Drone flights may help detect beetle infestation

Longmont will be gathering data from drone flights to help determine the spread of the destructive emerald ash borer in parts of a southwest area of the city.

The drone, or unmanned aircraft system, was flown over parts of the city on Thursday, according to city forestry supervisor Ken Wicklund.

The emerald ash borer is a non-native, wood-boring beetle that can attach to all ash tree species. This insect was first discovered in Michigan in 2002, and since then it has spread to 22 states, including Colorado.

The ash tree is a very commonly planted tree in many communities. The emerald ash borer has killed tens of millions of ash trees in the U.S. Once the emerald ash borer population builds in numbers, ash mortality is near 100 percent.

Aurora-based Arbor Drone LLC, a consulting company that specializes in aerial urban forestry and Spectrabotics LLC, a Colorado Springs-based data analytics firm, are collecting data from the drone flights over Longmont.

The companies stated in a news release that the Longmont

drone flights are using a multispectral sensor — a high-resolution sensor that collects light in both the visible and infrared spectrums to study plant health — to find recently attacked ash trees to help the city’s urban foresters monitor and plan for the destructive pest.

Wicklund said Thursday’s Arbor Drone flights were “kind of a test” of the potential of using that system in surveying and monitoring tree health in other parts of Longmont, particularly in city parks and open space areas — a technological approach that could help, he said, because emerald ash borer tree infestations can be difficult to detect in their early stages.

Authorities have said it can take several years before an infested tree shows visible signs of decline.

Dan Staley, a principal of Arbor Drone and the pilot in charge of Thursday’s project, said one benefit of the overflight and sensor technology to identify emerald ash borer infested trees is that “once you find it, you can define it and follow it.”

Staley said it could be three to four weeks before Arbor Drone and Spectrabotics reports back to Longmont the results of their analysis of Thursday’s overflight.

Arbor Drone and Spectrabotics performed similar emerald ash borer detection and monitoring studies in Denver and Boulder in 2017, and in Denver and in several sites in Boulder County in 2018.

Boulder first discovered and confirmed the presence of emerald ash borer in September 2013.

The first sighting of emerald ash borer reported in Longmont was on June 6, 2016.

Since then, the pest has also been found in Lafayette, Gunbarrel, Lyons and Superior.

Longmont city officials said Longmont is estimated to have an ash tree population of 43,000 trees on public and private property, and the city is working to protect 900 of the approximately 2,800 city–owned ash trees in Longmont.

Wicklund said Longmont has removed about 400 trees and treated 944.