash trees.
USDA scientists will inspect the traps beginning in July, and several times through September, hoping not to find the emerald borers mired there.
Nearby the tall tree where the trap is hung, MacDonald examined a younger ash tree where he found evidence of another, much less noxious pest — the lilac ash borer.
“If you see a bore hole like this one, don't panic,” he said, pointing to a small hole near the tree's base where a cocoon-like pupal casing was left behind by the adult borer.
The lilac borer is a Colorado native, and does little damage. “It's already here, and most ash trees can deal with these infestations,” MacDonald said.
An emerald ash borer that arrives in Colorado splattered on a car windshield is no threat, but those that might be transported westward in a load of firewood could pose problems.
That's the reason for a broad, federally imposed quarantine on the transport of ash trees or dead wood beyond the region where they are infested.
“Buy it where you burn it,” MacDonald said. “That's the key message.”